MIPS: do_sigaltstack() expects userland pointers
o32 compat does the right thing, native and n32 compat do not...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1700/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 604f077..5922342 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -390,7 +390,6 @@
{
struct rt_sigframe __user *frame;
sigset_t set;
- stack_t st;
int sig;
frame = (struct rt_sigframe __user *) regs.regs[29];
@@ -411,11 +410,9 @@
else if (sig)
force_sig(sig, current);
- if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
- goto badframe;
/* It is more difficult to avoid calling this function than to
call it and ignore errors. */
- do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
+ do_sigaltstack(&frame->rs_uc.uc_stack, NULL, regs.regs[29]);
/*
* Don't let your children do this ...
diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c
index 2c5df81..ee24d81 100644
--- a/arch/mips/kernel/signal_n32.c
+++ b/arch/mips/kernel/signal_n32.c
@@ -109,6 +109,7 @@
asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
{
struct rt_sigframe_n32 __user *frame;
+ mm_segment_t old_fs;
sigset_t set;
stack_t st;
s32 sp;
@@ -143,7 +144,11 @@
/* It is more difficult to avoid calling this function than to
call it and ignore errors. */
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
+ set_fs(old_fs);
+
/*
* Don't let your children do this ...