tci: Make direct jump patching thread-safe

Ensure direct jump patching in TCI is atomic by:
 * naturally aligning a location of direct jump address;
 * using atomic_read()/atomic_set() to load/store the address.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-4-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Sergey Fedorov 2016-04-22 19:08:45 +03:00 committed by Richard Henderson
parent 6b587d3cda
commit 76442a939e
3 changed files with 7 additions and 2 deletions

View file

@ -556,6 +556,8 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args,
if (s->tb_jmp_offset) {
/* Direct jump method. */
tcg_debug_assert(args[0] < ARRAY_SIZE(s->tb_jmp_offset));
/* Align for atomic patching and thread safety */
s->code_ptr = QEMU_ALIGN_PTR_UP(s->code_ptr, 4);
s->tb_jmp_offset[args[0]] = tcg_current_code_size(s);
tcg_out32(s, 0);
} else {