forked from OSchip/llvm-project
36 lines
1.1 KiB
C++
36 lines
1.1 KiB
C++
// RUN: %clangxx_msan -fsanitize-memory-track-origins=2 -O1 %s -o %t && not %run %t 2>&1 | FileCheck %s
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// musl does not define FP_XSTATE_MAGIC1.
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// REQUIRES: x86_64-target-arch && glibc-2.27
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#include <pthread.h>
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#include <signal.h>
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#include <stdint.h>
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#include <ucontext.h>
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void handler(int sig, siginfo_t *info, void *uctx) {
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volatile int uninit;
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auto *mctx = &static_cast<ucontext_t *>(uctx)->uc_mcontext;
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auto *fpregs = mctx->fpregs;
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// The member names differ across header versions, but the actual layout
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// is always the same. So avoid using members, just use arithmetic.
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const uint32_t *after_xmm =
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reinterpret_cast<const uint32_t *>(fpregs + 1) - 24;
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if (after_xmm[12] == FP_XSTATE_MAGIC1)
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reinterpret_cast<_xstate *>(mctx->fpregs)->ymmh.ymmh_space[0] = uninit;
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else
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mctx->gregs[REG_RAX] = uninit;
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}
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int main(int argc, char **argv) {
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struct sigaction act = {};
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act.sa_sigaction = handler;
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act.sa_flags = SA_SIGINFO;
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sigfillset(&act.sa_mask);
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sigaction(SIGPROF, &act, 0);
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pthread_kill(pthread_self(), SIGPROF);
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return 0;
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}
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// CHECK: WARNING: MemorySanitizer:
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