[PATCH] D19112: [asan] [SystemZ] Add slop for stack address detection.

[Marcin Kościelnicki via llvm-commits]

koriakin added inline comments.

================
Comment at: lib/asan/asan_posix.cc:49
@@ +48,3 @@
+  // page granularity.
+  bool IsStackAccess = sig.addr >= (sig.sp & ~0xFFF) &&
+                       sig.addr < sig.sp + 0xFFFF;
----------------
eugenis wrote:
> Do you mean that sig.addr is rounded down to the nearest page boundary?
> Do you need some extra space below sp (same as +512 in the common case below)? I.e. is it possible that the true fault address is below sp and falls into a different page, and then sig.addr would be ((sig.sp & 0xFFF) - 0x1000) ?
> 
sig.addr is rounded down to nearest page bounduary (because s390 gives you only the page index on a fault, not the full address).  However, there is no redzone - accesses below sp are verboten.  I'll try to think of a better wording for the comment before commiting.


Repository:
  rL LLVM

http://reviews.llvm.org/D19112