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From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Subject: [PATCH 10/15] riscv: Avoid clobbering register parameters in syscall
Date: Mon, 10 Feb 2020 19:21:00 -0000	[thread overview]
Message-ID: <20200210192038.23588-10-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20200210192038.23588-1-adhemerval.zanella@linaro.org>

The riscv INTERNAL_SYSCALL macro might clobber the register
parameter if the argument itself might clobber any register (a function
call for instance).

This patch fixes it by using temporary variables for the expressions
between the register assignments (as indicated by GCC documentation,
6.47.5.2 Specifying Registers for Local Variables).

It is similar to the fix done for MIPS (BZ#25523).

Checked with riscv64-linux-gnu-rv64imafdc-lp64d build.
---
 sysdeps/unix/sysv/linux/riscv/sysdep.h | 84 +++++++++++++++++---------
 1 file changed, 56 insertions(+), 28 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/riscv/sysdep.h b/sysdeps/unix/sysv/linux/riscv/sysdep.h
index 201bf9a91b..2bd9b16f32 100644
--- a/sysdeps/unix/sysv/linux/riscv/sysdep.h
+++ b/sysdeps/unix/sysv/linux/riscv/sysdep.h
@@ -176,10 +176,11 @@
 # define internal_syscall1(number, err, arg0)				\
 ({ 									\
 	long int _sys_result;						\
+	long int _arg0 = (long int) (arg0);				\
 									\
 	{								\
 	register long int __a7 asm ("a7") = number;			\
-	register long int __a0 asm ("a0") = (long int) (arg0);		\
+	register long int __a0 asm ("a0") = _arg0;			\
 	__asm__ volatile ( 						\
 	"scall\n\t" 							\
 	: "+r" (__a0)							\
@@ -193,11 +194,13 @@
 # define internal_syscall2(number, err, arg0, arg1)	    		\
 ({ 									\
 	long int _sys_result;						\
+	long int _arg0 = (long int) (arg0);				\
+	long int _arg1 = (long int) (arg1);				\
 									\
 	{								\
 	register long int __a7 asm ("a7") = number;			\
-	register long int __a0 asm ("a0") = (long int) (arg0);		\
-	register long int __a1 asm ("a1") = (long int) (arg1);		\
+	register long int __a0 asm ("a0") = _arg0;			\
+	register long int __a1 asm ("a1") = _arg1;			\
 	__asm__ volatile ( 						\
 	"scall\n\t" 							\
 	: "+r" (__a0)							\
@@ -211,12 +214,15 @@
 # define internal_syscall3(number, err, arg0, arg1, arg2)      		\
 ({ 									\
 	long int _sys_result;						\
+	long int _arg0 = (long int) (arg0);				\
+	long int _arg1 = (long int) (arg1);				\
+	long int _arg2 = (long int) (arg2);				\
 									\
 	{								\
 	register long int __a7 asm ("a7") = number;			\
-	register long int __a0 asm ("a0") = (long int) (arg0);		\
-	register long int __a1 asm ("a1") = (long int) (arg1);		\
-	register long int __a2 asm ("a2") = (long int) (arg2);		\
+	register long int __a0 asm ("a0") = _arg0;			\
+	register long int __a1 asm ("a1") = _arg1;			\
+	register long int __a2 asm ("a2") = _arg2;			\
 	__asm__ volatile ( 						\
 	"scall\n\t" 							\
 	: "+r" (__a0)							\
@@ -230,13 +236,17 @@
 # define internal_syscall4(number, err, arg0, arg1, arg2, arg3)	  \
 ({ 									\
 	long int _sys_result;						\
+	long int _arg0 = (long int) (arg0);				\
+	long int _arg1 = (long int) (arg1);				\
+	long int _arg2 = (long int) (arg2);				\
+	long int _arg3 = (long int) (arg3);				\
 									\
 	{								\
 	register long int __a7 asm ("a7") = number;			\
-	register long int __a0 asm ("a0") = (long int) (arg0);		\
-	register long int __a1 asm ("a1") = (long int) (arg1);		\
-	register long int __a2 asm ("a2") = (long int) (arg2);		\
-	register long int __a3 asm ("a3") = (long int) (arg3);		\
+	register long int __a0 asm ("a0") = _arg0;			\
+	register long int __a1 asm ("a1") = _arg1;			\
+	register long int __a2 asm ("a2") = _arg2;			\
+	register long int __a3 asm ("a3") = _arg3;			\
 	__asm__ volatile ( 						\
 	"scall\n\t" 							\
 	: "+r" (__a0)							\
@@ -250,14 +260,19 @@
 # define internal_syscall5(number, err, arg0, arg1, arg2, arg3, arg4)   \
 ({ 									\
 	long int _sys_result;						\
+	long int _arg0 = (long int) (arg0);				\
+	long int _arg1 = (long int) (arg1);				\
+	long int _arg2 = (long int) (arg2);				\
+	long int _arg3 = (long int) (arg3);				\
+	long int _arg4 = (long int) (arg4);				\
 									\
 	{								\
 	register long int __a7 asm ("a7") = number;			\
-	register long int __a0 asm ("a0") = (long int) (arg0);		\
-	register long int __a1 asm ("a1") = (long int) (arg1);		\
-	register long int __a2 asm ("a2") = (long int) (arg2);		\
-	register long int __a3 asm ("a3") = (long int) (arg3);		\
-	register long int __a4 asm ("a4") = (long int) (arg4);		\
+	register long int __a0 asm ("a0") = _arg0;			\
+	register long int __a1 asm ("a1") = _arg1;			\
+	register long int __a2 asm ("a2") = _arg2;			\
+	register long int __a3 asm ("a3") = _arg3;			\
+	register long int __a4 asm ("a4") = _arg4;			\
 	__asm__ volatile ( 						\
 	"scall\n\t" 							\
 	: "+r" (__a0)							\
@@ -271,15 +286,21 @@
 # define internal_syscall6(number, err, arg0, arg1, arg2, arg3, arg4, arg5) \
 ({ 									\
 	long int _sys_result;						\
+	long int _arg0 = (long int) (arg0);				\
+	long int _arg1 = (long int) (arg1);				\
+	long int _arg2 = (long int) (arg2);				\
+	long int _arg3 = (long int) (arg3);				\
+	long int _arg4 = (long int) (arg4);				\
+	long int _arg5 = (long int) (arg5);				\
 									\
 	{								\
 	register long int __a7 asm ("a7") = number;			\
-	register long int __a0 asm ("a0") = (long int) (arg0);		\
-	register long int __a1 asm ("a1") = (long int) (arg1);		\
-	register long int __a2 asm ("a2") = (long int) (arg2);		\
-	register long int __a3 asm ("a3") = (long int) (arg3);		\
-	register long int __a4 asm ("a4") = (long int) (arg4);		\
-	register long int __a5 asm ("a5") = (long int) (arg5);		\
+	register long int __a0 asm ("a0") = _arg0;			\
+	register long int __a1 asm ("a1") = _arg1;			\
+	register long int __a2 asm ("a2") = _arg2;			\
+	register long int __a3 asm ("a3") = _arg3;			\
+	register long int __a4 asm ("a4") = _arg4;			\
+	register long int __a5 asm ("a5") = _arg5;			\
 	__asm__ volatile ( 						\
 	"scall\n\t" 							\
 	: "+r" (__a0)							\
@@ -294,16 +315,23 @@
 # define internal_syscall7(number, err, arg0, arg1, arg2, arg3, arg4, arg5, arg6) \
 ({ 									\
 	long int _sys_result;						\
+	long int _arg0 = (long int) (arg0);				\
+	long int _arg1 = (long int) (arg1);				\
+	long int _arg2 = (long int) (arg2);				\
+	long int _arg3 = (long int) (arg3);				\
+	long int _arg4 = (long int) (arg4);				\
+	long int _arg5 = (long int) (arg5);				\
+	long int _arg6 = (long int) (arg6);				\
 									\
 	{								\
 	register long int __a7 asm ("a7") = number;			\
-	register long int __a0 asm ("a0") = (long int) (arg0);		\
-	register long int __a1 asm ("a1") = (long int) (arg1);		\
-	register long int __a2 asm ("a2") = (long int) (arg2);		\
-	register long int __a3 asm ("a3") = (long int) (arg3);		\
-	register long int __a4 asm ("a4") = (long int) (arg4);		\
-	register long int __a5 asm ("a5") = (long int) (arg5);		\
-	register long int __a6 asm ("a6") = (long int) (arg6);		\
+	register long int __a0 asm ("a0") = _arg0;			\
+	register long int __a1 asm ("a1") = _arg1;			\
+	register long int __a2 asm ("a2") = _arg2;			\
+	register long int __a3 asm ("a3") = _arg3;			\
+	register long int __a4 asm ("a4") = _arg4;			\
+	register long int __a5 asm ("a5") = _arg5;			\
+	register long int __a6 asm ("a6") = _arg6;			\
 	__asm__ volatile ( 						\
 	"scall\n\t" 							\
 	: "+r" (__a0)							\
-- 
2.17.1

  parent reply	other threads:[~2020-02-10 19:20 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-10 19:21 [PATCH 01/15] powerpc: Consolidate Linux syscall definition Adhemerval Zanella
2020-02-10 19:20 ` [PATCH 02/15] powerpc: Use Linux kABI for syscall return Adhemerval Zanella
2020-02-11 11:18   ` Florian Weimer
2020-02-11 12:14     ` Adhemerval Zanella
2020-02-11 12:32       ` Florian Weimer
2020-02-11 13:31         ` Adhemerval Zanella
2020-02-11 19:47           ` Florian Weimer
2020-02-11 19:47   ` Florian Weimer
2020-02-12 13:24     ` Adhemerval Zanella
2020-02-10 19:20 ` [PATCH 04/15] alpha: Refactor syscall and " Adhemerval Zanella
2020-02-10 19:20 ` [PATCH 09/15] microblaze: Avoid clobbering register parameters in syscall Adhemerval Zanella
2020-02-11 11:21   ` Florian Weimer
2020-02-11 19:10     ` Adhemerval Zanella
2020-02-10 19:20 ` [PATCH 03/15] sparc: Use Linux kABI for syscall return Adhemerval Zanella
2020-02-11 11:15   ` Florian Weimer
2020-02-11 18:55     ` Adhemerval Zanella
2020-02-11 19:26       ` Florian Weimer
2020-02-11 20:29         ` Adhemerval Zanella
2020-02-11 21:16           ` Florian Weimer
2020-02-12 12:35             ` Adhemerval Zanella
2020-02-12 12:40               ` Florian Weimer
2020-02-12 12:56                 ` Adhemerval Zanella
2020-02-10 19:21 ` [PATCH 05/15] ia64: " Adhemerval Zanella
2020-02-10 19:21 ` [PATCH 15/15] linux: Remove INTERNAL_SYSCALL_DECL Adhemerval Zanella
2020-02-11 12:34   ` Florian Weimer
2020-02-11 12:36   ` Florian Weimer
2020-02-11 20:58     ` Adhemerval Zanella
2020-02-11 12:48   ` Florian Weimer
2020-02-11 20:56     ` Adhemerval Zanella
2020-02-15  7:51   ` Andreas Schwab
2020-02-15  9:32     ` [PATCH] arm: fix use of INTERNAL_SYSCALL_CALL Andreas Schwab
2020-02-15  9:57       ` Florian Weimer
2020-02-10 19:21 ` [PATCH 12/15] sparc: Avoid clobbering register parameters in syscall Adhemerval Zanella
2020-02-11 11:22   ` Florian Weimer
2020-02-11 19:17     ` Adhemerval Zanella
2020-02-10 19:21 ` [PATCH 11/15] s390: Consolidate Linux syscall definition Adhemerval Zanella
2020-02-10 19:21 ` [PATCH 08/15] nios2: Use Linux kABI for syscall return Adhemerval Zanella
2020-02-11 11:20   ` Florian Weimer
2020-02-11 19:09     ` Adhemerval Zanella
2020-02-11 11:51   ` Andreas Schwab
2020-02-19 21:40   ` Vineet Gupta
2020-02-20 13:14     ` Adhemerval Zanella
2020-02-20 20:39       ` Vineet Gupta
2020-02-20 21:04         ` Vineet Gupta
2020-02-27 17:49           ` Adhemerval Zanella
2020-02-10 19:21 ` [PATCH 13/15] linux: Consolidate INLINE_SYSCALL Adhemerval Zanella
2020-02-11 12:04   ` Florian Weimer
2020-02-11 20:53     ` Adhemerval Zanella
2020-02-11 21:01       ` Florian Weimer
2020-02-10 19:21 ` [PATCH 07/15] mips: Use Linux kABI for syscall return Adhemerval Zanella
2020-02-10 19:21 ` Adhemerval Zanella [this message]
2020-02-10 19:51   ` [PATCH 10/15] riscv: Avoid clobbering register parameters in syscall DJ Delorie
2020-02-10 21:27     ` Palmer Dabbelt
2020-02-10 21:55       ` Adhemerval Zanella
2020-02-10 19:21 ` [PATCH 06/15] mips64: Consolidate Linux sysdep.h Adhemerval Zanella
2020-02-10 22:48   ` Joseph Myers
2020-02-11 19:05     ` Adhemerval Zanella
2020-02-10 19:21 ` [PATCH 14/15] nptl: Remove ununsed pthread-errnos.h rule Adhemerval Zanella
2020-02-11 11:24   ` Florian Weimer
2020-02-11 11:51     ` Florian Weimer
2020-02-11 21:01       ` Adhemerval Zanella
2020-02-11 19:45 ` [PATCH 01/15] powerpc: Consolidate Linux syscall definition Florian Weimer
2020-02-12 13:19   ` Adhemerval Zanella

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