From: Vincent Fazio <vfa...@gmail.com>
Previously, the signal handler would be byte swapped if the target and
host CPU used different endianness. This would cause a SIGSEGV when
attempting to translate the opcode pointed to by the swapped address.
Thread 1 "qemu-ppc64" received signal SIGSEGV, Segmentation fault.
0x00000000600a9257 in ldl_he_p (ptr=0x4c2c061000000000) at
qemu/include/qemu/bswap.h:351
351 __builtin_memcpy(&r, ptr, sizeof(r));
#0 0x00000000600a9257 in ldl_he_p (ptr=0x4c2c061000000000) at
qemu/include/qemu/bswap.h:351
#1 0x00000000600a92fe in ldl_be_p (ptr=0x4c2c061000000000) at
qemu/include/qemu/bswap.h:449
#2 0x00000000600c0790 in translator_ldl_swap at
qemu/include/exec/translator.h:201
#3 0x000000006011c1ab in ppc_tr_translate_insn at
qemu/target/ppc/translate.c:7856
#4 0x000000006005ae70 in translator_loop at qemu/accel/tcg/translator.c:102
Now, no swap is performed and execution continues properly.
Signed-off-by: Vincent Fazio <vfa...@gmail.com>
Reviewed-by: Laurent Vivier <laur...@vivier.eu>
---
Changes since v1:
- Drop host/target endianness callouts
- Drop unnecessary pointer cast
- Clarify commit message
linux-user/ppc/signal.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c
index 5b82af6cb6..b8613c5e1b 100644
--- a/linux-user/ppc/signal.c
+++ b/linux-user/ppc/signal.c
@@ -567,10 +567,8 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
env->nip = tswapl(handler->entry);
env->gpr[2] = tswapl(handler->toc);
} else {
- /* ELFv2 PPC64 function pointers are entry points, but R12
- * must also be set */
- env->nip = tswapl((target_ulong) ka->_sa_handler);
- env->gpr[12] = env->nip;
+ /* ELFv2 PPC64 function pointers are entry points. R12 must also be
set. */
+ env->gpr[12] = env->nip = ka->_sa_handler;
}
#else
env->nip = (target_ulong) ka->_sa_handler;
--
2.25.1
