x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame()

Straightforward, except for compat_save_altstack_ex() stuck in those.
Replace that thing with an analogue that would use unsafe_put_user()
instead of put_user_ex() (called unsafe_compat_save_altstack()) and
be done with that...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 26 insertions, 24 deletions

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index af673ec23a2d..a96995aa23da 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -326,35 +326,34 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
 
 	frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate);
 
-	if (!access_ok(frame, sizeof(*frame)))
+	if (!user_access_begin(frame, sizeof(*frame)))
 		return -EFAULT;
 
-	put_user_try {
-		put_user_ex(sig, &frame->sig);
-		put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
-		put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
+	unsafe_put_user(sig, &frame->sig, Efault);
+	unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault);
+	unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault);
 
-		/* Create the ucontext.  */
-		if (static_cpu_has(X86_FEATURE_XSAVE))
-			put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
-		else
-			put_user_ex(0, &frame->uc.uc_flags);
-		put_user_ex(0, &frame->uc.uc_link);
-		compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp);
+	/* Create the ucontext.  */
+	if (static_cpu_has(X86_FEATURE_XSAVE))
+		unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault);
+	else
+		unsafe_put_user(0, &frame->uc.uc_flags, Efault);
+	unsafe_put_user(0, &frame->uc.uc_link, Efault);
+	unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault);
 
-		if (ksig->ka.sa.sa_flags & SA_RESTORER)
-			restorer = ksig->ka.sa.sa_restorer;
-		else
-			restorer = current->mm->context.vdso +
-				vdso_image_32.sym___kernel_rt_sigreturn;
-		put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
+	if (ksig->ka.sa.sa_flags & SA_RESTORER)
+		restorer = ksig->ka.sa.sa_restorer;
+	else
+		restorer = current->mm->context.vdso +
+			vdso_image_32.sym___kernel_rt_sigreturn;
+	unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
 
-		/*
-		 * Not actually used anymore, but left because some gdb
-		 * versions need it.
-		 */
-		put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode);
-	} put_user_catch(err);
+	/*
+	 * Not actually used anymore, but left because some gdb
+	 * versions need it.
+	 */
+	unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault);
+	user_access_end();
 
 	err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false);
 	err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
@@ -380,4 +379,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig,
 	regs->ss = __USER32_DS;
 
 	return 0;
+Efault:
+	user_access_end();
+	return -EFAULT;
 }