On Tue, Dec 06, 2016 at 06:07:09PM +0000, Peter Maydell wrote: > A bug (1647683) was reported showing a crash when removing > breakpoints. The reproducer was bisected to 3359baad when tb_flush > was finally made thread safe. While in MTTCG the locking in > breakpoint_invalidate would have prevented any problems, but > currently tb_lock() is a NOP for system emulation. > > The race is between a tb_flush from the gdbstub and the > tb_invalidate_phys_addr() in breakpoint_invalidate(). > > Ideally we'd have actual locking here; for the moment the > simple fix is to do a full tb_flush() for a bp invalidate, > since that is thread-safe even if no lock is taken. > > Reported-by: Julian Brown <jul...@codesourcery.com> > Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> > --- > This is quite similar to Alex's patch > http://patchwork.ozlabs.org/patch/703188/ > ("exec.c: simplify the breakpoint invalidation logic"). > The difference is that this patch doesn't drop the > breakpoint_invalidate() function entirely. I think this > is better both for a future "correct fix" and as a > minimal "just fix this for 2.8 release" change. > --- > exec.c | 25 ++++++------------------- > 1 file changed, 6 insertions(+), 19 deletions(-)
Thanks, applied to my staging tree: https://github.com/stefanha/qemu/commits/staging Stefan
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