[Qemu-devel] [PATCH] exec-all.h: Don't use stl_p for patching x86 jumps

[Qemu-devel] [PATCH] exec-all.h: Don't use stl_p for patching x86 jumps

[Richard Henderson]

Partial revert of 86360ad71df0070283469b8ae59f33cdd013501d,
because get the "wrong" version of stl_p, the one that does
byte swapping appropriate for the target.

Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 include/exec/exec-all.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 0766e24..2c0c2d5 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -229,7 +229,8 @@ void ppc_tb_set_jmp_target(unsigned long jmp_addr, unsigned long addr);
 static inline void tb_set_jmp_target1(uintptr_t jmp_addr, uintptr_t addr)
 {
     /* patch the branch destination */
-    stl_p((void*)jmp_addr, addr - (jmp_addr + 4));
+    int32_t disp = addr - (jmp_addr + 4);
+    memcpy((void*)jmp_addr, &disp, 4);
     /* no need to flush icache explicitly */
 }
 #elif defined(__aarch64__)
-- 
1.9.0

Re: [Qemu-devel] [PATCH] exec-all.h: Don't use stl_p for patching x86 jumps

[Peter Maydell]

On 13 May 2014 17:05, Richard Henderson <rth@twiddle.net> wrote:
> Partial revert of 86360ad71df0070283469b8ae59f33cdd013501d,
> because get the "wrong" version of stl_p, the one that does
> byte swapping appropriate for the target.

Whoops. We could alternatively commit the patch renaming
the bswap.h functions to use _he_ infixes and then use
stl_he_p() here, yes?

Probably best to commit this as an immediate fix though.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [Qemu-devel] [PATCH] exec-all.h: Don't use stl_p for patching x86 jumps

[Richard Henderson]

On 05/13/2014 09:10 AM, Peter Maydell wrote:
> On 13 May 2014 17:05, Richard Henderson <rth@twiddle.net> wrote:
>> Partial revert of 86360ad71df0070283469b8ae59f33cdd013501d,
>> because get the "wrong" version of stl_p, the one that does
>> byte swapping appropriate for the target.
> 
> Whoops. We could alternatively commit the patch renaming
> the bswap.h functions to use _he_ infixes and then use
> stl_he_p() here, yes?

Yes.

> Probably best to commit this as an immediate fix though.

That's what I was thinking.


r~

Re: [Qemu-devel] [PATCH] exec-all.h: Don't use stl_p for patching x86 jumps

[Paolo Bonzini]

Il 13/05/2014 18:10, Peter Maydell ha scritto:
> On 13 May 2014 17:05, Richard Henderson <rth@twiddle.net> wrote:
>> Partial revert of 86360ad71df0070283469b8ae59f33cdd013501d,
>> because get the "wrong" version of stl_p, the one that does
>> byte swapping appropriate for the target.
>
> Whoops. We could alternatively commit the patch renaming
> the bswap.h functions to use _he_ infixes and then use
> stl_he_p() here, yes?

Or use stl_le_p (a bit more readable that _he_).

Paolo

Re: [Qemu-devel] [PATCH] exec-all.h: Don't use stl_p for patching x86 jumps

[Richard Henderson]

On 05/13/2014 09:55 AM, Paolo Bonzini wrote:
> Or use stl_le_p (a bit more readable that _he_).

Fair enough.  Will re-send.


r~