[Qemu-devel] [PATCH v2 10/11] tcg/mips: Make direct jump patching thread-safe

[Sergey Fedorov]

From: Sergey Fedorov <address@hidden>

Ensure direct jump patching in MIPS is atomic by using
atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <address@hidden>
Signed-off-by: Sergey Fedorov <address@hidden>
---

Changes in v2:
 * s/atomic_write/atomic_set/

 tcg/mips/tcg-target.inc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tcg/mips/tcg-target.inc.c b/tcg/mips/tcg-target.inc.c
index 682e19897db0..cefc0398018a 100644
--- a/tcg/mips/tcg-target.inc.c
+++ b/tcg/mips/tcg-target.inc.c
@@ -1886,6 +1886,7 @@ static void tcg_target_init(TCGContext *s)
 void tb_set_jmp_target1(uintptr_t jmp_addr, uintptr_t addr)
 {
     uint32_t *ptr = (uint32_t *)jmp_addr;
-    *ptr = deposit32(*ptr, 0, 26, addr >> 2);
+    uint32_t insn = atomic_read(ptr);
+    atomic_set(ptr, deposit32(insn, 0, 26, addr >> 2));
     flush_icache_range(jmp_addr, jmp_addr + 4);
 }
-- 
2.8.1