[compiler-rt] r264644 - [asan] Add runtime support for __asan_(un)register_image_globals
Ryan Govostes via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 28 13:28:18 PDT 2016
Author: rgov
Date: Mon Mar 28 15:28:17 2016
New Revision: 264644
URL: http://llvm.org/viewvc/llvm-project?rev=264644&view=rev
Log:
[asan] Add runtime support for __asan_(un)register_image_globals
This change introduces routines that register and unregister all
instrumented globals in a loaded executable image.
These routines are only implemented on Darwin, where globals metadata
is expected to be placed in the __DATA,__asan_globals section.
Review: http://reviews.llvm.org/D16841
Added:
compiler-rt/trunk/test/asan/TestCases/Darwin/dead-strip.c
Modified:
compiler-rt/trunk/lib/asan/asan_globals.cc
compiler-rt/trunk/lib/asan/asan_init_version.h
compiler-rt/trunk/lib/asan/asan_interface_internal.h
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_win.cc
compiler-rt/trunk/test/asan/TestCases/initialization-bug.cc
Modified: compiler-rt/trunk/lib/asan/asan_globals.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_globals.cc?rev=264644&r1=264643&r2=264644&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_globals.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_globals.cc Mon Mar 28 15:28:17 2016
@@ -284,6 +284,25 @@ void StopInitOrderChecking() {
// ---------------------- Interface ---------------- {{{1
using namespace __asan; // NOLINT
+
+// Apply __asan_register_globals to all globals found in the same loaded
+// executable or shared library as `flag'. The flag tracks whether globals have
+// already been registered or not for this image.
+void __asan_register_image_globals(uptr *flag) {
+ if (*flag)
+ return;
+ AsanApplyToGlobals(__asan_register_globals, flag);
+ *flag = 1;
+}
+
+// This mirrors __asan_register_image_globals.
+void __asan_unregister_image_globals(uptr *flag) {
+ if (!*flag)
+ return;
+ AsanApplyToGlobals(__asan_unregister_globals, flag);
+ *flag = 0;
+}
+
// Register an array of globals.
void __asan_register_globals(__asan_global *globals, uptr n) {
if (!flags()->report_globals) return;
Modified: compiler-rt/trunk/lib/asan/asan_init_version.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_init_version.h?rev=264644&r1=264643&r2=264644&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_init_version.h (original)
+++ compiler-rt/trunk/lib/asan/asan_init_version.h Mon Mar 28 15:28:17 2016
@@ -19,17 +19,20 @@ extern "C" {
// Every time the ASan ABI changes we also change the version number in the
// __asan_init function name. Objects built with incompatible ASan ABI
// versions will not link with run-time.
+ //
// Changes between ABI versions:
// v1=>v2: added 'module_name' to __asan_global
// v2=>v3: stack frame description (created by the compiler)
- // contains the function PC as the 3-rd field (see
- // DescribeAddressIfStack).
- // v3=>v4: added '__asan_global_source_location' to __asan_global.
+ // contains the function PC as the 3rd field (see
+ // DescribeAddressIfStack)
+ // v3=>v4: added '__asan_global_source_location' to __asan_global
// v4=>v5: changed the semantics and format of __asan_stack_malloc_ and
- // __asan_stack_free_ functions.
+ // __asan_stack_free_ functions
// v5=>v6: changed the name of the version check symbol
- // v6=>v7: added 'odr_indicator' to __asan_global.
- #define __asan_version_mismatch_check __asan_version_mismatch_check_v7
+ // v6=>v7: added 'odr_indicator' to __asan_global
+ // v7=>v8: added '__asan_(un)register_image_globals' functions for dead
+ // stripping support on Mach-O platforms
+ #define __asan_version_mismatch_check __asan_version_mismatch_check_v8
}
#endif // ASAN_INIT_VERSION_H
Modified: compiler-rt/trunk/lib/asan/asan_interface_internal.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_interface_internal.h?rev=264644&r1=264643&r2=264644&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_interface_internal.h (original)
+++ compiler-rt/trunk/lib/asan/asan_interface_internal.h Mon Mar 28 15:28:17 2016
@@ -57,6 +57,14 @@ extern "C" {
uptr odr_indicator; // The address of the ODR indicator symbol.
};
+ // These functions can be called on some platforms to find globals in the same
+ // loaded image as `flag' and apply __asan_(un)register_globals to them,
+ // filtering out redundant calls.
+ SANITIZER_INTERFACE_ATTRIBUTE
+ void __asan_register_image_globals(uptr *flag);
+ SANITIZER_INTERFACE_ATTRIBUTE
+ void __asan_unregister_image_globals(uptr *flag);
+
// These two functions should be called by the instrumented code.
// 'globals' is an array of structures describing 'n' globals.
SANITIZER_INTERFACE_ATTRIBUTE
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=264644&r1=264643&r2=264644&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_internal.h (original)
+++ compiler-rt/trunk/lib/asan/asan_internal.h Mon Mar 28 15:28:17 2016
@@ -73,6 +73,13 @@ void *AsanDoesNotSupportStaticLinkage();
void AsanCheckDynamicRTPrereqs();
void AsanCheckIncompatibleRT();
+// Support function for __asan_(un)register_image_globals. Searches for the
+// loaded image containing `needle' and then enumerates all global metadata
+// structures declared in that image, applying `op' (e.g.,
+// __asan_(un)register_globals) to them.
+typedef void (*globals_op_fptr)(__asan_global *, uptr);
+void AsanApplyToGlobals(globals_op_fptr op, const void *needle);
+
void AsanOnDeadlySignal(int, void *siginfo, void *context);
void ReadContextStack(void *context, uptr *stack, uptr *ssize);
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=264644&r1=264643&r2=264644&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_linux.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_linux.cc Mon Mar 28 15:28:17 2016
@@ -75,6 +75,10 @@ void *AsanDoesNotSupportStaticLinkage()
return &_DYNAMIC; // defined in link.h
}
+void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
+ UNIMPLEMENTED();
+}
+
#if SANITIZER_ANDROID
// FIXME: should we do anything for Android?
void AsanCheckDynamicRTPrereqs() {}
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=264644&r1=264643&r2=264644&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_mac.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_mac.cc Mon Mar 28 15:28:17 2016
@@ -24,9 +24,11 @@
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_mac.h"
+#include <dlfcn.h>
#include <fcntl.h>
#include <libkern/OSAtomic.h>
#include <mach-o/dyld.h>
+#include <mach-o/getsect.h>
#include <mach-o/loader.h>
#include <pthread.h>
#include <stdlib.h> // for free()
@@ -66,6 +68,30 @@ void AsanCheckDynamicRTPrereqs() {}
// No-op. Mac does not support static linkage anyway.
void AsanCheckIncompatibleRT() {}
+void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
+ // Find the Mach-O header for the image containing the needle
+ Dl_info info;
+ int err = dladdr(needle, &info);
+ if (err == 0) return;
+
+#if __LP64__
+ const struct mach_header_64 *mh = (struct mach_header_64 *)info.dli_fbase;
+#else
+ const struct mach_header *mh = (struct mach_header *)info.dli_fbase;
+#endif
+
+ // Look up the __asan_globals section in that image and register its globals
+ unsigned long size = 0;
+ __asan_global *globals = (__asan_global *)getsectiondata(
+ mh,
+ "__DATA", "__asan_globals",
+ &size);
+
+ if (!globals) return;
+ if (size % sizeof(__asan_global) != 0) return;
+ op(globals, size / sizeof(__asan_global));
+}
+
void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
UNIMPLEMENTED();
}
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=264644&r1=264643&r2=264644&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_win.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_win.cc Mon Mar 28 15:28:17 2016
@@ -149,6 +149,10 @@ void InitializePlatformInterceptors() {
(uptr *)&REAL(NtWaitForWorkViaWorkerFactory)));
}
+void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
+ UNIMPLEMENTED();
+}
+
// ---------------------- TSD ---------------- {{{
static bool tsd_key_inited = false;
Added: compiler-rt/trunk/test/asan/TestCases/Darwin/dead-strip.c
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Darwin/dead-strip.c?rev=264644&view=auto
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/Darwin/dead-strip.c (added)
+++ compiler-rt/trunk/test/asan/TestCases/Darwin/dead-strip.c Mon Mar 28 15:28:17 2016
@@ -0,0 +1,21 @@
+// Test that AddressSanitizer does not re-animate dead globals when dead
+// stripping is turned on.
+//
+// This test verifies that an out-of-bounds access on a global variable is
+// detected after dead stripping has been performed. This proves that the
+// runtime is able to register globals in the __DATA,__asan_globals section.
+
+// RUN: %clang_asan -Xlinker -dead_strip -o %t %s
+// RUN: llvm-nm -format=posix %t | FileCheck --check-prefix NM-CHECK %s
+// RUN: not %run %t 2>&1 | FileCheck --check-prefix ASAN-CHECK %s
+
+int alive[1] = {};
+int dead[1] = {};
+// NM-CHECK: {{^_alive }}
+// NM-CHECK-NOT: {{^_dead }}
+
+int main(int argc, char *argv[]) {
+ alive[argc] = 0;
+ // ASAN-CHECK: {{0x.* is located 0 bytes to the right of global variable}}
+ return 0;
+}
Modified: compiler-rt/trunk/test/asan/TestCases/initialization-bug.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/initialization-bug.cc?rev=264644&r1=264643&r2=264644&view=diff
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/initialization-bug.cc (original)
+++ compiler-rt/trunk/test/asan/TestCases/initialization-bug.cc Mon Mar 28 15:28:17 2016
@@ -6,7 +6,7 @@
// Do not test with optimization -- the error may be optimized away.
// FIXME: https://code.google.com/p/address-sanitizer/issues/detail?id=186
-// XFAIL: darwin,win32
+// XFAIL: win32
#include <cstdio>
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