qemu/accel/tcg
Emilio G. Cota cc689485ee translate-all: exit from tb_phys_invalidate if qht_remove fails
Two or more threads might race while invalidating the same TB. We currently
do not check for this at all despite taking tb_lock, which means we would
wrongly invalidate the same TB more than once. This bug has actually been
hit by users: I recently saw a report on IRC, although I have yet to see
the corresponding test case.

Fix this by using qht_remove as the synchronization point; if it fails,
that means the TB has already been invalidated, and therefore there
is nothing left to do in tb_phys_invalidate.

Note that this solution works now that we still have tb_lock, and will
continue working once we remove tb_lock.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1508445114-4717-1-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-10-24 13:53:42 -07:00
..
atomic_template.h accel/tcg: move atomic_template.h to accel/tcg/ 2017-09-17 06:52:19 -07:00
cpu-exec-common.c tcg: make tcg_allowed global 2017-07-04 16:01:16 +02:00
cpu-exec.c tcg: take tb_ctx out of TCGContext 2017-10-24 13:53:42 -07:00
cputlb.c accel/tcg: allow to invalidate a write TLB entry immediately 2017-10-20 13:32:10 +02:00
Makefile.objs accel/tcg: move tcg-runtime to accel/tcg/ 2017-09-17 06:52:19 -07:00
softmmu_template.h accel/tcg: allow to invalidate a write TLB entry immediately 2017-10-20 13:32:10 +02:00
tcg-all.c tcg: make tcg_allowed global 2017-07-04 16:01:16 +02:00
tcg-runtime.c tcg: define tcg_init_ctx and make tcg_ctx a pointer 2017-10-24 13:53:42 -07:00
tcg-runtime.h tcg: remove addr argument from lookup_tb_ptr 2017-10-10 07:37:10 -07:00
trace-events trace-events: fix code style: print 0x before hex numbers 2017-08-01 12:13:07 +01:00
translate-all.c translate-all: exit from tb_phys_invalidate if qht_remove fails 2017-10-24 13:53:42 -07:00
translate-all.h
translator.c tcg: convert tb->cflags reads to tb_cflags(tb) 2017-10-24 13:53:41 -07:00
user-exec-stub.c accel/tcg: move user-exec to accel/tcg/ 2017-09-17 06:52:19 -07:00
user-exec.c accel/tcg: move USER code to user-exec.c 2017-09-17 06:52:19 -07:00