Create a function to match target_save_altstack.
Fix some style and unlock issues in do_sigaltstack.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
linux-user/signal-common.h | 1 +
linux-user/signal.c | 115 +++++++++++++++++++++----------------
2 files changed, 66 insertions(+), 50 deletions(-)
diff --git a/linux-user/signal-common.h b/linux-user/signal-common.h
index 1df1068552..34b963af9a 100644
--- a/linux-user/signal-common.h
+++ b/linux-user/signal-common.h
@@ -24,6 +24,7 @@ int on_sig_stack(unsigned long sp);
int sas_ss_flags(unsigned long sp);
abi_ulong target_sigsp(abi_ulong sp, struct target_sigaction *ka);
void target_save_altstack(target_stack_t *uss, CPUArchState *env);
+abi_long target_restore_altstack(target_stack_t *uss, abi_ulong sp);
static inline void target_sigemptyset(target_sigset_t *set)
{
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 44a5012930..306f3edec5 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -297,6 +297,50 @@ void target_save_altstack(target_stack_t *uss,
CPUArchState *env)
__put_user(ts->sigaltstack_used.ss_size, &uss->ss_size);
}
+abi_long target_restore_altstack(target_stack_t *uss, abi_ulong sp)
+{
+ TaskState *ts = (TaskState *)thread_cpu->opaque;
+ size_t minstacksize = TARGET_MINSIGSTKSZ;
+ target_stack_t ss;
+
+#if defined(TARGET_PPC64)
+ /* ELF V2 for PPC64 has a 4K minimum stack size for signal handlers */
+ struct image_info *image = ts->info;
+ if (get_ppc64_abi(image) > 1) {
+ minstacksize = 4096;
+ }
+#endif
+
+ __get_user(ss.ss_sp, &uss->ss_sp);
+ __get_user(ss.ss_size, &uss->ss_size);
+ __get_user(ss.ss_flags, &uss->ss_flags);
+
+ if (on_sig_stack(sp)) {
+ return -TARGET_EPERM;
+ }
+
+ switch (ss.ss_flags) {
+ default:
+ return -TARGET_EINVAL;
+
+ case TARGET_SS_DISABLE:
+ ss.ss_size = 0;
+ ss.ss_sp = 0;
+ break;
+
+ case TARGET_SS_ONSTACK:
+ case 0:
+ if (ss.ss_size < minstacksize) {
+ return -TARGET_ENOMEM;
+ }
+ break;
+ }
+
+ ts->sigaltstack_used.ss_sp = ss.ss_sp;
+ ts->sigaltstack_used.ss_size = ss.ss_size;
+ return 0;
+}
+
/* siginfo conversion */
static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo,
@@ -758,73 +802,44 @@ static void host_signal_handler(int host_signum,
siginfo_t *info,
/* compare linux/kernel/signal.c:do_sigaltstack() */
abi_long do_sigaltstack(abi_ulong uss_addr, abi_ulong uoss_addr, abi_ulong sp)
{
- int ret;
- struct target_sigaltstack oss;
- TaskState *ts = (TaskState *)thread_cpu->opaque;
+ target_stack_t oss, *uoss = NULL;
+ abi_long ret = -TARGET_EFAULT;
- /* XXX: test errors */
- if(uoss_addr)
- {
+ if (uoss_addr) {
+ TaskState *ts = (TaskState *)thread_cpu->opaque;
+
+ /* Verify writability now, but do not alter user memory yet. */
+ if (!lock_user_struct(VERIFY_WRITE, uoss, uoss_addr, 0)) {
+ goto out;
+ }
__put_user(ts->sigaltstack_used.ss_sp, &oss.ss_sp);
__put_user(ts->sigaltstack_used.ss_size, &oss.ss_size);
__put_user(sas_ss_flags(sp), &oss.ss_flags);
}
- if(uss_addr)
- {
- struct target_sigaltstack *uss;
- struct target_sigaltstack ss;
- size_t minstacksize = TARGET_MINSIGSTKSZ;
+ if (uss_addr) {
+ target_stack_t *uss;
-#if defined(TARGET_PPC64)
- /* ELF V2 for PPC64 has a 4K minimum stack size for signal handlers */
- struct image_info *image = ((TaskState *)thread_cpu->opaque)->info;
- if (get_ppc64_abi(image) > 1) {
- minstacksize = 4096;
- }
-#endif
-
- ret = -TARGET_EFAULT;
if (!lock_user_struct(VERIFY_READ, uss, uss_addr, 1)) {
goto out;
}
- __get_user(ss.ss_sp, &uss->ss_sp);
- __get_user(ss.ss_size, &uss->ss_size);
- __get_user(ss.ss_flags, &uss->ss_flags);
- unlock_user_struct(uss, uss_addr, 0);
-
- ret = -TARGET_EPERM;
- if (on_sig_stack(sp))
+ ret = target_restore_altstack(uss, sp);
+ if (ret) {
goto out;
-
- ret = -TARGET_EINVAL;
- if (ss.ss_flags != TARGET_SS_DISABLE
- && ss.ss_flags != TARGET_SS_ONSTACK
- && ss.ss_flags != 0)
- goto out;
-
- if (ss.ss_flags == TARGET_SS_DISABLE) {
- ss.ss_size = 0;
- ss.ss_sp = 0;
- } else {
- ret = -TARGET_ENOMEM;
- if (ss.ss_size < minstacksize) {
- goto out;
- }
}
-
- ts->sigaltstack_used.ss_sp = ss.ss_sp;
- ts->sigaltstack_used.ss_size = ss.ss_size;
}
if (uoss_addr) {
- ret = -TARGET_EFAULT;
- if (copy_to_user(uoss_addr, &oss, sizeof(oss)))
- goto out;
+ memcpy(uoss, &oss, sizeof(oss));
+ unlock_user_struct(uoss, uoss_addr, 1);
+ uoss = NULL;
}
-
ret = 0;
-out:
+
+ out:
+ if (uoss) {
+ unlock_user_struct(uoss, uoss_addr, 0);
+ }
return ret;
}
--
2.25.1
