Backported from LLVM git id 67474c60d libsanitizer/ChangeLog:
2019-11-05 Matthew Malcomson <matthew.malcom...@arm.com> * hwasan/hwasan.h (__hw_jmp_buf_struct, __hw_jmp_buf, __hw_sigjmp_buf): Define new types for internal longjmp implementation. * hwasan/hwasan_interceptors.cpp (__sigjmp_save, InternalLongjmp, siglongjmp, longjmp, __libc_longjmp): New. * hwasan/hwasan_setjmp.S: New file. * hwasan/hwasan_type_test.cpp: New file. ############### Attachment also inlined for ease of reply ############### diff --git a/libsanitizer/hwasan/hwasan.h b/libsanitizer/hwasan/hwasan.h index 9e0ced93b55d361cd5aae787db7562741683944c..64cdcf30f5c7059dcc1916f72e14b6649ca701f5 100644 --- a/libsanitizer/hwasan/hwasan.h +++ b/libsanitizer/hwasan/hwasan.h @@ -172,4 +172,24 @@ void AndroidTestTlsSlot(); RunFreeHooks(ptr); \ } while (false) +#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__) +// For both bionic and glibc __sigset_t is an unsigned long. +typedef unsigned long __hw_sigset_t; +// Setjmp and longjmp implementations are platform specific, and hence the +// interception code is platform specific too. As yet we've only implemented +// the interception for AArch64. +typedef unsigned long long __hw_register_buf[22]; +struct __hw_jmp_buf_struct { + // NOTE: The machine-dependent definition of `__sigsetjmp' + // assume that a `__hw_jmp_buf' begins with a `__hw_register_buf' and that + // `__mask_was_saved' follows it. Do not move these members or add others + // before it. + __hw_register_buf __jmpbuf; // Calling environment. + int __mask_was_saved; // Saved the signal mask? + __hw_sigset_t __saved_mask; // Saved signal mask. +}; +typedef struct __hw_jmp_buf_struct __hw_jmp_buf[1]; +typedef struct __hw_jmp_buf_struct __hw_sigjmp_buf[1]; +#endif // HWASAN_WITH_INTERCEPTORS && __aarch64__ + #endif // HWASAN_H diff --git a/libsanitizer/hwasan/hwasan_interceptors.cpp b/libsanitizer/hwasan/hwasan_interceptors.cpp index 47fed0fc9abb821996efcd8d12f7e5442916326d..f6758efa65c051376468d3cad2c1530fa7329627 100644 --- a/libsanitizer/hwasan/hwasan_interceptors.cpp +++ b/libsanitizer/hwasan/hwasan_interceptors.cpp @@ -220,6 +220,80 @@ DEFINE_REAL(int, vfork) DECLARE_EXTERN_INTERCEPTOR_AND_WRAPPER(int, vfork) #endif +#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__) +// Get and/or change the set of blocked signals. +extern "C" int sigprocmask(int __how, const __hw_sigset_t *__restrict __set, + __hw_sigset_t *__restrict __oset); +#define SIG_BLOCK 0 +#define SIG_SETMASK 2 +extern "C" int __sigjmp_save(__hw_sigjmp_buf env, int savemask) { + env[0].__mask_was_saved = + (savemask && sigprocmask(SIG_BLOCK, (__hw_sigset_t *)0, + &env[0].__saved_mask) == 0); + return 0; +} + +static void __attribute__((always_inline)) +InternalLongjmp(__hw_register_buf env, int retval) { + // Clear all memory tags on the stack between here and where we're going. + unsigned long long stack_pointer = env[13]; + // The stack pointer should never be tagged, so we don't need to clear the + // tag for this function call. + __hwasan_handle_longjmp((void *)stack_pointer); + + // Run code for handling a longjmp. + // Need to use a register that isn't going to be loaded from the environment + // buffer -- hence why we need to specify the register to use. + // Must implement this ourselves, since we don't know the order of registers + // in different libc implementations and many implementations mangle the + // stack pointer so we can't use it without knowing the demangling scheme. + register long int retval_tmp asm("x1") = retval; + register void *env_address asm("x0") = &env[0]; + asm volatile("ldp x19, x20, [%0, #0<<3];" + "ldp x21, x22, [%0, #2<<3];" + "ldp x23, x24, [%0, #4<<3];" + "ldp x25, x26, [%0, #6<<3];" + "ldp x27, x28, [%0, #8<<3];" + "ldp x29, x30, [%0, #10<<3];" + "ldp d8, d9, [%0, #14<<3];" + "ldp d10, d11, [%0, #16<<3];" + "ldp d12, d13, [%0, #18<<3];" + "ldp d14, d15, [%0, #20<<3];" + "ldr x5, [%0, #13<<3];" + "mov sp, x5;" + // Return the value requested to return through arguments. + // This should be in x1 given what we requested above. + "cmp %1, #0;" + "mov x0, #1;" + "csel x0, %1, x0, ne;" + "br x30;" + : "+r"(env_address) + : "r"(retval_tmp)); +} + +INTERCEPTOR(void, siglongjmp, __hw_sigjmp_buf env, int val) { + if (env[0].__mask_was_saved) + // Restore the saved signal mask. + (void)sigprocmask(SIG_SETMASK, &env[0].__saved_mask, + (__hw_sigset_t *)0); + InternalLongjmp(env[0].__jmpbuf, val); +} + +// Required since glibc libpthread calls __libc_longjmp on pthread_exit, and +// _setjmp on start_thread. Hence we have to intercept the longjmp on +// pthread_exit so the __hw_jmp_buf order matches. +INTERCEPTOR(void, __libc_longjmp, __hw_jmp_buf env, int val) { + InternalLongjmp(env[0].__jmpbuf, val); +} + +INTERCEPTOR(void, longjmp, __hw_jmp_buf env, int val) { + InternalLongjmp(env[0].__jmpbuf, val); +} +#undef SIG_BLOCK +#undef SIG_SETMASK + +#endif // HWASAN_WITH_INTERCEPTORS && __aarch64__ + static void BeforeFork() { StackDepotLockAll(); } diff --git a/libsanitizer/hwasan/hwasan_setjmp.S b/libsanitizer/hwasan/hwasan_setjmp.S new file mode 100644 index 0000000000000000000000000000000000000000..0c1354331940e23acad1ca4becba87199a211653 --- /dev/null +++ b/libsanitizer/hwasan/hwasan_setjmp.S @@ -0,0 +1,100 @@ +//===-- hwasan_setjmp.S --------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of HWAddressSanitizer. +// +// HWAddressSanitizer runtime. +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_asm.h" + +#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__) +#include "sanitizer_common/sanitizer_platform.h" + +// We want to save the context of the calling function. +// That requires +// 1) No modification of the link register by this function. +// 2) No modification of the stack pointer by this function. +// 3) (no modification of any other saved register, but that's not really going +// to occur, and hence isn't as much of a worry). +// +// There's essentially no way to ensure that the compiler will not modify the +// stack pointer when compiling a C function. +// Hence we have to write this function in assembly. + +.section .text +.file "hwasan_setjmp.S" + +.global __interceptor_setjmp +ASM_TYPE_FUNCTION(__interceptor_setjmp) +__interceptor_setjmp: + CFI_STARTPROC + mov x1, #0 + b __interceptor_sigsetjmp + CFI_ENDPROC +ASM_SIZE(__interceptor_setjmp) + +#if SANITIZER_ANDROID +// Bionic also defines a function `setjmp` that calls `sigsetjmp` saving the +// current signal. +.global __interceptor_setjmp_bionic +ASM_TYPE_FUNCTION(__interceptor_setjmp_bionic) +__interceptor_setjmp_bionic: + CFI_STARTPROC + mov x1, #1 + b __interceptor_sigsetjmp + CFI_ENDPROC +ASM_SIZE(__interceptor_setjmp_bionic) +#endif + +.global __interceptor_sigsetjmp +ASM_TYPE_FUNCTION(__interceptor_sigsetjmp) +__interceptor_sigsetjmp: + CFI_STARTPROC + stp x19, x20, [x0, #0<<3] + stp x21, x22, [x0, #2<<3] + stp x23, x24, [x0, #4<<3] + stp x25, x26, [x0, #6<<3] + stp x27, x28, [x0, #8<<3] + stp x29, x30, [x0, #10<<3] + stp d8, d9, [x0, #14<<3] + stp d10, d11, [x0, #16<<3] + stp d12, d13, [x0, #18<<3] + stp d14, d15, [x0, #20<<3] + mov x2, sp + str x2, [x0, #13<<3] + // We always have the second argument to __sigjmp_save (savemask) set, since + // the _setjmp function above has set it for us as `false`. + // This function is defined in hwasan_interceptors.cc + b __sigjmp_save + CFI_ENDPROC +ASM_SIZE(__interceptor_sigsetjmp) + + +.macro ALIAS first second + .globl \second + .equ \second\(), \first +.endm + +#if SANITIZER_ANDROID +ALIAS __interceptor_sigsetjmp, sigsetjmp +.weak sigsetjmp + +ALIAS __interceptor_setjmp_bionic, setjmp +.weak setjmp +#else +ALIAS __interceptor_sigsetjmp, __sigsetjmp +.weak __sigsetjmp +#endif + +ALIAS __interceptor_setjmp, _setjmp +.weak _setjmp +#endif + +// We do not need executable stack. +NO_EXEC_STACK_DIRECTIVE diff --git a/libsanitizer/hwasan/hwasan_type_test.cpp b/libsanitizer/hwasan/hwasan_type_test.cpp new file mode 100644 index 0000000000000000000000000000000000000000..8cff495bae153eb728a9dc7d12e80be3bc976a85 --- /dev/null +++ b/libsanitizer/hwasan/hwasan_type_test.cpp @@ -0,0 +1,25 @@ +//===-- hwasan_type_test.cpp ------------------------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of HWAddressSanitizer. +// +// Compile-time tests of the internal type definitions. +//===----------------------------------------------------------------------===// + +#include "interception/interception.h" +#include "sanitizer_common/sanitizer_platform_limits_posix.h" +#include "hwasan.h" +#include <setjmp.h> + +#define CHECK_TYPE_SIZE_FITS(TYPE) \ + COMPILER_CHECK(sizeof(__hw_##TYPE) <= sizeof(TYPE)) + +#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__) +CHECK_TYPE_SIZE_FITS(jmp_buf); +CHECK_TYPE_SIZE_FITS(sigjmp_buf); +#endif
diff --git a/libsanitizer/hwasan/hwasan.h b/libsanitizer/hwasan/hwasan.h index 9e0ced93b55d361cd5aae787db7562741683944c..64cdcf30f5c7059dcc1916f72e14b6649ca701f5 100644 --- a/libsanitizer/hwasan/hwasan.h +++ b/libsanitizer/hwasan/hwasan.h @@ -172,4 +172,24 @@ void AndroidTestTlsSlot(); RunFreeHooks(ptr); \ } while (false) +#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__) +// For both bionic and glibc __sigset_t is an unsigned long. +typedef unsigned long __hw_sigset_t; +// Setjmp and longjmp implementations are platform specific, and hence the +// interception code is platform specific too. As yet we've only implemented +// the interception for AArch64. +typedef unsigned long long __hw_register_buf[22]; +struct __hw_jmp_buf_struct { + // NOTE: The machine-dependent definition of `__sigsetjmp' + // assume that a `__hw_jmp_buf' begins with a `__hw_register_buf' and that + // `__mask_was_saved' follows it. Do not move these members or add others + // before it. + __hw_register_buf __jmpbuf; // Calling environment. + int __mask_was_saved; // Saved the signal mask? + __hw_sigset_t __saved_mask; // Saved signal mask. +}; +typedef struct __hw_jmp_buf_struct __hw_jmp_buf[1]; +typedef struct __hw_jmp_buf_struct __hw_sigjmp_buf[1]; +#endif // HWASAN_WITH_INTERCEPTORS && __aarch64__ + #endif // HWASAN_H diff --git a/libsanitizer/hwasan/hwasan_interceptors.cpp b/libsanitizer/hwasan/hwasan_interceptors.cpp index 47fed0fc9abb821996efcd8d12f7e5442916326d..f6758efa65c051376468d3cad2c1530fa7329627 100644 --- a/libsanitizer/hwasan/hwasan_interceptors.cpp +++ b/libsanitizer/hwasan/hwasan_interceptors.cpp @@ -220,6 +220,80 @@ DEFINE_REAL(int, vfork) DECLARE_EXTERN_INTERCEPTOR_AND_WRAPPER(int, vfork) #endif +#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__) +// Get and/or change the set of blocked signals. +extern "C" int sigprocmask(int __how, const __hw_sigset_t *__restrict __set, + __hw_sigset_t *__restrict __oset); +#define SIG_BLOCK 0 +#define SIG_SETMASK 2 +extern "C" int __sigjmp_save(__hw_sigjmp_buf env, int savemask) { + env[0].__mask_was_saved = + (savemask && sigprocmask(SIG_BLOCK, (__hw_sigset_t *)0, + &env[0].__saved_mask) == 0); + return 0; +} + +static void __attribute__((always_inline)) +InternalLongjmp(__hw_register_buf env, int retval) { + // Clear all memory tags on the stack between here and where we're going. + unsigned long long stack_pointer = env[13]; + // The stack pointer should never be tagged, so we don't need to clear the + // tag for this function call. + __hwasan_handle_longjmp((void *)stack_pointer); + + // Run code for handling a longjmp. + // Need to use a register that isn't going to be loaded from the environment + // buffer -- hence why we need to specify the register to use. + // Must implement this ourselves, since we don't know the order of registers + // in different libc implementations and many implementations mangle the + // stack pointer so we can't use it without knowing the demangling scheme. + register long int retval_tmp asm("x1") = retval; + register void *env_address asm("x0") = &env[0]; + asm volatile("ldp x19, x20, [%0, #0<<3];" + "ldp x21, x22, [%0, #2<<3];" + "ldp x23, x24, [%0, #4<<3];" + "ldp x25, x26, [%0, #6<<3];" + "ldp x27, x28, [%0, #8<<3];" + "ldp x29, x30, [%0, #10<<3];" + "ldp d8, d9, [%0, #14<<3];" + "ldp d10, d11, [%0, #16<<3];" + "ldp d12, d13, [%0, #18<<3];" + "ldp d14, d15, [%0, #20<<3];" + "ldr x5, [%0, #13<<3];" + "mov sp, x5;" + // Return the value requested to return through arguments. + // This should be in x1 given what we requested above. + "cmp %1, #0;" + "mov x0, #1;" + "csel x0, %1, x0, ne;" + "br x30;" + : "+r"(env_address) + : "r"(retval_tmp)); +} + +INTERCEPTOR(void, siglongjmp, __hw_sigjmp_buf env, int val) { + if (env[0].__mask_was_saved) + // Restore the saved signal mask. + (void)sigprocmask(SIG_SETMASK, &env[0].__saved_mask, + (__hw_sigset_t *)0); + InternalLongjmp(env[0].__jmpbuf, val); +} + +// Required since glibc libpthread calls __libc_longjmp on pthread_exit, and +// _setjmp on start_thread. Hence we have to intercept the longjmp on +// pthread_exit so the __hw_jmp_buf order matches. +INTERCEPTOR(void, __libc_longjmp, __hw_jmp_buf env, int val) { + InternalLongjmp(env[0].__jmpbuf, val); +} + +INTERCEPTOR(void, longjmp, __hw_jmp_buf env, int val) { + InternalLongjmp(env[0].__jmpbuf, val); +} +#undef SIG_BLOCK +#undef SIG_SETMASK + +#endif // HWASAN_WITH_INTERCEPTORS && __aarch64__ + static void BeforeFork() { StackDepotLockAll(); } diff --git a/libsanitizer/hwasan/hwasan_setjmp.S b/libsanitizer/hwasan/hwasan_setjmp.S new file mode 100644 index 0000000000000000000000000000000000000000..0c1354331940e23acad1ca4becba87199a211653 --- /dev/null +++ b/libsanitizer/hwasan/hwasan_setjmp.S @@ -0,0 +1,100 @@ +//===-- hwasan_setjmp.S --------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of HWAddressSanitizer. +// +// HWAddressSanitizer runtime. +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_asm.h" + +#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__) +#include "sanitizer_common/sanitizer_platform.h" + +// We want to save the context of the calling function. +// That requires +// 1) No modification of the link register by this function. +// 2) No modification of the stack pointer by this function. +// 3) (no modification of any other saved register, but that's not really going +// to occur, and hence isn't as much of a worry). +// +// There's essentially no way to ensure that the compiler will not modify the +// stack pointer when compiling a C function. +// Hence we have to write this function in assembly. + +.section .text +.file "hwasan_setjmp.S" + +.global __interceptor_setjmp +ASM_TYPE_FUNCTION(__interceptor_setjmp) +__interceptor_setjmp: + CFI_STARTPROC + mov x1, #0 + b __interceptor_sigsetjmp + CFI_ENDPROC +ASM_SIZE(__interceptor_setjmp) + +#if SANITIZER_ANDROID +// Bionic also defines a function `setjmp` that calls `sigsetjmp` saving the +// current signal. +.global __interceptor_setjmp_bionic +ASM_TYPE_FUNCTION(__interceptor_setjmp_bionic) +__interceptor_setjmp_bionic: + CFI_STARTPROC + mov x1, #1 + b __interceptor_sigsetjmp + CFI_ENDPROC +ASM_SIZE(__interceptor_setjmp_bionic) +#endif + +.global __interceptor_sigsetjmp +ASM_TYPE_FUNCTION(__interceptor_sigsetjmp) +__interceptor_sigsetjmp: + CFI_STARTPROC + stp x19, x20, [x0, #0<<3] + stp x21, x22, [x0, #2<<3] + stp x23, x24, [x0, #4<<3] + stp x25, x26, [x0, #6<<3] + stp x27, x28, [x0, #8<<3] + stp x29, x30, [x0, #10<<3] + stp d8, d9, [x0, #14<<3] + stp d10, d11, [x0, #16<<3] + stp d12, d13, [x0, #18<<3] + stp d14, d15, [x0, #20<<3] + mov x2, sp + str x2, [x0, #13<<3] + // We always have the second argument to __sigjmp_save (savemask) set, since + // the _setjmp function above has set it for us as `false`. + // This function is defined in hwasan_interceptors.cc + b __sigjmp_save + CFI_ENDPROC +ASM_SIZE(__interceptor_sigsetjmp) + + +.macro ALIAS first second + .globl \second + .equ \second\(), \first +.endm + +#if SANITIZER_ANDROID +ALIAS __interceptor_sigsetjmp, sigsetjmp +.weak sigsetjmp + +ALIAS __interceptor_setjmp_bionic, setjmp +.weak setjmp +#else +ALIAS __interceptor_sigsetjmp, __sigsetjmp +.weak __sigsetjmp +#endif + +ALIAS __interceptor_setjmp, _setjmp +.weak _setjmp +#endif + +// We do not need executable stack. +NO_EXEC_STACK_DIRECTIVE diff --git a/libsanitizer/hwasan/hwasan_type_test.cpp b/libsanitizer/hwasan/hwasan_type_test.cpp new file mode 100644 index 0000000000000000000000000000000000000000..8cff495bae153eb728a9dc7d12e80be3bc976a85 --- /dev/null +++ b/libsanitizer/hwasan/hwasan_type_test.cpp @@ -0,0 +1,25 @@ +//===-- hwasan_type_test.cpp ------------------------------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of HWAddressSanitizer. +// +// Compile-time tests of the internal type definitions. +//===----------------------------------------------------------------------===// + +#include "interception/interception.h" +#include "sanitizer_common/sanitizer_platform_limits_posix.h" +#include "hwasan.h" +#include <setjmp.h> + +#define CHECK_TYPE_SIZE_FITS(TYPE) \ + COMPILER_CHECK(sizeof(__hw_##TYPE) <= sizeof(TYPE)) + +#if HWASAN_WITH_INTERCEPTORS && defined(__aarch64__) +CHECK_TYPE_SIZE_FITS(jmp_buf); +CHECK_TYPE_SIZE_FITS(sigjmp_buf); +#endif