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author | Julian Lettner <jlettner@apple.com> | 2019-07-15 20:22:27 +0000 |
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committer | Julian Lettner <jlettner@apple.com> | 2019-07-15 20:22:27 +0000 |
commit | 86475d75a5f3f6c0664c02dadd5d8d21e49e0764 (patch) | |
tree | fa61f5531ca4a00bae4b473b927fab7891289c0d | |
parent | a1e6f4e36818256f13b968d90555789378da081f (diff) | |
download | compiler-rt-86475d75a5f3f6c0664c02dadd5d8d21e49e0764.tar.gz |
[TSan] Improve handling of stack pointer mangling in {set,long}jmp, pt.9
Switch over to computing the xor key in C, instead of assembly for
Linux/AArch64.
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@366126 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/tsan/rtl/tsan_platform_linux.cc | 27 |
1 files changed, 5 insertions, 22 deletions
diff --git a/lib/tsan/rtl/tsan_platform_linux.cc b/lib/tsan/rtl/tsan_platform_linux.cc index 0f23da0e8..db85d547b 100644 --- a/lib/tsan/rtl/tsan_platform_linux.cc +++ b/lib/tsan/rtl/tsan_platform_linux.cc @@ -302,26 +302,8 @@ void InitializePlatform() { CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1); reexec = true; } - // Initialize the guard pointer used in {sig}{set,long}jump. - longjmp_xor_key = InitializeGuardPtr(); - // uptr old_value = longjmp_xor_key; - // InitializeLongjmpXorKey(); - // CHECK_EQ(longjmp_xor_key, old_value); - // If the above check fails for you, please contact me (jlettner@apple.com) - // and let me know the values of the two differing keys. Please also set a - // breakpoint on `InitializeGuardPtr` and `InitializeLongjmpXorKey` and tell - // me the stack pointer (SP) values that go into the XOR operation (where we - // derive the key): - // - // InitializeLongjmpXorKey: - // uptr sp = (uptr)__builtin_frame_address(0); - // - // InitializeGuardPtr (in tsan_rtl_aarch64.S): - // mov x0, sp - // ... - // eor x0, x0, x1 - // - // Then feel free to comment out the call to `InitializeLongjmpXorKey`. + // Initialize the xor key used in {sig}{set,long}jump. + InitializeLongjmpXorKey(); #endif if (reexec) ReExec(); @@ -437,9 +419,10 @@ static void InitializeLongjmpXorKey() { jmp_buf env; REAL(_setjmp)(env); - // 2. Retrieve mangled/vanilla SP. + // 2. Retrieve vanilla/mangled SP. + uptr sp; + asm("mov %0, %%sp" : "=r" (sp)); uptr mangled_sp = ((uptr *)&env)[LONG_JMP_SP_ENV_SLOT]; - uptr sp = (uptr)__builtin_frame_address(0); // 3. xor SPs to obtain key. longjmp_xor_key = mangled_sp ^ sp; |