MIPS: do_sigaltstack() expects userland pointers

o32 compat does the right thing, native and n32 compat do not... Signed-off-by: Al Viro <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Patchwork: http://patchwork.linux-mips.org/patch/1700/ Signed-off-by: Ralf Baechle <[email protected]>
mgowda · Oct 18, 2010 · 4bfb8c5 · 4bfb8c5
1 parent 5b89c00
commit 4bfb8c5
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Showing 2 changed files with 6 additions and 4 deletions.
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
@@ -390,7 +390,6 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 {
 	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 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	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
@@ -109,6 +109,7 @@ asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
 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 @@ asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 
 	/* 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 ...