tree 0c85067ab440ccba46d3282cbe15cf75c8d6640f
parent 28a76be8f4536619ab15ce452308df78cfc65e39
author aurel32 <aurel32@c046a42c-6fe2-441c-8c8c-71466251a162> 1236376080 +0000
committer aurel32 <aurel32@c046a42c-6fe2-441c-8c8c-71466251a162> 1236376080 +0000

Fix race condition on access to env->interrupt_request

env->interrupt_request is accessed as the bit level from both main code
and signal handler, making a race condition possible even on CISC CPU.
This causes freeze of QEMU under high load when running the dyntick
clock.

The patch below move the bit corresponding to CPU_INTERRUPT_EXIT in a
separate variable, declared as volatile sig_atomic_t, so it should be
work even on RISC CPU.

We may want to move the cpu_interrupt(env, CPU_INTERRUPT_EXIT) case in
its own function and get rid of CPU_INTERRUPT_EXIT. That can be done
later, I wanted to keep the patch short for easier review.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6728 c046a42c-6fe2-441c-8c8c-71466251a162