[compiler-rt] 4220531 - [AArch64][compiler-rt] Strip PAC from the link register.
Daniel Kiss via llvm-commits
llvm-commits at lists.llvm.org
Thu Mar 18 14:04:36 PDT 2021
Author: Daniel Kiss
Date: 2021-03-18T22:01:50+01:00
New Revision: 4220531ceff0742851b8a2a5836400a7a521491d
URL: https://github.com/llvm/llvm-project/commit/4220531ceff0742851b8a2a5836400a7a521491d
DIFF: https://github.com/llvm/llvm-project/commit/4220531ceff0742851b8a2a5836400a7a521491d.diff
LOG: [AArch64][compiler-rt] Strip PAC from the link register.
-mbranch-protection protects the LR on the stack with PAC.
When the frames are walked the LR need to be cleared.
This inline assembly later will be replaced with a new builtin.
Test: build with -DCMAKE_C_FLAGS="-mbranch-protection=standard".
Reviewed By: kubamracek
Differential Revision: https://reviews.llvm.org/D98008
Added:
Modified:
compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h
compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
compiler-rt/lib/tsan/rtl/tsan_external.cpp
compiler-rt/lib/tsan/rtl/tsan_interface.cpp
compiler-rt/lib/tsan/rtl/tsan_interface_inl.h
Removed:
################################################################################
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h b/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h
index a288068bf943..520035469485 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h
@@ -11,6 +11,24 @@
#if __has_feature(ptrauth_calls)
#include <ptrauth.h>
+#elif defined(__ARM_FEATURE_PAC_DEFAULT) && !defined(__APPLE__)
+inline unsigned long ptrauth_strip(void* __value, unsigned int __key) {
+ // On the stack the link register is protected with Pointer
+ // Authentication Code when compiled with -mbranch-protection.
+ // Let's stripping the PAC unconditionally because xpaclri is in
+ // the NOP space so will do nothing when it is not enabled or not available.
+ unsigned long ret;
+ asm volatile(
+ "mov x30, %1\n\t"
+ "hint #7\n\t" // xpaclri
+ "mov %0, x30\n\t"
+ : "=r"(ret)
+ : "r"(__value)
+ : "x30");
+ return ret;
+}
+#define ptrauth_auth_data(__value, __old_key, __old_data) __value
+#define ptrauth_string_discriminator(__string) ((int)0)
#else
// Copied from <ptrauth.h>
#define ptrauth_strip(__value, __key) __value
@@ -18,6 +36,6 @@
#define ptrauth_string_discriminator(__string) ((int)0)
#endif
-#define STRIP_PC(pc) ((uptr)ptrauth_strip(pc, 0))
+#define STRIP_PAC_PC(pc) ((uptr)ptrauth_strip(pc, 0))
#endif // SANITIZER_PTRAUTH_H
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
index b0487d8987db..07e4409f4a5d 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
@@ -15,6 +15,7 @@
#include "sanitizer_common.h"
#include "sanitizer_flags.h"
#include "sanitizer_platform.h"
+#include "sanitizer_ptrauth.h"
namespace __sanitizer {
@@ -122,7 +123,7 @@ void BufferedStackTrace::UnwindFast(uptr pc, uptr bp, uptr stack_top,
// frame[-1] contains the return address
uhwptr pc1 = frame[-1];
#else
- uhwptr pc1 = frame[1];
+ uhwptr pc1 = STRIP_PAC_PC((void *)frame[1]);
#endif
// Let's assume that any pointer in the 0th page (i.e. <0x1000 on i386 and
// x86_64) is invalid and stop unwinding here. If we're adding support for
diff --git a/compiler-rt/lib/tsan/rtl/tsan_external.cpp b/compiler-rt/lib/tsan/rtl/tsan_external.cpp
index 466b2bf0f66c..a87e12f2936f 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_external.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_external.cpp
@@ -111,12 +111,12 @@ void __tsan_external_assign_tag(void *addr, void *tag) {
SANITIZER_INTERFACE_ATTRIBUTE
void __tsan_external_read(void *addr, void *caller_pc, void *tag) {
- ExternalAccess(addr, STRIP_PC(caller_pc), tag, MemoryRead);
+ ExternalAccess(addr, STRIP_PAC_PC(caller_pc), tag, MemoryRead);
}
SANITIZER_INTERFACE_ATTRIBUTE
void __tsan_external_write(void *addr, void *caller_pc, void *tag) {
- ExternalAccess(addr, STRIP_PC(caller_pc), tag, MemoryWrite);
+ ExternalAccess(addr, STRIP_PAC_PC(caller_pc), tag, MemoryWrite);
}
} // extern "C"
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interface.cpp b/compiler-rt/lib/tsan/rtl/tsan_interface.cpp
index 55f1c9834f70..9bd0e8580b17 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interface.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interface.cpp
@@ -40,13 +40,13 @@ void __tsan_write16(void *addr) {
}
void __tsan_read16_pc(void *addr, void *pc) {
- MemoryRead(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog8);
- MemoryRead(cur_thread(), STRIP_PC(pc), (uptr)addr + 8, kSizeLog8);
+ MemoryRead(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog8);
+ MemoryRead(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr + 8, kSizeLog8);
}
void __tsan_write16_pc(void *addr, void *pc) {
- MemoryWrite(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog8);
- MemoryWrite(cur_thread(), STRIP_PC(pc), (uptr)addr + 8, kSizeLog8);
+ MemoryWrite(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog8);
+ MemoryWrite(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr + 8, kSizeLog8);
}
// __tsan_unaligned_read/write calls are emitted by compiler.
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interface_inl.h b/compiler-rt/lib/tsan/rtl/tsan_interface_inl.h
index f5d743c10772..5e77d4d3d288 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interface_inl.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_interface_inl.h
@@ -51,35 +51,35 @@ void __tsan_write8(void *addr) {
}
void __tsan_read1_pc(void *addr, void *pc) {
- MemoryRead(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog1);
+ MemoryRead(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog1);
}
void __tsan_read2_pc(void *addr, void *pc) {
- MemoryRead(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog2);
+ MemoryRead(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog2);
}
void __tsan_read4_pc(void *addr, void *pc) {
- MemoryRead(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog4);
+ MemoryRead(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog4);
}
void __tsan_read8_pc(void *addr, void *pc) {
- MemoryRead(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog8);
+ MemoryRead(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog8);
}
void __tsan_write1_pc(void *addr, void *pc) {
- MemoryWrite(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog1);
+ MemoryWrite(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog1);
}
void __tsan_write2_pc(void *addr, void *pc) {
- MemoryWrite(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog2);
+ MemoryWrite(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog2);
}
void __tsan_write4_pc(void *addr, void *pc) {
- MemoryWrite(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog4);
+ MemoryWrite(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog4);
}
void __tsan_write8_pc(void *addr, void *pc) {
- MemoryWrite(cur_thread(), STRIP_PC(pc), (uptr)addr, kSizeLog8);
+ MemoryWrite(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, kSizeLog8);
}
void __tsan_vptr_update(void **vptr_p, void *new_val) {
@@ -101,7 +101,7 @@ void __tsan_vptr_read(void **vptr_p) {
}
void __tsan_func_entry(void *pc) {
- FuncEntry(cur_thread(), STRIP_PC(pc));
+ FuncEntry(cur_thread(), STRIP_PAC_PC(pc));
}
void __tsan_func_exit() {
@@ -125,9 +125,9 @@ void __tsan_write_range(void *addr, uptr size) {
}
void __tsan_read_range_pc(void *addr, uptr size, void *pc) {
- MemoryAccessRange(cur_thread(), STRIP_PC(pc), (uptr)addr, size, false);
+ MemoryAccessRange(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, size, false);
}
void __tsan_write_range_pc(void *addr, uptr size, void *pc) {
- MemoryAccessRange(cur_thread(), STRIP_PC(pc), (uptr)addr, size, true);
+ MemoryAccessRange(cur_thread(), STRIP_PAC_PC(pc), (uptr)addr, size, true);
}
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