[compiler-rt] r305569 - [Sanitizers] Secondary allocator respects allocator_may_return_null=1.
Alex Shlyapnikov via llvm-commits
llvm-commits at lists.llvm.org
Fri Jun 16 11:48:09 PDT 2017
Author: alekseyshl
Date: Fri Jun 16 13:48:08 2017
New Revision: 305569
URL: http://llvm.org/viewvc/llvm-project?rev=305569&view=rev
Log:
[Sanitizers] Secondary allocator respects allocator_may_return_null=1.
Summary:
Context: https://github.com/google/sanitizers/issues/740.
Making secondary allocator to respect allocator_may_return_null=1 flag
and return nullptr when "out of memory" happens.
More changes in primary allocator and operator new will follow.
Reviewers: eugenis
Subscribers: kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D34243
Added:
compiler-rt/trunk/test/asan/TestCases/Linux/allocator_oom_test.cc
Modified:
compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator_secondary.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator_secondary.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator_secondary.h?rev=305569&r1=305568&r2=305569&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator_secondary.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_allocator_secondary.h Fri Jun 16 13:48:08 2017
@@ -36,9 +36,12 @@ class LargeMmapAllocator {
if (alignment > page_size_)
map_size += alignment;
// Overflow.
- if (map_size < size) return ReturnNullOrDieOnBadRequest();
+ if (map_size < size)
+ return ReturnNullOrDieOnBadRequest();
uptr map_beg = reinterpret_cast<uptr>(
- MmapOrDie(map_size, "LargeMmapAllocator"));
+ MmapOrDieOnFatalError(map_size, "LargeMmapAllocator"));
+ if (!map_beg)
+ return ReturnNullOrDieOnOOM();
CHECK(IsAligned(map_beg, page_size_));
MapUnmapCallback().OnMap(map_beg, map_size);
uptr map_end = map_beg + map_size;
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h?rev=305569&r1=305568&r2=305569&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h Fri Jun 16 13:48:08 2017
@@ -85,6 +85,9 @@ INLINE void *MmapOrDieQuietly(uptr size,
return MmapOrDie(size, mem_type, /*raw_report*/ true);
}
void UnmapOrDie(void *addr, uptr size);
+// Behaves just like MmapOrDie, but tolerates out of memory condition, in that
+// case returns nullptr.
+void *MmapOrDieOnFatalError(uptr size, const char *mem_type);
void *MmapFixedNoReserve(uptr fixed_addr, uptr size,
const char *name = nullptr);
void *MmapNoReserveOrDie(uptr size, const char *mem_type);
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc?rev=305569&r1=305568&r2=305569&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc Fri Jun 16 13:48:08 2017
@@ -22,6 +22,7 @@
#include "sanitizer_procmaps.h"
#include "sanitizer_stacktrace.h"
+#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/mman.h>
@@ -145,6 +146,21 @@ void UnmapOrDie(void *addr, uptr size) {
DecreaseTotalMmap(size);
}
+void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
+ size = RoundUpTo(size, GetPageSizeCached());
+ uptr res = internal_mmap(nullptr, size,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON, -1, 0);
+ int reserrno;
+ if (internal_iserror(res, &reserrno)) {
+ if (reserrno == ENOMEM)
+ return nullptr;
+ ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
+ }
+ IncreaseTotalMmap(size);
+ return (void *)res;
+}
+
// We want to map a chunk of address space aligned to 'alignment'.
// We do it by maping a bit more and then unmaping redundant pieces.
// We probably can do it with fewer syscalls in some OS-dependent way.
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=305569&r1=305568&r2=305569&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_win.cc Fri Jun 16 13:48:08 2017
@@ -131,6 +131,16 @@ void UnmapOrDie(void *addr, uptr size) {
}
}
+void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
+ void *rv = VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
+ if (rv == 0) {
+ error_t last_error = GetLastError();
+ if (last_error != ERROR_NOT_ENOUGH_MEMORY)
+ ReportMmapFailureAndDie(size, mem_type, "allocate", last_error);
+ }
+ return rv;
+}
+
// We want to map a chunk of address space aligned to 'alignment'.
void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
CHECK(IsPowerOfTwo(size));
Added: compiler-rt/trunk/test/asan/TestCases/Linux/allocator_oom_test.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Linux/allocator_oom_test.cc?rev=305569&view=auto
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/Linux/allocator_oom_test.cc (added)
+++ compiler-rt/trunk/test/asan/TestCases/Linux/allocator_oom_test.cc Fri Jun 16 13:48:08 2017
@@ -0,0 +1,82 @@
+// Test the behavior of malloc/calloc/realloc when the allocation causes OOM
+// in the secondary allocator.
+// By default (allocator_may_return_null=0) the process should crash.
+// With allocator_may_return_null=1 the allocator should return 0.
+// Set the limit to 20.5T on 64 bits to account for ASan shadow memory,
+// allocator buffers etc. so that the test allocation of ~1T will trigger OOM.
+// Limit this test to Linux since we're relying on allocator internal
+// limits (shadow memory size, allocation limits etc.)
+
+// RUN: %clangxx_asan -O0 %s -o %t
+// RUN: ulimit -v 22024290304
+// RUN: not %run %t malloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-MALLOC,CHECK-CRASH
+// RUN: %env_asan_opts=allocator_may_return_null=0 not %run %t malloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-MALLOC,CHECK-CRASH
+// RUN: %env_asan_opts=allocator_may_return_null=1 %run %t malloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-MALLOC,CHECK-NULL
+// RUN: %env_asan_opts=allocator_may_return_null=0 not %run %t calloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-CALLOC,CHECK-CRASH
+// RUN: %env_asan_opts=allocator_may_return_null=1 %run %t calloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-CALLOC,CHECK-NULL
+// RUN: %env_asan_opts=allocator_may_return_null=0 not %run %t realloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-REALLOC,CHECK-CRASH
+// RUN: %env_asan_opts=allocator_may_return_null=1 %run %t realloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-REALLOC,CHECK-NULL
+// RUN: %env_asan_opts=allocator_may_return_null=0 not %run %t realloc-after-malloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-MALLOC-REALLOC,CHECK-CRASH
+// RUN: %env_asan_opts=allocator_may_return_null=1 %run %t realloc-after-malloc 2>&1 \
+// RUN: | FileCheck %s --check-prefixes=CHECK-MALLOC-REALLOC,CHECK-NULL
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+
+int main(int argc, char **argv) {
+ assert(argc == 2);
+ const char *action = argv[1];
+ fprintf(stderr, "%s:\n", action);
+
+ // Allocate just a bit less than max allocation size enforced by ASan's
+ // allocator (currently 1T and 3G).
+ const size_t size =
+#if __LP64__
+ (1ULL << 40) - (1ULL << 30);
+#else
+ (3ULL << 30) - (1ULL << 20);
+#endif
+
+ void *x = 0;
+
+ if (!strcmp(action, "malloc")) {
+ x = malloc(size);
+ } else if (!strcmp(action, "calloc")) {
+ x = calloc(size / 4, 4);
+ } else if (!strcmp(action, "realloc")) {
+ x = realloc(0, size);
+ } else if (!strcmp(action, "realloc-after-malloc")) {
+ char *t = (char*)malloc(100);
+ *t = 42;
+ x = realloc(t, size);
+ assert(*t == 42);
+ free(t);
+ } else {
+ assert(0);
+ }
+
+ // The NULL pointer is printed differently on different systems, while (long)0
+ // is always the same.
+ fprintf(stderr, "x: %lx\n", (long)x);
+ free(x);
+
+ return x != 0;
+}
+
+// CHECK-MALLOC: malloc:
+// CHECK-CALLOC: calloc:
+// CHECK-REALLOC: realloc:
+// CHECK-MALLOC-REALLOC: realloc-after-malloc:
+
+// CHECK-CRASH: AddressSanitizer's allocator is terminating the process
+// CHECK-NULL: x: 0
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