X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;ds=inline;f=lib%2Flizard-safe.c;h=0473e34ae7270215267adb6b59e342eb43140485;hb=baa9f9a3368c8d318b9711340727f822d8fc8a34;hp=dcc01d11f59a6a69528eac1fd75f86f867230d35;hpb=54952ff4cd9e28755d0fb0d38e2dab3c1299a6ab;p=libucw.git

diff --git a/lib/lizard-safe.c b/lib/lizard-safe.c
index dcc01d11..0473e34a 100644
--- a/lib/lizard-safe.c
+++ b/lib/lizard-safe.c
@@ -8,11 +8,10 @@
  */
 
 #include "lib/lib.h"
+#include "lib/threads.h"
 #include "lib/lizard.h"
 
-#include <stdlib.h>
 #include <sys/mman.h>
-#include <sys/user.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <setjmp.h>
@@ -21,7 +20,6 @@
 struct lizard_buffer {
   uns len;
   void *ptr;
-  struct sigaction *old_sigsegv_handler;
 };
 
 struct lizard_buffer *
@@ -30,24 +28,22 @@ lizard_alloc(void)
   struct lizard_buffer *buf = xmalloc(sizeof(struct lizard_buffer));
   buf->len = 0;
   buf->ptr = NULL;
-  buf->old_sigsegv_handler = xmalloc(sizeof(struct sigaction));
-  handle_signal(SIGSEGV, buf->old_sigsegv_handler);
+  handle_signal(SIGSEGV);
   return buf;
 }
 
 void
 lizard_free(struct lizard_buffer *buf)
 {
+  unhandle_signal(SIGSEGV);
   if (buf->ptr)
-    munmap(buf->ptr, buf->len + PAGE_SIZE);
-  unhandle_signal(SIGSEGV, buf->old_sigsegv_handler);
-  xfree(buf->old_sigsegv_handler);
+    munmap(buf->ptr, buf->len + CPU_PAGE_SIZE);
   xfree(buf);
 }
 
 static void
 lizard_realloc(struct lizard_buffer *buf, uns max_len)
-  /* max_len needs to be aligned to PAGE_SIZE */
+  /* max_len needs to be aligned to CPU_PAGE_SIZE */
 {
   if (max_len <= buf->len)
     return;
@@ -55,12 +51,12 @@ lizard_realloc(struct lizard_buffer *buf, uns max_len)
     max_len = 2*buf->len;
 
   if (buf->ptr)
-    munmap(buf->ptr, buf->len + PAGE_SIZE);
+    munmap(buf->ptr, buf->len + CPU_PAGE_SIZE);
   buf->len = max_len;
-  buf->ptr = mmap(NULL, buf->len + PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+  buf->ptr = mmap(NULL, buf->len + CPU_PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
   if (buf->ptr == MAP_FAILED)
-    die("mmap(anonymous): %m");
-  if (mprotect(buf->ptr + buf->len, PAGE_SIZE, PROT_NONE) < 0)
+    die("mmap(anonymous, %d bytes): %m", (uns)(buf->len + CPU_PAGE_SIZE));
+  if (mprotect(buf->ptr + buf->len, CPU_PAGE_SIZE, PROT_NONE) < 0)
     die("mprotect: %m");
 }
 
@@ -68,36 +64,39 @@ static jmp_buf safe_decompress_jump;
 static int
 sigsegv_handler(int signal UNUSED)
 {
-  log(L_ERROR, "SIGSEGV caught in lizard_decompress()");
   longjmp(safe_decompress_jump, 1);
   return 1;
 }
 
-int
-lizard_decompress_safe(byte *in, struct lizard_buffer *buf, uns expected_length, byte **ptr)
+byte *
+lizard_decompress_safe(byte *in, struct lizard_buffer *buf, uns expected_length)
   /* Decompresses in into buf, sets *ptr to the data, and returns the
    * uncompressed length.  If an error has occured, -1 is returned and errno is
    * set.  The buffer buf is automatically reallocated.  SIGSEGV is caught in
    * case of buffer-overflow.  The function is not re-entrant because of a
    * static longjmp handler.  */
 {
-  uns lock_offset = ALIGN(expected_length + 3, PAGE_SIZE);	// +3 due to the unaligned access
+  uns lock_offset = ALIGN_TO(expected_length + 3, CPU_PAGE_SIZE);	// +3 due to the unaligned access
   if (lock_offset > buf->len)
     lizard_realloc(buf, lock_offset);
-  volatile sh_sighandler_t old_handler = signal_handler[SIGSEGV];
-  signal_handler[SIGSEGV] = sigsegv_handler;
-  int len;
+  volatile sh_sighandler_t old_handler = set_signal_handler(SIGSEGV, sigsegv_handler);
+  byte *ptr;
   if (!setjmp(safe_decompress_jump))
   {
-    *ptr = buf->ptr + buf->len - lock_offset;
-    len = lizard_decompress(in, *ptr);
+    ptr = buf->ptr + buf->len - lock_offset;
+    int len = lizard_decompress(in, ptr);
+    if (len != (int) expected_length)
+    {
+      ptr = NULL;
+      errno = EINVAL;
+    }
   }
   else
   {
-    *ptr = NULL;
-    len = -1;
+    log(L_ERROR, "SIGSEGV caught in lizard_decompress()");
+    ptr = NULL;
     errno = EFAULT;
   }
-  signal_handler[SIGSEGV] = old_handler;
-  return len;
+  set_signal_handler(SIGSEGV, old_handler);
+  return ptr;
 }