Add FreeBSD support to Asan test cases that use mmap() with MAP_ANON

[emaste]

test/asan/TestCases/Posix/large_allocator_unpoisons_on_free.cc

30 ↗

(On Diff #11578)

Do the other platforms require it to be 0? Can it just be -1 for all?

[kutuzov.viktor.84]

-1 does work on my Linux 3.13, but I'm not sure about Darwin. Will try to test it.

[samsonov]

test/asan/TestCases/Posix/large_allocator_unpoisons_on_free.cc

30 ↗

(On Diff #11578)

I think we should just change it to -1. "man mmap" tells that "The fd and offset arguments are ignored; however, some implementations require fd to be -1 if MAP_ANONYMOUS (or MAP_ANON) is specified, and portable applications should ensure this."

[kutuzov.viktor.84]

man mmap on

Darwin Kernel Version 11.4.2: Thu Aug 23 16:25:48 PDT 2012; root:xnu-1699.32.7~1/RELEASE_X86_64 x86_64

reads:

   MAP_ANON          Map anonymous memory not associated with any specific
                     file.  The offset argument is ignored.  Mac OS X spe-
                     cific: the file descriptor used for creating MAP_ANON
                     regions can be used to pass some Mach VM flags, and can
                     be specified as -1 if no such flags are associated with
                     the region.  Mach VM flags are defined in <mach/vm_sta-
                     tistics.h> and the ones that currently apply to mmap
                     are:
...

So, it looks it actually should be (-1) on Darwin. Will update the patch ASAP.

[kutuzov.viktor.84]

Updated.

[samsonov]

LGTM

[kutuzov.viktor.84]

Closed by commit rL213858 (authored by vkutuzov).

compiler-rt/trunk/test/asan/TestCases/Posix/large_allocator_unpoisons_on_free.cc

 }
 #endif
 
 int main() {
   const int kPageSize = 4096;
   void *p = my_memalign(kPageSize, 1024 * 1024);
   free(p);
 
-  char *q = (char *)mmap(p, kPageSize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON | MAP_FIXED, 0, 0);
+  char *q = (char *)mmap(p, kPageSize, PROT_READ | PROT_WRITE,
+                         MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
   assert(q == p);
 
   memset(q, 42, kPageSize);
 
   munmap(q, kPageSize);
   return 0;
 }

compiler-rt/trunk/test/asan/TestCases/dlclose-test.cc

int main(int argc, char *argv[]) {
   if (dlclose(lib)) {
     printf("failed to dlclose\n");
     return 1;
   }
   // Now, the page where 'addr' is unmapped. Map it.
   size_t page_beg = ((size_t)addr) & ~(PageSize - 1);
   void *res = mmap((void*)(page_beg), PageSize,
                    PROT_READ | PROT_WRITE,
-                   MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_NORESERVE, 0, 0);
+                   MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_NORESERVE, -1, 0);
   if (res == (char*)-1L) {
     printf("failed to mmap\n");
     return 1;
   }
   addr[1] = 2;  // BOOM (if the bug is not fixed).
   printf("PASS\n");
   // CHECK: PASS
   return 0;