Add retguard to amd64 syscalls.

Since we got rid of padded syscalls we have enough registers to do this.

ok deraadt@ ok kettenis@

8 files changed, 67 insertions, 24 deletions

diff --git a/lib/libc/arch/amd64/SYS.h b/lib/libc/arch/amd64/SYS.h
index e20e50c7875..ce67ad0325c 100644
--- a/lib/libc/arch/amd64/SYS.h
+++ b/lib/libc/arch/amd64/SYS.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: SYS.h,v 1.20 2016/09/06 18:33:35 kettenis Exp $	*/
+/*	$OpenBSD: SYS.h,v 1.21 2023/01/11 01:55:17 mortimer Exp $	*/
 
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
@@ -82,25 +82,36 @@
 	HANDLE_ERRNO
 
 
-/* return, handling errno for failed calls */
-#define _RSYSCALL_RET							\
-	jc	99f;							\
-	ret;								\
-	99: SET_ERRNO;							\
-	ret
-
 #define PSEUDO_NOERROR(x,y)						\
-	_SYSCALL_NOERROR(x,y);						\
+	SYSENTRY(x);							\
+	RETGUARD_SETUP(_thread_sys_##x, r11);				\
+	RETGUARD_PUSH(r11);						\
+	SYSTRAP(y);							\
+	RETGUARD_POP(r11);						\
+	RETGUARD_CHECK(_thread_sys_##x, r11);				\
 	ret;								\
 	SYSCALL_END(x)
 
 #define PSEUDO(x,y)							\
-	_SYSCALL_NOERROR(x,y);						\
-	_RSYSCALL_RET;							\
+	SYSENTRY(x);							\
+	RETGUARD_SETUP(_thread_sys_##x, r11);				\
+	RETGUARD_PUSH(r11);						\
+	SYSTRAP(y);							\
+	HANDLE_ERRNO;							\
+	RETGUARD_POP(r11);						\
+	RETGUARD_CHECK(_thread_sys_##x, r11);				\
+	ret;								\
 	SYSCALL_END(x)
+
 #define PSEUDO_HIDDEN(x,y)						\
-	_SYSCALL_HIDDEN_NOERROR(x,y);					\
-	_RSYSCALL_RET;							\
+	SYSENTRY_HIDDEN(x);						\
+	RETGUARD_SETUP(_thread_sys_##x, r11);				\
+	RETGUARD_PUSH(r11);						\
+	SYSTRAP(y);							\
+	HANDLE_ERRNO;							\
+	RETGUARD_POP(r11);						\
+	RETGUARD_CHECK(_thread_sys_##x , r11);				\
+	ret;								\
 	SYSCALL_END_HIDDEN(x)
 
 #define RSYSCALL_NOERROR(x)						\
diff --git a/lib/libc/arch/amd64/sys/Ovfork.S b/lib/libc/arch/amd64/sys/Ovfork.S
index e42649e28ce..3d129eeb222 100644
--- a/lib/libc/arch/amd64/sys/Ovfork.S
+++ b/lib/libc/arch/amd64/sys/Ovfork.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: Ovfork.S,v 1.8 2016/05/07 19:05:21 guenther Exp $	*/
+/*	$OpenBSD: Ovfork.S,v 1.9 2023/01/11 01:55:17 mortimer Exp $	*/
 /*	$NetBSD: Ovfork.S,v 1.2 2002/06/03 18:30:33 fvdl Exp $	*/
 
 /*-
@@ -41,11 +41,15 @@
 
 SYSENTRY_HIDDEN(vfork)
 	popq	%r9		/* my rta into r9 */
+	RETGUARD_SETUP(_thread_sys_vfork, r11);
+	RETGUARD_PUSH(r11);
 	SYSTRAP(vfork)
+	RETGUARD_POP(r11)
 	jc	1f
 	jmp	*%r9
 1:
 	pushq	%r9
 	SET_ERRNO
+	RETGUARD_CHECK(_thread_sys_vfork, r11);
 	ret
 SYSCALL_END_HIDDEN(vfork)
diff --git a/lib/libc/arch/amd64/sys/brk.S b/lib/libc/arch/amd64/sys/brk.S
index e00f74099eb..0fa17dbedce 100644
--- a/lib/libc/arch/amd64/sys/brk.S
+++ b/lib/libc/arch/amd64/sys/brk.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: brk.S,v 1.12 2022/01/01 23:47:14 guenther Exp $	*/
+/*	$OpenBSD: brk.S,v 1.13 2023/01/11 01:55:17 mortimer Exp $	*/
 /*	$NetBSD: brk.S,v 1.2 2002/06/03 18:30:33 fvdl Exp $	*/
 
 /*-
@@ -49,6 +49,8 @@ __minbrk:
 	.type	__minbrk,@object
 
 ENTRY_NB(brk)
+	RETGUARD_SETUP(brk, r11);
+	RETGUARD_PUSH(r11);
 	cmpq	%rdi,__minbrk(%rip)
 	jb	1f
 	movq	__minbrk(%rip),%rdi
@@ -57,9 +59,12 @@ ENTRY_NB(brk)
 	jc	1f
 	movq	%rdi,__curbrk(%rip)
 	xorl	%eax,%eax
-	ret
+	jmp	2f
 1:
 	SET_ERRNO
+2:
+	RETGUARD_POP(r11);
+	RETGUARD_CHECK(brk, r11);
 	ret
 END(brk)
 	.weak	brk
diff --git a/lib/libc/arch/amd64/sys/sbrk.S b/lib/libc/arch/amd64/sys/sbrk.S
index 80a6a16d4e1..836f40a1784 100644
--- a/lib/libc/arch/amd64/sys/sbrk.S
+++ b/lib/libc/arch/amd64/sys/sbrk.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sbrk.S,v 1.12 2022/01/01 23:47:14 guenther Exp $	*/
+/*	$OpenBSD: sbrk.S,v 1.13 2023/01/11 01:55:17 mortimer Exp $	*/
 /*	$NetBSD: sbrk.S,v 1.1 2001/06/19 00:25:06 fvdl Exp $	*/
 
 /*-
@@ -54,6 +54,8 @@ __curbrk:
 	.type	__curbrk,@object
 
 ENTRY_NB(sbrk)
+	RETGUARD_SETUP(sbrk, r11);
+	RETGUARD_PUSH(r11);
 	movq	__curbrk(%rip),%rax
 	movslq	%edi,%rsi
 	movq	%rsi,%rdi
@@ -62,9 +64,12 @@ ENTRY_NB(sbrk)
 	jc	1f
 	movq	__curbrk(%rip),%rax
 	addq	%rsi,__curbrk(%rip)
-	ret
+	jmp	2f
 1:
 	SET_ERRNO
+2:
+	RETGUARD_POP(r11);
+	RETGUARD_CHECK(sbrk, r11);
 	ret
 END(sbrk)
 	.weak	sbrk
diff --git a/lib/libc/arch/amd64/sys/sigpending.S b/lib/libc/arch/amd64/sys/sigpending.S
index 6d8a2201791..576eff08766 100644
--- a/lib/libc/arch/amd64/sys/sigpending.S
+++ b/lib/libc/arch/amd64/sys/sigpending.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sigpending.S,v 1.3 2015/06/17 03:04:50 uebayasi Exp $	*/
+/*	$OpenBSD: sigpending.S,v 1.4 2023/01/11 01:55:17 mortimer Exp $	*/
 /*	$NetBSD: sigpending.S,v 1.1 2001/06/19 00:25:06 fvdl Exp $	*/
 
 /*-
@@ -40,7 +40,11 @@
 #include "SYS.h"
 
 SYSCALL(sigpending)
+	RETGUARD_SETUP(_thread_sys_sigpending, r11);
+	RETGUARD_PUSH(r11);
 	movl	%eax,(%rdi)		# store old mask
 	xorl	%eax,%eax
+	RETGUARD_POP(r11)
+	RETGUARD_CHECK(_thread_sys_sigpending, r11);
 	ret
 SYSCALL_END(sigpending)
diff --git a/lib/libc/arch/amd64/sys/sigprocmask.S b/lib/libc/arch/amd64/sys/sigprocmask.S
index 308c5800b50..ddcae14576c 100644
--- a/lib/libc/arch/amd64/sys/sigprocmask.S
+++ b/lib/libc/arch/amd64/sys/sigprocmask.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sigprocmask.S,v 1.9 2016/05/07 19:05:21 guenther Exp $	*/
+/*	$OpenBSD: sigprocmask.S,v 1.10 2023/01/11 01:55:17 mortimer Exp $	*/
 /*	$NetBSD: sigprocmask.S,v 1.1 2001/06/19 00:25:06 fvdl Exp $	*/
 
 /*-
@@ -40,6 +40,8 @@
 #include "SYS.h"
 
 SYSENTRY_HIDDEN(sigprocmask)
+	RETGUARD_SETUP(_thread_sys_sigprocmask, r11);
+	RETGUARD_PUSH(r11);
 	testq	%rsi,%rsi		# check new sigset pointer
 	jnz	1f			# if not null, indirect
 	movl	$1,%edi			# SIG_BLOCK
@@ -52,8 +54,11 @@ SYSENTRY_HIDDEN(sigprocmask)
 	movl	%eax,(%rdx)		# store old mask
 3:
 	xorl	%eax,%eax
-	ret
+	jmp	2f
 1:
 	SET_ERRNO
+2:
+	RETGUARD_POP(r11);
+	RETGUARD_CHECK(_thread_sys_sigprocmask, r11);
 	ret
 SYSCALL_END_HIDDEN(sigprocmask)
diff --git a/lib/libc/arch/amd64/sys/sigsuspend.S b/lib/libc/arch/amd64/sys/sigsuspend.S
index 9abb04e1079..2a08beb361e 100644
--- a/lib/libc/arch/amd64/sys/sigsuspend.S
+++ b/lib/libc/arch/amd64/sys/sigsuspend.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sigsuspend.S,v 1.7 2016/05/07 19:05:21 guenther Exp $	*/
+/*	$OpenBSD: sigsuspend.S,v 1.8 2023/01/11 01:55:17 mortimer Exp $	*/
 /*	$NetBSD: sigsuspend.S,v 1.1 2001/06/19 00:25:07 fvdl Exp $	*/
 
 /*-
@@ -40,8 +40,12 @@
 #include "SYS.h"
 
 SYSENTRY_HIDDEN(sigsuspend)
+	RETGUARD_SETUP(_thread_sys_sigsuspend, r11);
+	RETGUARD_PUSH(r11);
 	movl	(%rdi),%edi		# indirect to mask arg
 	SYSTRAP(sigsuspend)
 	SET_ERRNO
+	RETGUARD_POP(r11);
+	RETGUARD_CHECK(_thread_sys_sigsuspend, r11);
 	ret
 SYSCALL_END_HIDDEN(sigsuspend)
diff --git a/lib/libc/arch/amd64/sys/tfork_thread.S b/lib/libc/arch/amd64/sys/tfork_thread.S
index b543296b04e..8de236b7d21 100644
--- a/lib/libc/arch/amd64/sys/tfork_thread.S
+++ b/lib/libc/arch/amd64/sys/tfork_thread.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tfork_thread.S,v 1.10 2020/10/18 14:28:17 deraadt Exp $ */
+/*	$OpenBSD: tfork_thread.S,v 1.11 2023/01/11 01:55:17 mortimer Exp $ */
 /*-
  * Copyright (c) 2000 Peter Wemm <peter@FreeBSD.org>
  * Copyright (c) 2003 Alan L. Cox <alc@cs.rice.edu>
@@ -46,6 +46,8 @@
 
 ENTRY(__tfork_thread)
 	.cfi_startproc
+	RETGUARD_SETUP(__tfork_thread, r11);
+	RETGUARD_PUSH(r11);
 	movq	%rdx, %r8
 	movq	%rcx, %r9
 
@@ -62,7 +64,7 @@ ENTRY(__tfork_thread)
 	 */
 	cmpl	$0, %eax
 	jz	1f
-	ret
+	jmp	3f
 
 	/* the retpoline we'll use to call the child's main */
 	_ALIGN_TRAPS
@@ -96,6 +98,9 @@ ENTRY(__tfork_thread)
 	 */
 2:
 	SET_ERRNO
+3:
+	RETGUARD_POP(r11);
+	RETGUARD_CHECK(__tfork_thread, r11);
 	ret
 	.cfi_endproc
 END(__tfork_thread)