From: Vincent Fazio <vfa...@gmail.com>
In ELFv2, function pointers are entry points and are in host endianness.
Previously, the signal handler would be swapped if the target CPU was a
different endianness than the host. 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>
---
linux-user/ppc/signal.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/linux-user/ppc/signal.c b/linux-user/ppc/signal.c
index 5b82af6cb6..c7f6455170 100644
--- a/linux-user/ppc/signal.c
+++ b/linux-user/ppc/signal.c
@@ -567,9 +567,13 @@ 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);
+ /*
+ * ELFv2 PPC64 function pointers are entry points and are in host
+ * endianness so should not to be swapped.
+ *
+ * Note: R12 must also be set.
+ */
+ env->nip = (target_ulong) ka->_sa_handler;
env->gpr[12] = env->nip;
}
#else
--
2.25.1
