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authorAl Viro <viro@zeniv.linux.org.uk>2012-11-20 14:24:26 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2012-12-19 18:07:41 -0500
commitc40702c49faef05ae324f121d8b3e215244ee152 (patch)
treeb0b2a51b07e944497da5cb48fb461963a3762cad
parent9026843952adac5b123c7b8dc961e5c15828d9e1 (diff)
new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those
note that they are relying on access_ok() already checked by caller. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--arch/x86/ia32/ia32_signal.c5
-rw-r--r--arch/x86/kernel/signal.c18
-rw-r--r--arch/x86/um/signal.c9
-rw-r--r--include/linux/compat.h1
-rw-r--r--include/linux/signal.h1
-rw-r--r--kernel/signal.c16
6 files changed, 25 insertions, 25 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a866411a2fcc..a1daf4a65009 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -467,10 +467,7 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
- put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
- put_user_ex(sas_ss_flags(regs->sp),
- &frame->uc.uc_stack.ss_flags);
- put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp);
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index b17ed37c61a2..a6c8a347b8c6 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -363,10 +363,7 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
- put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
- put_user_ex(sas_ss_flags(regs->sp),
- &frame->uc.uc_stack.ss_flags);
- put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
/* Set up to return from userspace. */
restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
@@ -413,7 +410,6 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
struct rt_sigframe __user *frame;
void __user *fp = NULL;
int err = 0;
- struct task_struct *me = current;
frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
@@ -432,10 +428,7 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
- put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
- put_user_ex(sas_ss_flags(regs->sp),
- &frame->uc.uc_stack.ss_flags);
- put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
@@ -502,10 +495,7 @@ static int x32_setup_rt_frame(int sig, struct k_sigaction *ka,
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
- put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
- put_user_ex(sas_ss_flags(regs->sp),
- &frame->uc.uc_stack.ss_flags);
- put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp);
put_user_ex(0, &frame->uc.uc__pad0);
if (ka->sa.sa_flags & SA_RESTORER) {
@@ -651,7 +641,7 @@ long sys_rt_sigreturn(struct pt_regs *regs)
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
- if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
+ if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return ax;
diff --git a/arch/x86/um/signal.c b/arch/x86/um/signal.c
index bdaa08cfbcf4..71cef48ea5cd 100644
--- a/arch/x86/um/signal.c
+++ b/arch/x86/um/signal.c
@@ -342,9 +342,7 @@ static int copy_ucontext_to_user(struct ucontext __user *uc,
{
int err = 0;
- err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
- err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
- err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
+ err |= __save_altstack(&uc->uc_stack, sp);
err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, 0);
err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
return err;
@@ -529,10 +527,7 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
- err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
- err |= __put_user(sas_ss_flags(PT_REGS_SP(regs)),
- &frame->uc.uc_stack.ss_flags);
- err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
set->sig[0]);
err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
diff --git a/include/linux/compat.h b/include/linux/compat.h
index cb5637e2ee2c..334813307ec1 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -647,6 +647,7 @@ asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr,
compat_stack_t __user *uoss_ptr);
int compat_restore_altstack(const compat_stack_t __user *uss);
+int __compat_save_altstack(compat_stack_t __user *, unsigned long);
#endif
#else
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 5969522136fe..0a89ffc48466 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -386,5 +386,6 @@ int unhandled_signal(struct task_struct *tsk, int sig);
void signals_init(void);
int restore_altstack(const stack_t __user *);
+int __save_altstack(stack_t __user *, unsigned long);
#endif /* _LINUX_SIGNAL_H */
diff --git a/kernel/signal.c b/kernel/signal.c
index aee85bd76b8a..f072513302c3 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3117,6 +3117,14 @@ int restore_altstack(const stack_t __user *uss)
return err == -EFAULT ? err : 0;
}
+int __save_altstack(stack_t __user *uss, unsigned long sp)
+{
+ struct task_struct *t = current;
+ return __put_user((void __user *)t->sas_ss_sp, &uss->ss_sp) |
+ __put_user(sas_ss_flags(sp), &uss->ss_flags) |
+ __put_user(t->sas_ss_size, &uss->ss_size);
+}
+
#ifdef CONFIG_COMPAT
#ifdef CONFIG_GENERIC_SIGALTSTACK
asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr,
@@ -3158,6 +3166,14 @@ int compat_restore_altstack(const compat_stack_t __user *uss)
/* squash all but -EFAULT for now */
return err == -EFAULT ? err : 0;
}
+
+int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp)
+{
+ struct task_struct *t = current;
+ return __put_user(ptr_to_compat((void __user *)t->sas_ss_sp), &uss->ss_sp) |
+ __put_user(sas_ss_flags(sp), &uss->ss_flags) |
+ __put_user(t->sas_ss_size, &uss->ss_size);
+}
#endif
#endif