src/runtime/linux-os.c

   1 /*
   2  * the Linux incarnation of OS-dependent routines.  See also
   3  * $(sbcl_arch)-linux-os.c
   4  *
   5  * This file (along with os.h) exports an OS-independent interface to
   6  * the operating system VM facilities. Surprise surprise, this
   7  * interface looks a lot like the Mach interface (but simpler in some
   8  * places). For some operating systems, a subset of these functions
   9  * will have to be emulated.
  10  */
  11
  12 /*
  13  * This software is part of the SBCL system. See the README file for
  14  * more information.
  15  *
  16  * This software is derived from the CMU CL system, which was
  17  * written at Carnegie Mellon University and released into the
  18  * public domain. The software is in the public domain and is
  19  * provided with absolutely no warranty. See the COPYING and CREDITS
  20  * files for more information.
  21  */
  22
  23 #include <stdio.h>
  24 #include <sys/param.h>
  25 #include <sys/file.h>
  26 #include "sbcl.h"
  27 #include "./signal.h"
  28 #include "os.h"
  29 #include "arch.h"
  30 #include "globals.h"
  31 #include "sbcl.h"
  32 #include "interrupt.h"
  33 #include "interr.h"
  34 #include "lispregs.h"
  35 #include <sys/socket.h>
  36 #include <sys/utsname.h>
  37
  38 #include <sys/types.h>
  39 #include <signal.h>
  40 /* #include <sys/sysinfo.h> */
  41 #include <sys/time.h>
  42 #include <sys/stat.h>
  43 #include <unistd.h>
  44 #include <linux/version.h>
  45
  46 #include "validate.h"
  47 #include "thread.h"
  48 size_t os_vm_page_size;
  49
  50 #include "gc.h"
  51 \f
  52 int linux_sparc_siginfo_bug = 0;
  53
  54 void os_init(void)
  55 {
  56     /* Conduct various version checks: do we have enough mmap(), is
  57      * this a sparc running 2.2, can we do threads? */
  58     {
  59         struct utsname name;
  60         int major_version;
  61         int minor_version;
  62         char *p;
  63         uname(&name);
  64         p=name.release;
  65         major_version = atoi(p);
  66         p=strchr(p,'.')+1;
  67         minor_version = atoi(p);
  68         if (major_version<2) {
  69             lose("linux kernel version too old: major version=%d (can't run in version < 2.0.0)",
  70                  major_version);
  71         }
  72 #ifdef LISP_FEATURE_SB_THREAD
  73         if ((major_version <2) || (major_version==2 && minor_version < 4)) {
  74             lose("linux kernel 2.4 required for thread-enabled SBCL");
  75         }
  76 #endif
  77 #ifdef LISP_FEATURE_SPARC
  78         if ((major_version <2) || (major_version==2 && minor_version < 4)) {
  79             FSHOW((stderr,"linux kernel %d.%d predates 2.4;\n enabling workarounds for SPARC kernel bugs in signal handling.\n", major_version,minor_version));
  80             linux_sparc_siginfo_bug = 1;
  81         }
  82 #endif
  83     }
  84
  85     os_vm_page_size = getpagesize();
  86     /* This could just as well be in arch_init(), but it's not. */
  87 #ifdef __i386__
  88     /* FIXME: This used to be here.  However, I have just removed it
  89        with no apparent ill effects (it may be that earlier kernels
  90        started up a process with a different set of traps, or
  91        something?) Find out what this was meant to do, and reenable it
  92        or delete it if possible. -- CSR, 2002-07-15 */
  93     /* SET_FPU_CONTROL_WORD(0x1372|4|8|16|32);  no interrupts */
  94 #endif
  95 }
  96
  97
  98 #ifdef LISP_FEATURE_ALPHA
  99 /* The Alpha is a 64 bit CPU.  SBCL is a 32 bit application.  Due to all
 100  * the places that assume we can get a pointer into a fixnum with no
 101  * information loss, we have to make sure it allocates all its ram in the
 102  * 0-2Gb region.  */
 103
 104 static void * under_2gb_free_pointer=DYNAMIC_1_SPACE_END;
 105 #endif
 106
 107 os_vm_address_t
 108 os_validate(os_vm_address_t addr, os_vm_size_t len)
 109 {
 110     int flags =  MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
 111     os_vm_address_t actual ;
 112
 113     if (addr)
 114         flags |= MAP_FIXED;
 115 #ifdef LISP_FEATURE_ALPHA
 116     else {
 117         flags |= MAP_FIXED;
 118         addr=under_2gb_free_pointer;
 119     }
 120 #endif
 121     actual = mmap(addr, len, OS_VM_PROT_ALL, flags, -1, 0);
 122     if (actual == MAP_FAILED || (addr && (addr!=actual))) {
 123         perror("mmap");
 124         return 0;               /* caller should check this */
 125     }
 126
 127 #ifdef LISP_FEATURE_ALPHA
 128
 129     len=(len+(os_vm_page_size-1))&(~(os_vm_page_size-1));
 130     under_2gb_free_pointer+=len;
 131 #endif
 132
 133     return actual;
 134 }
 135
 136 void
 137 os_invalidate(os_vm_address_t addr, os_vm_size_t len)
 138 {
 139     if (munmap(addr,len) == -1) {
 140         perror("munmap");
 141     }
 142 }
 143
 144 os_vm_address_t
 145 os_map(int fd, int offset, os_vm_address_t addr, os_vm_size_t len)
 146 {
 147     addr = mmap(addr, len,
 148                 OS_VM_PROT_ALL,
 149                 MAP_PRIVATE | MAP_FILE | MAP_FIXED,
 150                 fd, (off_t) offset);
 151
 152     if (addr == MAP_FAILED) {
 153         perror("mmap");
 154         lose("unexpected mmap(..) failure");
 155     }
 156
 157     return addr;
 158 }
 159
 160 void
 161 os_protect(os_vm_address_t address, os_vm_size_t length, os_vm_prot_t prot)
 162 {
 163     if (mprotect(address, length, prot) == -1) {
 164         perror("mprotect");
 165     }
 166 }
 167 \f
 168 /* FIXME: Now that FOO_END, rather than FOO_SIZE, is the fundamental
 169  * description of a space, we could probably punt this and just do
 170  * (FOO_START <= x && x < FOO_END) everywhere it's called. */
 171 static boolean
 172 in_range_p(os_vm_address_t a, lispobj sbeg, size_t slen)
 173 {
 174     char* beg = (char*)((long)sbeg);
 175     char* end = (char*)((long)sbeg) + slen;
 176     char* adr = (char*)a;
 177     return (adr >= beg && adr < end);
 178 }
 179
 180 boolean
 181 is_valid_lisp_addr(os_vm_address_t addr)
 182 {
 183     struct thread *th;
 184     if(in_range_p(addr, READ_ONLY_SPACE_START, READ_ONLY_SPACE_SIZE) ||
 185        in_range_p(addr, STATIC_SPACE_START   , STATIC_SPACE_SIZE) ||
 186        in_range_p(addr, DYNAMIC_SPACE_START  , DYNAMIC_SPACE_SIZE))
 187         return 1;
 188     for_each_thread(th) {
 189         if((th->control_stack_start <= addr) && (addr < th->control_stack_end))
 190             return 1;
 191         if(in_range_p(addr, th->binding_stack_start, BINDING_STACK_SIZE))
 192             return 1;
 193     }
 194     return 0;
 195 }
 196 \f
 197 /*
 198  * any OS-dependent special low-level handling for signals
 199  */
 200
 201
 202 #if defined LISP_FEATURE_GENCGC
 203
 204 /*
 205  * The GENCGC needs to be hooked into whatever signal is raised for
 206  * page fault on this OS.
 207  */
 208 void
 209 sigsegv_handler(int signal, siginfo_t *info, void* void_context)
 210 {
 211     os_context_t *context = arch_os_get_context(&void_context);
 212     void* fault_addr = (void*)context->uc_mcontext.cr2;
 213     if (!gencgc_handle_wp_violation(fault_addr))
 214         if(!handle_control_stack_guard_triggered(context,fault_addr))
 215             interrupt_handle_now(signal, info, void_context);
 216 }
 217
 218 #else
 219
 220 static void
 221 sigsegv_handler(int signal, siginfo_t *info, void* void_context)
 222 {
 223     os_context_t *context = arch_os_get_context(&void_context);
 224     os_vm_address_t addr;
 225
 226     addr = arch_get_bad_addr(signal,info,context);
 227     if (addr != NULL &&
 228         *os_context_register_addr(context,reg_ALLOC) & (1L<<63)){
 229
 230         /* Alpha stuff: This is the end of a pseudo-atomic section
 231          * during which a signal was received.  We must deal with the
 232          * pending interrupt (see also interrupt.c,
 233          * ../code/interrupt.lisp)
 234          */
 235         /* (how we got here: when interrupting, we set bit 63 in
 236          * reg_Alloc.  At the end of the atomic section we tried to
 237          * write to reg_ALLOC, got a SIGSEGV (there's nothing mapped
 238          * there) so ended up here
 239          */
 240         *os_context_register_addr(context,reg_ALLOC) -= (1L<<63);
 241         interrupt_handle_pending(context);
 242     } else {
 243         if(!interrupt_maybe_gc(signal, info, context))
 244             if(!handle_control_stack_guard_triggered(context,addr))
 245                 interrupt_handle_now(signal, info, context);
 246     }
 247 }
 248 #endif
 249
 250 void sigcont_handler(int signal, siginfo_t *info, void *void_context)
 251 {
 252     /* We need to have a handler installed for this signal so that
 253      * sigwaitinfo() for it actually returns at the appropriate time.
 254      * We don't need it to actually do anything.  This mkes it
 255      * possibly the only signal handler in SBCL that doesn't depend on
 256      * not-guaranteed-by-POSIX features
 257      */
 258 }
 259
 260 void
 261 os_install_interrupt_handlers(void)
 262 {
 263     undoably_install_low_level_interrupt_handler(SIG_MEMORY_FAULT,
 264                                                  sigsegv_handler);
 265 #ifdef LISP_FEATURE_SB_THREAD
 266     undoably_install_low_level_interrupt_handler(SIG_INTERRUPT_THREAD,
 267                                                  handle_rt_signal);
 268     undoably_install_low_level_interrupt_handler(SIG_STOP_FOR_GC,
 269                                                  sig_stop_for_gc_handler);
 270 #endif
 271     undoably_install_low_level_interrupt_handler(SIGCONT,
 272                                                  sigcont_handler);
 273 }
 274