1 #include <linux/compiler.h>
2 #include <linux/rbtree.h>
11 static int vmlinux_matches_kallsyms_filter(struct map
*map __maybe_unused
,
14 bool *visited
= symbol__priv(sym
);
19 int test__vmlinux_matches_kallsyms(void)
24 struct map
*kallsyms_map
, *vmlinux_map
;
25 struct machine kallsyms
, vmlinux
;
26 enum map_type type
= MAP__FUNCTION
;
27 struct ref_reloc_sym ref_reloc_sym
= { .name
= "_stext", };
32 * Init the machines that will hold kernel, modules obtained from
33 * both vmlinux + .ko files and from /proc/kallsyms split by modules.
35 machine__init(&kallsyms
, "", HOST_KERNEL_ID
);
36 machine__init(&vmlinux
, "", HOST_KERNEL_ID
);
41 * Create the kernel maps for kallsyms and the DSO where we will then
42 * load /proc/kallsyms. Also create the modules maps from /proc/modules
43 * and find the .ko files that match them in /lib/modules/`uname -r`/.
45 if (machine__create_kernel_maps(&kallsyms
) < 0) {
46 pr_debug("machine__create_kernel_maps ");
53 * Load and split /proc/kallsyms into multiple maps, one per module.
55 if (machine__load_kallsyms(&kallsyms
, "/proc/kallsyms", type
, NULL
) <= 0) {
56 pr_debug("dso__load_kallsyms ");
63 * kallsyms will be internally on demand sorted by name so that we can
64 * find the reference relocation * symbol, i.e. the symbol we will use
65 * to see if the running kernel was relocated by checking if it has the
66 * same value in the vmlinux file we load.
68 kallsyms_map
= machine__kernel_map(&kallsyms
, type
);
70 sym
= map__find_symbol_by_name(kallsyms_map
, ref_reloc_sym
.name
, NULL
);
72 pr_debug("dso__find_symbol_by_name ");
76 ref_reloc_sym
.addr
= sym
->start
;
81 * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
83 if (machine__create_kernel_maps(&vmlinux
) < 0) {
84 pr_debug("machine__create_kernel_maps ");
88 vmlinux_map
= machine__kernel_map(&vmlinux
, type
);
89 map__kmap(vmlinux_map
)->ref_reloc_sym
= &ref_reloc_sym
;
94 * Locate a vmlinux file in the vmlinux path that has a buildid that
95 * matches the one of the running kernel.
97 * While doing that look if we find the ref reloc symbol, if we find it
98 * we'll have its ref_reloc_symbol.unrelocated_addr and then
99 * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
100 * to fixup the symbols.
102 if (machine__load_vmlinux_path(&vmlinux
, type
,
103 vmlinux_matches_kallsyms_filter
) <= 0) {
104 pr_debug("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n");
113 * Now look at the symbols in the vmlinux DSO and check if we find all of them
114 * in the kallsyms dso. For the ones that are in both, check its names and
117 for (nd
= rb_first(&vmlinux_map
->dso
->symbols
[type
]); nd
; nd
= rb_next(nd
)) {
118 struct symbol
*pair
, *first_pair
;
119 bool backwards
= true;
121 sym
= rb_entry(nd
, struct symbol
, rb_node
);
123 if (sym
->start
== sym
->end
)
126 first_pair
= machine__find_kernel_symbol(&kallsyms
, type
, sym
->start
, NULL
, NULL
);
129 if (pair
&& pair
->start
== sym
->start
) {
131 if (strcmp(sym
->name
, pair
->name
) == 0) {
133 * kallsyms don't have the symbol end, so we
134 * set that by using the next symbol start - 1,
135 * in some cases we get this up to a page
136 * wrong, trace_kmalloc when I was developing
137 * this code was one such example, 2106 bytes
138 * off the real size. More than that and we
139 * _really_ have a problem.
141 s64 skew
= sym
->end
- pair
->end
;
142 if (llabs(skew
) < page_size
)
145 pr_debug("%#" PRIx64
": diff end addr for %s v: %#" PRIx64
" k: %#" PRIx64
"\n",
146 sym
->start
, sym
->name
, sym
->end
, pair
->end
);
150 nnd
= backwards
? rb_prev(&pair
->rb_node
) :
151 rb_next(&pair
->rb_node
);
153 struct symbol
*next
= rb_entry(nnd
, struct symbol
, rb_node
);
155 if (next
->start
== sym
->start
) {
167 pr_debug("%#" PRIx64
": diff name v: %s k: %s\n",
168 sym
->start
, sym
->name
, pair
->name
);
171 pr_debug("%#" PRIx64
": %s not on kallsyms\n", sym
->start
, sym
->name
);
179 pr_info("Maps only in vmlinux:\n");
181 for (nd
= rb_first(&vmlinux
.kmaps
.maps
[type
]); nd
; nd
= rb_next(nd
)) {
182 struct map
*pos
= rb_entry(nd
, struct map
, rb_node
), *pair
;
184 * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
185 * the kernel will have the path for the vmlinux file being used,
186 * so use the short name, less descriptive but the same ("[kernel]" in
189 pair
= map_groups__find_by_name(&kallsyms
.kmaps
, type
,
191 pos
->dso
->short_name
:
196 map__fprintf(pos
, stderr
);
199 pr_info("Maps in vmlinux with a different name in kallsyms:\n");
201 for (nd
= rb_first(&vmlinux
.kmaps
.maps
[type
]); nd
; nd
= rb_next(nd
)) {
202 struct map
*pos
= rb_entry(nd
, struct map
, rb_node
), *pair
;
204 pair
= map_groups__find(&kallsyms
.kmaps
, type
, pos
->start
);
205 if (pair
== NULL
|| pair
->priv
)
208 if (pair
->start
== pos
->start
) {
210 pr_info(" %" PRIx64
"-%" PRIx64
" %" PRIx64
" %s in kallsyms as",
211 pos
->start
, pos
->end
, pos
->pgoff
, pos
->dso
->name
);
212 if (pos
->pgoff
!= pair
->pgoff
|| pos
->end
!= pair
->end
)
213 pr_info(": \n*%" PRIx64
"-%" PRIx64
" %" PRIx64
"",
214 pair
->start
, pair
->end
, pair
->pgoff
);
215 pr_info(" %s\n", pair
->dso
->name
);
220 pr_info("Maps only in kallsyms:\n");
222 for (nd
= rb_first(&kallsyms
.kmaps
.maps
[type
]);
223 nd
; nd
= rb_next(nd
)) {
224 struct map
*pos
= rb_entry(nd
, struct map
, rb_node
);
227 map__fprintf(pos
, stderr
);
230 machine__exit(&kallsyms
);
231 machine__exit(&vmlinux
);