[compiler-rt] [compiler-rt][rtsan] Use sanitizer internal allocator during rtsan init to avoid segfault in dlsym (PR #98679)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 12 11:55:56 PDT 2024
https://github.com/davidtrevelyan created https://github.com/llvm/llvm-project/pull/98679
Follows https://github.com/llvm/llvm-project/pull/98268 with a fix for a segfault during preinit on `ubuntu:20.04` environments. Previously, `rtsan` was not handling the situation where `dlsym` calls `calloc` during the interceptors initialization, resulting in a call to a function at a null address.
@cjappl and I took inspiration from the solution in `nsan`, but we re-used the sanitizer internal allocator instead of our own static buffer. This PR also re-enables the existing non-instrumented `rtsan` tests for `x86_64` and `arm64` architectures.
>From 3e2be4933fb68b12ca1895c08adb75c10c09ef92 Mon Sep 17 00:00:00 2001
From: Chris Apple <cja-private at pm.me>
Date: Fri, 12 Jul 2024 10:06:55 +0200
Subject: [PATCH 1/4] Init check
---
compiler-rt/lib/rtsan/rtsan.cpp | 16 ++++++++-
compiler-rt/lib/rtsan/rtsan.h | 8 +++++
compiler-rt/lib/rtsan/rtsan_interceptors.cpp | 37 ++++++++++++++++++++
3 files changed, 60 insertions(+), 1 deletion(-)
diff --git a/compiler-rt/lib/rtsan/rtsan.cpp b/compiler-rt/lib/rtsan/rtsan.cpp
index 43a63b4636f1e..fae4de12f344d 100644
--- a/compiler-rt/lib/rtsan/rtsan.cpp
+++ b/compiler-rt/lib/rtsan/rtsan.cpp
@@ -12,10 +12,24 @@
#include <rtsan/rtsan_context.h>
#include <rtsan/rtsan_interceptors.h>
+using namespace __rtsan;
+
+bool __rtsan::rtsan_initialized;
+bool __rtsan::rtsan_init_is_running;
+
+
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE void __rtsan_init() {
- __rtsan::InitializeInterceptors();
+ CHECK(!rtsan_init_is_running);
+ if (rtsan_initialized)
+ return;
+ rtsan_init_is_running = true;
+
+ InitializeInterceptors();
+
+ rtsan_init_is_running = false;
+ rtsan_initialized = true;
}
SANITIZER_INTERFACE_ATTRIBUTE void __rtsan_realtime_enter() {
diff --git a/compiler-rt/lib/rtsan/rtsan.h b/compiler-rt/lib/rtsan/rtsan.h
index 8b1219c13cbd3..c2f8c3a917fa4 100644
--- a/compiler-rt/lib/rtsan/rtsan.h
+++ b/compiler-rt/lib/rtsan/rtsan.h
@@ -14,6 +14,14 @@
extern "C" {
+namespace __rtsan {
+
+extern bool rtsan_initialized;
+extern bool rtsan_init_is_running;
+
+} // namespace __rtsan
+
+
// Initialise rtsan interceptors.
// A call to this method is added to the preinit array on Linux systems.
SANITIZER_INTERFACE_ATTRIBUTE void __rtsan_init();
diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
index 3a65f9d3f779d..671f7ec8b9f2d 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
@@ -14,6 +14,7 @@
#include "sanitizer_common/sanitizer_platform_interceptors.h"
#include "interception/interception.h"
+#include "rtsan/rtsan.h"
#include "rtsan/rtsan_context.h"
#if SANITIZER_APPLE
@@ -35,6 +36,30 @@
using namespace __sanitizer;
+using __rtsan::rtsan_init_is_running;
+using __rtsan::rtsan_initialized;
+
+constexpr uptr kEarlyAllocBufSize = 16384;
+static uptr allocated_bytes;
+static char early_alloc_buf[kEarlyAllocBufSize];
+
+static bool IsInEarlyAllocBuf(const void *ptr) {
+ return ((uptr)ptr >= (uptr)early_alloc_buf &&
+ ((uptr)ptr - (uptr)early_alloc_buf) < sizeof(early_alloc_buf));
+}
+
+template <typename T> T min(T a, T b) { return a < b ? a : b; }
+
+// Handle allocation requests early (before all interceptors are setup). dlsym,
+// for example, calls calloc.
+static void *HandleEarlyAlloc(uptr size) {
+ void *Mem = (void *)&early_alloc_buf[allocated_bytes];
+ allocated_bytes += size;
+ CHECK_LT(allocated_bytes, kEarlyAllocBufSize);
+ return Mem;
+}
+
+
void ExpectNotRealtime(const char *intercepted_function_name) {
__rtsan::GetContextForThisThread().ExpectNotRealtime(
intercepted_function_name);
@@ -238,11 +263,19 @@ INTERCEPTOR(int, nanosleep, const struct timespec *rqtp,
// Memory
INTERCEPTOR(void *, calloc, SIZE_T num, SIZE_T size) {
+ if (rtsan_init_is_running && REAL(calloc) == nullptr) {
+ // Note: EarlyAllocBuf is initialized with zeros.
+ return HandleEarlyAlloc(num * size);
+ }
+
ExpectNotRealtime("calloc");
return REAL(calloc)(num, size);
}
INTERCEPTOR(void, free, void *ptr) {
+ if (IsInEarlyAllocBuf(ptr))
+ return;
+
if (ptr != NULL) {
ExpectNotRealtime("free");
}
@@ -250,6 +283,10 @@ INTERCEPTOR(void, free, void *ptr) {
}
INTERCEPTOR(void *, malloc, SIZE_T size) {
+ if (rtsan_init_is_running && REAL(malloc) == nullptr) {
+ return HandleEarlyAlloc(size);
+ }
+
ExpectNotRealtime("malloc");
return REAL(malloc)(size);
}
>From b07a4350c61c3d5f6d3a838649854ca38bfa69cd Mon Sep 17 00:00:00 2001
From: Chris Apple <cja-private at pm.me>
Date: Fri, 12 Jul 2024 10:37:36 +0200
Subject: [PATCH 2/4] Clang tidy run
---
compiler-rt/lib/rtsan/rtsan.cpp | 1 -
compiler-rt/lib/rtsan/rtsan.h | 1 -
compiler-rt/lib/rtsan/rtsan_interceptors.cpp | 1 -
3 files changed, 3 deletions(-)
diff --git a/compiler-rt/lib/rtsan/rtsan.cpp b/compiler-rt/lib/rtsan/rtsan.cpp
index fae4de12f344d..cf7fbddd9eb9c 100644
--- a/compiler-rt/lib/rtsan/rtsan.cpp
+++ b/compiler-rt/lib/rtsan/rtsan.cpp
@@ -17,7 +17,6 @@ using namespace __rtsan;
bool __rtsan::rtsan_initialized;
bool __rtsan::rtsan_init_is_running;
-
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE void __rtsan_init() {
diff --git a/compiler-rt/lib/rtsan/rtsan.h b/compiler-rt/lib/rtsan/rtsan.h
index c2f8c3a917fa4..ccddaf2c893ef 100644
--- a/compiler-rt/lib/rtsan/rtsan.h
+++ b/compiler-rt/lib/rtsan/rtsan.h
@@ -21,7 +21,6 @@ extern bool rtsan_init_is_running;
} // namespace __rtsan
-
// Initialise rtsan interceptors.
// A call to this method is added to the preinit array on Linux systems.
SANITIZER_INTERFACE_ATTRIBUTE void __rtsan_init();
diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
index 671f7ec8b9f2d..800cac189db11 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
@@ -59,7 +59,6 @@ static void *HandleEarlyAlloc(uptr size) {
return Mem;
}
-
void ExpectNotRealtime(const char *intercepted_function_name) {
__rtsan::GetContextForThisThread().ExpectNotRealtime(
intercepted_function_name);
>From cdffa129cba3083df5cd6a20328767dfd10ef14b Mon Sep 17 00:00:00 2001
From: David Trevelyan <david.trevelyan at gmail.com>
Date: Fri, 12 Jul 2024 13:18:42 +0100
Subject: [PATCH 3/4] Use sanitizer internal allocator during rtsan init
---
compiler-rt/lib/rtsan/rtsan_interceptors.cpp | 39 +++++---------------
1 file changed, 10 insertions(+), 29 deletions(-)
diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
index 800cac189db11..f7e75b15ca33e 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors.cpp
@@ -10,6 +10,7 @@
#include "rtsan/rtsan_interceptors.h"
+#include "sanitizer_common/sanitizer_allocator_internal.h"
#include "sanitizer_common/sanitizer_platform.h"
#include "sanitizer_common/sanitizer_platform_interceptors.h"
@@ -39,26 +40,6 @@ using namespace __sanitizer;
using __rtsan::rtsan_init_is_running;
using __rtsan::rtsan_initialized;
-constexpr uptr kEarlyAllocBufSize = 16384;
-static uptr allocated_bytes;
-static char early_alloc_buf[kEarlyAllocBufSize];
-
-static bool IsInEarlyAllocBuf(const void *ptr) {
- return ((uptr)ptr >= (uptr)early_alloc_buf &&
- ((uptr)ptr - (uptr)early_alloc_buf) < sizeof(early_alloc_buf));
-}
-
-template <typename T> T min(T a, T b) { return a < b ? a : b; }
-
-// Handle allocation requests early (before all interceptors are setup). dlsym,
-// for example, calls calloc.
-static void *HandleEarlyAlloc(uptr size) {
- void *Mem = (void *)&early_alloc_buf[allocated_bytes];
- allocated_bytes += size;
- CHECK_LT(allocated_bytes, kEarlyAllocBufSize);
- return Mem;
-}
-
void ExpectNotRealtime(const char *intercepted_function_name) {
__rtsan::GetContextForThisThread().ExpectNotRealtime(
intercepted_function_name);
@@ -262,18 +243,16 @@ INTERCEPTOR(int, nanosleep, const struct timespec *rqtp,
// Memory
INTERCEPTOR(void *, calloc, SIZE_T num, SIZE_T size) {
- if (rtsan_init_is_running && REAL(calloc) == nullptr) {
- // Note: EarlyAllocBuf is initialized with zeros.
- return HandleEarlyAlloc(num * size);
- }
+ if (rtsan_init_is_running && REAL(calloc) == nullptr)
+ return __sanitizer::InternalCalloc(num, size);
ExpectNotRealtime("calloc");
return REAL(calloc)(num, size);
}
INTERCEPTOR(void, free, void *ptr) {
- if (IsInEarlyAllocBuf(ptr))
- return;
+ if (__sanitizer::internal_allocator()->PointerIsMine(ptr))
+ return __sanitizer::InternalFree(ptr);
if (ptr != NULL) {
ExpectNotRealtime("free");
@@ -282,15 +261,17 @@ INTERCEPTOR(void, free, void *ptr) {
}
INTERCEPTOR(void *, malloc, SIZE_T size) {
- if (rtsan_init_is_running && REAL(malloc) == nullptr) {
- return HandleEarlyAlloc(size);
- }
+ if (rtsan_init_is_running && REAL(malloc) == nullptr)
+ return __sanitizer::InternalAlloc(size);
ExpectNotRealtime("malloc");
return REAL(malloc)(size);
}
INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
+ if (rtsan_init_is_running && REAL(realloc) == nullptr)
+ return __sanitizer::InternalRealloc(ptr, size);
+
ExpectNotRealtime("realloc");
return REAL(realloc)(ptr, size);
}
>From a61fff6e2ebf6581f528e523b7c278546c631857 Mon Sep 17 00:00:00 2001
From: David Trevelyan <david.trevelyan at gmail.com>
Date: Fri, 12 Jul 2024 19:24:11 +0100
Subject: [PATCH 4/4] Re-enable rtsan tests
---
compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake b/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
index c8bec41db36e9..647f67b66af85 100644
--- a/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
+++ b/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
@@ -32,9 +32,7 @@ set(ALL_ASAN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${RISCV64}
${LOONGARCH64})
set(ALL_ASAN_ABI_SUPPORTED_ARCH ${X86_64} ${ARM64} ${ARM64_32})
set(ALL_DFSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64} ${LOONGARCH64})
-#set(ALL_RTSAN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${RISCV64}
-# ${MIPS32} ${MIPS64} ${PPC64} ${S390X} ${SPARC} ${SPARCV9} ${HEXAGON}
-# ${LOONGARCH64})
+set(ALL_RTSAN_SUPPORTED_ARCH ${X86_64} ${ARM64})
if(ANDROID)
set(OS_NAME "Android")
More information about the llvm-commits
mailing list