From 00198a6eaf66609de5e4de9163bb42c7ca9dd7b7 Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolvanen@google.com>
Date: Tue, 8 Oct 2019 15:40:47 -0700
Subject: syscalls/x86: Use COMPAT_SYSCALL_DEFINE0 for IA32 (rt_)sigreturn

Use COMPAT_SYSCALL_DEFINE0 to define (rt_)sigreturn() syscalls to
replace sys32_sigreturn() and sys32_rt_sigreturn(). This fixes indirect
call mismatches with Control-Flow Integrity (CFI) checking.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H . Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191008224049.115427-4-samitolvanen@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/ia32/ia32_signal.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

(limited to 'arch/x86/ia32')

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 1cee10091b9f..30416d7f19d4 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -21,6 +21,7 @@
 #include <linux/personality.h>
 #include <linux/compat.h>
 #include <linux/binfmts.h>
+#include <linux/syscalls.h>
 #include <asm/ucontext.h>
 #include <linux/uaccess.h>
 #include <asm/fpu/internal.h>
@@ -118,7 +119,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
 	return err;
 }
 
-asmlinkage long sys32_sigreturn(void)
+COMPAT_SYSCALL_DEFINE0(sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
 	struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
@@ -144,7 +145,7 @@ badframe:
 	return 0;
 }
 
-asmlinkage long sys32_rt_sigreturn(void)
+COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe_ia32 __user *frame;
-- 
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