[compiler-rt] r261233 - [WinASan] Fix page size and mmap granularity confusion

[Reid Kleckner via llvm-commits]

Author: rnk
Date: Thu Feb 18 11:58:22 2016
New Revision: 261233

URL: http://llvm.org/viewvc/llvm-project?rev=261233&view=rev
Log:
[WinASan] Fix page size and mmap granularity confusion

We were erroneously reporting 16K as the page size on Windows because
the code that does the shadow mapping was using page size instead of
allocation granularity. After fixing that, we can resolve the FIXMEs in
the Windows implementations of GetPageSize and GetMmapGranularity by
calling GetSystemInfo instead of returning hard-coded, incorrect
answers.

Modified:
    compiler-rt/trunk/lib/asan/asan_rtl.cc
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc

Modified: compiler-rt/trunk/lib/asan/asan_rtl.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_rtl.cc?rev=261233&r1=261232&r2=261233&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_rtl.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_rtl.cc Thu Feb 18 11:58:22 2016
@@ -86,8 +86,8 @@ void ShowStatsAndAbort() {
 // Reserve memory range [beg, end].
 // We need to use inclusive range because end+1 may not be representable.
 void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name) {
-  CHECK_EQ((beg % GetPageSizeCached()), 0);
-  CHECK_EQ(((end + 1) % GetPageSizeCached()), 0);
+  CHECK_EQ((beg % GetMmapGranularity()), 0);
+  CHECK_EQ(((end + 1) % GetMmapGranularity()), 0);
   uptr size = end - beg + 1;
   DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
   void *res = MmapFixedNoReserve(beg, size, name);
@@ -320,9 +320,9 @@ static void InitializeHighMemEnd() {
   kHighMemEnd = GetMaxVirtualAddress();
   // Increase kHighMemEnd to make sure it's properly
   // aligned together with kHighMemBeg:
-  kHighMemEnd |= SHADOW_GRANULARITY * GetPageSizeCached() - 1;
+  kHighMemEnd |= SHADOW_GRANULARITY * GetMmapGranularity() - 1;
 #endif  // !ASAN_FIXED_MAPPING
-  CHECK_EQ((kHighMemBeg % GetPageSizeCached()), 0);
+  CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0);
 }
 
 static void ProtectGap(uptr addr, uptr size) {
@@ -335,7 +335,7 @@ static void ProtectGap(uptr addr, uptr s
   // But we really want to protect as much as possible, to prevent this memory
   // being returned as a result of a non-FIXED mmap().
   if (addr == kZeroBaseShadowStart) {
-    uptr step = GetPageSizeCached();
+    uptr step = GetMmapGranularity();
     while (size > step && addr < kZeroBaseMaxShadowStart) {
       addr += step;
       size -= step;

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc?rev=261233&r1=261232&r2=261233&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc Thu Feb 18 11:58:22 2016
@@ -35,13 +35,15 @@ namespace __sanitizer {
 
 // --------------------- sanitizer_common.h
 uptr GetPageSize() {
-  // FIXME: there is an API for getting the system page size (GetSystemInfo or
-  // GetNativeSystemInfo), but if we use it here we get test failures elsewhere.
-  return 1U << 14;
+  SYSTEM_INFO si;
+  GetSystemInfo(&si);
+  return si.dwPageSize;
 }
 
 uptr GetMmapGranularity() {
-  return 1U << 16;  // FIXME: is this configurable?
+  SYSTEM_INFO si;
+  GetSystemInfo(&si);
+  return si.dwAllocationGranularity;
 }
 
 uptr GetMaxVirtualAddress() {