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| author | Fangrui Song <i@maskray.me> | 2023-12-18 13:48:46 -0800 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-12-18 13:48:46 -0800 |
| commit | b9935bb02a506e9142ae79b6c58303cb2e1ffb08 (patch) | |
| tree | 7f160ee3bc1e00b063d148485a8982b623761bc2 | |
| parent | 5ccad1b9c39744dbef7a4d476c69b07e51117a15 (diff) | |
| download | llvm-b9935bb02a506e9142ae79b6c58303cb2e1ffb08.zip llvm-b9935bb02a506e9142ae79b6c58303cb2e1ffb08.tar.gz llvm-b9935bb02a506e9142ae79b6c58303cb2e1ffb08.tar.bz2 | |
asan_static x86-64: Support 64-bit ASAN_SHADOW_OFFSET_CONST (#75748)
Fix #57086: when ASAN_SHADOW_OFFSET_CONST >= 0x80000000 (FreeBSD,
NetBSD, etc), `movsbl ASAN_SHADOW_OFFSET_CONST(%r10),%r10d` has an
invalid displacement (not representable as a signed 32-bit integer),
which will be diagnosed by GNU assembler.
```
% cat a.s
movsbl 0x80000000(%r10),%r10d
% as a.s
a.s: Assembler messages:
a.s:1: Error: 0x80000000 out of range of signed 32bit displacement
% clang -c a.s
```
The integrated assembler after #75747 will diagnose the invalid
displacement as well.
```
% clang -c a.s
a.s:1:19: error: displacement 2147483648 is not within [-2147483648, 2147483647]
movsbl 0x80000000(%r10),%r10d
^
```
If ASAN_SHADOW_OFFSET_CONST cannot be encoded as a displacement, switch
to `movabsq+movsbl`.
| -rw-r--r-- | compiler-rt/lib/asan/asan_rtl_x86_64.S | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler-rt/lib/asan/asan_rtl_x86_64.S b/compiler-rt/lib/asan/asan_rtl_x86_64.S index 0b73630..e44587a 100644 --- a/compiler-rt/lib/asan/asan_rtl_x86_64.S +++ b/compiler-rt/lib/asan/asan_rtl_x86_64.S @@ -27,7 +27,12 @@ FNAME(reg, op, s, i): ;\ #define ASAN_MEMORY_ACCESS_INITIAL_CHECK_ADD(reg, op, s) \ mov %##reg,%r10 ;\ shr $0x3,%r10 ;\ + .if ASAN_SHADOW_OFFSET_CONST < 0x80000000 ;\ movsbl ASAN_SHADOW_OFFSET_CONST(%r10),%r10d ;\ + .else ;\ + movabsq $ASAN_SHADOW_OFFSET_CONST,%r11 ;\ + movsbl (%r10,%r11),%r10d ;\ + .endif ;\ test %r10d,%r10d ;\ jne CLABEL(reg, op, s, add) ;\ RLABEL(reg, op, s, add): ;\ |