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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2016-08-03 22:38:51 +1000
committerDavid Gibson <david@gibson.dropbear.id.au>2016-09-23 10:29:40 +1000
commit95cda4c44ee2ae8616b2f9d8a2d68882cf437859 (patch)
treeec6ab3158b21ede4c1f43cbe398c17640d42e2c2
parentab04543602b7fa8fbc33401c66f071ae4570da04 (diff)
downloadqemu-arm-95cda4c44ee2ae8616b2f9d8a2d68882cf437859.tar.gz
ppc: Fix signal delivery in ppc-user and ppc64-user
There were a number of bugs in the implementation: - The structure alignment was wrong for 64-bit. - Also 64-bit only does RT signals. - On 64-bit, we need to put a pointer to the (aligned) vector registers in the frame and use it for restoring - We had endian bugs when saving/restoring vector registers - My recent fixes for exception NIP broke sigreturn in user mode causing us to resume one instruction too far. - Add VSR second halves Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
-rw-r--r--linux-user/main.c2
-rw-r--r--linux-user/ppc/syscall_nr.h2
-rw-r--r--linux-user/signal.c124
3 files changed, 90 insertions, 38 deletions
diff --git a/linux-user/main.c b/linux-user/main.c
index aba58c78bc..8daebe0767 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -1992,12 +1992,12 @@ void cpu_loop(CPUPPCState *env)
if (ret == -TARGET_ERESTARTSYS) {
break;
}
- env->nip += 4;
if (ret == (target_ulong)(-TARGET_QEMU_ESIGRETURN)) {
/* Returning from a successful sigreturn syscall.
Avoid corrupting register state. */
break;
}
+ env->nip += 4;
if (ret > (target_ulong)(-515)) {
env->crf[0] |= 0x1;
ret = -ret;
diff --git a/linux-user/ppc/syscall_nr.h b/linux-user/ppc/syscall_nr.h
index 46ed8a68ce..afa36544f1 100644
--- a/linux-user/ppc/syscall_nr.h
+++ b/linux-user/ppc/syscall_nr.h
@@ -120,7 +120,9 @@
#define TARGET_NR_sysinfo 116
#define TARGET_NR_ipc 117
#define TARGET_NR_fsync 118
+#if !defined(TARGET_PPC64)
#define TARGET_NR_sigreturn 119
+#endif
#define TARGET_NR_clone 120
#define TARGET_NR_setdomainname 121
#define TARGET_NR_uname 122
diff --git a/linux-user/signal.c b/linux-user/signal.c
index e4eea697b4..c750053edd 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -4454,7 +4454,12 @@ struct target_mcontext {
target_ulong mc_gregs[48];
/* Includes fpscr. */
uint64_t mc_fregs[33];
+#if defined(TARGET_PPC64)
+ /* Pointer to the vector regs */
+ target_ulong v_regs;
+#else
target_ulong mc_pad[2];
+#endif
/* We need to handle Altivec and SPE at the same time, which no
kernel needs to do. Fortunately, the kernel defines this bit to
be Altivec-register-large all the time, rather than trying to
@@ -4464,15 +4469,30 @@ struct target_mcontext {
uint32_t spe[33];
/* Altivec vector registers. The packing of VSCR and VRSAVE
varies depending on whether we're PPC64 or not: PPC64 splits
- them apart; PPC32 stuffs them together. */
+ them apart; PPC32 stuffs them together.
+ We also need to account for the VSX registers on PPC64
+ */
#if defined(TARGET_PPC64)
-#define QEMU_NVRREG 34
+#define QEMU_NVRREG (34 + 16)
+ /* On ppc64, this mcontext structure is naturally *unaligned*,
+ * or rather it is aligned on a 8 bytes boundary but not on
+ * a 16 bytes one. This pad fixes it up. This is also why the
+ * vector regs are referenced by the v_regs pointer above so
+ * any amount of padding can be added here
+ */
+ target_ulong pad;
#else
+ /* On ppc32, we are already aligned to 16 bytes */
#define QEMU_NVRREG 33
#endif
- ppc_avr_t altivec[QEMU_NVRREG];
+ /* We cannot use ppc_avr_t here as we do *not* want the implied
+ * 16-bytes alignment that would result from it. This would have
+ * the effect of making the whole struct target_mcontext aligned
+ * which breaks the layout of struct target_ucontext on ppc64.
+ */
+ uint64_t altivec[QEMU_NVRREG][2];
#undef QEMU_NVRREG
- } mc_vregs __attribute__((__aligned__(16)));
+ } mc_vregs;
};
/* See arch/powerpc/include/asm/sigcontext.h. */
@@ -4626,6 +4646,16 @@ static target_ulong get_sigframe(struct target_sigaction *ka,
return (oldsp - frame_size) & ~0xFUL;
}
+#if ((defined(TARGET_WORDS_BIGENDIAN) && defined(HOST_WORDS_BIGENDIAN)) || \
+ (!defined(HOST_WORDS_BIGENDIAN) && !defined(TARGET_WORDS_BIGENDIAN)))
+#define PPC_VEC_HI 0
+#define PPC_VEC_LO 1
+#else
+#define PPC_VEC_HI 1
+#define PPC_VEC_LO 0
+#endif
+
+
static void save_user_regs(CPUPPCState *env, struct target_mcontext *frame)
{
target_ulong msr = env->msr;
@@ -4652,18 +4682,33 @@ static void save_user_regs(CPUPPCState *env, struct target_mcontext *frame)
/* Save Altivec registers if necessary. */
if (env->insns_flags & PPC_ALTIVEC) {
+ uint32_t *vrsave;
for (i = 0; i < ARRAY_SIZE(env->avr); i++) {
ppc_avr_t *avr = &env->avr[i];
- ppc_avr_t *vreg = &frame->mc_vregs.altivec[i];
+ ppc_avr_t *vreg = (ppc_avr_t *)&frame->mc_vregs.altivec[i];
- __put_user(avr->u64[0], &vreg->u64[0]);
- __put_user(avr->u64[1], &vreg->u64[1]);
+ __put_user(avr->u64[PPC_VEC_HI], &vreg->u64[0]);
+ __put_user(avr->u64[PPC_VEC_LO], &vreg->u64[1]);
}
/* Set MSR_VR in the saved MSR value to indicate that
frame->mc_vregs contains valid data. */
msr |= MSR_VR;
- __put_user((uint32_t)env->spr[SPR_VRSAVE],
- &frame->mc_vregs.altivec[32].u32[3]);
+#if defined(TARGET_PPC64)
+ vrsave = (uint32_t *)&frame->mc_vregs.altivec[33];
+ /* 64-bit needs to put a pointer to the vectors in the frame */
+ __put_user(h2g(frame->mc_vregs.altivec), &frame->v_regs);
+#else
+ vrsave = (uint32_t *)&frame->mc_vregs.altivec[32];
+#endif
+ __put_user((uint32_t)env->spr[SPR_VRSAVE], vrsave);
+ }
+
+ /* Save VSX second halves */
+ if (env->insns_flags2 & PPC2_VSX) {
+ uint64_t *vsregs = (uint64_t *)&frame->mc_vregs.altivec[34];
+ for (i = 0; i < ARRAY_SIZE(env->vsr); i++) {
+ __put_user(env->vsr[i], &vsregs[i]);
+ }
}
/* Save floating point registers. */
@@ -4743,17 +4788,39 @@ static void restore_user_regs(CPUPPCState *env,
/* Restore Altivec registers if necessary. */
if (env->insns_flags & PPC_ALTIVEC) {
+ ppc_avr_t *v_regs;
+ uint32_t *vrsave;
+#if defined(TARGET_PPC64)
+ uint64_t v_addr;
+ /* 64-bit needs to recover the pointer to the vectors from the frame */
+ __get_user(v_addr, &frame->v_regs);
+ v_regs = g2h(v_addr);
+#else
+ v_regs = (ppc_avr_t *)frame->mc_vregs.altivec;
+#endif
for (i = 0; i < ARRAY_SIZE(env->avr); i++) {
ppc_avr_t *avr = &env->avr[i];
- ppc_avr_t *vreg = &frame->mc_vregs.altivec[i];
+ ppc_avr_t *vreg = &v_regs[i];
- __get_user(avr->u64[0], &vreg->u64[0]);
- __get_user(avr->u64[1], &vreg->u64[1]);
+ __get_user(avr->u64[PPC_VEC_HI], &vreg->u64[0]);
+ __get_user(avr->u64[PPC_VEC_LO], &vreg->u64[1]);
}
/* Set MSR_VEC in the saved MSR value to indicate that
frame->mc_vregs contains valid data. */
- __get_user(env->spr[SPR_VRSAVE],
- (target_ulong *)(&frame->mc_vregs.altivec[32].u32[3]));
+#if defined(TARGET_PPC64)
+ vrsave = (uint32_t *)&v_regs[33];
+#else
+ vrsave = (uint32_t *)&v_regs[32];
+#endif
+ __get_user(env->spr[SPR_VRSAVE], vrsave);
+ }
+
+ /* Restore VSX second halves */
+ if (env->insns_flags2 & PPC2_VSX) {
+ uint64_t *vsregs = (uint64_t *)&frame->mc_vregs.altivec[34];
+ for (i = 0; i < ARRAY_SIZE(env->vsr); i++) {
+ __get_user(env->vsr[i], &vsregs[i]);
+ }
}
/* Restore floating point registers. */
@@ -4784,6 +4851,7 @@ static void restore_user_regs(CPUPPCState *env,
}
}
+#if !defined(TARGET_PPC64)
static void setup_frame(int sig, struct target_sigaction *ka,
target_sigset_t *set, CPUPPCState *env)
{
@@ -4791,9 +4859,6 @@ static void setup_frame(int sig, struct target_sigaction *ka,
struct target_sigcontext *sc;
target_ulong frame_addr, newsp;
int err = 0;
-#if defined(TARGET_PPC64)
- struct image_info *image = ((TaskState *)thread_cpu->opaque)->info;
-#endif
frame_addr = get_sigframe(ka, env, sizeof(*frame));
trace_user_setup_frame(env, frame_addr);
@@ -4803,11 +4868,7 @@ static void setup_frame(int sig, struct target_sigaction *ka,
__put_user(ka->_sa_handler, &sc->handler);
__put_user(set->sig[0], &sc->oldmask);
-#if TARGET_ABI_BITS == 64
- __put_user(set->sig[0] >> 32, &sc->_unused[3]);
-#else
__put_user(set->sig[1], &sc->_unused[3]);
-#endif
__put_user(h2g(&frame->mctx), &sc->regs);
__put_user(sig, &sc->signal);
@@ -4836,22 +4897,7 @@ static void setup_frame(int sig, struct target_sigaction *ka,
env->gpr[3] = sig;
env->gpr[4] = frame_addr + offsetof(struct target_sigframe, sctx);
-#if defined(TARGET_PPC64)
- if (get_ppc64_abi(image) < 2) {
- /* ELFv1 PPC64 function pointers are pointers to OPD entries. */
- struct target_func_ptr *handler =
- (struct target_func_ptr *)g2h(ka->_sa_handler);
- 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;
- }
-#else
env->nip = (target_ulong) ka->_sa_handler;
-#endif
/* Signal handlers are entered in big-endian mode. */
env->msr &= ~(1ull << MSR_LE);
@@ -4863,6 +4909,7 @@ sigsegv:
unlock_user_struct(frame, frame_addr, 1);
force_sigsegv(sig);
}
+#endif /* !defined(TARGET_PPC64) */
static void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
@@ -4960,6 +5007,7 @@ sigsegv:
}
+#if !defined(TARGET_PPC64)
long do_sigreturn(CPUPPCState *env)
{
struct target_sigcontext *sc = NULL;
@@ -4996,6 +5044,7 @@ sigsegv:
force_sig(TARGET_SIGSEGV);
return -TARGET_QEMU_ESIGRETURN;
}
+#endif /* !defined(TARGET_PPC64) */
/* See arch/powerpc/kernel/signal_32.c. */
static int do_setcontext(struct target_ucontext *ucp, CPUPPCState *env, int sig)
@@ -5939,7 +5988,8 @@ static void handle_pending_signal(CPUArchState *cpu_env, int sig,
#endif
/* prepare the stack frame of the virtual CPU */
#if defined(TARGET_ABI_MIPSN32) || defined(TARGET_ABI_MIPSN64) \
- || defined(TARGET_OPENRISC) || defined(TARGET_TILEGX)
+ || defined(TARGET_OPENRISC) || defined(TARGET_TILEGX) \
+ || defined(TARGET_PPC64)
/* These targets do not have traditional signals. */
setup_rt_frame(sig, sa, &k->info, &target_old_set, cpu_env);
#else