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authorSergey Fedorov <serge.fdrv@gmail.com>2016-04-22 19:08:50 +0300
committerRichard Henderson <rth@twiddle.net>2016-05-12 14:06:41 -1000
commit9e269112953be4d670cb0d25042bd6546fcf3e45 (patch)
tree5fee12d3d27049af5e883e2026be6e336c93b7de /tcg
parent7d14e0e2d661479985197203589c38840e1066df (diff)
tcg/aarch64: Make direct jump patching thread-safe
Ensure direct jump patching in AArch64 is atomic by using atomic_read()/atomic_set() for code patching. Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com> Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org> Message-Id: <1461341333-19646-9-git-send-email-sergey.fedorov@linaro.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg')
-rw-r--r--tcg/aarch64/tcg-target.inc.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/tcg/aarch64/tcg-target.inc.c b/tcg/aarch64/tcg-target.inc.c
index a8fb4420de..88183c830f 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;
+ tcg_debug_assert(offset == sextract64(offset, 0, 26));
+ /* read instruction, mask away previous PC_REL26 parameter contents,
+ set the proper offset, then write back the instruction. */
+ insn = atomic_read(code_ptr);
+ atomic_set(code_ptr, deposit32(insn, 0, 26, offset));
+}
+
static inline void reloc_pc19(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
{
ptrdiff_t offset = target - code_ptr;
@@ -835,7 +847,7 @@ void aarch64_tb_set_jmp_target(uintptr_t jmp_addr, uintptr_t addr)
tcg_insn_unit *code_ptr = (tcg_insn_unit *)jmp_addr;
tcg_insn_unit *target = (tcg_insn_unit *)addr;
- reloc_pc26(code_ptr, target);
+ reloc_pc26_atomic(code_ptr, target);
flush_icache_range(jmp_addr, jmp_addr + 4);
}