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Commit 2823d4da authored by H. Peter Anvin's avatar H. Peter Anvin Committed by H. Peter Anvin
Browse files

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: default avatarH. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1465414726-197858-2-git-send-email-hpa@linux.intel.com


Reviewed-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
parent f5967101

arch/x86/include/asm/bitops.h

+12 −12
Original line number Diff line number Diff line
@@ -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;

arch/x86/include/asm/percpu.h

+6 −6
Original line number Diff line number Diff line
@@ -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;

arch/x86/include/asm/signal.h

+3 −3
Original line number Diff line number Diff line
@@ -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;

}

arch/x86/include/asm/sync_bitops.h

+9 −9
Original line number Diff line number Diff line
@@ -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;

}

arch/x86/kernel/vm86_32.c

+1 −4
Original line number Diff line number Diff line
@@ -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])