From 5f3bdfd4fa33255542a4b6249913d9ffb11b44f9 Mon Sep 17 00:00:00 2001 From: Pavel Dovgalyuk Date: Tue, 27 Feb 2018 12:51:41 +0300 Subject: cpu-exec: fix exception_index handling Function cpu_handle_interrupt calls cc->cpu_exec_interrupt to process pending hardware interrupts. Under the hood cpu_exec_interrupt uses cpu->exception_index to pass information to the internal function which is usually common for exception and interrupt processing. But this value is not reset after return and may be processed again by cpu_handle_exception. This does not happen due to overwriting the exception_index at the end of cpu_handle_interrupt. But this branch may also overwrite the valid exception_index in some cases. Therefore this patch: 1. resets exception_index just after the call to cpu_exec_interrupt 2. prevents overwriting the meaningful value of exception_index Signed-off-by: Pavel Dovgalyuk Signed-off-by: Paolo Bonzini Message-Id: <20180227095140.1060.61357.stgit@pasha-VirtualBox> Signed-off-by: Paolo Bonzini Signed-off-by: Pavel Dovgalyuk --- accel/tcg/cpu-exec.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'accel') diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 280200f737..9cc697205c 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -585,6 +585,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu, else { if (cc->cpu_exec_interrupt(cpu, interrupt_request)) { replay_interrupt(); + cpu->exception_index = -1; *last_tb = NULL; } /* The target hook may have updated the 'cpu->interrupt_request'; @@ -606,7 +607,9 @@ static inline bool cpu_handle_interrupt(CPUState *cpu, if (unlikely(atomic_read(&cpu->exit_request) || (use_icount && cpu->icount_decr.u16.low + cpu->icount_extra == 0))) { atomic_set(&cpu->exit_request, 0); - cpu->exception_index = EXCP_INTERRUPT; + if (cpu->exception_index == -1) { + cpu->exception_index = EXCP_INTERRUPT; + } return true; } -- cgit v1.2.1