[compiler-rt] r275107 - [asan] Add exception handler to map memory on demand on Win64.
Etienne Bergeron via llvm-commits
llvm-commits at lists.llvm.org
Mon Jul 11 14:41:00 PDT 2016
Author: etienneb
Date: Mon Jul 11 16:40:59 2016
New Revision: 275107
URL: http://llvm.org/viewvc/llvm-project?rev=275107&view=rev
Log:
[asan] Add exception handler to map memory on demand on Win64.
Memory will be committed on demand when exception happens while accessing
shadow memeory region.
Patch by: Wei Wang
Differential Revision: http://reviews.llvm.org/D21942
Modified:
compiler-rt/trunk/lib/asan/asan_internal.h
compiler-rt/trunk/lib/asan/asan_linux.cc
compiler-rt/trunk/lib/asan/asan_mac.cc
compiler-rt/trunk/lib/asan/asan_rtl.cc
compiler-rt/trunk/lib/asan/asan_win.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc
Modified: compiler-rt/trunk/lib/asan/asan_internal.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_internal.h?rev=275107&r1=275106&r2=275107&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_internal.h (original)
+++ compiler-rt/trunk/lib/asan/asan_internal.h Mon Jul 11 16:40:59 2016
@@ -62,6 +62,9 @@ using __sanitizer::StackTrace;
void AsanInitFromRtl();
+// asan_win.cc
+void InitializePlatformExceptionHandlers();
+
// asan_rtl.cc
void NORETURN ShowStatsAndAbort();
@@ -127,7 +130,6 @@ extern int asan_inited;
// Used to avoid infinite recursion in __asan_init().
extern bool asan_init_is_running;
extern void (*death_callback)(void);
-
// These magic values are written to shadow for better error reporting.
const int kAsanHeapLeftRedzoneMagic = 0xfa;
const int kAsanHeapRightRedzoneMagic = 0xfb;
Modified: compiler-rt/trunk/lib/asan/asan_linux.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_linux.cc?rev=275107&r1=275106&r2=275107&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_linux.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_linux.cc Mon Jul 11 16:40:59 2016
@@ -69,6 +69,7 @@ asan_rt_version_t __asan_rt_version;
namespace __asan {
void InitializePlatformInterceptors() {}
+void InitializePlatformExceptionHandlers() {}
void *AsanDoesNotSupportStaticLinkage() {
// This will fail to link with -static.
Modified: compiler-rt/trunk/lib/asan/asan_mac.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_mac.cc?rev=275107&r1=275106&r2=275107&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_mac.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_mac.cc Mon Jul 11 16:40:59 2016
@@ -47,6 +47,7 @@ extern "C" {
namespace __asan {
void InitializePlatformInterceptors() {}
+void InitializePlatformExceptionHandlers() {}
bool PlatformHasDifferentMemcpyAndMemmove() {
// On OS X 10.7 memcpy() and memmove() are both resolved
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=275107&r1=275106&r2=275107&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_rtl.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_rtl.cc Mon Jul 11 16:40:59 2016
@@ -420,6 +420,8 @@ static void AsanInitInternal() {
SetCanPoisonMemory(flags()->poison_heap);
SetMallocContextSize(common_flags()->malloc_context_size);
+ InitializePlatformExceptionHandlers();
+
InitializeHighMemEnd();
// Make sure we are not statically linked.
Modified: compiler-rt/trunk/lib/asan/asan_win.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_win.cc?rev=275107&r1=275106&r2=275107&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_win.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_win.cc Mon Jul 11 16:40:59 2016
@@ -24,6 +24,7 @@
#include "asan_report.h"
#include "asan_stack.h"
#include "asan_thread.h"
+#include "asan_mapping.h"
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_mutex.h"
@@ -215,6 +216,55 @@ void AsanOnDeadlySignal(int, void *sigin
UNIMPLEMENTED();
}
+#if SANITIZER_WINDOWS64
+// Exception handler for dealing with shadow memory.
+static LONG CALLBACK
+ShadowExceptionHandler(PEXCEPTION_POINTERS exception_pointers) {
+ static uptr page_size = GetPageSizeCached();
+ static uptr alloc_granularity = GetMmapGranularity();
+ // Only handle access violations.
+ if (exception_pointers->ExceptionRecord->ExceptionCode !=
+ EXCEPTION_ACCESS_VIOLATION) {
+ return EXCEPTION_CONTINUE_SEARCH;
+ }
+
+ // Only handle access violations that land within the shadow memory.
+ uptr addr =
+ (uptr)(exception_pointers->ExceptionRecord->ExceptionInformation[1]);
+
+ // Check valid shadow range.
+ if (!AddrIsInShadow(addr)) return EXCEPTION_CONTINUE_SEARCH;
+
+ // This is an access violation while trying to read from the shadow. Commit
+ // the relevant page and let execution continue.
+
+ // Determine the address of the page that is being accessed.
+ uptr page = RoundDownTo(addr, page_size);
+
+ // Query the existing page.
+ MEMORY_BASIC_INFORMATION mem_info = {};
+ if (::VirtualQuery((LPVOID)page, &mem_info, sizeof(mem_info)) == 0)
+ return EXCEPTION_CONTINUE_SEARCH;
+
+ // Commit the page.
+ uptr result =
+ (uptr)::VirtualAlloc((LPVOID)page, page_size, MEM_COMMIT, PAGE_READWRITE);
+ if (result != page) return EXCEPTION_CONTINUE_SEARCH;
+
+ // The page mapping succeeded, so continue execution as usual.
+ return EXCEPTION_CONTINUE_EXECUTION;
+}
+
+#endif
+
+void InitializePlatformExceptionHandlers() {
+#if SANITIZER_WINDOWS64
+ // On Win64, we map memory on demand with access violation handler.
+ // Install our exception handler.
+ CHECK(AddVectoredExceptionHandler(TRUE, &ShadowExceptionHandler));
+#endif
+}
+
static LPTOP_LEVEL_EXCEPTION_FILTER default_seh_handler;
static long WINAPI SEHHandler(EXCEPTION_POINTERS *info) {
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=275107&r1=275106&r2=275107&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc Mon Jul 11 16:40:59 2016
@@ -171,9 +171,16 @@ void *MmapAlignedOrDie(uptr size, uptr a
void *MmapFixedNoReserve(uptr fixed_addr, uptr size, const char *name) {
// FIXME: is this really "NoReserve"? On Win32 this does not matter much,
// but on Win64 it does.
- (void)name; // unsupported
- void *p = VirtualAlloc((LPVOID)fixed_addr, size,
- MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
+ (void)name; // unsupported
+#if SANITIZER_WINDOWS64
+ // On Windows64, use MEM_COMMIT would result in error
+ // 1455:ERROR_COMMITMENT_LIMIT.
+ // We use exception handler to commit page on demand.
+ void *p = VirtualAlloc((LPVOID)fixed_addr, size, MEM_RESERVE, PAGE_READWRITE);
+#else
+ void *p = VirtualAlloc((LPVOID)fixed_addr, size, MEM_RESERVE | MEM_COMMIT,
+ PAGE_READWRITE);
+#endif
if (p == 0)
Report("ERROR: %s failed to "
"allocate %p (%zd) bytes at %p (error code: %d)\n",
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