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[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
This commit is contained in:
Daniel Kiss 2021-03-15 10:24:44 +01:00
parent c1940aac99
commit 4220531cef
5 changed files with 38 additions and 19 deletions
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20
compiler-rt/lib/sanitizer_common/sanitizer_ptrauth.h
View File

@ -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

3
compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
View File

@ -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

4
compiler-rt/lib/tsan/rtl/tsan_external.cpp
View File

@ -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"

8
compiler-rt/lib/tsan/rtl/tsan_interface.cpp
View File

@ -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.

22
compiler-rt/lib/tsan/rtl/tsan_interface_inl.h
View File

@ -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);
}