| 1 | // RUN: %clangxx_msan -fsanitize-memory-track-origins=2 -O1 %s -o %t && %run %t 2>&1 | FileCheck %s |
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| 2 | |
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| 3 | #include <pthread.h> |
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| 4 | #include <sanitizer/msan_interface.h> |
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| 5 | #include <signal.h> |
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| 6 | #include <stdint.h> |
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| 7 | #include <stdio.h> |
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| 8 | #include <ucontext.h> |
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| 9 | #include <unistd.h> |
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| 10 | |
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| 11 | void handler(int sig, siginfo_t *info, void *uctx) { |
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| 12 | __msan_check_mem_is_initialized(x: uctx, size: sizeof(ucontext_t)); |
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| 13 | #if defined(__GLIBC__) && defined(__x86_64__) |
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| 14 | auto *mctx = &static_cast<ucontext_t *>(uctx)->uc_mcontext; |
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| 15 | if (auto *fpregs = mctx->fpregs) { |
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| 16 | // The member names differ across header versions, but the actual layout |
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| 17 | // is always the same. So avoid using members, just use arithmetic. |
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| 18 | const uint32_t *after_xmm = |
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| 19 | reinterpret_cast<const uint32_t *>(fpregs + 1) - 24; |
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| 20 | if (after_xmm[12] == FP_XSTATE_MAGIC1) { |
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| 21 | auto *xstate = reinterpret_cast<_xstate *>(mctx->fpregs); |
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| 22 | __msan_check_mem_is_initialized(x: xstate, size: sizeof(*xstate)); |
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| 23 | } |
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| 24 | } |
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| 25 | #endif |
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| 26 | } |
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| 27 | |
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| 28 | __attribute__((noinline)) void poison_stack() { |
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| 29 | char buf[64 << 10]; |
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| 30 | printf(format: "buf: %p-%p\n" , buf, buf + sizeof(buf)); |
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| 31 | } |
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| 32 | |
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| 33 | int main(int argc, char **argv) { |
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| 34 | struct sigaction act = {}; |
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| 35 | act.sa_sigaction = handler; |
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| 36 | act.sa_flags = SA_SIGINFO; |
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| 37 | sigaction(SIGPROF, act: &act, oact: 0); |
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| 38 | poison_stack(); |
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| 39 | pthread_kill(threadid: pthread_self(), SIGPROF); |
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| 40 | return 0; |
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| 41 | } |
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| 42 | |
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| 43 | // CHECK-NOT: WARNING: MemorySanitizer: |
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| 44 | |
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