On 04/20/2016 11:22 AM, Alex Bennée wrote:
Richard Henderson <r...@twiddle.net> writes:
On 04/20/2016 07:01 AM, Alex Bennée wrote:
Sergey Fedorov <sergey.fedo...@linaro.org> writes:
From: Sergey Fedorov <serge.f...@gmail.com>
Ensure direct jump patching in AArch64 is atomic by using
atomic_read()/atomic_set() for code patching.
Signed-off-by: Sergey Fedorov <serge.f...@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedo...@linaro.org>
---
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. */
This comment could be moved from here and reloc_pc26 and made common for
the two following functions.
There's a significant amount of cleanup that ought to happen here, now that
we're not re-translating TBs. I don't know if Sergey should be gated
on that.
Is this stuff already in the works? Otherwise we are trying to get
pre-cursors to MTTCG into the code (once the tree re-opens) to keep the
main diff down. This also is beneficial for linux-user stuff.
We're talking past one another.
No, it's not yet in the works. I'm saying that this patch set should not wait
for it. Thus I don't care if what he adds here is a little messy; we'll clean
it all up at once later. Thus don't bother refactoring reloc_pc26 and
reloc_pc26_atomic.
r~
