lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <tip-2823d4da5d8a0c222747b24eceb65f5b30717d02@git.kernel.org>
Date:	Wed, 8 Jun 2016 12:45:56 -0700
From:	"tip-bot for H. Peter Anvin" <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	luto@...nel.org, bp@...e.de, peterz@...radead.org, hpa@...or.com,
	linux-kernel@...r.kernel.org, mingo@...nel.org, tglx@...utronix.de
Subject: [tip:x86/asm] x86, bitops: remove use of "sbb" to return CF

Commit-ID:  2823d4da5d8a0c222747b24eceb65f5b30717d02
Gitweb:     http://git.kernel.org/tip/2823d4da5d8a0c222747b24eceb65f5b30717d02
Author:     H. Peter Anvin <hpa@...or.com>
AuthorDate: Wed, 8 Jun 2016 12:38:37 -0700
Committer:  H. Peter Anvin <hpa@...ux.intel.com>
CommitDate: Wed, 8 Jun 2016 12:41:20 -0700

x86, bitops: remove use of "sbb" to return CF

Use SETC instead of SBB to return the value of CF from assembly. Using
SETcc enables uniformity with other flags-returning pieces of assembly
code.

Signed-off-by: H. Peter Anvin <hpa@...or.com>
Link: http://lkml.kernel.org/r/1465414726-197858-2-git-send-email-hpa@linux.intel.com
Reviewed-by: Andy Lutomirski <luto@...nel.org>
Reviewed-by: Borislav Petkov <bp@...e.de>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 arch/x86/include/asm/bitops.h      | 24 ++++++++++++------------
 arch/x86/include/asm/percpu.h      | 12 ++++++------
 arch/x86/include/asm/signal.h      |  6 +++---
 arch/x86/include/asm/sync_bitops.h | 18 +++++++++---------
 arch/x86/kernel/vm86_32.c          |  5 +----
 5 files changed, 31 insertions(+), 34 deletions(-)

diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
index 7766d1c..b2b797d 100644
--- a/arch/x86/include/asm/bitops.h
+++ b/arch/x86/include/asm/bitops.h
@@ -230,11 +230,11 @@ test_and_set_bit_lock(long nr, volatile unsigned long *addr)
  */
 static __always_inline int __test_and_set_bit(long nr, volatile unsigned long *addr)
 {
-	int oldbit;
+	unsigned char oldbit;
 
 	asm("bts %2,%1\n\t"
-	    "sbb %0,%0"
-	    : "=r" (oldbit), ADDR
+	    "setc %0"
+	    : "=qm" (oldbit), ADDR
 	    : "Ir" (nr));
 	return oldbit;
 }
@@ -270,11 +270,11 @@ static __always_inline int test_and_clear_bit(long nr, volatile unsigned long *a
  */
 static __always_inline int __test_and_clear_bit(long nr, volatile unsigned long *addr)
 {
-	int oldbit;
+	unsigned char oldbit;
 
 	asm volatile("btr %2,%1\n\t"
-		     "sbb %0,%0"
-		     : "=r" (oldbit), ADDR
+		     "setc %0"
+		     : "=qm" (oldbit), ADDR
 		     : "Ir" (nr));
 	return oldbit;
 }
@@ -282,11 +282,11 @@ static __always_inline int __test_and_clear_bit(long nr, volatile unsigned long
 /* WARNING: non atomic and it can be reordered! */
 static __always_inline int __test_and_change_bit(long nr, volatile unsigned long *addr)
 {
-	int oldbit;
+	unsigned char oldbit;
 
 	asm volatile("btc %2,%1\n\t"
-		     "sbb %0,%0"
-		     : "=r" (oldbit), ADDR
+		     "setc %0"
+		     : "=qm" (oldbit), ADDR
 		     : "Ir" (nr) : "memory");
 
 	return oldbit;
@@ -313,11 +313,11 @@ static __always_inline int constant_test_bit(long nr, const volatile unsigned lo
 
 static __always_inline int variable_test_bit(long nr, volatile const unsigned long *addr)
 {
-	int oldbit;
+	unsigned char oldbit;
 
 	asm volatile("bt %2,%1\n\t"
-		     "sbb %0,%0"
-		     : "=r" (oldbit)
+		     "setc %0"
+		     : "=qm" (oldbit)
 		     : "m" (*(unsigned long *)addr), "Ir" (nr));
 
 	return oldbit;
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index e0ba66c..65039e9 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -510,9 +510,9 @@ do {									\
 /* This is not atomic against other CPUs -- CPU preemption needs to be off */
 #define x86_test_and_clear_bit_percpu(bit, var)				\
 ({									\
-	int old__;							\
-	asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0"		\
-		     : "=r" (old__), "+m" (var)				\
+	unsigned char old__;						\
+	asm volatile("btr %2,"__percpu_arg(1)"\n\tsetc %0"		\
+		     : "=qm" (old__), "+m" (var)			\
 		     : "dIr" (bit));					\
 	old__;								\
 })
@@ -532,11 +532,11 @@ static __always_inline int x86_this_cpu_constant_test_bit(unsigned int nr,
 static inline int x86_this_cpu_variable_test_bit(int nr,
                         const unsigned long __percpu *addr)
 {
-	int oldbit;
+	unsigned char oldbit;
 
 	asm volatile("bt "__percpu_arg(2)",%1\n\t"
-			"sbb %0,%0"
-			: "=r" (oldbit)
+			"setc %0"
+			: "=qm" (oldbit)
 			: "m" (*(unsigned long *)addr), "Ir" (nr));
 
 	return oldbit;
diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h
index 2138c9a..dd1e7d6 100644
--- a/arch/x86/include/asm/signal.h
+++ b/arch/x86/include/asm/signal.h
@@ -81,9 +81,9 @@ static inline int __const_sigismember(sigset_t *set, int _sig)
 
 static inline int __gen_sigismember(sigset_t *set, int _sig)
 {
-	int ret;
-	asm("btl %2,%1\n\tsbbl %0,%0"
-	    : "=r"(ret) : "m"(*set), "Ir"(_sig-1) : "cc");
+	unsigned char ret;
+	asm("btl %2,%1\n\tsetc %0"
+	    : "=qm"(ret) : "m"(*set), "Ir"(_sig-1) : "cc");
 	return ret;
 }
 
diff --git a/arch/x86/include/asm/sync_bitops.h b/arch/x86/include/asm/sync_bitops.h
index f28a24b..cbf8847 100644
--- a/arch/x86/include/asm/sync_bitops.h
+++ b/arch/x86/include/asm/sync_bitops.h
@@ -79,10 +79,10 @@ static inline void sync_change_bit(long nr, volatile unsigned long *addr)
  */
 static inline int sync_test_and_set_bit(long nr, volatile unsigned long *addr)
 {
-	int oldbit;
+	unsigned char oldbit;
 
-	asm volatile("lock; bts %2,%1\n\tsbbl %0,%0"
-		     : "=r" (oldbit), "+m" (ADDR)
+	asm volatile("lock; bts %2,%1\n\tsetc %0"
+		     : "=qm" (oldbit), "+m" (ADDR)
 		     : "Ir" (nr) : "memory");
 	return oldbit;
 }
@@ -97,10 +97,10 @@ static inline int sync_test_and_set_bit(long nr, volatile unsigned long *addr)
  */
 static inline int sync_test_and_clear_bit(long nr, volatile unsigned long *addr)
 {
-	int oldbit;
+	unsigned char oldbit;
 
-	asm volatile("lock; btr %2,%1\n\tsbbl %0,%0"
-		     : "=r" (oldbit), "+m" (ADDR)
+	asm volatile("lock; btr %2,%1\n\tsetc %0"
+		     : "=qm" (oldbit), "+m" (ADDR)
 		     : "Ir" (nr) : "memory");
 	return oldbit;
 }
@@ -115,10 +115,10 @@ static inline int sync_test_and_clear_bit(long nr, volatile unsigned long *addr)
  */
 static inline int sync_test_and_change_bit(long nr, volatile unsigned long *addr)
 {
-	int oldbit;
+	unsigned char oldbit;
 
-	asm volatile("lock; btc %2,%1\n\tsbbl %0,%0"
-		     : "=r" (oldbit), "+m" (ADDR)
+	asm volatile("lock; btc %2,%1\n\tsetc %0"
+		     : "=qm" (oldbit), "+m" (ADDR)
 		     : "Ir" (nr) : "memory");
 	return oldbit;
 }
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 3dce1ca..01f30e5 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -440,10 +440,7 @@ static inline unsigned long get_vflags(struct kernel_vm86_regs *regs)
 
 static inline int is_revectored(int nr, struct revectored_struct *bitmap)
 {
-	__asm__ __volatile__("btl %2,%1\n\tsbbl %0,%0"
-		:"=r" (nr)
-		:"m" (*bitmap), "r" (nr));
-	return nr;
+	return test_bit(nr, bitmap->__map);
 }
 
 #define val_byte(val, n) (((__u8 *)&val)[n])

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ