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[PR] Instrumentation: Disable signals on mutex lock

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Summary:
When indirect call is instrmented it locks SimpleHashTable's mutex on get() call.
If while locked we we receive a signal and signal handler also will call
indirect function we will end up with deadlock.

PR facebookincubator/BOLT#167

Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei

(cherry picked from FBD28909921)
This commit is contained in:
Vladislav Khmelevsky 2021-06-04 19:51:06 +03:00 committed by Maksim Panchenko
parent 1efadeedf2
commit 2cf9008a60
1 changed files with 29 additions and 1 deletions
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30
bolt/runtime/common.h
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@ -151,6 +151,28 @@ uint64_t __munmap(void *addr, uint64_t size) {
return ret;
}
#define SIG_BLOCK 0
#define SIG_UNBLOCK 1
#define SIG_SETMASK 2
static const uint64_t MaskAllSignals[] = {-1ULL};
uint64_t __sigprocmask(int how, const void *set, void *oldset) {
#if defined(__APPLE__)
#define SIGPROCMASK_SYSCALL 0x2000030
#else
#define SIGPROCMASK_SYSCALL 14
#endif
uint64_t ret;
register long r10 asm("r10") = sizeof(uint64_t);
__asm__ __volatile__("movq $" STRINGIFY(SIGPROCMASK_SYSCALL) ", %%rax\n"
"syscall\n"
: "=a"(ret)
: "D"(how), "S"(set), "d"(oldset), "r"(r10)
: "cc", "rcx", "r11", "memory");
return ret;
}
uint64_t __exit(uint64_t code) {
#if defined(__APPLE__)
#define EXIT_SYSCALL 0x2000001
@ -409,13 +431,19 @@ public:
/// RAII wrapper for Mutex
class Lock {
Mutex &M;
uint64_t SignalMask[1] = {};
public:
Lock(Mutex &M) : M(M) {
__sigprocmask(SIG_BLOCK, MaskAllSignals, SignalMask);
while (!M.acquire()) {
}
}
~Lock() { M.release(); }
~Lock() {
M.release();
__sigprocmask(SIG_SETMASK, SignalMask, nullptr);
}
};
inline uint64_t alignTo(uint64_t Value, uint64_t Align) {