зеркало из https://github.com/mozilla/gecko-dev.git
46 строки
1.2 KiB
C++
46 строки
1.2 KiB
C++
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef mozilla_LinuxSignal_h
|
|
#define mozilla_LinuxSignal_h
|
|
|
|
namespace mozilla {
|
|
|
|
#if defined(__arm__)
|
|
|
|
// Some (old) Linux kernels on ARM have a bug where a signal handler
|
|
// can be called without clearing the IT bits in CPSR first. The result
|
|
// is that the first few instructions of the handler could be skipped,
|
|
// ultimately resulting in crashes. To workaround this bug, the handler
|
|
// on ARM is a trampoline that starts with enough NOP instructions, so
|
|
// that even if the IT bits are not cleared, only the NOP instructions
|
|
// will be skipped over.
|
|
|
|
template <void (*H)(int, siginfo_t*, void*)>
|
|
__attribute__((naked)) void
|
|
SignalTrampoline(int aSignal, siginfo_t* aInfo, void* aContext)
|
|
{
|
|
asm volatile (
|
|
"nop; nop; nop; nop"
|
|
: : : "memory");
|
|
|
|
asm volatile (
|
|
"b %0"
|
|
:
|
|
: "X"(H)
|
|
: "memory");
|
|
}
|
|
|
|
# define MOZ_SIGNAL_TRAMPOLINE(h) (mozilla::SignalTrampoline<h>)
|
|
|
|
#else // __arm__
|
|
|
|
# define MOZ_SIGNAL_TRAMPOLINE(h) (h)
|
|
|
|
#endif // __arm__
|
|
|
|
} // namespace mozilla
|
|
|
|
#endif // mozilla_LinuxSignal_h
|