From: Sergey Fedorov <address@hidden>
Ensure direct jump patching in AArch64 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>
---
tcg/aarch64/tcg-target.inc.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/tcg/aarch64/tcg-target.inc.c b/tcg/aarch64/tcg-target.inc.c
index 0ed10a974121..15fdebec921f 100644
--- a/tcg/aarch64/tcg-target.inc.c
+++ b/tcg/aarch64/tcg-target.inc.c
@@ -73,6 +73,18 @@ static inline void reloc_pc26(tcg_insn_unit *code_ptr,
tcg_insn_unit *target)
*code_ptr = deposit32(*code_ptr, 0, 26, offset);
}
+static inline void reloc_pc26_atomic(tcg_insn_unit *code_ptr,
+ tcg_insn_unit *target)
+{
+ ptrdiff_t offset = target - code_ptr;
+ tcg_insn_unit insn;
+ assert(offset == sextract64(offset, 0, 26));
+ /* read instruction, mask away previous PC_REL26 parameter contents,
+ set the proper offset, then write back the instruction. */