0.9.6.42:

[sbcl.git] / src / runtime / linux-os.c

diff --git a/src/runtime/linux-os.c b/src/runtime/linux-os.c
index 9bc5ea1..d0aa95a 100644 (file)
--- a/src/runtime/linux-os.c
+++ b/src/runtime/linux-os.c
@@ -98,16 +98,17 @@ int linux_sparc_siginfo_bug = 0;
 int linux_no_threads_p = 0;
 
 #ifdef LISP_FEATURE_SB_THREAD
-int isnptl (void)
+int
+isnptl (void)
 {
   size_t n = confstr (_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
-  if (n > 0)
-    {
+  if (n > 0) {
       char *buf = alloca (n);
       confstr (_CS_GNU_LIBPTHREAD_VERSION, buf, n);
-      if (strstr (buf, "NPTL"))
-        return 1;
-    }
+      if (strstr (buf, "NPTL")) {
+          return 1;
+      }
+  }
   return 0;
 }
 #endif
@@ -123,12 +124,15 @@ os_init(char *argv[], char *envp[])
     struct utsname name;
     int major_version;
     int minor_version;
+    int patch_version;
     char *p;
     uname(&name);
     p=name.release;
     major_version = atoi(p);
     p=strchr(p,'.')+1;
     minor_version = atoi(p);
+    p=strchr(p,'.')+1;
+    patch_version = atoi(p);
     if (major_version<2) {
         lose("linux kernel version too old: major version=%d (can't run in version < 2.0.0)",
              major_version);
@@ -160,13 +164,28 @@ Please use a more recent kernel or a version of SBCL without threading support.\
      * don't do this trick on other platforms.
      */
 #ifdef LISP_FEATURE_X86
-    if ((major_version == 2 && minor_version >= 6)
+    if ((major_version == 2
+         /* Some old kernels will apparently lose unsupported personality flags
+          * on exec() */
+         && ((minor_version == 6 && patch_version >= 11)
+             || (minor_version > 6)))
         || major_version >= 3)
     {
-        long pers = personality(-1);
+        int pers = personality(0xffffffffUL);
         /* 0x40000 aka. ADDR_NO_RANDOMIZE */
         if (!(pers & 0x40000)) {
-            if (personality(pers | 0x40000) != -1) {
+            int retval = personality(pers | 0x40000);
+            /* Allegedly some Linux kernels (the reported case was
+             * "hardened Linux 2.6.7") won't set the new personality,
+             * but nor will they return -1 for an error. So as a
+             * workaround query the new personality...
+             */
+            int newpers = personality(0xffffffffUL);
+            /* ... and don't re-execute if either the setting resulted
+             * in an error or if the value didn't change. Otherwise
+             * this might result in an infinite loop.
+             */
+            if (retval != -1 && newpers != pers) {
                 /* Use /proc/self/exe instead of trying to figure out
                  * the executable path from PATH and argv[0], since
                  * that's unreliable. We follow the symlink instead of
@@ -211,11 +230,17 @@ os_validate(os_vm_address_t addr, os_vm_size_t len)
     }
 #endif
     actual = mmap(addr, len, OS_VM_PROT_ALL, flags, -1, 0);
-    if (actual == MAP_FAILED || (addr && (addr!=actual))) {
+    if (actual == MAP_FAILED) {
         perror("mmap");
         return 0;               /* caller should check this */
     }
 
+    if (addr && (addr!=actual)) {
+        fprintf(stderr, "mmap: wanted %lu bytes at %p, actually mapped at %p\n",
+                (unsigned long) len, addr, actual);
+        return 0;
+    }
+
 #ifdef LISP_FEATURE_ALPHA
 
     len=(len+(os_vm_page_size-1))&(~(os_vm_page_size-1));
@@ -287,34 +312,15 @@ is_valid_lisp_addr(os_vm_address_t addr)
  * any OS-dependent special low-level handling for signals
  */
 
-
-#if defined LISP_FEATURE_GENCGC
-
 /*
- * The GENCGC needs to be hooked into whatever signal is raised for
+ * The GC needs to be hooked into whatever signal is raised for
  * page fault on this OS.
  */
 static void
 sigsegv_handler(int signal, siginfo_t *info, void* void_context)
 {
     os_context_t *context = arch_os_get_context(&void_context);
-    void* fault_addr = (void*)info->si_addr;
-    if (!gencgc_handle_wp_violation(fault_addr))
-        if(!handle_guard_page_triggered(context,fault_addr))
-#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
-            arrange_return_to_lisp_function(context, SymbolFunction(MEMORY_FAULT_ERROR));
-#else
-            interrupt_handle_now(signal, info, context);
-#endif
-}
-
-#else
-
-static void
-sigsegv_handler(int signal, siginfo_t *info, void* void_context)
-{
-    os_context_t *context = arch_os_get_context(&void_context);
-    os_vm_address_t addr = arch_get_bad_addr(signal,info,context);
+    os_vm_address_t addr = arch_get_bad_addr(signal, info, context);
 
 #ifdef LISP_FEATURE_ALPHA
     /* Alpha stuff: This is the end of a pseudo-atomic section during
@@ -325,18 +331,25 @@ sigsegv_handler(int signal, siginfo_t *info, void* void_context)
        At the end of the atomic section we tried to write to reg_ALLOC,
        got a SIGSEGV (there's nothing mapped there) so ended up here. */
     if (addr != NULL &&
-        *os_context_register_addr(context,reg_ALLOC) & (1L<<63)){
-        *os_context_register_addr(context,reg_ALLOC) -= (1L<<63);
+        *os_context_register_addr(context, reg_ALLOC) & (1L<<63)) {
+        *os_context_register_addr(context, reg_ALLOC) -= (1L<<63);
         interrupt_handle_pending(context);
         return;
     }
 #endif
 
-    if(!interrupt_maybe_gc(signal, info, context))
-        if(!handle_guard_page_triggered(context,addr))
+#ifdef LISP_FEATURE_GENCGC
+    if (!gencgc_handle_wp_violation(addr))
+#else
+    if (!interrupt_maybe_gc(signal, info, context))
+#endif
+        if (!handle_guard_page_triggered(context, addr))
+#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
+            arrange_return_to_lisp_function(context, SymbolFunction(MEMORY_FAULT_ERROR));
+#else
             interrupt_handle_now(signal, info, context);
-}
 #endif
+}
 
 void
 os_install_interrupt_handlers(void)