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>
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index a866411..a1daf4a 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -467,10 +467,7 @@
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 b17ed37..a6c8a34 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -363,10 +363,7 @@
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 @@
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 @@
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 @@
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 @@
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 bdaa08c..71cef48 100644
--- a/arch/x86/um/signal.c
+++ b/arch/x86/um/signal.c
@@ -342,9 +342,7 @@
{
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, ¤t->thread.regs, 0);
err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
return err;
@@ -529,10 +527,7 @@
/* 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 cb5637e..3348133 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -647,6 +647,7 @@
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 5969522..0a89ffc 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -386,5 +386,6 @@
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 aee85bd..f072513 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3117,6 +3117,14 @@
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 @@
/* 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