1 /* Copyright (C) 2007-2008 Ksplice, Inc.
2 * Authors: Jeff Arnold, Anders Kasoerg, Tim Abbott
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
18 #include <linux/module.h>
19 #include <linux/version.h>
20 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
21 #include <linux/bug.h>
22 #else /* LINUX_VERSION_CODE */
23 /* 7664c5a1da4711bb6383117f51b94c8dc8f3f1cd was after 2.6.19 */
24 #endif /* LINUX_VERSION_CODE */
25 #include <linux/ctype.h>
26 #if defined CONFIG_DEBUG_FS || LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
27 #include <linux/debugfs.h>
28 #else /* CONFIG_DEBUG_FS */
29 /* a7a76cefc4b12bb6508afa4c77f11c2752cc365d was after 2.6.11 */
30 #endif /* CONFIG_DEBUG_FS */
31 #include <linux/errno.h>
32 #include <linux/kallsyms.h>
33 #include <linux/kobject.h>
34 #include <linux/kthread.h>
35 #include <linux/pagemap.h>
36 #include <linux/sched.h>
37 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,12)
38 #include <linux/sort.h>
39 #else /* LINUX_VERSION_CODE < */
40 /* 8c63b6d337534a6b5fb111dc27d0850f535118c0 was after 2.6.11 */
41 #endif /* LINUX_VERSION_CODE */
42 #include <linux/stop_machine.h>
43 #include <linux/sysfs.h>
44 #include <linux/time.h>
45 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
46 #include <linux/uaccess.h>
47 #else /* LINUX_VERSION_CODE < */
48 /* linux/uaccess.h doesn't exist in kernels before 2.6.18 */
49 #include <asm/uaccess.h>
50 #endif /* LINUX_VERSION_CODE */
51 #include <linux/vmalloc.h>
52 #ifdef KSPLICE_STANDALONE
54 #else /* !KSPLICE_STANDALONE */
55 #include <linux/ksplice.h>
56 #endif /* KSPLICE_STANDALONE */
57 #ifdef KSPLICE_NEED_PARAINSTRUCTIONS
58 #include <asm/alternative.h>
59 #endif /* KSPLICE_NEED_PARAINSTRUCTIONS */
61 #if defined(KSPLICE_STANDALONE) && \
62 !defined(CONFIG_KSPLICE) && !defined(CONFIG_KSPLICE_MODULE)
63 #define KSPLICE_NO_KERNEL_SUPPORT 1
64 #endif /* KSPLICE_STANDALONE && !CONFIG_KSPLICE && !CONFIG_KSPLICE_MODULE */
67 STAGE_PREPARING
, /* the update is not yet applied */
68 STAGE_APPLIED
, /* the update is applied */
69 STAGE_REVERSED
, /* the update has been applied and reversed */
72 /* parameter to modify run-pre matching */
74 RUN_PRE_INITIAL
, /* dry run (only change temp_labelvals) */
75 RUN_PRE_DEBUG
, /* dry run with byte-by-byte debugging */
76 RUN_PRE_FINAL
, /* finalizes the matching */
77 #ifdef KSPLICE_STANDALONE
79 #endif /* KSPLICE_STANDALONE */
82 enum { NOVAL
, TEMP
, VAL
};
84 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,9)
85 /* 5d7b32de9935c65ca8285ac6ec2382afdbb5d479 was after 2.6.8 */
87 #elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)
88 /* af4ca457eaf2d6682059c18463eb106e2ce58198 was after 2.6.14 */
89 #define __bitwise__ __bitwise
92 typedef int __bitwise__ abort_t
;
94 #define OK ((__force abort_t) 0)
95 #define NO_MATCH ((__force abort_t) 1)
96 #define CODE_BUSY ((__force abort_t) 2)
97 #define MODULE_BUSY ((__force abort_t) 3)
98 #define OUT_OF_MEMORY ((__force abort_t) 4)
99 #define FAILED_TO_FIND ((__force abort_t) 5)
100 #define ALREADY_REVERSED ((__force abort_t) 6)
101 #define MISSING_EXPORT ((__force abort_t) 7)
102 #define UNEXPECTED_RUNNING_TASK ((__force abort_t) 8)
103 #define UNEXPECTED ((__force abort_t) 9)
104 #define TARGET_NOT_LOADED ((__force abort_t) 10)
105 #define CALL_FAILED ((__force abort_t) 11)
106 #define COLD_UPDATE_LOADED ((__force abort_t) 12)
107 #ifdef KSPLICE_STANDALONE
108 #define BAD_SYSTEM_MAP ((__force abort_t) 13)
109 #endif /* KSPLICE_STANDALONE */
118 #ifdef CONFIG_DEBUG_FS
119 struct debugfs_blob_wrapper debug_blob
;
120 struct dentry
*debugfs_dentry
;
121 #else /* !CONFIG_DEBUG_FS */
122 bool debug_continue_line
;
123 #endif /* CONFIG_DEBUG_FS */
124 bool partial
; /* is it OK if some target mods aren't loaded */
125 struct list_head packs
; /* packs for loaded target mods */
126 struct list_head unused_packs
; /* packs for non-loaded target mods */
127 struct list_head conflicts
;
128 struct list_head list
;
129 struct list_head ksplice_module_list
;
132 /* a process conflicting with an update */
134 const char *process_name
;
136 struct list_head stack
;
137 struct list_head list
;
140 /* an address on the stack of a conflict */
141 struct conflict_addr
{
142 unsigned long addr
; /* the address on the stack */
143 bool has_conflict
; /* does this address in particular conflict? */
144 const char *label
; /* the label of the conflicting safety_record */
145 struct list_head list
;
148 #if defined(CONFIG_DEBUG_FS) && LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17)
149 /* Old kernels don't have debugfs_create_blob */
150 struct debugfs_blob_wrapper
{
154 #endif /* CONFIG_DEBUG_FS && LINUX_VERSION_CODE */
156 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
157 /* 930631edd4b1fe2781d9fe90edbe35d89dfc94cc was after 2.6.18 */
158 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
162 struct list_head list
;
163 struct ksplice_symbol
*symbol
;
164 struct list_head
*saved_vals
;
167 /* region to be checked for conflicts in the stack check */
168 struct safety_record
{
169 struct list_head list
;
171 unsigned long addr
; /* the address to be checked for conflicts
172 * (e.g. an obsolete function's starting addr)
174 unsigned long size
; /* the size of the region to be checked */
177 /* possible value for a symbol */
178 struct candidate_val
{
179 struct list_head list
;
183 /* private struct used by init_symbol_array */
184 struct ksplice_lookup
{
186 struct ksplice_pack
*pack
;
187 struct ksplice_symbol
**arr
;
193 #ifdef KSPLICE_NO_KERNEL_SUPPORT
195 const struct kernel_symbol
*start
, *stop
;
196 const unsigned long *crcs
;
204 #endif /* KSPLICE_NO_KERNEL_SUPPORT */
206 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,26)
207 /* c33fa9f5609e918824446ef9a75319d4a802f1f4 was after 2.6.25 */
209 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
210 /* 2fff0a48416af891dce38fd425246e337831e0bb was after 2.6.19 */
211 static bool virtual_address_mapped(unsigned long addr
)
214 return probe_kernel_address(addr
, retval
) != -EFAULT
;
216 #else /* LINUX_VERSION_CODE < */
217 static bool virtual_address_mapped(unsigned long addr
);
218 #endif /* LINUX_VERSION_CODE */
220 static long probe_kernel_read(void *dst
, void *src
, size_t size
)
224 if (!virtual_address_mapped((unsigned long)src
) ||
225 !virtual_address_mapped((unsigned long)src
+ size
- 1))
228 memcpy(dst
, src
, size
);
231 #endif /* LINUX_VERSION_CODE */
233 static LIST_HEAD(updates
);
234 #ifdef KSPLICE_STANDALONE
235 #if defined(CONFIG_KSPLICE) || defined(CONFIG_KSPLICE_MODULE)
236 extern struct list_head ksplice_module_list
;
237 #else /* !CONFIG_KSPLICE */
238 LIST_HEAD(ksplice_module_list
);
239 #endif /* CONFIG_KSPLICE */
240 #else /* !KSPLICE_STANDALONE */
241 LIST_HEAD(ksplice_module_list
);
242 EXPORT_SYMBOL_GPL(ksplice_module_list
);
243 static struct kobject
*ksplice_kobj
;
244 #endif /* KSPLICE_STANDALONE */
246 static struct kobj_type update_ktype
;
248 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,9)
249 /* Old kernels do not have kcalloc
250 * e629946abd0bb8266e9c3d0fd1bff2ef8dec5443 was after 2.6.8
252 static void *kcalloc(size_t n
, size_t size
, typeof(GFP_KERNEL
) flags
)
255 if (n
!= 0 && size
> ULONG_MAX
/ n
)
257 mem
= kmalloc(n
* size
, flags
);
259 memset(mem
, 0, n
* size
);
262 #endif /* LINUX_VERSION_CODE */
264 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,12)
265 /* 8c63b6d337534a6b5fb111dc27d0850f535118c0 was after 2.6.11 */
266 static void u32_swap(void *a
, void *b
, int size
)
269 *(u32
*)a
= *(u32
*)b
;
273 static void generic_swap(void *a
, void *b
, int size
)
279 *(char *)a
++ = *(char *)b
;
281 } while (--size
> 0);
285 * sort - sort an array of elements
286 * @base: pointer to data to sort
287 * @num: number of elements
288 * @size: size of each element
289 * @cmp: pointer to comparison function
290 * @swap: pointer to swap function or NULL
292 * This function does a heapsort on the given array. You may provide a
293 * swap function optimized to your element type.
295 * Sorting time is O(n log n) both on average and worst-case. While
296 * qsort is about 20% faster on average, it suffers from exploitable
297 * O(n*n) worst-case behavior and extra memory requirements that make
298 * it less suitable for kernel use.
301 void sort(void *base
, size_t num
, size_t size
,
302 int (*cmp
)(const void *, const void *),
303 void (*swap
)(void *, void *, int size
))
305 /* pre-scale counters for performance */
306 int i
= (num
/ 2 - 1) * size
, n
= num
* size
, c
, r
;
309 swap
= (size
== 4 ? u32_swap
: generic_swap
);
312 for (; i
>= 0; i
-= size
) {
313 for (r
= i
; r
* 2 + size
< n
; r
= c
) {
315 if (c
< n
- size
&& cmp(base
+ c
, base
+ c
+ size
) < 0)
317 if (cmp(base
+ r
, base
+ c
) >= 0)
319 swap(base
+ r
, base
+ c
, size
);
324 for (i
= n
- size
; i
> 0; i
-= size
) {
325 swap(base
, base
+ i
, size
);
326 for (r
= 0; r
* 2 + size
< i
; r
= c
) {
328 if (c
< i
- size
&& cmp(base
+ c
, base
+ c
+ size
) < 0)
330 if (cmp(base
+ r
, base
+ c
) >= 0)
332 swap(base
+ r
, base
+ c
, size
);
336 #endif /* LINUX_VERSION_CODE < */
338 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
339 /* Old kernels do not have kstrdup
340 * 543537bd922692bc978e2e356fcd8bfc9c2ee7d5 was 2.6.13-rc4
342 static char *kstrdup(const char *s
, typeof(GFP_KERNEL
) gfp
)
351 buf
= kmalloc(len
, gfp
);
356 #endif /* LINUX_VERSION_CODE */
358 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17)
359 /* Old kernels use semaphore instead of mutex
360 * 97d1f15b7ef52c1e9c28dc48b454024bb53a5fd2 was after 2.6.16
362 #define mutex semaphore
363 #define mutex_lock down
364 #define mutex_unlock up
365 #endif /* LINUX_VERSION_CODE */
367 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
368 /* 11443ec7d9286dd25663516436a14edfb5f43857 was after 2.6.21 */
369 static char * __attribute_used__
370 kvasprintf(typeof(GFP_KERNEL
) gfp
, const char *fmt
, va_list ap
)
377 len
= vsnprintf(dummy
, 0, fmt
, aq
);
380 p
= kmalloc(len
+ 1, gfp
);
384 vsnprintf(p
, len
+ 1, fmt
, ap
);
390 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
391 /* e905914f96e11862b130dd229f73045dad9a34e8 was after 2.6.17 */
392 static char * __attribute__((format (printf
, 2, 3)))
393 kasprintf(typeof(GFP_KERNEL
) gfp
, const char *fmt
, ...)
399 p
= kvasprintf(gfp
, fmt
, ap
);
406 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
407 /* 06b2a76d25d3cfbd14680021c1d356c91be6904e was after 2.6.24 */
408 static int strict_strtoul(const char *cp
, unsigned int base
, unsigned long *res
)
419 val
= simple_strtoul(cp
, &tail
, base
);
420 if ((*tail
== '\0') ||
421 ((len
== (size_t)(tail
- cp
) + 1) && (*tail
== '\n'))) {
430 #ifndef task_thread_info
431 #define task_thread_info(task) (task)->thread_info
432 #endif /* !task_thread_info */
434 #ifdef KSPLICE_STANDALONE
436 static bool bootstrapped
= false;
438 #ifdef CONFIG_KALLSYMS
439 extern unsigned long kallsyms_addresses
[], kallsyms_num_syms
;
440 extern u8 kallsyms_names
[];
441 #endif /* CONFIG_KALLSYMS */
443 /* defined by ksplice-create */
444 extern const struct ksplice_reloc ksplice_init_relocs
[],
445 ksplice_init_relocs_end
[];
447 /* Obtained via System.map */
448 extern struct list_head modules
;
449 extern struct mutex module_mutex
;
450 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18) && defined(CONFIG_UNUSED_SYMBOLS)
451 /* f71d20e961474dde77e6558396efb93d6ac80a4b was after 2.6.17 */
452 #define KSPLICE_KSYMTAB_UNUSED_SUPPORT 1
453 #endif /* LINUX_VERSION_CODE */
454 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
455 /* 9f28bb7e1d0188a993403ab39b774785892805e1 was after 2.6.16 */
456 #define KSPLICE_KSYMTAB_FUTURE_SUPPORT 1
457 #endif /* LINUX_VERSION_CODE */
458 extern const struct kernel_symbol __start___ksymtab
[];
459 extern const struct kernel_symbol __stop___ksymtab
[];
460 extern const unsigned long __start___kcrctab
[];
461 extern const struct kernel_symbol __start___ksymtab_gpl
[];
462 extern const struct kernel_symbol __stop___ksymtab_gpl
[];
463 extern const unsigned long __start___kcrctab_gpl
[];
464 #ifdef KSPLICE_KSYMTAB_UNUSED_SUPPORT
465 extern const struct kernel_symbol __start___ksymtab_unused
[];
466 extern const struct kernel_symbol __stop___ksymtab_unused
[];
467 extern const unsigned long __start___kcrctab_unused
[];
468 extern const struct kernel_symbol __start___ksymtab_unused_gpl
[];
469 extern const struct kernel_symbol __stop___ksymtab_unused_gpl
[];
470 extern const unsigned long __start___kcrctab_unused_gpl
[];
471 #endif /* KSPLICE_KSYMTAB_UNUSED_SUPPORT */
472 #ifdef KSPLICE_KSYMTAB_FUTURE_SUPPORT
473 extern const struct kernel_symbol __start___ksymtab_gpl_future
[];
474 extern const struct kernel_symbol __stop___ksymtab_gpl_future
[];
475 extern const unsigned long __start___kcrctab_gpl_future
[];
476 #endif /* KSPLICE_KSYMTAB_FUTURE_SUPPORT */
478 #endif /* KSPLICE_STANDALONE */
480 static struct update
*init_ksplice_update(const char *kid
);
481 static void cleanup_ksplice_update(struct update
*update
);
482 static void maybe_cleanup_ksplice_update(struct update
*update
);
483 static void add_to_update(struct ksplice_pack
*pack
, struct update
*update
);
484 static int ksplice_sysfs_init(struct update
*update
);
486 /* Preparing the relocations and patches for application */
487 static abort_t
apply_update(struct update
*update
);
488 static abort_t
prepare_pack(struct ksplice_pack
*pack
);
489 static abort_t
finalize_pack(struct ksplice_pack
*pack
);
490 static abort_t
finalize_patches(struct ksplice_pack
*pack
);
491 static abort_t
add_dependency_on_address(struct ksplice_pack
*pack
,
493 static abort_t
map_trampoline_pages(struct update
*update
);
494 static void unmap_trampoline_pages(struct update
*update
);
495 static void *map_writable(void *addr
, size_t len
);
496 static abort_t
apply_relocs(struct ksplice_pack
*pack
,
497 const struct ksplice_reloc
*relocs
,
498 const struct ksplice_reloc
*relocs_end
);
499 static abort_t
apply_reloc(struct ksplice_pack
*pack
,
500 const struct ksplice_reloc
*r
);
501 static abort_t
apply_howto_reloc(struct ksplice_pack
*pack
,
502 const struct ksplice_reloc
*r
);
503 static abort_t
apply_howto_date(struct ksplice_pack
*pack
,
504 const struct ksplice_reloc
*r
);
505 static abort_t
read_reloc_value(struct ksplice_pack
*pack
,
506 const struct ksplice_reloc
*r
,
507 unsigned long addr
, unsigned long *valp
);
508 static abort_t
write_reloc_value(struct ksplice_pack
*pack
,
509 const struct ksplice_reloc
*r
,
510 unsigned long addr
, unsigned long sym_addr
);
511 static abort_t
create_module_list_entry(struct ksplice_pack
*pack
,
513 static void cleanup_module_list_entries(struct update
*update
);
514 static void __attribute__((noreturn
)) ksplice_deleted(void);
516 /* run-pre matching */
517 static abort_t
match_pack_sections(struct ksplice_pack
*pack
,
518 bool consider_data_sections
);
519 static abort_t
find_section(struct ksplice_pack
*pack
,
520 struct ksplice_section
*sect
);
521 static abort_t
try_addr(struct ksplice_pack
*pack
,
522 struct ksplice_section
*sect
,
523 unsigned long run_addr
,
524 struct list_head
*safety_records
,
525 enum run_pre_mode mode
);
526 static abort_t
run_pre_cmp(struct ksplice_pack
*pack
,
527 const struct ksplice_section
*sect
,
528 unsigned long run_addr
,
529 struct list_head
*safety_records
,
530 enum run_pre_mode mode
);
531 #ifndef CONFIG_FUNCTION_DATA_SECTIONS
532 /* defined in arch/ARCH/kernel/ksplice-arch.c */
533 static abort_t
arch_run_pre_cmp(struct ksplice_pack
*pack
,
534 struct ksplice_section
*sect
,
535 unsigned long run_addr
,
536 struct list_head
*safety_records
,
537 enum run_pre_mode mode
);
538 #endif /* CONFIG_FUNCTION_DATA_SECTIONS */
539 static void print_bytes(struct ksplice_pack
*pack
,
540 const unsigned char *run
, int runc
,
541 const unsigned char *pre
, int prec
);
542 #if defined(KSPLICE_STANDALONE) && !defined(CONFIG_KALLSYMS)
543 static abort_t
brute_search(struct ksplice_pack
*pack
,
544 struct ksplice_section
*sect
,
545 const void *start
, unsigned long len
,
546 struct list_head
*vals
);
547 static abort_t
brute_search_all(struct ksplice_pack
*pack
,
548 struct ksplice_section
*sect
,
549 struct list_head
*vals
);
550 #endif /* KSPLICE_STANDALONE && !CONFIG_KALLSYMS */
551 static const struct ksplice_reloc
*
552 init_reloc_search(struct ksplice_pack
*pack
,
553 const struct ksplice_section
*sect
);
554 static const struct ksplice_reloc
*find_reloc(const struct ksplice_reloc
*start
,
555 const struct ksplice_reloc
*end
,
556 unsigned long address
,
558 static abort_t
lookup_reloc(struct ksplice_pack
*pack
,
559 const struct ksplice_reloc
**fingerp
,
561 const struct ksplice_reloc
**relocp
);
562 static abort_t
handle_reloc(struct ksplice_pack
*pack
,
563 const struct ksplice_section
*sect
,
564 const struct ksplice_reloc
*r
,
565 unsigned long run_addr
, enum run_pre_mode mode
);
566 static abort_t
handle_howto_date(struct ksplice_pack
*pack
,
567 const struct ksplice_section
*sect
,
568 const struct ksplice_reloc
*r
,
569 unsigned long run_addr
,
570 enum run_pre_mode mode
);
571 static abort_t
handle_howto_reloc(struct ksplice_pack
*pack
,
572 const struct ksplice_section
*sect
,
573 const struct ksplice_reloc
*r
,
574 unsigned long run_addr
,
575 enum run_pre_mode mode
);
576 static struct ksplice_section
*symbol_section(struct ksplice_pack
*pack
,
577 const struct ksplice_symbol
*sym
);
578 static int compare_section_labels(const void *va
, const void *vb
);
579 static int symbol_section_bsearch_compare(const void *a
, const void *b
);
580 static const struct ksplice_reloc
*patch_reloc(struct ksplice_pack
*pack
,
581 const struct ksplice_patch
*p
);
583 /* Computing possible addresses for symbols */
584 static abort_t
lookup_symbol(struct ksplice_pack
*pack
,
585 const struct ksplice_symbol
*ksym
,
586 struct list_head
*vals
);
587 static void cleanup_symbol_arrays(struct ksplice_pack
*pack
);
588 static abort_t
init_symbol_arrays(struct ksplice_pack
*pack
);
589 static abort_t
init_symbol_array(struct ksplice_pack
*pack
,
590 struct ksplice_symbol
*start
,
591 struct ksplice_symbol
*end
);
592 static abort_t
uniquify_symbols(struct ksplice_pack
*pack
);
593 static abort_t
add_matching_values(struct ksplice_lookup
*lookup
,
594 const char *sym_name
, unsigned long sym_val
);
595 static bool add_export_values(const struct symsearch
*syms
,
596 struct module
*owner
,
597 unsigned int symnum
, void *data
);
598 static int symbolp_bsearch_compare(const void *key
, const void *elt
);
599 static int compare_symbolp_names(const void *a
, const void *b
);
600 static int compare_symbolp_labels(const void *a
, const void *b
);
601 #ifdef CONFIG_KALLSYMS
602 static int add_kallsyms_values(void *data
, const char *name
,
603 struct module
*owner
, unsigned long val
);
604 #endif /* CONFIG_KALLSYMS */
605 #ifdef KSPLICE_STANDALONE
607 add_system_map_candidates(struct ksplice_pack
*pack
,
608 const struct ksplice_system_map
*start
,
609 const struct ksplice_system_map
*end
,
610 const char *label
, struct list_head
*vals
);
611 static int compare_system_map(const void *a
, const void *b
);
612 static int system_map_bsearch_compare(const void *key
, const void *elt
);
613 #endif /* KSPLICE_STANDALONE */
614 static abort_t
new_export_lookup(struct ksplice_pack
*ipack
, const char *name
,
615 struct list_head
*vals
);
617 /* Atomic update trampoline insertion and removal */
618 static abort_t
apply_patches(struct update
*update
);
619 static abort_t
reverse_patches(struct update
*update
);
620 static int __apply_patches(void *update
);
621 static int __reverse_patches(void *update
);
622 static abort_t
check_each_task(struct update
*update
);
623 static abort_t
check_task(struct update
*update
,
624 const struct task_struct
*t
, bool rerun
);
625 static abort_t
check_stack(struct update
*update
, struct conflict
*conf
,
626 const struct thread_info
*tinfo
,
627 const unsigned long *stack
);
628 static abort_t
check_address(struct update
*update
,
629 struct conflict
*conf
, unsigned long addr
);
630 static abort_t
check_record(struct conflict_addr
*ca
,
631 const struct safety_record
*rec
,
633 static bool is_stop_machine(const struct task_struct
*t
);
634 static void cleanup_conflicts(struct update
*update
);
635 static void print_conflicts(struct update
*update
);
636 static void insert_trampoline(struct ksplice_patch
*p
);
637 static abort_t
verify_trampoline(struct ksplice_pack
*pack
,
638 const struct ksplice_patch
*p
);
639 static void remove_trampoline(const struct ksplice_patch
*p
);
641 static abort_t
create_labelval(struct ksplice_pack
*pack
,
642 struct ksplice_symbol
*ksym
,
643 unsigned long val
, int status
);
644 static abort_t
create_safety_record(struct ksplice_pack
*pack
,
645 const struct ksplice_section
*sect
,
646 struct list_head
*record_list
,
647 unsigned long run_addr
,
648 unsigned long run_size
);
649 static abort_t
add_candidate_val(struct ksplice_pack
*pack
,
650 struct list_head
*vals
, unsigned long val
);
651 static void release_vals(struct list_head
*vals
);
652 static void set_temp_labelvals(struct ksplice_pack
*pack
, int status_val
);
654 static int contains_canary(struct ksplice_pack
*pack
, unsigned long blank_addr
,
655 const struct ksplice_reloc_howto
*howto
);
656 static unsigned long follow_trampolines(struct ksplice_pack
*pack
,
658 static bool patches_module(const struct module
*a
, const struct module
*b
);
659 static bool starts_with(const char *str
, const char *prefix
);
660 static bool singular(struct list_head
*list
);
661 static void *bsearch(const void *key
, const void *base
, size_t n
,
662 size_t size
, int (*cmp
)(const void *key
, const void *elt
));
663 static int compare_relocs(const void *a
, const void *b
);
664 static int reloc_bsearch_compare(const void *key
, const void *elt
);
667 static abort_t
init_debug_buf(struct update
*update
);
668 static void clear_debug_buf(struct update
*update
);
669 static int __attribute__((format(printf
, 2, 3)))
670 _ksdebug(struct update
*update
, const char *fmt
, ...);
671 #define ksdebug(pack, fmt, ...) \
672 _ksdebug(pack->update, fmt, ## __VA_ARGS__)
674 #ifdef KSPLICE_NO_KERNEL_SUPPORT
675 /* Functions defined here that will be exported in later kernels */
676 #ifdef CONFIG_KALLSYMS
677 static int kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
678 struct module
*, unsigned long),
680 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10)
681 static unsigned int kallsyms_expand_symbol(unsigned int off
, char *result
);
682 #endif /* LINUX_VERSION_CODE */
683 static int module_kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
687 #endif /* CONFIG_KALLSYMS */
688 static struct module
*find_module(const char *name
);
689 static int use_module(struct module
*a
, struct module
*b
);
690 static const struct kernel_symbol
*find_symbol(const char *name
,
691 struct module
**owner
,
692 const unsigned long **crc
,
693 bool gplok
, bool warn
);
694 static bool each_symbol(bool (*fn
)(const struct symsearch
*arr
,
695 struct module
*owner
,
696 unsigned int symnum
, void *data
),
698 static struct module
*__module_data_address(unsigned long addr
);
699 #endif /* KSPLICE_NO_KERNEL_SUPPORT */
701 /* Architecture-specific functions defined in arch/ARCH/kernel/ksplice-arch.c */
703 /* Prepare a trampoline for the given patch */
704 static abort_t
prepare_trampoline(struct ksplice_pack
*pack
,
705 struct ksplice_patch
*p
);
706 /* What address does the trampoline at addr jump to? */
707 static abort_t
trampoline_target(struct ksplice_pack
*pack
, unsigned long addr
,
708 unsigned long *new_addr
);
709 /* Hook to handle pc-relative jumps inserted by parainstructions */
710 static abort_t
handle_paravirt(struct ksplice_pack
*pack
, unsigned long pre
,
711 unsigned long run
, int *matched
);
712 /* Called for relocations of type KSPLICE_HOWTO_BUG */
713 static abort_t
handle_bug(struct ksplice_pack
*pack
,
714 const struct ksplice_reloc
*r
,
715 unsigned long run_addr
);
716 /* Called for relocations of type KSPLICE_HOWTO_EXTABLE */
717 static abort_t
handle_extable(struct ksplice_pack
*pack
,
718 const struct ksplice_reloc
*r
,
719 unsigned long run_addr
);
720 /* Is address p on the stack of the given thread? */
721 static bool valid_stack_ptr(const struct thread_info
*tinfo
, const void *p
);
723 #ifndef KSPLICE_STANDALONE
724 #include "ksplice-arch.c"
725 #elif defined CONFIG_X86
726 #include "x86/ksplice-arch.c"
727 #elif defined CONFIG_ARM
728 #include "arm/ksplice-arch.c"
729 #endif /* KSPLICE_STANDALONE */
731 #define clear_list(head, type, member) \
733 struct list_head *_pos, *_n; \
734 list_for_each_safe(_pos, _n, head) { \
736 kfree(list_entry(_pos, type, member)); \
741 * init_ksplice_pack() - Initializes a ksplice pack
742 * @pack: The pack to be initialized. All of the public fields of the
743 * pack and its associated data structures should be populated
744 * before this function is called. The values of the private
745 * fields will be ignored.
747 int init_ksplice_pack(struct ksplice_pack
*pack
)
749 struct update
*update
;
750 struct ksplice_patch
*p
;
751 struct ksplice_section
*s
;
754 #ifdef KSPLICE_STANDALONE
757 #endif /* KSPLICE_STANDALONE */
759 INIT_LIST_HEAD(&pack
->temp_labelvals
);
760 INIT_LIST_HEAD(&pack
->safety_records
);
762 sort(pack
->helper_relocs
,
763 pack
->helper_relocs_end
- pack
->helper_relocs
,
764 sizeof(*pack
->helper_relocs
), compare_relocs
, NULL
);
765 sort(pack
->primary_relocs
,
766 pack
->primary_relocs_end
- pack
->primary_relocs
,
767 sizeof(*pack
->primary_relocs
), compare_relocs
, NULL
);
768 sort(pack
->helper_sections
,
769 pack
->helper_sections_end
- pack
->helper_sections
,
770 sizeof(*pack
->helper_sections
), compare_section_labels
, NULL
);
771 #ifdef KSPLICE_STANDALONE
772 sort(pack
->primary_system_map
,
773 pack
->primary_system_map_end
- pack
->primary_system_map
,
774 sizeof(*pack
->primary_system_map
), compare_system_map
, NULL
);
775 sort(pack
->helper_system_map
,
776 pack
->helper_system_map_end
- pack
->helper_system_map
,
777 sizeof(*pack
->helper_system_map
), compare_system_map
, NULL
);
778 #endif /* KSPLICE_STANDALONE */
780 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++)
782 for (s
= pack
->helper_sections
; s
< pack
->helper_sections_end
; s
++)
784 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++) {
785 const struct ksplice_reloc
*r
= patch_reloc(pack
, p
);
788 if (p
->type
== KSPLICE_PATCH_DATA
) {
789 s
= symbol_section(pack
, r
->symbol
);
792 /* Ksplice creates KSPLICE_PATCH_DATA patches in order
793 * to modify rodata sections that have been explicitly
794 * marked for patching using the ksplice-patch.h macro
795 * ksplice_assume_rodata. Here we modify the section
796 * flags appropriately.
798 if (s
->flags
& KSPLICE_SECTION_DATA
)
799 s
->flags
= (s
->flags
& ~KSPLICE_SECTION_DATA
) |
800 KSPLICE_SECTION_RODATA
;
804 mutex_lock(&module_mutex
);
805 list_for_each_entry(update
, &updates
, list
) {
806 if (strcmp(pack
->kid
, update
->kid
) == 0) {
807 if (update
->stage
!= STAGE_PREPARING
) {
811 add_to_update(pack
, update
);
816 update
= init_ksplice_update(pack
->kid
);
817 if (update
== NULL
) {
821 ret
= ksplice_sysfs_init(update
);
823 cleanup_ksplice_update(update
);
826 add_to_update(pack
, update
);
828 mutex_unlock(&module_mutex
);
831 EXPORT_SYMBOL_GPL(init_ksplice_pack
);
834 * cleanup_ksplice_pack() - Cleans up a pack
835 * @pack: The pack to be cleaned up
837 void cleanup_ksplice_pack(struct ksplice_pack
*pack
)
839 if (pack
->update
== NULL
)
842 mutex_lock(&module_mutex
);
843 if (pack
->update
->stage
== STAGE_APPLIED
) {
844 /* If the pack wasn't actually applied (because we
845 * only applied this update to loaded modules and this
846 * target was not loaded), then unregister the pack
847 * from the list of unused packs.
849 struct ksplice_pack
*p
;
852 list_for_each_entry(p
, &pack
->update
->unused_packs
, list
) {
857 list_del(&pack
->list
);
858 mutex_unlock(&module_mutex
);
861 list_del(&pack
->list
);
862 if (pack
->update
->stage
== STAGE_PREPARING
)
863 maybe_cleanup_ksplice_update(pack
->update
);
865 mutex_unlock(&module_mutex
);
867 EXPORT_SYMBOL_GPL(cleanup_ksplice_pack
);
869 static struct update
*init_ksplice_update(const char *kid
)
871 struct update
*update
;
872 update
= kcalloc(1, sizeof(struct update
), GFP_KERNEL
);
875 update
->name
= kasprintf(GFP_KERNEL
, "ksplice_%s", kid
);
876 if (update
->name
== NULL
) {
880 update
->kid
= kstrdup(kid
, GFP_KERNEL
);
881 if (update
->kid
== NULL
) {
886 if (try_module_get(THIS_MODULE
) != 1) {
892 INIT_LIST_HEAD(&update
->packs
);
893 INIT_LIST_HEAD(&update
->unused_packs
);
894 INIT_LIST_HEAD(&update
->ksplice_module_list
);
895 if (init_debug_buf(update
) != OK
) {
896 module_put(THIS_MODULE
);
902 list_add(&update
->list
, &updates
);
903 update
->stage
= STAGE_PREPARING
;
904 update
->abort_cause
= OK
;
906 INIT_LIST_HEAD(&update
->conflicts
);
910 static void cleanup_ksplice_update(struct update
*update
)
912 list_del(&update
->list
);
913 cleanup_conflicts(update
);
914 clear_debug_buf(update
);
915 cleanup_module_list_entries(update
);
919 module_put(THIS_MODULE
);
922 /* Clean up the update if it no longer has any packs */
923 static void maybe_cleanup_ksplice_update(struct update
*update
)
925 if (list_empty(&update
->packs
) && list_empty(&update
->unused_packs
))
926 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)
927 kobject_put(&update
->kobj
);
928 #else /* LINUX_VERSION_CODE < */
929 /* 6d06adfaf82d154023141ddc0c9de18b6a49090b was after 2.6.24 */
930 kobject_unregister(&update
->kobj
);
931 #endif /* LINUX_VERSION_CODE */
934 static void add_to_update(struct ksplice_pack
*pack
, struct update
*update
)
936 pack
->update
= update
;
937 list_add(&pack
->list
, &update
->unused_packs
);
940 static int ksplice_sysfs_init(struct update
*update
)
943 memset(&update
->kobj
, 0, sizeof(update
->kobj
));
944 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)
945 #ifndef KSPLICE_STANDALONE
946 ret
= kobject_init_and_add(&update
->kobj
, &update_ktype
,
947 ksplice_kobj
, "%s", update
->kid
);
948 #else /* KSPLICE_STANDALONE */
949 /* 6d06adfaf82d154023141ddc0c9de18b6a49090b was after 2.6.24 */
950 ret
= kobject_init_and_add(&update
->kobj
, &update_ktype
,
951 &THIS_MODULE
->mkobj
.kobj
, "ksplice");
952 #endif /* KSPLICE_STANDALONE */
953 #else /* LINUX_VERSION_CODE < */
954 ret
= kobject_set_name(&update
->kobj
, "%s", "ksplice");
957 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,11)
958 update
->kobj
.parent
= &THIS_MODULE
->mkobj
.kobj
;
959 #else /* LINUX_VERSION_CODE < */
960 /* b86ab02803095190d6b72bcc18dcf620bf378df9 was after 2.6.10 */
961 update
->kobj
.parent
= &THIS_MODULE
->mkobj
->kobj
;
962 #endif /* LINUX_VERSION_CODE */
963 update
->kobj
.ktype
= &update_ktype
;
964 ret
= kobject_register(&update
->kobj
);
965 #endif /* LINUX_VERSION_CODE */
968 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15)
969 kobject_uevent(&update
->kobj
, KOBJ_ADD
);
970 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10)
971 /* 312c004d36ce6c739512bac83b452f4c20ab1f62 was after 2.6.14 */
972 /* 12025235884570ba7f02a6f427f973ac6be7ec54 was after 2.6.9 */
973 kobject_uevent(&update
->kobj
, KOBJ_ADD
, NULL
);
974 #endif /* LINUX_VERSION_CODE */
978 static abort_t
apply_update(struct update
*update
)
980 struct ksplice_pack
*pack
, *n
;
984 list_for_each_entry(pack
, &update
->packs
, list
) {
985 ret
= create_module_list_entry(pack
, true);
990 list_for_each_entry_safe(pack
, n
, &update
->unused_packs
, list
) {
991 if (strcmp(pack
->target_name
, "vmlinux") == 0) {
993 } else if (pack
->target
== NULL
) {
994 pack
->target
= find_module(pack
->target_name
);
995 if (pack
->target
== NULL
||
996 !module_is_live(pack
->target
)) {
997 if (!update
->partial
) {
998 ret
= TARGET_NOT_LOADED
;
1001 ret
= create_module_list_entry(pack
, false);
1006 retval
= use_module(pack
->primary
, pack
->target
);
1012 ret
= create_module_list_entry(pack
, true);
1015 list_del(&pack
->list
);
1016 list_add_tail(&pack
->list
, &update
->packs
);
1018 #ifdef KSPLICE_NEED_PARAINSTRUCTIONS
1019 if (pack
->target
== NULL
) {
1020 apply_paravirt(pack
->primary_parainstructions
,
1021 pack
->primary_parainstructions_end
);
1022 apply_paravirt(pack
->helper_parainstructions
,
1023 pack
->helper_parainstructions_end
);
1025 #endif /* KSPLICE_NEED_PARAINSTRUCTIONS */
1028 list_for_each_entry(pack
, &update
->packs
, list
) {
1029 const struct ksplice_section
*sect
;
1030 for (sect
= pack
->primary_sections
;
1031 sect
< pack
->primary_sections_end
; sect
++) {
1032 struct safety_record
*rec
= kmalloc(sizeof(*rec
),
1035 ret
= OUT_OF_MEMORY
;
1038 rec
->addr
= sect
->address
;
1039 rec
->size
= sect
->size
;
1040 rec
->label
= sect
->symbol
->label
;
1041 list_add(&rec
->list
, &pack
->safety_records
);
1045 list_for_each_entry(pack
, &update
->packs
, list
) {
1046 ret
= init_symbol_arrays(pack
);
1048 cleanup_symbol_arrays(pack
);
1051 ret
= prepare_pack(pack
);
1052 cleanup_symbol_arrays(pack
);
1056 ret
= apply_patches(update
);
1058 list_for_each_entry(pack
, &update
->packs
, list
) {
1059 struct ksplice_section
*s
;
1060 if (update
->stage
== STAGE_PREPARING
)
1061 clear_list(&pack
->safety_records
, struct safety_record
,
1063 for (s
= pack
->helper_sections
; s
< pack
->helper_sections_end
;
1065 if (s
->match_map
!= NULL
) {
1066 vfree(s
->match_map
);
1067 s
->match_map
= NULL
;
1071 if (update
->stage
== STAGE_PREPARING
)
1072 cleanup_module_list_entries(update
);
1076 static int compare_symbolp_names(const void *a
, const void *b
)
1078 const struct ksplice_symbol
*const *sympa
= a
, *const *sympb
= b
;
1079 if ((*sympa
)->name
== NULL
&& (*sympb
)->name
== NULL
)
1081 if ((*sympa
)->name
== NULL
)
1083 if ((*sympb
)->name
== NULL
)
1085 return strcmp((*sympa
)->name
, (*sympb
)->name
);
1088 static int compare_symbolp_labels(const void *a
, const void *b
)
1090 const struct ksplice_symbol
*const *sympa
= a
, *const *sympb
= b
;
1091 return strcmp((*sympa
)->label
, (*sympb
)->label
);
1094 static int symbolp_bsearch_compare(const void *key
, const void *elt
)
1096 const char *name
= key
;
1097 const struct ksplice_symbol
*const *symp
= elt
;
1098 const struct ksplice_symbol
*sym
= *symp
;
1099 if (sym
->name
== NULL
)
1101 return strcmp(name
, sym
->name
);
1104 static abort_t
add_matching_values(struct ksplice_lookup
*lookup
,
1105 const char *sym_name
, unsigned long sym_val
)
1107 struct ksplice_symbol
**symp
;
1110 symp
= bsearch(sym_name
, lookup
->arr
, lookup
->size
,
1111 sizeof(*lookup
->arr
), symbolp_bsearch_compare
);
1115 while (symp
> lookup
->arr
&&
1116 symbolp_bsearch_compare(sym_name
, symp
- 1) == 0)
1119 for (; symp
< lookup
->arr
+ lookup
->size
; symp
++) {
1120 struct ksplice_symbol
*sym
= *symp
;
1121 if (sym
->name
== NULL
|| strcmp(sym_name
, sym
->name
) != 0)
1123 ret
= add_candidate_val(lookup
->pack
, sym
->vals
, sym_val
);
1130 #ifdef CONFIG_KALLSYMS
1131 static int add_kallsyms_values(void *data
, const char *name
,
1132 struct module
*owner
, unsigned long val
)
1134 struct ksplice_lookup
*lookup
= data
;
1135 if (owner
== lookup
->pack
->primary
||
1136 !patches_module(owner
, lookup
->pack
->target
))
1137 return (__force
int)OK
;
1138 return (__force
int)add_matching_values(lookup
, name
, val
);
1140 #endif /* CONFIG_KALLSYMS */
1142 static bool add_export_values(const struct symsearch
*syms
,
1143 struct module
*owner
,
1144 unsigned int symnum
, void *data
)
1146 struct ksplice_lookup
*lookup
= data
;
1149 ret
= add_matching_values(lookup
, syms
->start
[symnum
].name
,
1150 syms
->start
[symnum
].value
);
1158 static void cleanup_symbol_arrays(struct ksplice_pack
*pack
)
1160 struct ksplice_symbol
*sym
;
1161 for (sym
= pack
->primary_symbols
; sym
< pack
->primary_symbols_end
;
1163 if (sym
->vals
!= NULL
) {
1164 clear_list(sym
->vals
, struct candidate_val
, list
);
1169 for (sym
= pack
->helper_symbols
; sym
< pack
->helper_symbols_end
; sym
++) {
1170 if (sym
->vals
!= NULL
) {
1171 clear_list(sym
->vals
, struct candidate_val
, list
);
1179 * The primary and helper modules each have their own independent
1180 * ksplice_symbol structures. uniquify_symbols unifies these separate
1181 * pieces of kernel symbol information by replacing all references to
1182 * the helper copy of symbols with references to the primary copy.
1184 static abort_t
uniquify_symbols(struct ksplice_pack
*pack
)
1186 struct ksplice_reloc
*r
;
1187 struct ksplice_section
*s
;
1188 struct ksplice_symbol
*sym
, **sym_arr
, **symp
;
1189 size_t size
= pack
->primary_symbols_end
- pack
->primary_symbols
;
1194 sym_arr
= vmalloc(sizeof(*sym_arr
) * size
);
1195 if (sym_arr
== NULL
)
1196 return OUT_OF_MEMORY
;
1198 for (symp
= sym_arr
, sym
= pack
->primary_symbols
;
1199 symp
< sym_arr
+ size
&& sym
< pack
->primary_symbols_end
;
1203 sort(sym_arr
, size
, sizeof(*sym_arr
), compare_symbolp_labels
, NULL
);
1205 for (r
= pack
->helper_relocs
; r
< pack
->helper_relocs_end
; r
++) {
1206 symp
= bsearch(&r
->symbol
, sym_arr
, size
, sizeof(*sym_arr
),
1207 compare_symbolp_labels
);
1209 if ((*symp
)->name
== NULL
)
1210 (*symp
)->name
= r
->symbol
->name
;
1215 for (s
= pack
->helper_sections
; s
< pack
->helper_sections_end
; s
++) {
1216 symp
= bsearch(&s
->symbol
, sym_arr
, size
, sizeof(*sym_arr
),
1217 compare_symbolp_labels
);
1219 if ((*symp
)->name
== NULL
)
1220 (*symp
)->name
= s
->symbol
->name
;
1230 * Initialize the ksplice_symbol structures in the given array using
1231 * the kallsyms and exported symbol tables.
1233 static abort_t
init_symbol_array(struct ksplice_pack
*pack
,
1234 struct ksplice_symbol
*start
,
1235 struct ksplice_symbol
*end
)
1237 struct ksplice_symbol
*sym
, **sym_arr
, **symp
;
1238 struct ksplice_lookup lookup
;
1239 size_t size
= end
- start
;
1245 for (sym
= start
; sym
< end
; sym
++) {
1246 if (starts_with(sym
->label
, "__ksymtab")) {
1247 const struct kernel_symbol
*ksym
;
1248 const char *colon
= strchr(sym
->label
, ':');
1249 const char *name
= colon
+ 1;
1252 ksym
= find_symbol(name
, NULL
, NULL
, true, false);
1254 ksdebug(pack
, "Could not find kernel_symbol "
1255 "structure for %s\n", name
);
1258 sym
->value
= (unsigned long)ksym
;
1263 sym
->vals
= kmalloc(sizeof(*sym
->vals
), GFP_KERNEL
);
1264 if (sym
->vals
== NULL
)
1265 return OUT_OF_MEMORY
;
1266 INIT_LIST_HEAD(sym
->vals
);
1270 sym_arr
= vmalloc(sizeof(*sym_arr
) * size
);
1271 if (sym_arr
== NULL
)
1272 return OUT_OF_MEMORY
;
1274 for (symp
= sym_arr
, sym
= start
; symp
< sym_arr
+ size
&& sym
< end
;
1278 sort(sym_arr
, size
, sizeof(*sym_arr
), compare_symbolp_names
, NULL
);
1281 lookup
.arr
= sym_arr
;
1285 each_symbol(add_export_values
, &lookup
);
1287 #ifdef CONFIG_KALLSYMS
1289 ret
= (__force abort_t
)
1290 kallsyms_on_each_symbol(add_kallsyms_values
, &lookup
);
1291 #endif /* CONFIG_KALLSYMS */
1296 /* Prepare the pack's ksplice_symbol structures for run-pre matching */
1297 static abort_t
init_symbol_arrays(struct ksplice_pack
*pack
)
1301 ret
= uniquify_symbols(pack
);
1305 ret
= init_symbol_array(pack
, pack
->helper_symbols
,
1306 pack
->helper_symbols_end
);
1310 ret
= init_symbol_array(pack
, pack
->primary_symbols
,
1311 pack
->primary_symbols_end
);
1318 static abort_t
prepare_pack(struct ksplice_pack
*pack
)
1322 ksdebug(pack
, "Preparing and checking %s\n", pack
->name
);
1323 ret
= match_pack_sections(pack
, false);
1324 if (ret
== NO_MATCH
) {
1325 /* It is possible that by using relocations from .data sections
1326 * we can successfully run-pre match the rest of the sections.
1327 * To avoid using any symbols obtained from .data sections
1328 * (which may be unreliable) in the post code, we first prepare
1329 * the post code and then try to run-pre match the remaining
1330 * sections with the help of .data sections.
1332 ksdebug(pack
, "Continuing without some sections; we might "
1333 "find them later.\n");
1334 ret
= finalize_pack(pack
);
1336 ksdebug(pack
, "Aborted. Unable to continue without "
1337 "the unmatched sections.\n");
1341 ksdebug(pack
, "run-pre: Considering .data sections to find the "
1342 "unmatched sections\n");
1343 ret
= match_pack_sections(pack
, true);
1347 ksdebug(pack
, "run-pre: Found all previously unmatched "
1350 } else if (ret
!= OK
) {
1354 return finalize_pack(pack
);
1358 * Finish preparing the pack for insertion into the kernel.
1359 * Afterwards, the replacement code should be ready to run and the
1360 * ksplice_patches should all be ready for trampoline insertion.
1362 static abort_t
finalize_pack(struct ksplice_pack
*pack
)
1365 ret
= apply_relocs(pack
, pack
->primary_relocs
,
1366 pack
->primary_relocs_end
);
1370 ret
= finalize_patches(pack
);
1377 static abort_t
finalize_patches(struct ksplice_pack
*pack
)
1379 struct ksplice_patch
*p
;
1380 struct safety_record
*rec
;
1383 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++) {
1385 list_for_each_entry(rec
, &pack
->safety_records
, list
) {
1386 if (rec
->addr
<= p
->oldaddr
&&
1387 p
->oldaddr
< rec
->addr
+ rec
->size
) {
1392 if (!found
&& p
->type
!= KSPLICE_PATCH_EXPORT
) {
1393 const struct ksplice_reloc
*r
= patch_reloc(pack
, p
);
1395 ksdebug(pack
, "A patch with no ksplice_reloc at"
1396 " its oldaddr has no safety record\n");
1399 ksdebug(pack
, "No safety record for patch with oldaddr "
1400 "%s+%lx\n", r
->symbol
->label
, r
->target_addend
);
1404 if (p
->type
== KSPLICE_PATCH_TEXT
) {
1405 ret
= prepare_trampoline(pack
, p
);
1410 if (found
&& rec
->addr
+ rec
->size
< p
->oldaddr
+ p
->size
) {
1411 ksdebug(pack
, "Safety record %s is too short for "
1412 "patch\n", rec
->label
);
1416 if (p
->type
== KSPLICE_PATCH_TEXT
) {
1417 if (p
->repladdr
== 0)
1418 p
->repladdr
= (unsigned long)ksplice_deleted
;
1424 static abort_t
map_trampoline_pages(struct update
*update
)
1426 struct ksplice_pack
*pack
;
1427 list_for_each_entry(pack
, &update
->packs
, list
) {
1428 struct ksplice_patch
*p
;
1429 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++) {
1430 p
->vaddr
= map_writable((void *)p
->oldaddr
, p
->size
);
1431 if (p
->vaddr
== NULL
) {
1432 ksdebug(pack
, "Unable to map oldaddr read/write"
1434 unmap_trampoline_pages(update
);
1442 static void unmap_trampoline_pages(struct update
*update
)
1444 struct ksplice_pack
*pack
;
1445 list_for_each_entry(pack
, &update
->packs
, list
) {
1446 struct ksplice_patch
*p
;
1447 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++) {
1448 vunmap((void *)((unsigned long)p
->vaddr
& PAGE_MASK
));
1455 * map_writable creates a shadow page mapping of the range
1456 * [addr, addr + len) so that we can write to code mapped read-only.
1458 * It is similar to a generalized version of x86's text_poke. But
1459 * because one cannot use vmalloc/vfree() inside stop_machine, we use
1460 * map_writable to map the pages before stop_machine, then use the
1461 * mapping inside stop_machine, and unmap the pages afterwards.
1463 static void *map_writable(void *addr
, size_t len
)
1466 int nr_pages
= DIV_ROUND_UP(offset_in_page(addr
) + len
, PAGE_SIZE
);
1467 struct page
**pages
= kmalloc(nr_pages
* sizeof(*pages
), GFP_KERNEL
);
1468 void *page_addr
= (void *)((unsigned long)addr
& PAGE_MASK
);
1474 for (i
= 0; i
< nr_pages
; i
++) {
1475 if (__module_text_address((unsigned long)page_addr
) == NULL
&&
1476 __module_data_address((unsigned long)page_addr
) == NULL
) {
1477 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22) || !defined(CONFIG_X86_64)
1478 pages
[i
] = virt_to_page(page_addr
);
1479 #else /* LINUX_VERSION_CODE < && CONFIG_X86_64 */
1480 /* e3ebadd95cb621e2c7436f3d3646447ac9d5c16d was after 2.6.21 */
1482 pfn_to_page(__pa_symbol(page_addr
) >> PAGE_SHIFT
);
1483 #endif /* LINUX_VERSION_CODE || !CONFIG_X86_64 */
1484 WARN_ON(!PageReserved(pages
[i
]));
1486 pages
[i
] = vmalloc_to_page(addr
);
1488 if (pages
[i
] == NULL
) {
1492 page_addr
+= PAGE_SIZE
;
1494 vaddr
= vmap(pages
, nr_pages
, VM_MAP
, PAGE_KERNEL
);
1498 return vaddr
+ offset_in_page(addr
);
1502 * Ksplice adds a dependency on any symbol address used to resolve relocations
1503 * in the primary module.
1505 * Be careful to follow_trampolines so that we always depend on the
1506 * latest version of the target function, since that's the code that
1507 * will run if we call addr.
1509 static abort_t
add_dependency_on_address(struct ksplice_pack
*pack
,
1512 struct ksplice_pack
*p
;
1514 __module_text_address(follow_trampolines(pack
, addr
));
1517 list_for_each_entry(p
, &pack
->update
->packs
, list
) {
1518 if (m
== p
->primary
)
1521 if (use_module(pack
->primary
, m
) != 1)
1526 static abort_t
apply_relocs(struct ksplice_pack
*pack
,
1527 const struct ksplice_reloc
*relocs
,
1528 const struct ksplice_reloc
*relocs_end
)
1530 const struct ksplice_reloc
*r
;
1531 for (r
= relocs
; r
< relocs_end
; r
++) {
1532 abort_t ret
= apply_reloc(pack
, r
);
1539 static abort_t
apply_reloc(struct ksplice_pack
*pack
,
1540 const struct ksplice_reloc
*r
)
1542 switch (r
->howto
->type
) {
1543 case KSPLICE_HOWTO_RELOC
:
1544 case KSPLICE_HOWTO_RELOC_PATCH
:
1545 return apply_howto_reloc(pack
, r
);
1546 case KSPLICE_HOWTO_DATE
:
1547 case KSPLICE_HOWTO_TIME
:
1548 return apply_howto_date(pack
, r
);
1550 ksdebug(pack
, "Unexpected howto type %d\n", r
->howto
->type
);
1556 * Applies a relocation. Aborts if the symbol referenced in it has
1557 * not been uniquely resolved.
1559 static abort_t
apply_howto_reloc(struct ksplice_pack
*pack
,
1560 const struct ksplice_reloc
*r
)
1564 unsigned long sym_addr
;
1567 canary_ret
= contains_canary(pack
, r
->blank_addr
, r
->howto
);
1570 if (canary_ret
== 0) {
1571 ksdebug(pack
, "reloc: skipped %lx to %s+%lx (altinstr)\n",
1572 r
->blank_addr
, r
->symbol
->label
, r
->target_addend
);
1576 #ifdef KSPLICE_STANDALONE
1577 if (!bootstrapped
) {
1578 ret
= add_system_map_candidates(pack
,
1579 pack
->primary_system_map
,
1580 pack
->primary_system_map_end
,
1581 r
->symbol
->label
, &vals
);
1583 release_vals(&vals
);
1587 #endif /* KSPLICE_STANDALONE */
1588 ret
= lookup_symbol(pack
, r
->symbol
, &vals
);
1590 release_vals(&vals
);
1594 * Relocations for the oldaddr fields of patches must have
1595 * been resolved via run-pre matching.
1597 if (!singular(&vals
) || (r
->symbol
->vals
!= NULL
&&
1598 r
->howto
->type
== KSPLICE_HOWTO_RELOC_PATCH
)) {
1599 release_vals(&vals
);
1600 ksdebug(pack
, "Failed to find %s for reloc\n",
1602 return FAILED_TO_FIND
;
1604 sym_addr
= list_entry(vals
.next
, struct candidate_val
, list
)->val
;
1605 release_vals(&vals
);
1607 ret
= write_reloc_value(pack
, r
, r
->blank_addr
,
1608 r
->howto
->pcrel
? sym_addr
- r
->blank_addr
:
1613 ksdebug(pack
, "reloc: %lx to %s+%lx (S=%lx ", r
->blank_addr
,
1614 r
->symbol
->label
, r
->target_addend
, sym_addr
);
1615 switch (r
->howto
->size
) {
1617 ksdebug(pack
, "aft=%02x)\n", *(uint8_t *)r
->blank_addr
);
1620 ksdebug(pack
, "aft=%04x)\n", *(uint16_t *)r
->blank_addr
);
1623 ksdebug(pack
, "aft=%08x)\n", *(uint32_t *)r
->blank_addr
);
1625 #if BITS_PER_LONG >= 64
1627 ksdebug(pack
, "aft=%016llx)\n", *(uint64_t *)r
->blank_addr
);
1629 #endif /* BITS_PER_LONG */
1631 ksdebug(pack
, "Aborted. Invalid relocation size.\n");
1634 #ifdef KSPLICE_STANDALONE
1637 #endif /* KSPLICE_STANDALONE */
1640 * Create labelvals so that we can verify our choices in the
1641 * second round of run-pre matching that considers data sections.
1643 ret
= create_labelval(pack
, r
->symbol
, sym_addr
, VAL
);
1647 return add_dependency_on_address(pack
, sym_addr
);
1651 * Date relocations are created wherever __DATE__ or __TIME__ is used
1652 * in the kernel; we resolve them by simply copying in the date/time
1653 * obtained from run-pre matching the relevant compilation unit.
1655 static abort_t
apply_howto_date(struct ksplice_pack
*pack
,
1656 const struct ksplice_reloc
*r
)
1658 if (r
->symbol
->vals
!= NULL
) {
1659 ksdebug(pack
, "Failed to find %s for date\n", r
->symbol
->label
);
1660 return FAILED_TO_FIND
;
1662 memcpy((unsigned char *)r
->blank_addr
,
1663 (const unsigned char *)r
->symbol
->value
, r
->howto
->size
);
1668 * Given a relocation and its run address, compute the address of the
1669 * symbol the relocation referenced, and store it in *valp.
1671 static abort_t
read_reloc_value(struct ksplice_pack
*pack
,
1672 const struct ksplice_reloc
*r
,
1673 unsigned long addr
, unsigned long *valp
)
1675 unsigned char bytes
[sizeof(long)];
1677 const struct ksplice_reloc_howto
*howto
= r
->howto
;
1679 if (howto
->size
<= 0 || howto
->size
> sizeof(long)) {
1680 ksdebug(pack
, "Aborted. Invalid relocation size.\n");
1684 if (probe_kernel_read(bytes
, (void *)addr
, howto
->size
) == -EFAULT
)
1687 switch (howto
->size
) {
1689 val
= *(uint8_t *)bytes
;
1692 val
= *(uint16_t *)bytes
;
1695 val
= *(uint32_t *)bytes
;
1697 #if BITS_PER_LONG >= 64
1699 val
= *(uint64_t *)bytes
;
1701 #endif /* BITS_PER_LONG */
1703 ksdebug(pack
, "Aborted. Invalid relocation size.\n");
1707 val
&= howto
->dst_mask
;
1708 if (howto
->signed_addend
)
1709 val
|= -(val
& (howto
->dst_mask
& ~(howto
->dst_mask
>> 1)));
1710 val
<<= howto
->rightshift
;
1711 val
-= r
->insn_addend
+ r
->target_addend
;
1717 * Given a relocation, the address of its storage unit, and the
1718 * address of the symbol the relocation references, write the
1719 * relocation's final value into the storage unit.
1721 static abort_t
write_reloc_value(struct ksplice_pack
*pack
,
1722 const struct ksplice_reloc
*r
,
1723 unsigned long addr
, unsigned long sym_addr
)
1725 unsigned long val
= sym_addr
+ r
->target_addend
+ r
->insn_addend
;
1726 const struct ksplice_reloc_howto
*howto
= r
->howto
;
1727 val
>>= howto
->rightshift
;
1728 switch (howto
->size
) {
1730 *(uint8_t *)addr
= (*(uint8_t *)addr
& ~howto
->dst_mask
) |
1731 (val
& howto
->dst_mask
);
1734 *(uint16_t *)addr
= (*(uint16_t *)addr
& ~howto
->dst_mask
) |
1735 (val
& howto
->dst_mask
);
1738 *(uint32_t *)addr
= (*(uint32_t *)addr
& ~howto
->dst_mask
) |
1739 (val
& howto
->dst_mask
);
1741 #if BITS_PER_LONG >= 64
1743 *(uint64_t *)addr
= (*(uint64_t *)addr
& ~howto
->dst_mask
) |
1744 (val
& howto
->dst_mask
);
1746 #endif /* BITS_PER_LONG */
1748 ksdebug(pack
, "Aborted. Invalid relocation size.\n");
1752 if (read_reloc_value(pack
, r
, addr
, &val
) != OK
|| val
!= sym_addr
) {
1753 ksdebug(pack
, "Aborted. Relocation overflow.\n");
1760 static abort_t
create_module_list_entry(struct ksplice_pack
*pack
,
1763 struct ksplice_module_list_entry
*entry
=
1764 kmalloc(sizeof(*entry
), GFP_KERNEL
);
1766 return OUT_OF_MEMORY
;
1767 entry
->primary_name
= kstrdup(pack
->primary
->name
, GFP_KERNEL
);
1768 if (entry
->primary_name
== NULL
) {
1770 return OUT_OF_MEMORY
;
1772 entry
->target_name
= kstrdup(pack
->target_name
, GFP_KERNEL
);
1773 if (entry
->target_name
== NULL
) {
1774 kfree(entry
->primary_name
);
1776 return OUT_OF_MEMORY
;
1778 /* The update's kid is guaranteed to outlast the module_list_entry */
1779 entry
->kid
= pack
->update
->kid
;
1780 entry
->applied
= to_be_applied
;
1781 list_add(&entry
->update_list
, &pack
->update
->ksplice_module_list
);
1785 static void cleanup_module_list_entries(struct update
*update
)
1787 struct ksplice_module_list_entry
*entry
;
1788 list_for_each_entry(entry
, &update
->ksplice_module_list
, update_list
) {
1789 kfree(entry
->target_name
);
1790 kfree(entry
->primary_name
);
1792 clear_list(&update
->ksplice_module_list
,
1793 struct ksplice_module_list_entry
, update_list
);
1796 /* Replacement address used for functions deleted by the patch */
1797 static void __attribute__((noreturn
)) ksplice_deleted(void)
1799 printk(KERN_CRIT
"Called a kernel function deleted by Ksplice!\n");
1801 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
1802 /* 91768d6c2bad0d2766a166f13f2f57e197de3458 was after 2.6.19 */
1807 /* Floodfill to run-pre match the sections within a pack. */
1808 static abort_t
match_pack_sections(struct ksplice_pack
*pack
,
1809 bool consider_data_sections
)
1811 struct ksplice_section
*sect
;
1816 for (sect
= pack
->helper_sections
; sect
< pack
->helper_sections_end
;
1818 if ((sect
->flags
& KSPLICE_SECTION_DATA
) == 0 &&
1819 (sect
->flags
& KSPLICE_SECTION_STRING
) == 0 &&
1820 (sect
->flags
& KSPLICE_SECTION_MATCHED
) == 0)
1824 while (remaining
> 0) {
1826 for (sect
= pack
->helper_sections
;
1827 sect
< pack
->helper_sections_end
; sect
++) {
1828 if ((sect
->flags
& KSPLICE_SECTION_MATCHED
) != 0)
1830 if ((!consider_data_sections
&&
1831 (sect
->flags
& KSPLICE_SECTION_DATA
) != 0) ||
1832 (sect
->flags
& KSPLICE_SECTION_STRING
) != 0)
1834 ret
= find_section(pack
, sect
);
1836 sect
->flags
|= KSPLICE_SECTION_MATCHED
;
1837 if ((sect
->flags
& KSPLICE_SECTION_DATA
) == 0)
1840 } else if (ret
!= NO_MATCH
) {
1848 for (sect
= pack
->helper_sections
;
1849 sect
< pack
->helper_sections_end
; sect
++) {
1850 if ((sect
->flags
& KSPLICE_SECTION_MATCHED
) != 0 ||
1851 (sect
->flags
& KSPLICE_SECTION_STRING
) != 0)
1853 ksdebug(pack
, "run-pre: could not match %s "
1855 (sect
->flags
& KSPLICE_SECTION_DATA
) != 0 ?
1857 (sect
->flags
& KSPLICE_SECTION_RODATA
) != 0 ?
1858 "rodata" : "text", sect
->symbol
->label
);
1860 ksdebug(pack
, "Aborted. run-pre: could not match some "
1868 * Search for the section in the running kernel. Returns OK if and
1869 * only if it finds precisely one address in the kernel matching the
1872 static abort_t
find_section(struct ksplice_pack
*pack
,
1873 struct ksplice_section
*sect
)
1877 unsigned long run_addr
;
1879 struct candidate_val
*v
, *n
;
1881 #ifdef KSPLICE_STANDALONE
1882 ret
= add_system_map_candidates(pack
, pack
->helper_system_map
,
1883 pack
->helper_system_map_end
,
1884 sect
->symbol
->label
, &vals
);
1886 release_vals(&vals
);
1889 #endif /* KSPLICE_STANDALONE */
1890 ret
= lookup_symbol(pack
, sect
->symbol
, &vals
);
1892 release_vals(&vals
);
1896 ksdebug(pack
, "run-pre: starting sect search for %s\n",
1897 sect
->symbol
->label
);
1899 list_for_each_entry_safe(v
, n
, &vals
, list
) {
1903 ret
= try_addr(pack
, sect
, run_addr
, NULL
, RUN_PRE_INITIAL
);
1904 if (ret
== NO_MATCH
) {
1907 } else if (ret
!= OK
) {
1908 release_vals(&vals
);
1913 #if defined(KSPLICE_STANDALONE) && !defined(CONFIG_KALLSYMS)
1914 if (list_empty(&vals
) && (sect
->flags
& KSPLICE_SECTION_DATA
) == 0) {
1915 ret
= brute_search_all(pack
, sect
, &vals
);
1917 release_vals(&vals
);
1921 * Make sure run-pre matching output is displayed if
1922 * brute_search succeeds.
1924 if (singular(&vals
)) {
1925 run_addr
= list_entry(vals
.next
, struct candidate_val
,
1927 ret
= try_addr(pack
, sect
, run_addr
, NULL
,
1930 ksdebug(pack
, "run-pre: Debug run failed for "
1931 "sect %s:\n", sect
->symbol
->label
);
1932 release_vals(&vals
);
1937 #endif /* KSPLICE_STANDALONE && !CONFIG_KALLSYMS */
1939 if (singular(&vals
)) {
1940 LIST_HEAD(safety_records
);
1941 run_addr
= list_entry(vals
.next
, struct candidate_val
,
1943 ret
= try_addr(pack
, sect
, run_addr
, &safety_records
,
1945 release_vals(&vals
);
1947 clear_list(&safety_records
, struct safety_record
, list
);
1948 ksdebug(pack
, "run-pre: Final run failed for sect "
1949 "%s:\n", sect
->symbol
->label
);
1951 list_splice(&safety_records
, &pack
->safety_records
);
1954 } else if (!list_empty(&vals
)) {
1955 struct candidate_val
*val
;
1956 ksdebug(pack
, "run-pre: multiple candidates for sect %s:\n",
1957 sect
->symbol
->label
);
1959 list_for_each_entry(val
, &vals
, list
) {
1961 ksdebug(pack
, "%lx\n", val
->val
);
1963 ksdebug(pack
, "...\n");
1967 release_vals(&vals
);
1970 release_vals(&vals
);
1975 * try_addr is the the interface to run-pre matching. Its primary
1976 * purpose is to manage debugging information for run-pre matching;
1977 * all the hard work is in run_pre_cmp.
1979 static abort_t
try_addr(struct ksplice_pack
*pack
,
1980 struct ksplice_section
*sect
,
1981 unsigned long run_addr
,
1982 struct list_head
*safety_records
,
1983 enum run_pre_mode mode
)
1986 const struct module
*run_module
;
1988 if ((sect
->flags
& KSPLICE_SECTION_RODATA
) != 0 ||
1989 (sect
->flags
& KSPLICE_SECTION_DATA
) != 0)
1990 run_module
= __module_data_address(run_addr
);
1992 run_module
= __module_text_address(run_addr
);
1993 if (run_module
== pack
->primary
) {
1994 ksdebug(pack
, "run-pre: unexpected address %lx in primary "
1995 "module %s for sect %s\n", run_addr
, run_module
->name
,
1996 sect
->symbol
->label
);
1999 if (!patches_module(run_module
, pack
->target
)) {
2000 ksdebug(pack
, "run-pre: ignoring address %lx in other module "
2001 "%s for sect %s\n", run_addr
, run_module
== NULL
?
2002 "vmlinux" : run_module
->name
, sect
->symbol
->label
);
2006 ret
= create_labelval(pack
, sect
->symbol
, run_addr
, TEMP
);
2010 #ifdef CONFIG_FUNCTION_DATA_SECTIONS
2011 ret
= run_pre_cmp(pack
, sect
, run_addr
, safety_records
, mode
);
2012 #else /* !CONFIG_FUNCTION_DATA_SECTIONS */
2013 if ((sect
->flags
& KSPLICE_SECTION_TEXT
) != 0)
2014 ret
= arch_run_pre_cmp(pack
, sect
, run_addr
, safety_records
,
2017 ret
= run_pre_cmp(pack
, sect
, run_addr
, safety_records
, mode
);
2018 #endif /* CONFIG_FUNCTION_DATA_SECTIONS */
2019 if (ret
== NO_MATCH
&& mode
!= RUN_PRE_FINAL
) {
2020 set_temp_labelvals(pack
, NOVAL
);
2021 ksdebug(pack
, "run-pre: %s sect %s does not match (r_a=%lx "
2023 (sect
->flags
& KSPLICE_SECTION_RODATA
) != 0 ? "rodata" :
2024 (sect
->flags
& KSPLICE_SECTION_DATA
) != 0 ? "data" :
2025 "text", sect
->symbol
->label
, run_addr
, sect
->address
,
2027 ksdebug(pack
, "run-pre: ");
2028 if (pack
->update
->debug
>= 1) {
2029 #ifdef CONFIG_FUNCTION_DATA_SECTIONS
2030 ret
= run_pre_cmp(pack
, sect
, run_addr
, safety_records
,
2032 #else /* !CONFIG_FUNCTION_DATA_SECTIONS */
2033 if ((sect
->flags
& KSPLICE_SECTION_TEXT
) != 0)
2034 ret
= arch_run_pre_cmp(pack
, sect
, run_addr
,
2038 ret
= run_pre_cmp(pack
, sect
, run_addr
,
2041 #endif /* CONFIG_FUNCTION_DATA_SECTIONS */
2042 set_temp_labelvals(pack
, NOVAL
);
2044 ksdebug(pack
, "\n");
2046 } else if (ret
!= OK
) {
2047 set_temp_labelvals(pack
, NOVAL
);
2051 if (mode
!= RUN_PRE_FINAL
) {
2052 set_temp_labelvals(pack
, NOVAL
);
2053 ksdebug(pack
, "run-pre: candidate for sect %s=%lx\n",
2054 sect
->symbol
->label
, run_addr
);
2058 set_temp_labelvals(pack
, VAL
);
2059 ksdebug(pack
, "run-pre: found sect %s=%lx\n", sect
->symbol
->label
,
2065 * run_pre_cmp is the primary run-pre matching function; it determines
2066 * whether the given ksplice_section matches the code or data in the
2067 * running kernel starting at run_addr.
2069 * If run_pre_mode is RUN_PRE_FINAL, a safety record for the matched
2070 * section is created.
2072 * The run_pre_mode is also used to determine what debugging
2073 * information to display.
2075 static abort_t
run_pre_cmp(struct ksplice_pack
*pack
,
2076 const struct ksplice_section
*sect
,
2077 unsigned long run_addr
,
2078 struct list_head
*safety_records
,
2079 enum run_pre_mode mode
)
2083 const struct ksplice_reloc
*r
, *finger
;
2084 const unsigned char *pre
, *run
, *pre_start
, *run_start
;
2085 unsigned char runval
;
2087 pre_start
= (const unsigned char *)sect
->address
;
2088 run_start
= (const unsigned char *)run_addr
;
2090 finger
= init_reloc_search(pack
, sect
);
2094 while (pre
< pre_start
+ sect
->size
) {
2095 unsigned long offset
= pre
- pre_start
;
2096 ret
= lookup_reloc(pack
, &finger
, (unsigned long)pre
, &r
);
2098 ret
= handle_reloc(pack
, sect
, r
, (unsigned long)run
,
2101 if (mode
== RUN_PRE_INITIAL
)
2102 ksdebug(pack
, "reloc in sect does not "
2103 "match after %lx/%lx bytes\n",
2104 offset
, sect
->size
);
2107 if (mode
== RUN_PRE_DEBUG
)
2108 print_bytes(pack
, run
, r
->howto
->size
, pre
,
2110 pre
+= r
->howto
->size
;
2111 run
+= r
->howto
->size
;
2114 } else if (ret
!= NO_MATCH
) {
2118 if ((sect
->flags
& KSPLICE_SECTION_TEXT
) != 0) {
2119 ret
= handle_paravirt(pack
, (unsigned long)pre
,
2120 (unsigned long)run
, &matched
);
2124 if (mode
== RUN_PRE_DEBUG
)
2125 print_bytes(pack
, run
, matched
, pre
,
2133 if (probe_kernel_read(&runval
, (void *)run
, 1) == -EFAULT
) {
2134 if (mode
== RUN_PRE_INITIAL
)
2135 ksdebug(pack
, "sect unmapped after %lx/%lx "
2136 "bytes\n", offset
, sect
->size
);
2140 if (runval
!= *pre
&&
2141 (sect
->flags
& KSPLICE_SECTION_DATA
) == 0) {
2142 if (mode
== RUN_PRE_INITIAL
)
2143 ksdebug(pack
, "sect does not match after "
2144 "%lx/%lx bytes\n", offset
, sect
->size
);
2145 if (mode
== RUN_PRE_DEBUG
) {
2146 print_bytes(pack
, run
, 1, pre
, 1);
2147 ksdebug(pack
, "[p_o=%lx] ! ", offset
);
2148 print_bytes(pack
, run
+ 1, 2, pre
+ 1, 2);
2152 if (mode
== RUN_PRE_DEBUG
)
2153 print_bytes(pack
, run
, 1, pre
, 1);
2157 return create_safety_record(pack
, sect
, safety_records
, run_addr
,
2161 static void print_bytes(struct ksplice_pack
*pack
,
2162 const unsigned char *run
, int runc
,
2163 const unsigned char *pre
, int prec
)
2166 int matched
= min(runc
, prec
);
2167 for (o
= 0; o
< matched
; o
++) {
2168 if (run
[o
] == pre
[o
])
2169 ksdebug(pack
, "%02x ", run
[o
]);
2171 ksdebug(pack
, "%02x/%02x ", run
[o
], pre
[o
]);
2173 for (o
= matched
; o
< runc
; o
++)
2174 ksdebug(pack
, "%02x/ ", run
[o
]);
2175 for (o
= matched
; o
< prec
; o
++)
2176 ksdebug(pack
, "/%02x ", pre
[o
]);
2179 #if defined(KSPLICE_STANDALONE) && !defined(CONFIG_KALLSYMS)
2180 static abort_t
brute_search(struct ksplice_pack
*pack
,
2181 struct ksplice_section
*sect
,
2182 const void *start
, unsigned long len
,
2183 struct list_head
*vals
)
2189 for (addr
= (unsigned long)start
; addr
< (unsigned long)start
+ len
;
2191 if (addr
% 100000 == 0)
2194 if (probe_kernel_read(&run
, (void *)addr
, 1) == -EFAULT
)
2197 pre
= *(const unsigned char *)(sect
->address
);
2202 ret
= try_addr(pack
, sect
, addr
, NULL
, RUN_PRE_INITIAL
);
2204 ret
= add_candidate_val(pack
, vals
, addr
);
2207 } else if (ret
!= NO_MATCH
) {
2215 static abort_t
brute_search_all(struct ksplice_pack
*pack
,
2216 struct ksplice_section
*sect
,
2217 struct list_head
*vals
)
2223 ksdebug(pack
, "brute_search: searching for %s\n", sect
->symbol
->label
);
2224 saved_debug
= pack
->update
->debug
;
2225 pack
->update
->debug
= 0;
2227 list_for_each_entry(m
, &modules
, list
) {
2228 if (!patches_module(m
, pack
->target
) || m
== pack
->primary
)
2230 ret
= brute_search(pack
, sect
, m
->module_core
, m
->core_size
,
2234 ret
= brute_search(pack
, sect
, m
->module_init
, m
->init_size
,
2240 ret
= brute_search(pack
, sect
, (const void *)init_mm
.start_code
,
2241 init_mm
.end_code
- init_mm
.start_code
, vals
);
2244 pack
->update
->debug
= saved_debug
;
2247 #endif /* KSPLICE_STANDALONE && !CONFIG_KALLSYMS */
2250 unsigned long address
;
2254 static int reloc_bsearch_compare(const void *key
, const void *elt
)
2256 const struct range
*range
= key
;
2257 const struct ksplice_reloc
*r
= elt
;
2258 if (range
->address
+ range
->size
<= r
->blank_addr
)
2260 if (range
->address
> r
->blank_addr
)
2265 static const struct ksplice_reloc
*find_reloc(const struct ksplice_reloc
*start
,
2266 const struct ksplice_reloc
*end
,
2267 unsigned long address
,
2270 const struct ksplice_reloc
*r
;
2271 struct range range
= { address
, size
};
2272 r
= bsearch((void *)&range
, start
, end
- start
, sizeof(*r
),
2273 reloc_bsearch_compare
);
2276 while (r
> start
&& (r
- 1)->blank_addr
>= address
)
2281 static const struct ksplice_reloc
*
2282 init_reloc_search(struct ksplice_pack
*pack
, const struct ksplice_section
*sect
)
2284 const struct ksplice_reloc
*r
;
2285 r
= find_reloc(pack
->helper_relocs
, pack
->helper_relocs_end
,
2286 sect
->address
, sect
->size
);
2288 return pack
->helper_relocs_end
;
2293 * lookup_reloc implements an amortized O(1) lookup for the next
2294 * helper relocation. It must be called with a strictly increasing
2295 * sequence of addresses.
2297 * The fingerp is private data for lookup_reloc, and needs to have
2298 * been initialized as a pointer to the result of find_reloc (or
2299 * init_reloc_search).
2301 static abort_t
lookup_reloc(struct ksplice_pack
*pack
,
2302 const struct ksplice_reloc
**fingerp
,
2304 const struct ksplice_reloc
**relocp
)
2306 const struct ksplice_reloc
*r
= *fingerp
;
2309 while (r
< pack
->helper_relocs_end
&&
2310 addr
>= r
->blank_addr
+ r
->howto
->size
&&
2311 !(addr
== r
->blank_addr
&& r
->howto
->size
== 0))
2314 if (r
== pack
->helper_relocs_end
)
2316 if (addr
< r
->blank_addr
)
2319 if (r
->howto
->type
!= KSPLICE_HOWTO_RELOC
)
2322 canary_ret
= contains_canary(pack
, r
->blank_addr
, r
->howto
);
2325 if (canary_ret
== 0) {
2326 ksdebug(pack
, "run-pre: reloc skipped at p_a=%lx to %s+%lx "
2327 "(altinstr)\n", r
->blank_addr
, r
->symbol
->label
,
2331 if (addr
!= r
->blank_addr
) {
2332 ksdebug(pack
, "Invalid nonzero relocation offset\n");
2338 static abort_t
handle_reloc(struct ksplice_pack
*pack
,
2339 const struct ksplice_section
*sect
,
2340 const struct ksplice_reloc
*r
,
2341 unsigned long run_addr
, enum run_pre_mode mode
)
2343 switch (r
->howto
->type
) {
2344 case KSPLICE_HOWTO_RELOC
:
2345 return handle_howto_reloc(pack
, sect
, r
, run_addr
, mode
);
2346 case KSPLICE_HOWTO_DATE
:
2347 case KSPLICE_HOWTO_TIME
:
2348 return handle_howto_date(pack
, sect
, r
, run_addr
, mode
);
2349 case KSPLICE_HOWTO_BUG
:
2350 return handle_bug(pack
, r
, run_addr
);
2351 case KSPLICE_HOWTO_EXTABLE
:
2352 return handle_extable(pack
, r
, run_addr
);
2354 ksdebug(pack
, "Unexpected howto type %d\n", r
->howto
->type
);
2360 * For date/time relocations, we check that the sequence of bytes
2361 * matches the format of a date or time.
2363 static abort_t
handle_howto_date(struct ksplice_pack
*pack
,
2364 const struct ksplice_section
*sect
,
2365 const struct ksplice_reloc
*r
,
2366 unsigned long run_addr
, enum run_pre_mode mode
)
2369 char *buf
= kmalloc(r
->howto
->size
, GFP_KERNEL
);
2372 return OUT_OF_MEMORY
;
2373 if (probe_kernel_read(buf
, (void *)run_addr
, r
->howto
->size
) == -EFAULT
) {
2378 switch (r
->howto
->type
) {
2379 case KSPLICE_HOWTO_TIME
:
2380 if (isdigit(buf
[0]) && isdigit(buf
[1]) && buf
[2] == ':' &&
2381 isdigit(buf
[3]) && isdigit(buf
[4]) && buf
[5] == ':' &&
2382 isdigit(buf
[6]) && isdigit(buf
[7]))
2387 case KSPLICE_HOWTO_DATE
:
2388 if (isalpha(buf
[0]) && isalpha(buf
[1]) && isalpha(buf
[2]) &&
2389 buf
[3] == ' ' && (buf
[4] == ' ' || isdigit(buf
[4])) &&
2390 isdigit(buf
[5]) && buf
[6] == ' ' && isdigit(buf
[7]) &&
2391 isdigit(buf
[8]) && isdigit(buf
[9]) && isdigit(buf
[10]))
2399 if (ret
== NO_MATCH
&& mode
== RUN_PRE_INITIAL
)
2400 ksdebug(pack
, "%s string: \"%.*s\" does not match format\n",
2401 r
->howto
->type
== KSPLICE_HOWTO_DATE
? "date" : "time",
2402 r
->howto
->size
, buf
);
2406 ret
= create_labelval(pack
, r
->symbol
, run_addr
, TEMP
);
2413 * Extract the value of a symbol used in a relocation in the pre code
2414 * during run-pre matching, giving an error if it conflicts with a
2415 * previously found value of that symbol
2417 static abort_t
handle_howto_reloc(struct ksplice_pack
*pack
,
2418 const struct ksplice_section
*sect
,
2419 const struct ksplice_reloc
*r
,
2420 unsigned long run_addr
,
2421 enum run_pre_mode mode
)
2423 struct ksplice_section
*sym_sect
= symbol_section(pack
, r
->symbol
);
2424 unsigned long offset
= r
->target_addend
;
2428 ret
= read_reloc_value(pack
, r
, run_addr
, &val
);
2431 if (r
->howto
->pcrel
)
2434 #ifdef KSPLICE_STANDALONE
2435 /* The match_map is only used in KSPLICE_STANDALONE */
2436 if (sym_sect
== NULL
|| sym_sect
->match_map
== NULL
|| offset
== 0) {
2438 } else if (offset
< 0 || offset
>= sym_sect
->size
) {
2439 ksdebug(pack
, "Out of range relocation: %s+%lx -> %s+%lx",
2440 sect
->symbol
->label
, r
->blank_addr
- sect
->address
,
2441 r
->symbol
->label
, offset
);
2443 } else if (sect
== sym_sect
&& sect
->match_map
[offset
] == NULL
) {
2444 sym_sect
->match_map
[offset
] =
2445 (const unsigned char *)r
->symbol
->value
+ offset
;
2446 } else if (sect
== sym_sect
&& (unsigned long)sect
->match_map
[offset
] ==
2447 r
->symbol
->value
+ offset
) {
2449 } else if (sect
== sym_sect
) {
2450 ksdebug(pack
, "Relocations to nonmatching locations within "
2451 "section %s: %lx does not match %lx\n",
2452 sect
->symbol
->label
, offset
,
2453 (unsigned long)sect
->match_map
[offset
] -
2456 } else if ((sym_sect
->flags
& KSPLICE_SECTION_MATCHED
) == 0) {
2457 if (mode
== RUN_PRE_INITIAL
)
2458 ksdebug(pack
, "Delaying matching of %s due to reloc "
2459 "from to unmatching section: %s+%lx\n",
2460 sect
->symbol
->label
, r
->symbol
->label
, offset
);
2462 } else if (sym_sect
->match_map
[offset
] == NULL
) {
2463 if (mode
== RUN_PRE_INITIAL
)
2464 ksdebug(pack
, "Relocation not to instruction boundary: "
2465 "%s+%lx -> %s+%lx", sect
->symbol
->label
,
2466 r
->blank_addr
- sect
->address
, r
->symbol
->label
,
2469 } else if ((unsigned long)sym_sect
->match_map
[offset
] !=
2470 r
->symbol
->value
+ offset
) {
2471 if (mode
== RUN_PRE_INITIAL
)
2472 ksdebug(pack
, "Match map shift %s+%lx: %lx != %lx\n",
2473 r
->symbol
->label
, offset
,
2474 r
->symbol
->value
+ offset
,
2475 (unsigned long)sym_sect
->match_map
[offset
]);
2476 val
+= r
->symbol
->value
+ offset
-
2477 (unsigned long)sym_sect
->match_map
[offset
];
2479 #endif /* KSPLICE_STANDALONE */
2481 if (mode
== RUN_PRE_INITIAL
)
2482 ksdebug(pack
, "run-pre: reloc at r_a=%lx p_a=%lx to %s+%lx: "
2483 "found %s = %lx\n", run_addr
, r
->blank_addr
,
2484 r
->symbol
->label
, offset
, r
->symbol
->label
, val
);
2486 if (contains_canary(pack
, run_addr
, r
->howto
) != 0) {
2487 ksdebug(pack
, "Aborted. Unexpected canary in run code at %lx"
2492 if ((sect
->flags
& KSPLICE_SECTION_DATA
) != 0 &&
2493 sect
->symbol
== r
->symbol
)
2495 ret
= create_labelval(pack
, r
->symbol
, val
, TEMP
);
2496 if (ret
== NO_MATCH
&& mode
== RUN_PRE_INITIAL
)
2497 ksdebug(pack
, "run-pre: reloc at r_a=%lx p_a=%lx: labelval %s "
2498 "= %lx does not match expected %lx\n", run_addr
,
2499 r
->blank_addr
, r
->symbol
->label
, r
->symbol
->value
, val
);
2503 if (sym_sect
!= NULL
&& (sym_sect
->flags
& KSPLICE_SECTION_MATCHED
) == 0
2504 && (sym_sect
->flags
& KSPLICE_SECTION_STRING
) != 0) {
2505 if (mode
== RUN_PRE_INITIAL
)
2506 ksdebug(pack
, "Recursively comparing string section "
2507 "%s\n", sym_sect
->symbol
->label
);
2508 else if (mode
== RUN_PRE_DEBUG
)
2509 ksdebug(pack
, "[str start] ");
2510 ret
= run_pre_cmp(pack
, sym_sect
, val
, NULL
, mode
);
2511 if (mode
== RUN_PRE_DEBUG
)
2512 ksdebug(pack
, "[str end] ");
2513 if (ret
== OK
&& mode
== RUN_PRE_INITIAL
)
2514 ksdebug(pack
, "Successfully matched string section %s"
2515 "\n", sym_sect
->symbol
->label
);
2516 else if (mode
== RUN_PRE_INITIAL
)
2517 ksdebug(pack
, "Failed to match string section %s\n",
2518 sym_sect
->symbol
->label
);
2523 static int symbol_section_bsearch_compare(const void *a
, const void *b
)
2525 const struct ksplice_symbol
*sym
= a
;
2526 const struct ksplice_section
*sect
= b
;
2527 return strcmp(sym
->label
, sect
->symbol
->label
);
2530 static int compare_section_labels(const void *va
, const void *vb
)
2532 const struct ksplice_section
*a
= va
, *b
= vb
;
2533 return strcmp(a
->symbol
->label
, b
->symbol
->label
);
2536 static struct ksplice_section
*symbol_section(struct ksplice_pack
*pack
,
2537 const struct ksplice_symbol
*sym
)
2539 return bsearch(sym
, pack
->helper_sections
, pack
->helper_sections_end
-
2540 pack
->helper_sections
, sizeof(struct ksplice_section
),
2541 symbol_section_bsearch_compare
);
2544 /* Find the relocation for the oldaddr of a ksplice_patch */
2545 static const struct ksplice_reloc
*patch_reloc(struct ksplice_pack
*pack
,
2546 const struct ksplice_patch
*p
)
2548 unsigned long addr
= (unsigned long)&p
->oldaddr
;
2549 const struct ksplice_reloc
*r
=
2550 find_reloc(pack
->primary_relocs
, pack
->primary_relocs_end
, addr
,
2552 if (r
== NULL
|| r
->blank_addr
< addr
||
2553 r
->blank_addr
>= addr
+ sizeof(addr
))
2559 * Populates vals with the possible values for ksym from the various
2560 * sources Ksplice uses to resolve symbols
2562 static abort_t
lookup_symbol(struct ksplice_pack
*pack
,
2563 const struct ksplice_symbol
*ksym
,
2564 struct list_head
*vals
)
2568 #ifdef KSPLICE_STANDALONE
2571 #endif /* KSPLICE_STANDALONE */
2573 if (ksym
->vals
== NULL
) {
2575 ksdebug(pack
, "using detected sym %s=%lx\n", ksym
->label
,
2577 return add_candidate_val(pack
, vals
, ksym
->value
);
2580 #ifdef CONFIG_MODULE_UNLOAD
2581 if (strcmp(ksym
->label
, "cleanup_module") == 0 && pack
->target
!= NULL
2582 && pack
->target
->exit
!= NULL
) {
2583 ret
= add_candidate_val(pack
, vals
,
2584 (unsigned long)pack
->target
->exit
);
2590 if (ksym
->name
!= NULL
) {
2591 struct candidate_val
*val
;
2592 list_for_each_entry(val
, ksym
->vals
, list
) {
2593 ret
= add_candidate_val(pack
, vals
, val
->val
);
2598 ret
= new_export_lookup(pack
, ksym
->name
, vals
);
2606 #ifdef KSPLICE_STANDALONE
2608 add_system_map_candidates(struct ksplice_pack
*pack
,
2609 const struct ksplice_system_map
*start
,
2610 const struct ksplice_system_map
*end
,
2611 const char *label
, struct list_head
*vals
)
2616 const struct ksplice_system_map
*smap
;
2618 /* Some Fedora kernel releases have System.map files whose symbol
2619 * addresses disagree with the running kernel by a constant address
2620 * offset because of the CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN
2621 * values used to compile these kernels. This constant address offset
2622 * is always a multiple of 0x100000.
2624 * If we observe an offset that is NOT a multiple of 0x100000, then the
2625 * user provided us with an incorrect System.map file, and we should
2627 * If we observe an offset that is a multiple of 0x100000, then we can
2628 * adjust the System.map address values accordingly and proceed.
2630 off
= (unsigned long)printk
- pack
->map_printk
;
2631 if (off
& 0xfffff) {
2632 ksdebug(pack
, "Aborted. System.map does not match kernel.\n");
2633 return BAD_SYSTEM_MAP
;
2636 smap
= bsearch(label
, start
, end
- start
, sizeof(*smap
),
2637 system_map_bsearch_compare
);
2641 for (i
= 0; i
< smap
->nr_candidates
; i
++) {
2642 ret
= add_candidate_val(pack
, vals
, smap
->candidates
[i
] + off
);
2649 static int system_map_bsearch_compare(const void *key
, const void *elt
)
2651 const struct ksplice_system_map
*map
= elt
;
2652 const char *label
= key
;
2653 return strcmp(label
, map
->label
);
2655 #endif /* !KSPLICE_STANDALONE */
2658 * An update could one module to export a symbol and at the same time
2659 * change another module to use that symbol. This violates the normal
2660 * situation where the packs can be handled independently.
2662 * new_export_lookup obtains symbol values from the changes to the
2663 * exported symbol table made by other packs.
2665 static abort_t
new_export_lookup(struct ksplice_pack
*ipack
, const char *name
,
2666 struct list_head
*vals
)
2668 struct ksplice_pack
*pack
;
2669 struct ksplice_patch
*p
;
2670 list_for_each_entry(pack
, &ipack
->update
->packs
, list
) {
2671 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++) {
2672 const struct kernel_symbol
*sym
;
2673 const struct ksplice_reloc
*r
;
2674 if (p
->type
!= KSPLICE_PATCH_EXPORT
||
2675 strcmp(name
, *(const char **)p
->contents
) != 0)
2678 /* Check that the p->oldaddr reloc has been resolved. */
2679 r
= patch_reloc(pack
, p
);
2681 contains_canary(pack
, r
->blank_addr
, r
->howto
) != 0)
2683 sym
= (const struct kernel_symbol
*)r
->symbol
->value
;
2686 * Check that the sym->value reloc has been resolved,
2687 * if there is a Ksplice relocation there.
2689 r
= find_reloc(pack
->primary_relocs
,
2690 pack
->primary_relocs_end
,
2691 (unsigned long)&sym
->value
,
2692 sizeof(&sym
->value
));
2694 r
->blank_addr
== (unsigned long)&sym
->value
&&
2695 contains_canary(pack
, r
->blank_addr
, r
->howto
) != 0)
2697 return add_candidate_val(ipack
, vals
, sym
->value
);
2704 * When apply_patches is called, the update should be fully prepared.
2705 * apply_patches will try to actually insert trampolines for the
2708 static abort_t
apply_patches(struct update
*update
)
2712 struct ksplice_pack
*pack
;
2714 ret
= map_trampoline_pages(update
);
2718 list_for_each_entry(pack
, &update
->packs
, list
) {
2719 const typeof(int (*)(void)) *f
;
2720 for (f
= pack
->pre_apply
; f
< pack
->pre_apply_end
; f
++) {
2728 for (i
= 0; i
< 5; i
++) {
2729 cleanup_conflicts(update
);
2730 #ifdef KSPLICE_STANDALONE
2732 #endif /* KSPLICE_STANDALONE */
2733 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
2734 ret
= (__force abort_t
)stop_machine(__apply_patches
, update
,
2736 #else /* LINUX_VERSION_CODE < */
2737 /* 9b1a4d38373a5581a4e01032a3ccdd94cd93477b was after 2.6.26 */
2738 ret
= (__force abort_t
)stop_machine_run(__apply_patches
, update
,
2740 #endif /* LINUX_VERSION_CODE */
2741 #ifdef KSPLICE_STANDALONE
2743 #endif /* KSPLICE_STANDALONE */
2744 if (ret
!= CODE_BUSY
)
2746 set_current_state(TASK_INTERRUPTIBLE
);
2747 schedule_timeout(msecs_to_jiffies(1000));
2750 unmap_trampoline_pages(update
);
2752 if (ret
== CODE_BUSY
) {
2753 print_conflicts(update
);
2754 _ksdebug(update
, "Aborted %s. stack check: to-be-replaced "
2755 "code is busy.\n", update
->kid
);
2756 } else if (ret
== ALREADY_REVERSED
) {
2757 _ksdebug(update
, "Aborted %s. Ksplice update %s is already "
2758 "reversed.\n", update
->kid
, update
->kid
);
2762 list_for_each_entry(pack
, &update
->packs
, list
) {
2763 const typeof(void (*)(void)) *f
;
2764 for (f
= pack
->fail_apply
; f
< pack
->fail_apply_end
;
2772 list_for_each_entry(pack
, &update
->packs
, list
) {
2773 const typeof(void (*)(void)) *f
;
2774 for (f
= pack
->post_apply
; f
< pack
->post_apply_end
; f
++)
2778 _ksdebug(update
, "Atomic patch insertion for %s complete\n",
2783 static abort_t
reverse_patches(struct update
*update
)
2787 struct ksplice_pack
*pack
;
2789 clear_debug_buf(update
);
2790 ret
= init_debug_buf(update
);
2794 _ksdebug(update
, "Preparing to reverse %s\n", update
->kid
);
2796 ret
= map_trampoline_pages(update
);
2800 list_for_each_entry(pack
, &update
->packs
, list
) {
2801 const typeof(int (*)(void)) *f
;
2802 for (f
= pack
->pre_reverse
; f
< pack
->pre_reverse_end
; f
++) {
2810 for (i
= 0; i
< 5; i
++) {
2811 cleanup_conflicts(update
);
2812 clear_list(&update
->conflicts
, struct conflict
, list
);
2813 #ifdef KSPLICE_STANDALONE
2815 #endif /* KSPLICE_STANDALONE */
2816 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
2817 ret
= (__force abort_t
)stop_machine(__reverse_patches
, update
,
2819 #else /* LINUX_VERSION_CODE < */
2820 /* 9b1a4d38373a5581a4e01032a3ccdd94cd93477b was after 2.6.26 */
2821 ret
= (__force abort_t
)stop_machine_run(__reverse_patches
,
2823 #endif /* LINUX_VERSION_CODE */
2824 #ifdef KSPLICE_STANDALONE
2826 #endif /* KSPLICE_STANDALONE */
2827 if (ret
!= CODE_BUSY
)
2829 set_current_state(TASK_INTERRUPTIBLE
);
2830 schedule_timeout(msecs_to_jiffies(1000));
2833 unmap_trampoline_pages(update
);
2835 if (ret
== CODE_BUSY
) {
2836 print_conflicts(update
);
2837 _ksdebug(update
, "Aborted %s. stack check: to-be-reversed "
2838 "code is busy.\n", update
->kid
);
2839 } else if (ret
== MODULE_BUSY
) {
2840 _ksdebug(update
, "Update %s is in use by another module\n",
2845 list_for_each_entry(pack
, &update
->packs
, list
) {
2846 const typeof(void (*)(void)) *f
;
2847 for (f
= pack
->fail_reverse
; f
< pack
->fail_reverse_end
;
2855 list_for_each_entry(pack
, &update
->packs
, list
) {
2856 const typeof(void (*)(void)) *f
;
2857 for (f
= pack
->post_reverse
; f
< pack
->post_reverse_end
; f
++)
2861 list_for_each_entry(pack
, &update
->packs
, list
)
2862 clear_list(&pack
->safety_records
, struct safety_record
, list
);
2864 _ksdebug(update
, "Atomic patch removal for %s complete\n", update
->kid
);
2868 /* Atomically insert the update; run from within stop_machine */
2869 static int __apply_patches(void *updateptr
)
2871 struct update
*update
= updateptr
;
2872 struct ksplice_pack
*pack
;
2873 struct ksplice_module_list_entry
*entry
;
2874 struct ksplice_patch
*p
;
2877 if (update
->stage
== STAGE_APPLIED
)
2878 return (__force
int)OK
;
2880 if (update
->stage
!= STAGE_PREPARING
)
2881 return (__force
int)UNEXPECTED
;
2883 ret
= check_each_task(update
);
2885 return (__force
int)ret
;
2887 list_for_each_entry(pack
, &update
->packs
, list
) {
2888 if (try_module_get(pack
->primary
) != 1) {
2889 struct ksplice_pack
*pack1
;
2890 list_for_each_entry(pack1
, &update
->packs
, list
) {
2893 module_put(pack1
->primary
);
2895 module_put(THIS_MODULE
);
2896 return (__force
int)UNEXPECTED
;
2900 list_for_each_entry(pack
, &update
->packs
, list
) {
2901 const typeof(int (*)(void)) *f
;
2902 for (f
= pack
->check_apply
; f
< pack
->check_apply_end
; f
++)
2904 return (__force
int)CALL_FAILED
;
2907 /* Commit point: the update application will succeed. */
2909 update
->stage
= STAGE_APPLIED
;
2910 #ifdef TAINT_KSPLICE
2911 add_taint(TAINT_KSPLICE
);
2914 list_for_each_entry(entry
, &update
->ksplice_module_list
, update_list
)
2915 list_add(&entry
->list
, &ksplice_module_list
);
2917 list_for_each_entry(pack
, &update
->packs
, list
) {
2918 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++)
2919 insert_trampoline(p
);
2922 list_for_each_entry(pack
, &update
->packs
, list
) {
2923 const typeof(void (*)(void)) *f
;
2924 for (f
= pack
->apply
; f
< pack
->apply_end
; f
++)
2928 return (__force
int)OK
;
2931 /* Atomically remove the update; run from within stop_machine */
2932 static int __reverse_patches(void *updateptr
)
2934 struct update
*update
= updateptr
;
2935 struct ksplice_pack
*pack
;
2936 struct ksplice_module_list_entry
*entry
;
2937 const struct ksplice_patch
*p
;
2940 if (update
->stage
!= STAGE_APPLIED
)
2941 return (__force
int)OK
;
2943 #ifdef CONFIG_MODULE_UNLOAD
2944 list_for_each_entry(pack
, &update
->packs
, list
) {
2945 if (module_refcount(pack
->primary
) != 1)
2946 return (__force
int)MODULE_BUSY
;
2948 #endif /* CONFIG_MODULE_UNLOAD */
2950 list_for_each_entry(entry
, &update
->ksplice_module_list
, update_list
) {
2951 if (!entry
->applied
&& find_module(entry
->target_name
) != NULL
)
2952 return COLD_UPDATE_LOADED
;
2955 ret
= check_each_task(update
);
2957 return (__force
int)ret
;
2959 list_for_each_entry(pack
, &update
->packs
, list
) {
2960 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++) {
2961 ret
= verify_trampoline(pack
, p
);
2963 return (__force
int)ret
;
2967 list_for_each_entry(pack
, &update
->packs
, list
) {
2968 const typeof(int (*)(void)) *f
;
2969 for (f
= pack
->check_reverse
; f
< pack
->check_reverse_end
; f
++)
2971 return (__force
int)CALL_FAILED
;
2974 /* Commit point: the update reversal will succeed. */
2976 update
->stage
= STAGE_REVERSED
;
2978 list_for_each_entry(pack
, &update
->packs
, list
)
2979 module_put(pack
->primary
);
2981 list_for_each_entry(entry
, &update
->ksplice_module_list
, update_list
)
2982 list_del(&entry
->list
);
2984 list_for_each_entry(pack
, &update
->packs
, list
) {
2985 const typeof(void (*)(void)) *f
;
2986 for (f
= pack
->reverse
; f
< pack
->reverse_end
; f
++)
2990 list_for_each_entry(pack
, &update
->packs
, list
) {
2991 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++)
2992 remove_trampoline(p
);
2995 return (__force
int)OK
;
2999 * Check whether any thread's instruction pointer or any address of
3000 * its stack is contained in one of the safety_records associated with
3003 * check_each_task must be called from inside stop_machine, because it
3004 * does not take tasklist_lock (which cannot be held by anyone else
3005 * during stop_machine).
3007 static abort_t
check_each_task(struct update
*update
)
3009 const struct task_struct
*g
, *p
;
3010 abort_t status
= OK
, ret
;
3011 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,11)
3012 /* 5d4564e68210e4b1edb3f013bc3e59982bb35737 was after 2.6.10 */
3013 read_lock(&tasklist_lock
);
3014 #endif /* LINUX_VERSION_CODE */
3015 do_each_thread(g
, p
) {
3016 /* do_each_thread is a double loop! */
3017 ret
= check_task(update
, p
, false);
3019 check_task(update
, p
, true);
3022 if (ret
!= OK
&& ret
!= CODE_BUSY
)
3023 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,11)
3024 /* 5d4564e68210e4b1edb3f013bc3e59982bb35737 was after 2.6.10 */
3026 #else /* LINUX_VERSION_CODE < */
3028 #endif /* LINUX_VERSION_CODE */
3029 } while_each_thread(g
, p
);
3030 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,11)
3031 /* 5d4564e68210e4b1edb3f013bc3e59982bb35737 was after 2.6.10 */
3033 read_unlock(&tasklist_lock
);
3034 #endif /* LINUX_VERSION_CODE */
3038 static abort_t
check_task(struct update
*update
,
3039 const struct task_struct
*t
, bool rerun
)
3041 abort_t status
, ret
;
3042 struct conflict
*conf
= NULL
;
3045 conf
= kmalloc(sizeof(*conf
), GFP_ATOMIC
);
3047 return OUT_OF_MEMORY
;
3048 conf
->process_name
= kstrdup(t
->comm
, GFP_ATOMIC
);
3049 if (conf
->process_name
== NULL
) {
3051 return OUT_OF_MEMORY
;
3054 INIT_LIST_HEAD(&conf
->stack
);
3055 list_add(&conf
->list
, &update
->conflicts
);
3058 status
= check_address(update
, conf
, KSPLICE_IP(t
));
3060 ret
= check_stack(update
, conf
, task_thread_info(t
),
3061 (unsigned long *)__builtin_frame_address(0));
3064 } else if (!task_curr(t
)) {
3065 ret
= check_stack(update
, conf
, task_thread_info(t
),
3066 (unsigned long *)KSPLICE_SP(t
));
3069 } else if (!is_stop_machine(t
)) {
3070 status
= UNEXPECTED_RUNNING_TASK
;
3075 static abort_t
check_stack(struct update
*update
, struct conflict
*conf
,
3076 const struct thread_info
*tinfo
,
3077 const unsigned long *stack
)
3079 abort_t status
= OK
, ret
;
3082 while (valid_stack_ptr(tinfo
, stack
)) {
3084 ret
= check_address(update
, conf
, addr
);
3091 static abort_t
check_address(struct update
*update
,
3092 struct conflict
*conf
, unsigned long addr
)
3094 abort_t status
= OK
, ret
;
3095 const struct safety_record
*rec
;
3096 struct ksplice_pack
*pack
;
3097 struct conflict_addr
*ca
= NULL
;
3100 ca
= kmalloc(sizeof(*ca
), GFP_ATOMIC
);
3102 return OUT_OF_MEMORY
;
3104 ca
->has_conflict
= false;
3106 list_add(&ca
->list
, &conf
->stack
);
3109 list_for_each_entry(pack
, &update
->packs
, list
) {
3110 unsigned long tramp_addr
= follow_trampolines(pack
, addr
);
3111 list_for_each_entry(rec
, &pack
->safety_records
, list
) {
3112 ret
= check_record(ca
, rec
, tramp_addr
);
3120 static abort_t
check_record(struct conflict_addr
*ca
,
3121 const struct safety_record
*rec
, unsigned long addr
)
3123 if (addr
>= rec
->addr
&& addr
< rec
->addr
+ rec
->size
) {
3125 ca
->label
= rec
->label
;
3126 ca
->has_conflict
= true;
3133 /* Is the task one of the stop_machine tasks? */
3134 static bool is_stop_machine(const struct task_struct
*t
)
3136 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
3137 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,28)
3138 const char *kstop_prefix
= "kstop/";
3139 #else /* LINUX_VERSION_CODE < */
3140 /* c9583e55fa2b08a230c549bd1e3c0bde6c50d9cc was after 2.6.27 */
3141 const char *kstop_prefix
= "kstop";
3142 #endif /* LINUX_VERSION_CODE */
3144 if (!starts_with(t
->comm
, kstop_prefix
))
3146 num
= t
->comm
+ strlen(kstop_prefix
);
3147 return num
[strspn(num
, "0123456789")] == '\0';
3148 #else /* LINUX_VERSION_CODE < */
3149 /* ffdb5976c47609c862917d4c186ecbb5706d2dda was after 2.6.26 */
3150 return strcmp(t
->comm
, "kstopmachine") == 0;
3151 #endif /* LINUX_VERSION_CODE */
3154 static void cleanup_conflicts(struct update
*update
)
3156 struct conflict
*conf
;
3157 list_for_each_entry(conf
, &update
->conflicts
, list
) {
3158 clear_list(&conf
->stack
, struct conflict_addr
, list
);
3159 kfree(conf
->process_name
);
3161 clear_list(&update
->conflicts
, struct conflict
, list
);
3164 static void print_conflicts(struct update
*update
)
3166 const struct conflict
*conf
;
3167 const struct conflict_addr
*ca
;
3168 list_for_each_entry(conf
, &update
->conflicts
, list
) {
3169 _ksdebug(update
, "stack check: pid %d (%s):", conf
->pid
,
3170 conf
->process_name
);
3171 list_for_each_entry(ca
, &conf
->stack
, list
) {
3172 _ksdebug(update
, " %lx", ca
->addr
);
3173 if (ca
->has_conflict
)
3174 _ksdebug(update
, " [<-CONFLICT]");
3176 _ksdebug(update
, "\n");
3180 static void insert_trampoline(struct ksplice_patch
*p
)
3182 mm_segment_t old_fs
= get_fs();
3184 memcpy(p
->saved
, p
->vaddr
, p
->size
);
3185 memcpy(p
->vaddr
, p
->contents
, p
->size
);
3186 flush_icache_range(p
->oldaddr
, p
->oldaddr
+ p
->size
);
3190 static abort_t
verify_trampoline(struct ksplice_pack
*pack
,
3191 const struct ksplice_patch
*p
)
3193 if (memcmp(p
->vaddr
, p
->contents
, p
->size
) != 0) {
3194 ksdebug(pack
, "Aborted. Trampoline at %lx has been "
3195 "overwritten.\n", p
->oldaddr
);
3201 static void remove_trampoline(const struct ksplice_patch
*p
)
3203 mm_segment_t old_fs
= get_fs();
3205 memcpy(p
->vaddr
, p
->saved
, p
->size
);
3206 flush_icache_range(p
->oldaddr
, p
->oldaddr
+ p
->size
);
3210 /* Returns NO_MATCH if there's already a labelval with a different value */
3211 static abort_t
create_labelval(struct ksplice_pack
*pack
,
3212 struct ksplice_symbol
*ksym
,
3213 unsigned long val
, int status
)
3215 val
= follow_trampolines(pack
, val
);
3216 if (ksym
->vals
== NULL
)
3217 return ksym
->value
== val
? OK
: NO_MATCH
;
3220 if (status
== TEMP
) {
3221 struct labelval
*lv
= kmalloc(sizeof(*lv
), GFP_KERNEL
);
3223 return OUT_OF_MEMORY
;
3225 lv
->saved_vals
= ksym
->vals
;
3226 list_add(&lv
->list
, &pack
->temp_labelvals
);
3233 * Creates a new safety_record for a helper section based on its
3234 * ksplice_section and run-pre matching information.
3236 static abort_t
create_safety_record(struct ksplice_pack
*pack
,
3237 const struct ksplice_section
*sect
,
3238 struct list_head
*record_list
,
3239 unsigned long run_addr
,
3240 unsigned long run_size
)
3242 struct safety_record
*rec
;
3243 struct ksplice_patch
*p
;
3245 if (record_list
== NULL
)
3248 for (p
= pack
->patches
; p
< pack
->patches_end
; p
++) {
3249 const struct ksplice_reloc
*r
= patch_reloc(pack
, p
);
3250 if (strcmp(sect
->symbol
->label
, r
->symbol
->label
) == 0)
3253 if (p
>= pack
->patches_end
)
3256 rec
= kmalloc(sizeof(*rec
), GFP_KERNEL
);
3258 return OUT_OF_MEMORY
;
3260 * The helper might be unloaded when checking reversing
3261 * patches, so we need to kstrdup the label here.
3263 rec
->label
= kstrdup(sect
->symbol
->label
, GFP_KERNEL
);
3264 if (rec
->label
== NULL
) {
3266 return OUT_OF_MEMORY
;
3268 rec
->addr
= run_addr
;
3269 rec
->size
= run_size
;
3271 list_add(&rec
->list
, record_list
);
3275 static abort_t
add_candidate_val(struct ksplice_pack
*pack
,
3276 struct list_head
*vals
, unsigned long val
)
3278 struct candidate_val
*tmp
, *new;
3281 * Careful: follow trampolines before comparing values so that we do
3282 * not mistake the obsolete function for another copy of the function.
3284 val
= follow_trampolines(pack
, val
);
3286 list_for_each_entry(tmp
, vals
, list
) {
3287 if (tmp
->val
== val
)
3290 new = kmalloc(sizeof(*new), GFP_KERNEL
);
3292 return OUT_OF_MEMORY
;
3294 list_add(&new->list
, vals
);
3298 static void release_vals(struct list_head
*vals
)
3300 clear_list(vals
, struct candidate_val
, list
);
3304 * The temp_labelvals list is used to cache those temporary labelvals
3305 * that have been created to cross-check the symbol values obtained
3306 * from different relocations within a single section being matched.
3308 * If status is VAL, commit the temp_labelvals as final values.
3310 * If status is NOVAL, restore the list of possible values to the
3311 * ksplice_symbol, so that it no longer has a known value.
3313 static void set_temp_labelvals(struct ksplice_pack
*pack
, int status
)
3315 struct labelval
*lv
, *n
;
3316 list_for_each_entry_safe(lv
, n
, &pack
->temp_labelvals
, list
) {
3317 if (status
== NOVAL
) {
3318 lv
->symbol
->vals
= lv
->saved_vals
;
3320 release_vals(lv
->saved_vals
);
3321 kfree(lv
->saved_vals
);
3323 list_del(&lv
->list
);
3328 /* Is there a Ksplice canary with given howto at blank_addr? */
3329 static int contains_canary(struct ksplice_pack
*pack
, unsigned long blank_addr
,
3330 const struct ksplice_reloc_howto
*howto
)
3332 switch (howto
->size
) {
3334 return (*(uint8_t *)blank_addr
& howto
->dst_mask
) ==
3335 (KSPLICE_CANARY
& howto
->dst_mask
);
3337 return (*(uint16_t *)blank_addr
& howto
->dst_mask
) ==
3338 (KSPLICE_CANARY
& howto
->dst_mask
);
3340 return (*(uint32_t *)blank_addr
& howto
->dst_mask
) ==
3341 (KSPLICE_CANARY
& howto
->dst_mask
);
3342 #if BITS_PER_LONG >= 64
3344 return (*(uint64_t *)blank_addr
& howto
->dst_mask
) ==
3345 (KSPLICE_CANARY
& howto
->dst_mask
);
3346 #endif /* BITS_PER_LONG */
3348 ksdebug(pack
, "Aborted. Invalid relocation size.\n");
3354 * Compute the address of the code you would actually run if you were
3355 * to call the function at addr (i.e., follow the sequence of jumps
3358 static unsigned long follow_trampolines(struct ksplice_pack
*pack
,
3361 unsigned long new_addr
;
3365 #ifdef KSPLICE_STANDALONE
3368 #endif /* KSPLICE_STANDALONE */
3369 if (!__kernel_text_address(addr
) ||
3370 trampoline_target(pack
, addr
, &new_addr
) != OK
)
3372 m
= __module_text_address(new_addr
);
3373 if (m
== NULL
|| m
== pack
->target
||
3374 !starts_with(m
->name
, "ksplice"))
3380 /* Does module a patch module b? */
3381 static bool patches_module(const struct module
*a
, const struct module
*b
)
3383 #ifdef KSPLICE_NO_KERNEL_SUPPORT
3387 if (a
== NULL
|| !starts_with(a
->name
, "ksplice_"))
3389 name
= a
->name
+ strlen("ksplice_");
3390 name
+= strcspn(name
, "_");
3394 return strcmp(name
, b
== NULL
? "vmlinux" : b
->name
) == 0;
3395 #else /* !KSPLICE_NO_KERNEL_SUPPORT */
3396 struct ksplice_module_list_entry
*entry
;
3399 list_for_each_entry(entry
, &ksplice_module_list
, list
) {
3400 if (strcmp(entry
->target_name
, b
->name
) == 0 &&
3401 strcmp(entry
->primary_name
, a
->name
) == 0)
3405 #endif /* KSPLICE_NO_KERNEL_SUPPORT */
3408 static bool starts_with(const char *str
, const char *prefix
)
3410 return strncmp(str
, prefix
, strlen(prefix
)) == 0;
3413 static bool singular(struct list_head
*list
)
3415 return !list_empty(list
) && list
->next
->next
== list
;
3418 static void *bsearch(const void *key
, const void *base
, size_t n
,
3419 size_t size
, int (*cmp
)(const void *key
, const void *elt
))
3421 int start
= 0, end
= n
- 1, mid
, result
;
3424 while (start
<= end
) {
3425 mid
= (start
+ end
) / 2;
3426 result
= cmp(key
, base
+ mid
* size
);
3429 else if (result
> 0)
3432 return (void *)base
+ mid
* size
;
3437 static int compare_relocs(const void *a
, const void *b
)
3439 const struct ksplice_reloc
*ra
= a
, *rb
= b
;
3440 if (ra
->blank_addr
> rb
->blank_addr
)
3442 else if (ra
->blank_addr
< rb
->blank_addr
)
3445 return ra
->howto
->size
- rb
->howto
->size
;
3448 #ifdef KSPLICE_STANDALONE
3449 static int compare_system_map(const void *a
, const void *b
)
3451 const struct ksplice_system_map
*sa
= a
, *sb
= b
;
3452 return strcmp(sa
->label
, sb
->label
);
3454 #endif /* KSPLICE_STANDALONE */
3456 #ifdef CONFIG_DEBUG_FS
3457 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17)
3458 /* Old kernels don't have debugfs_create_blob */
3459 static ssize_t
read_file_blob(struct file
*file
, char __user
*user_buf
,
3460 size_t count
, loff_t
*ppos
)
3462 struct debugfs_blob_wrapper
*blob
= file
->private_data
;
3463 return simple_read_from_buffer(user_buf
, count
, ppos
, blob
->data
,
3467 static int blob_open(struct inode
*inode
, struct file
*file
)
3469 if (inode
->i_private
)
3470 file
->private_data
= inode
->i_private
;
3474 static struct file_operations fops_blob
= {
3475 .read
= read_file_blob
,
3479 static struct dentry
*debugfs_create_blob(const char *name
, mode_t mode
,
3480 struct dentry
*parent
,
3481 struct debugfs_blob_wrapper
*blob
)
3483 return debugfs_create_file(name
, mode
, parent
, blob
, &fops_blob
);
3485 #endif /* LINUX_VERSION_CODE */
3487 static abort_t
init_debug_buf(struct update
*update
)
3489 update
->debug_blob
.size
= 0;
3490 update
->debug_blob
.data
= NULL
;
3491 update
->debugfs_dentry
=
3492 debugfs_create_blob(update
->name
, S_IFREG
| S_IRUSR
, NULL
,
3493 &update
->debug_blob
);
3494 if (update
->debugfs_dentry
== NULL
)
3495 return OUT_OF_MEMORY
;
3499 static void clear_debug_buf(struct update
*update
)
3501 if (update
->debugfs_dentry
== NULL
)
3503 debugfs_remove(update
->debugfs_dentry
);
3504 update
->debugfs_dentry
= NULL
;
3505 update
->debug_blob
.size
= 0;
3506 vfree(update
->debug_blob
.data
);
3507 update
->debug_blob
.data
= NULL
;
3510 static int _ksdebug(struct update
*update
, const char *fmt
, ...)
3513 unsigned long size
, old_size
, new_size
;
3515 if (update
->debug
== 0)
3518 /* size includes the trailing '\0' */
3519 va_start(args
, fmt
);
3520 size
= 1 + vsnprintf(update
->debug_blob
.data
, 0, fmt
, args
);
3522 old_size
= update
->debug_blob
.size
== 0 ? 0 :
3523 max(PAGE_SIZE
, roundup_pow_of_two(update
->debug_blob
.size
));
3524 new_size
= update
->debug_blob
.size
+ size
== 0 ? 0 :
3525 max(PAGE_SIZE
, roundup_pow_of_two(update
->debug_blob
.size
+ size
));
3526 if (new_size
> old_size
) {
3527 char *buf
= vmalloc(new_size
);
3530 memcpy(buf
, update
->debug_blob
.data
, update
->debug_blob
.size
);
3531 vfree(update
->debug_blob
.data
);
3532 update
->debug_blob
.data
= buf
;
3534 va_start(args
, fmt
);
3535 update
->debug_blob
.size
+= vsnprintf(update
->debug_blob
.data
+
3536 update
->debug_blob
.size
,
3541 #else /* CONFIG_DEBUG_FS */
3542 static abort_t
init_debug_buf(struct update
*update
)
3547 static void clear_debug_buf(struct update
*update
)
3552 static int _ksdebug(struct update
*update
, const char *fmt
, ...)
3556 if (update
->debug
== 0)
3559 if (!update
->debug_continue_line
)
3560 printk(KERN_DEBUG
"ksplice: ");
3562 va_start(args
, fmt
);
3563 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,9)
3565 #else /* LINUX_VERSION_CODE < */
3566 /* 683b229286b429244f35726b3c18caec429233bd was after 2.6.8 */
3568 char *buf
= kvasprintf(GFP_KERNEL
, fmt
, args
);
3572 #endif /* LINUX_VERSION_CODE */
3575 update
->debug_continue_line
=
3576 fmt
[0] == '\0' || fmt
[strlen(fmt
) - 1] != '\n';
3579 #endif /* CONFIG_DEBUG_FS */
3581 #ifdef KSPLICE_NO_KERNEL_SUPPORT
3582 #ifdef CONFIG_KALLSYMS
3583 static int kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
3584 struct module
*, unsigned long),
3587 char namebuf
[KSYM_NAME_LEN
];
3589 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10)
3591 #endif /* LINUX_VERSION_CODE */
3594 /* kallsyms compression was added by 5648d78927ca65e74aadc88a2b1d6431e55e78ec
3595 * 2.6.10 was the first release after this commit
3597 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10)
3598 for (i
= 0, off
= 0; i
< kallsyms_num_syms
; i
++) {
3599 off
= kallsyms_expand_symbol(off
, namebuf
);
3600 ret
= fn(data
, namebuf
, NULL
, kallsyms_addresses
[i
]);
3604 #else /* LINUX_VERSION_CODE < */
3607 for (i
= 0, knames
= kallsyms_names
; i
< kallsyms_num_syms
; i
++) {
3608 unsigned prefix
= *knames
++;
3610 strlcpy(namebuf
+ prefix
, knames
, KSYM_NAME_LEN
- prefix
);
3612 ret
= fn(data
, namebuf
, NULL
, kallsyms_addresses
[i
]);
3616 knames
+= strlen(knames
) + 1;
3618 #endif /* LINUX_VERSION_CODE */
3619 return module_kallsyms_on_each_symbol(fn
, data
);
3622 /* kallsyms compression was added by 5648d78927ca65e74aadc88a2b1d6431e55e78ec
3623 * 2.6.10 was the first release after this commit
3625 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,10)
3626 extern u8 kallsyms_token_table
[];
3627 extern u16 kallsyms_token_index
[];
3629 static unsigned int kallsyms_expand_symbol(unsigned int off
, char *result
)
3631 long len
, skipped_first
= 0;
3632 const u8
*tptr
, *data
;
3634 data
= &kallsyms_names
[off
];
3641 tptr
= &kallsyms_token_table
[kallsyms_token_index
[*data
]];
3646 if (skipped_first
) {
3659 #endif /* LINUX_VERSION_CODE */
3661 static int module_kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
3670 list_for_each_entry(mod
, &modules
, list
) {
3671 for (i
= 0; i
< mod
->num_symtab
; i
++) {
3672 ret
= fn(data
, mod
->strtab
+ mod
->symtab
[i
].st_name
,
3673 mod
, mod
->symtab
[i
].st_value
);
3680 #endif /* CONFIG_KALLSYMS */
3682 static struct module
*find_module(const char *name
)
3686 list_for_each_entry(mod
, &modules
, list
) {
3687 if (strcmp(mod
->name
, name
) == 0)
3693 #ifdef CONFIG_MODULE_UNLOAD
3695 struct list_head list
;
3696 struct module
*module_which_uses
;
3699 /* I'm not yet certain whether we need the strong form of this. */
3700 static inline int strong_try_module_get(struct module
*mod
)
3702 if (mod
&& mod
->state
!= MODULE_STATE_LIVE
)
3704 if (try_module_get(mod
))
3709 /* Does a already use b? */
3710 static int already_uses(struct module
*a
, struct module
*b
)
3712 struct module_use
*use
;
3713 list_for_each_entry(use
, &b
->modules_which_use_me
, list
) {
3714 if (use
->module_which_uses
== a
)
3720 /* Make it so module a uses b. Must be holding module_mutex */
3721 static int use_module(struct module
*a
, struct module
*b
)
3723 struct module_use
*use
;
3724 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
3725 /* 270a6c4cad809e92d7b81adde92d0b3d94eeb8ee was after 2.6.20 */
3727 #endif /* LINUX_VERSION_CODE */
3728 if (b
== NULL
|| already_uses(a
, b
))
3731 if (strong_try_module_get(b
) < 0)
3734 use
= kmalloc(sizeof(*use
), GFP_ATOMIC
);
3739 use
->module_which_uses
= a
;
3740 list_add(&use
->list
, &b
->modules_which_use_me
);
3741 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21)
3742 /* 270a6c4cad809e92d7b81adde92d0b3d94eeb8ee was after 2.6.20 */
3743 no_warn
= sysfs_create_link(b
->holders_dir
, &a
->mkobj
.kobj
, a
->name
);
3744 #endif /* LINUX_VERSION_CODE */
3747 #else /* CONFIG_MODULE_UNLOAD */
3748 static int use_module(struct module
*a
, struct module
*b
)
3752 #endif /* CONFIG_MODULE_UNLOAD */
3754 #ifndef CONFIG_MODVERSIONS
3755 #define symversion(base, idx) NULL
3757 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
3760 static bool each_symbol_in_section(const struct symsearch
*arr
,
3761 unsigned int arrsize
,
3762 struct module
*owner
,
3763 bool (*fn
)(const struct symsearch
*syms
,
3764 struct module
*owner
,
3765 unsigned int symnum
, void *data
),
3770 for (j
= 0; j
< arrsize
; j
++) {
3771 for (i
= 0; i
< arr
[j
].stop
- arr
[j
].start
; i
++)
3772 if (fn(&arr
[j
], owner
, i
, data
))
3779 /* Returns true as soon as fn returns true, otherwise false. */
3780 static bool each_symbol(bool (*fn
)(const struct symsearch
*arr
,
3781 struct module
*owner
,
3782 unsigned int symnum
, void *data
),
3786 const struct symsearch arr
[] = {
3787 { __start___ksymtab
, __stop___ksymtab
, __start___kcrctab
,
3788 NOT_GPL_ONLY
, false },
3789 { __start___ksymtab_gpl
, __stop___ksymtab_gpl
,
3790 __start___kcrctab_gpl
,
3792 #ifdef KSPLICE_KSYMTAB_FUTURE_SUPPORT
3793 { __start___ksymtab_gpl_future
, __stop___ksymtab_gpl_future
,
3794 __start___kcrctab_gpl_future
,
3795 WILL_BE_GPL_ONLY
, false },
3796 #endif /* KSPLICE_KSYMTAB_FUTURE_SUPPORT */
3797 #ifdef KSPLICE_KSYMTAB_UNUSED_SUPPORT
3798 { __start___ksymtab_unused
, __stop___ksymtab_unused
,
3799 __start___kcrctab_unused
,
3800 NOT_GPL_ONLY
, true },
3801 { __start___ksymtab_unused_gpl
, __stop___ksymtab_unused_gpl
,
3802 __start___kcrctab_unused_gpl
,
3804 #endif /* KSPLICE_KSYMTAB_UNUSED_SUPPORT */
3807 if (each_symbol_in_section(arr
, ARRAY_SIZE(arr
), NULL
, fn
, data
))
3810 list_for_each_entry(mod
, &modules
, list
) {
3811 struct symsearch module_arr
[] = {
3812 { mod
->syms
, mod
->syms
+ mod
->num_syms
, mod
->crcs
,
3813 NOT_GPL_ONLY
, false },
3814 { mod
->gpl_syms
, mod
->gpl_syms
+ mod
->num_gpl_syms
,
3817 #ifdef KSPLICE_KSYMTAB_FUTURE_SUPPORT
3818 { mod
->gpl_future_syms
,
3819 mod
->gpl_future_syms
+ mod
->num_gpl_future_syms
,
3820 mod
->gpl_future_crcs
,
3821 WILL_BE_GPL_ONLY
, false },
3822 #endif /* KSPLICE_KSYMTAB_FUTURE_SUPPORT */
3823 #ifdef KSPLICE_KSYMTAB_UNUSED_SUPPORT
3825 mod
->unused_syms
+ mod
->num_unused_syms
,
3827 NOT_GPL_ONLY
, true },
3828 { mod
->unused_gpl_syms
,
3829 mod
->unused_gpl_syms
+ mod
->num_unused_gpl_syms
,
3830 mod
->unused_gpl_crcs
,
3832 #endif /* KSPLICE_KSYMTAB_UNUSED_SUPPORT */
3835 if (each_symbol_in_section(module_arr
, ARRAY_SIZE(module_arr
),
3842 struct find_symbol_arg
{
3849 struct module
*owner
;
3850 const unsigned long *crc
;
3851 const struct kernel_symbol
*sym
;
3854 static bool find_symbol_in_section(const struct symsearch
*syms
,
3855 struct module
*owner
,
3856 unsigned int symnum
, void *data
)
3858 struct find_symbol_arg
*fsa
= data
;
3860 if (strcmp(syms
->start
[symnum
].name
, fsa
->name
) != 0)
3864 if (syms
->licence
== GPL_ONLY
)
3866 if (syms
->licence
== WILL_BE_GPL_ONLY
&& fsa
->warn
) {
3867 printk(KERN_WARNING
"Symbol %s is being used "
3868 "by a non-GPL module, which will not "
3869 "be allowed in the future\n", fsa
->name
);
3870 printk(KERN_WARNING
"Please see the file "
3871 "Documentation/feature-removal-schedule.txt "
3872 "in the kernel source tree for more details.\n");
3876 #ifdef CONFIG_UNUSED_SYMBOLS
3877 if (syms
->unused
&& fsa
->warn
) {
3878 printk(KERN_WARNING
"Symbol %s is marked as UNUSED, "
3879 "however this module is using it.\n", fsa
->name
);
3881 "This symbol will go away in the future.\n");
3883 "Please evalute if this is the right api to use and if "
3884 "it really is, submit a report the linux kernel "
3885 "mailinglist together with submitting your code for "
3891 fsa
->crc
= symversion(syms
->crcs
, symnum
);
3892 fsa
->sym
= &syms
->start
[symnum
];
3896 /* Find a symbol and return it, along with, (optional) crc and
3897 * (optional) module which owns it */
3898 static const struct kernel_symbol
*find_symbol(const char *name
,
3899 struct module
**owner
,
3900 const unsigned long **crc
,
3901 bool gplok
, bool warn
)
3903 struct find_symbol_arg fsa
;
3909 if (each_symbol(find_symbol_in_section
, &fsa
)) {
3920 static struct module
*__module_data_address(unsigned long addr
)
3924 list_for_each_entry(mod
, &modules
, list
) {
3925 if (addr
>= (unsigned long)mod
->module_core
+
3926 mod
->core_text_size
&&
3927 addr
< (unsigned long)mod
->module_core
+ mod
->core_size
)
3932 #endif /* KSPLICE_NO_KERNEL_SUPPORT */
3934 struct update_attribute
{
3935 struct attribute attr
;
3936 ssize_t (*show
)(struct update
*update
, char *buf
);
3937 ssize_t (*store
)(struct update
*update
, const char *buf
, size_t len
);
3940 static ssize_t
update_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
3943 struct update_attribute
*attribute
=
3944 container_of(attr
, struct update_attribute
, attr
);
3945 struct update
*update
= container_of(kobj
, struct update
, kobj
);
3946 if (attribute
->show
== NULL
)
3948 return attribute
->show(update
, buf
);
3951 static ssize_t
update_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
3952 const char *buf
, size_t len
)
3954 struct update_attribute
*attribute
=
3955 container_of(attr
, struct update_attribute
, attr
);
3956 struct update
*update
= container_of(kobj
, struct update
, kobj
);
3957 if (attribute
->store
== NULL
)
3959 return attribute
->store(update
, buf
, len
);
3962 static struct sysfs_ops update_sysfs_ops
= {
3963 .show
= update_attr_show
,
3964 .store
= update_attr_store
,
3967 static void update_release(struct kobject
*kobj
)
3969 struct update
*update
;
3970 update
= container_of(kobj
, struct update
, kobj
);
3971 cleanup_ksplice_update(update
);
3974 static ssize_t
stage_show(struct update
*update
, char *buf
)
3976 switch (update
->stage
) {
3977 case STAGE_PREPARING
:
3978 return snprintf(buf
, PAGE_SIZE
, "preparing\n");
3980 return snprintf(buf
, PAGE_SIZE
, "applied\n");
3981 case STAGE_REVERSED
:
3982 return snprintf(buf
, PAGE_SIZE
, "reversed\n");
3987 static ssize_t
abort_cause_show(struct update
*update
, char *buf
)
3989 switch (update
->abort_cause
) {
3991 return snprintf(buf
, PAGE_SIZE
, "ok\n");
3993 return snprintf(buf
, PAGE_SIZE
, "no_match\n");
3994 #ifdef KSPLICE_STANDALONE
3995 case BAD_SYSTEM_MAP
:
3996 return snprintf(buf
, PAGE_SIZE
, "bad_system_map\n");
3997 #endif /* KSPLICE_STANDALONE */
3999 return snprintf(buf
, PAGE_SIZE
, "code_busy\n");
4001 return snprintf(buf
, PAGE_SIZE
, "module_busy\n");
4003 return snprintf(buf
, PAGE_SIZE
, "out_of_memory\n");
4004 case FAILED_TO_FIND
:
4005 return snprintf(buf
, PAGE_SIZE
, "failed_to_find\n");
4006 case ALREADY_REVERSED
:
4007 return snprintf(buf
, PAGE_SIZE
, "already_reversed\n");
4008 case MISSING_EXPORT
:
4009 return snprintf(buf
, PAGE_SIZE
, "missing_export\n");
4010 case UNEXPECTED_RUNNING_TASK
:
4011 return snprintf(buf
, PAGE_SIZE
, "unexpected_running_task\n");
4012 case TARGET_NOT_LOADED
:
4013 return snprintf(buf
, PAGE_SIZE
, "target_not_loaded\n");
4015 return snprintf(buf
, PAGE_SIZE
, "call_failed\n");
4016 case COLD_UPDATE_LOADED
:
4017 return snprintf(buf
, PAGE_SIZE
, "cold_update_loaded\n");
4019 return snprintf(buf
, PAGE_SIZE
, "unexpected\n");
4021 return snprintf(buf
, PAGE_SIZE
, "unknown\n");
4026 static ssize_t
conflict_show(struct update
*update
, char *buf
)
4028 const struct conflict
*conf
;
4029 const struct conflict_addr
*ca
;
4031 mutex_lock(&module_mutex
);
4032 list_for_each_entry(conf
, &update
->conflicts
, list
) {
4033 used
+= snprintf(buf
+ used
, PAGE_SIZE
- used
, "%s %d",
4034 conf
->process_name
, conf
->pid
);
4035 list_for_each_entry(ca
, &conf
->stack
, list
) {
4036 if (!ca
->has_conflict
)
4038 used
+= snprintf(buf
+ used
, PAGE_SIZE
- used
, " %s",
4041 used
+= snprintf(buf
+ used
, PAGE_SIZE
- used
, "\n");
4043 mutex_unlock(&module_mutex
);
4047 /* Used to pass maybe_cleanup_ksplice_update to kthread_run */
4048 static int maybe_cleanup_ksplice_update_wrapper(void *updateptr
)
4050 struct update
*update
= updateptr
;
4051 mutex_lock(&module_mutex
);
4052 maybe_cleanup_ksplice_update(update
);
4053 mutex_unlock(&module_mutex
);
4057 static ssize_t
stage_store(struct update
*update
, const char *buf
, size_t len
)
4059 enum stage old_stage
;
4060 mutex_lock(&module_mutex
);
4061 old_stage
= update
->stage
;
4062 if ((strncmp(buf
, "applied", len
) == 0 ||
4063 strncmp(buf
, "applied\n", len
) == 0) &&
4064 update
->stage
== STAGE_PREPARING
)
4065 update
->abort_cause
= apply_update(update
);
4066 else if ((strncmp(buf
, "reversed", len
) == 0 ||
4067 strncmp(buf
, "reversed\n", len
) == 0) &&
4068 update
->stage
== STAGE_APPLIED
)
4069 update
->abort_cause
= reverse_patches(update
);
4070 else if ((strncmp(buf
, "cleanup", len
) == 0 ||
4071 strncmp(buf
, "cleanup\n", len
) == 0) &&
4072 update
->stage
== STAGE_REVERSED
)
4073 kthread_run(maybe_cleanup_ksplice_update_wrapper
, update
,
4074 "ksplice_cleanup_%s", update
->kid
);
4076 if (old_stage
!= STAGE_REVERSED
&& update
->abort_cause
== OK
)
4077 printk(KERN_INFO
"ksplice: Update %s %s successfully\n",
4079 update
->stage
== STAGE_APPLIED
? "applied" : "reversed");
4080 mutex_unlock(&module_mutex
);
4084 static ssize_t
debug_show(struct update
*update
, char *buf
)
4086 return snprintf(buf
, PAGE_SIZE
, "%d\n", update
->debug
);
4089 static ssize_t
debug_store(struct update
*update
, const char *buf
, size_t len
)
4092 int ret
= strict_strtoul(buf
, 10, &l
);
4099 static ssize_t
partial_show(struct update
*update
, char *buf
)
4101 return snprintf(buf
, PAGE_SIZE
, "%d\n", update
->partial
);
4104 static ssize_t
partial_store(struct update
*update
, const char *buf
, size_t len
)
4107 int ret
= strict_strtoul(buf
, 10, &l
);
4110 update
->partial
= l
;
4114 static struct update_attribute stage_attribute
=
4115 __ATTR(stage
, 0600, stage_show
, stage_store
);
4116 static struct update_attribute abort_cause_attribute
=
4117 __ATTR(abort_cause
, 0400, abort_cause_show
, NULL
);
4118 static struct update_attribute debug_attribute
=
4119 __ATTR(debug
, 0600, debug_show
, debug_store
);
4120 static struct update_attribute partial_attribute
=
4121 __ATTR(partial
, 0600, partial_show
, partial_store
);
4122 static struct update_attribute conflict_attribute
=
4123 __ATTR(conflicts
, 0400, conflict_show
, NULL
);
4125 static struct attribute
*update_attrs
[] = {
4126 &stage_attribute
.attr
,
4127 &abort_cause_attribute
.attr
,
4128 &debug_attribute
.attr
,
4129 &partial_attribute
.attr
,
4130 &conflict_attribute
.attr
,
4134 static struct kobj_type update_ktype
= {
4135 .sysfs_ops
= &update_sysfs_ops
,
4136 .release
= update_release
,
4137 .default_attrs
= update_attrs
,
4140 #ifdef KSPLICE_STANDALONE
4142 module_param(debug
, int, 0600);
4143 MODULE_PARM_DESC(debug
, "Debug level");
4145 extern struct ksplice_system_map ksplice_system_map
[], ksplice_system_map_end
[];
4147 static struct ksplice_pack bootstrap_pack
= {
4148 .name
= "ksplice_" __stringify(KSPLICE_KID
),
4149 .kid
= "init_" __stringify(KSPLICE_KID
),
4150 .target_name
= NULL
,
4152 .map_printk
= MAP_PRINTK
,
4153 .primary
= THIS_MODULE
,
4154 .primary_system_map
= ksplice_system_map
,
4155 .primary_system_map_end
= ksplice_system_map_end
,
4157 #endif /* KSPLICE_STANDALONE */
4159 static int init_ksplice(void)
4161 #ifdef KSPLICE_STANDALONE
4162 struct ksplice_pack
*pack
= &bootstrap_pack
;
4163 pack
->update
= init_ksplice_update(pack
->kid
);
4164 sort(pack
->primary_system_map
,
4165 pack
->primary_system_map_end
- pack
->primary_system_map
,
4166 sizeof(struct ksplice_system_map
), compare_system_map
, NULL
);
4167 if (pack
->update
== NULL
)
4169 add_to_update(pack
, pack
->update
);
4170 pack
->update
->debug
= debug
;
4171 pack
->update
->abort_cause
=
4172 apply_relocs(pack
, ksplice_init_relocs
, ksplice_init_relocs_end
);
4173 if (pack
->update
->abort_cause
== OK
)
4174 bootstrapped
= true;
4175 cleanup_ksplice_update(bootstrap_pack
.update
);
4176 #else /* !KSPLICE_STANDALONE */
4177 ksplice_kobj
= kobject_create_and_add("ksplice", kernel_kobj
);
4178 if (ksplice_kobj
== NULL
)
4180 #endif /* KSPLICE_STANDALONE */
4184 static void cleanup_ksplice(void)
4186 #ifndef KSPLICE_STANDALONE
4187 kobject_put(ksplice_kobj
);
4188 #endif /* KSPLICE_STANDALONE */
4191 module_init(init_ksplice
);
4192 module_exit(cleanup_ksplice
);
4194 MODULE_AUTHOR("Ksplice, Inc.");
4195 MODULE_DESCRIPTION("Ksplice rebootless update system");
4196 #ifdef KSPLICE_VERSION
4197 MODULE_VERSION(KSPLICE_VERSION
);
4199 MODULE_LICENSE("GPL v2");