Commit 2b2fe605 authored by Mathieu Desnoyers's avatar Mathieu Desnoyers Committed by Shuah Khan
Browse files

selftests/rseq: Use rseq_unqual_scalar_typeof in macros 



Use rseq_unqual_scalar_typeof() rather than typeof() in macros to remove
the volatile qualifier (if there is one in the input argument), thus
generating better assembly code in those scenarios.

Also add extra brackets around the "p" parameter in RSEQ_READ_ONCE(),
RSEQ_WRITE_ONCE(), and rseq_unqual_scalar_typeof() across architectures
to preserve expectations of operator priority. Here is an example that
shows how operator priority may be an issue with missing parentheses:

    #define m(p) \
    do { \
            __typeof__(*p) v = 0; \
    } while (0)

    void fct(unsigned long long *p1)
    {
            m(p1 + 1);      /* works */
            m(1 + p1);      /* broken */
    }

Signed-off-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent 0fbbf07c

tools/testing/selftests/rseq/rseq-arm.h

+2 −2
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ 


#define rseq_smp_load_acquire(p)					\

__extension__ ({							\

	__typeof(*p) ____p1 = RSEQ_READ_ONCE(*p);			\

	rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p));	\

	rseq_smp_mb();							\

	____p1;								\

})
@@ -76,7 +76,7 @@ __extension__ ({ \ 
#define rseq_smp_store_release(p, v)					\

do {									\

	rseq_smp_mb();							\

	RSEQ_WRITE_ONCE(*p, v);						\

	RSEQ_WRITE_ONCE(*(p), v);					\

} while (0)



#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip,	\

tools/testing/selftests/rseq/rseq-mips.h

+2 −2
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ 


#define rseq_smp_load_acquire(p)					\

__extension__ ({							\

	__typeof(*p) ____p1 = RSEQ_READ_ONCE(*p);			\

	rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p));	\

	rseq_smp_mb();							\

	____p1;								\

})
@@ -55,7 +55,7 @@ __extension__ ({ \ 
#define rseq_smp_store_release(p, v)					\

do {									\

	rseq_smp_mb();							\

	RSEQ_WRITE_ONCE(*p, v);						\

	RSEQ_WRITE_ONCE(*(p), v);					\

} while (0)



#if _MIPS_SZLONG == 64

tools/testing/selftests/rseq/rseq-ppc.h

+2 −2
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ 


#define rseq_smp_load_acquire(p)					\

__extension__ ({							\

	__typeof(*p) ____p1 = RSEQ_READ_ONCE(*p);			\

	rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p));	\

	rseq_smp_lwsync();						\

	____p1;								\

})
@@ -33,7 +33,7 @@ __extension__ ({ \ 
#define rseq_smp_store_release(p, v)					\

do {									\

	rseq_smp_lwsync();						\

	RSEQ_WRITE_ONCE(*p, v);						\

	RSEQ_WRITE_ONCE(*(p), v);					\

} while (0)



/*

tools/testing/selftests/rseq/rseq-riscv.h

+3 −3
Original line number Diff line number Diff line
@@ -36,8 +36,8 @@ 


#define rseq_smp_load_acquire(p)					\

__extension__ ({							\

	__typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p));			\

	RISCV_FENCE(r, rw)						\

	rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p));	\

	RISCV_FENCE(r, rw);						\

	____p1;								\

})

tools/testing/selftests/rseq/rseq-s390.h

+2 −2
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ 


#define rseq_smp_load_acquire(p)					\

__extension__ ({							\

	__typeof(*p) ____p1 = RSEQ_READ_ONCE(*p);			\

	rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p));	\

	rseq_barrier();							\

	____p1;								\

})
@@ -25,7 +25,7 @@ __extension__ ({ \ 
#define rseq_smp_store_release(p, v)					\

do {									\

	rseq_barrier();							\

	RSEQ_WRITE_ONCE(*p, v);						\

	RSEQ_WRITE_ONCE(*(p), v);					\

} while (0)



#ifdef __s390x__