From e23a7a99f4e4045bd184f718364f70b6fbec92e2 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 12 Aug 2016 10:53:07 +0200 Subject: [PATCH] re PR sanitizer/71042 (libtsan requires __pointer_chk_guard@GLIBC_PRIVATE (6)) PR sanitizer/71042 * tsan/tsan_platform_linux.cc: Cherry-pick upstream r278292. * tsan/tsan_rtl_aarch64.S: Likewise. From-SVN: r239407 --- libsanitizer/ChangeLog | 6 ++ libsanitizer/tsan/tsan_platform_linux.cc | 8 +++ libsanitizer/tsan/tsan_rtl_aarch64.S | 78 ++++++++++++++++++++---- 3 files changed, 80 insertions(+), 12 deletions(-) diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog index b53b51f2a87..d9eb7fa3bd2 100644 --- a/libsanitizer/ChangeLog +++ b/libsanitizer/ChangeLog @@ -1,3 +1,9 @@ +2016-08-12 Jakub Jelinek + + PR sanitizer/71042 + * tsan/tsan_platform_linux.cc: Cherry-pick upstream r278292. + * tsan/tsan_rtl_aarch64.S: Likewise. + 2016-07-23 Alan Modra Revert 2015-11-09 Alan Modra diff --git a/libsanitizer/tsan/tsan_platform_linux.cc b/libsanitizer/tsan/tsan_platform_linux.cc index a2e89f22da6..09cec5fdffd 100644 --- a/libsanitizer/tsan/tsan_platform_linux.cc +++ b/libsanitizer/tsan/tsan_platform_linux.cc @@ -60,6 +60,10 @@ extern "C" void *__libc_stack_end; void *__libc_stack_end = 0; #endif +#if SANITIZER_LINUX && defined(__aarch64__) +void InitializeGuardPtr() __attribute__((visibility("hidden"))); +#endif + namespace __tsan { static uptr g_data_start; @@ -261,6 +265,10 @@ void InitializePlatform() { SetAddressSpaceUnlimited(); reexec = true; } +#if SANITIZER_LINUX && defined(__aarch64__) + // Initialize the guard pointer used in {sig}{set,long}jump. + InitializeGuardPtr(); +#endif if (reexec) ReExec(); } diff --git a/libsanitizer/tsan/tsan_rtl_aarch64.S b/libsanitizer/tsan/tsan_rtl_aarch64.S index 20bf00827e9..ef06f0444ae 100644 --- a/libsanitizer/tsan/tsan_rtl_aarch64.S +++ b/libsanitizer/tsan/tsan_rtl_aarch64.S @@ -1,4 +1,62 @@ #include "sanitizer_common/sanitizer_asm.h" + +.section .bss +.type __tsan_pointer_chk_guard, %object +.size __tsan_pointer_chk_guard, 8 +__tsan_pointer_chk_guard: +.zero 8 + +.section .text + +// GLIBC mangles the function pointers in jmp_buf (used in {set,long}*jmp +// functions) by XORing them with a random guard pointer. For AArch64 it is a +// global variable rather than a TCB one (as for x86_64/powerpc) and althought +// its value is exported by the loader, it lies within a private GLIBC +// namespace (meaning it should be only used by GLIBC itself and the ABI is +// not stable). So InitializeGuardPtr obtains the pointer guard value by +// issuing a setjmp and checking the resulting pointers values against the +// original ones. +.hidden _Z18InitializeGuardPtrv +.global _Z18InitializeGuardPtrv +.type _Z18InitializeGuardPtrv, @function +_Z18InitializeGuardPtrv: + CFI_STARTPROC + // Allocates a jmp_buf for the setjmp call. + stp x29, x30, [sp, -336]! + CFI_DEF_CFA_OFFSET (336) + CFI_OFFSET (29, -336) + CFI_OFFSET (30, -328) + add x29, sp, 0 + CFI_DEF_CFA_REGISTER (29) + add x0, x29, 24 + + // Call libc setjmp that mangle the stack pointer value + adrp x1, :got:_ZN14__interception12real__setjmpE + ldr x1, [x1, #:got_lo12:_ZN14__interception12real__setjmpE] + ldr x1, [x1] + blr x1 + + // glibc setjmp mangles both the frame pointer (FP, pc+4 on blr) and the + // stack pointer (SP). FP will be placed on ((uintptr*)jmp_buf)[11] and + // SP at ((uintptr*)jmp_buf)[13]. + // The mangle operation is just 'value' xor 'pointer guard value' and + // if we know the original value (SP) and the expected one, we can derive + // the guard pointer value. + mov x0, sp + + // Loads the mangled SP pointer. + ldr x1, [x29, 128] + eor x0, x0, x1 + adrp x2, __tsan_pointer_chk_guard + str x0, [x2, #:lo12:__tsan_pointer_chk_guard] + ldp x29, x30, [sp], 336 + CFI_RESTORE (30) + CFI_RESTORE (19) + CFI_DEF_CFA (31, 0) + ret + CFI_ENDPROC +.size _Z18InitializeGuardPtrv, .-_Z18InitializeGuardPtrv + .hidden __tsan_setjmp .comm _ZN14__interception11real_setjmpE,8,8 .type setjmp, @function @@ -21,10 +79,9 @@ setjmp: mov x19, x0 // SP pointer mangling (see glibc setjmp) - adrp x2, :got:__pointer_chk_guard - ldr x2, [x2, #:got_lo12:__pointer_chk_guard] + adrp x2, __tsan_pointer_chk_guard + ldr x2, [x2, #:lo12:__tsan_pointer_chk_guard] add x0, x29, 32 - ldr x2, [x2] eor x1, x2, x0 // call tsan interceptor @@ -69,10 +126,9 @@ _setjmp: mov x19, x0 // SP pointer mangling (see glibc setjmp) - adrp x2, :got:__pointer_chk_guard - ldr x2, [x2, #:got_lo12:__pointer_chk_guard] + adrp x2, __tsan_pointer_chk_guard + ldr x2, [x2, #:lo12:__tsan_pointer_chk_guard] add x0, x29, 32 - ldr x2, [x2] eor x1, x2, x0 // call tsan interceptor @@ -119,10 +175,9 @@ sigsetjmp: mov x19, x0 // SP pointer mangling (see glibc setjmp) - adrp x2, :got:__pointer_chk_guard - ldr x2, [x2, #:got_lo12:__pointer_chk_guard] + adrp x2, __tsan_pointer_chk_guard + ldr x2, [x2, #:lo12:__tsan_pointer_chk_guard] add x0, x29, 32 - ldr x2, [x2] eor x1, x2, x0 // call tsan interceptor @@ -171,10 +226,9 @@ __sigsetjmp: mov x19, x0 // SP pointer mangling (see glibc setjmp) - adrp x2, :got:__pointer_chk_guard - ldr x2, [x2, #:got_lo12:__pointer_chk_guard] + adrp x2, __tsan_pointer_chk_guard + ldr x2, [x2, #:lo12:__tsan_pointer_chk_guard] add x0, x29, 32 - ldr x2, [x2] eor x1, x2, x0 // call tsan interceptor -- 2.30.2