[Qemu-devel] [PATCH] tcg/s390: fix branch target change during code retranslation

[Aurelien Jarno]

Make sure to not modify the branch target. This ensure that the
branch target is not corrupted during partial retranslation.

Cc: Alexander Graf <address@hidden>
Cc: Richard Henderson <address@hidden>
Signed-off-by: Aurelien Jarno <address@hidden>
---
 tcg/s390/tcg-target.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/tcg/s390/tcg-target.c b/tcg/s390/tcg-target.c
index 669fafe..921991e 100644
--- a/tcg/s390/tcg-target.c
+++ b/tcg/s390/tcg-target.c
@@ -1643,8 +1643,10 @@ static void tcg_out_qemu_ld(TCGContext* s, TCGReg 
data_reg, TCGReg addr_reg,
 
     base_reg = tcg_out_tlb_read(s, addr_reg, opc, mem_index, 1);
 
-    label_ptr = s->code_ptr + 1;
-    tcg_out_insn(s, RI, BRC, S390_CC_NE, 0);
+    /* We need to keep the offset unchanged for retranslation.  */
+    tcg_out16(s, RI_BRC | (S390_CC_NE << 4));
+    label_ptr = s->code_ptr;
+    s->code_ptr += 1;
 
     tcg_out_qemu_ld_direct(s, opc, data_reg, base_reg, TCG_REG_R2, 0);
 
@@ -1669,8 +1671,10 @@ static void tcg_out_qemu_st(TCGContext* s, TCGReg 
data_reg, TCGReg addr_reg,
 
     base_reg = tcg_out_tlb_read(s, addr_reg, opc, mem_index, 0);
 
-    label_ptr = s->code_ptr + 1;
-    tcg_out_insn(s, RI, BRC, S390_CC_NE, 0);
+    /* We need to keep the offset unchanged for retranslation.  */
+    tcg_out16(s, RI_BRC | (S390_CC_NE << 4));
+    label_ptr = s->code_ptr;
+    s->code_ptr += 1;
 
     tcg_out_qemu_st_direct(s, opc, data_reg, base_reg, TCG_REG_R2, 0);
 
-- 
2.1.4