Attachment 92300 Details for Bug 73473 – patch adding check for PaX mprotect

[patch] patch adding check for PaX mprotect

mesa_pax_mprotect_check.patch (text/plain), 1.59 KB, created by Amadeusz on 2014-01-17 19:21:04 UTC

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Creator: Amadeusz

Created: 2014-01-17 19:21:04 UTC

Size: 1.59 KB

patch

obsolete

>diff -uNr a/src/gallium/auxiliary/rtasm/rtasm_execmem.c b/src/gallium/auxiliary/rtasm/rtasm_execmem.c
>--- a/src/gallium/auxiliary/rtasm/rtasm_execmem.c	2014-01-17 19:32:06.162056839 +0100
>+++ b/src/gallium/auxiliary/rtasm/rtasm_execmem.c	2014-01-17 19:32:49.556057529 +0100
>@@ -69,9 +69,32 @@
> static unsigned char *exec_mem = NULL;
> 
> 
>-static void
>+static int
> init_heap(void)
> {
>+   /* check for PaX mprotect
>+    * http://pax.grsecurity.net/docs/mprotect.txt */
>+   char *buf = NULL;
>+   size_t len = 0;
>+   FILE *f;
>+   int canexecmem;
>+   f = fopen ("/proc/self/status", "r");
>+   if (f == NULL)
>+      return 0;
>+   canexecmem = 0;
>+
>+   while (getline (&buf, &len, f) != -1)
>+      if (!strncmp (buf, "PaX:", 4)) {
>+         char memexec;
>+         if (sscanf (buf, "%*s %*c%*c%c", &memexec) == 1)
>+            canexecmem = (memexec == 'm');
>+         break;
>+      }
>+   free (buf);
>+   fclose (f);
>+   if (!canexecmem)
>+      return 0;
>+
>    if (!exec_heap)
>       exec_heap = u_mmInit( 0, EXEC_HEAP_SIZE );
>    
>@@ -79,6 +102,8 @@
>       exec_mem = (unsigned char *) mmap(0, EXEC_HEAP_SIZE, 
> 					PROT_EXEC | PROT_READ | PROT_WRITE, 
> 					MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
>+
>+   return (exec_mem != MAP_FAILED);
> }
> 
> 
>@@ -90,7 +115,8 @@
> 
>    pipe_mutex_lock(exec_mutex);
> 
>-   init_heap();
>+   if (!init_heap())
>+      goto bail;
> 
>    if (exec_heap) {
>       size = (size + 31) & ~31;  /* next multiple of 32 bytes */
>@@ -101,7 +127,8 @@
>       addr = exec_mem + block->ofs;
>    else 
>       debug_printf("rtasm_exec_malloc failed\n");
>-   
>+
>+bail:
>    pipe_mutex_unlock(exec_mutex);
>    
>    return addr;

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Attachments on bug 73473: 91834 | 92300

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