From: David Gibson <david@gibson.dropbear.id.au>
To: peter.maydell@linaro.org
Cc: aik@ozlabs.ru, Richard Henderson <richard.henderson@linaro.org>,
qemu-devel@nongnu.org, groug@kaod.org, qemu-ppc@nongnu.org,
clg@kaod.org, David Gibson <david@gibson.dropbear.id.au>,
Vincent Fazio <vfazio@gmail.com>,
Laurent Vivier <laurent@vivier.eu>
Subject: [PULL 4/7] target/ppc: don't byte swap ELFv2 signal handler
Date: Tue, 24 Mar 2020 16:14:53 +1100 [thread overview]
Message-ID: <20200324051456.256116-5-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20200324051456.256116-1-david@gibson.dropbear.id.au>
From: Vincent Fazio <vfazio@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
The signal handler will be byte swapped as a result of the __get_user()
call in sigaction() if it is necessary, no additional swap is required.
Signed-off-by: Vincent Fazio <vfazio@gmail.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200319133244.8818-1-vfazio@xes-inc.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
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 0c4e7ba54c..ecd99736b7 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
next prev parent reply other threads:[~2020-03-24 5:21 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 5:14 [PULL 0/7] ppc-for-5.0 queue 20200324 David Gibson
2020-03-24 5:14 ` [PULL 1/7] ppc/spapr: Set the effective address provided flag in mc error log David Gibson
2020-03-24 5:14 ` [PULL 2/7] target/ppc: Fix slbia TLB invalidation gap David Gibson
2020-03-24 5:14 ` [PULL 3/7] target/ppc: Fix ISA v3.0 (POWER9) slbia implementation David Gibson
2020-03-24 5:14 ` David Gibson [this message]
2020-03-24 5:14 ` [PULL 5/7] spapr: Fix memory leak in h_client_architecture_support() David Gibson
2020-03-24 5:14 ` [PULL 6/7] hw/ppc: Take QEMU lock when calling ppc_dcr_read/write() David Gibson
2020-03-24 5:14 ` [PULL 7/7] ppc/ppc405_boards: Remove unnecessary NULL check David Gibson
2020-03-24 11:07 ` [PULL 0/7] ppc-for-5.0 queue 20200324 Peter Maydell
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