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rseq/selftests,x86_64: Add rseq_offset_deref_addv()

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This patch adds rseq_offset_deref_addv() function to
tools/testing/selftests/rseq/rseq-x86.h, to be used in a selftest in
the next patch in the patchset.

Once an architecture adds support for this function they should define
"RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV".

Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lkml.kernel.org/r/20200923233618.2572849-2-posk@google.com
This commit is contained in:
Peter Oskolkov 2020-09-23 16:36:17 -07:00 committed by Peter Zijlstra
parent 2a36ab717e
commit ea366dd79c
1 changed files with 57 additions and 0 deletions
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57
tools/testing/selftests/rseq/rseq-x86.h
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@ -279,6 +279,63 @@ error1:
#endif
}
#define RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
/*
* pval = *(ptr+off)
* *pval += inc;
*/
static inline __attribute__((always_inline))
int rseq_offset_deref_addv(intptr_t *ptr, off_t off, intptr_t inc, int cpu)
{
RSEQ_INJECT_C(9)
__asm__ __volatile__ goto (
RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
#endif
/* Start rseq by storing table entry pointer into rseq_cs. */
RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
RSEQ_INJECT_ASM(3)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
#endif
/* get p+v */
"movq %[ptr], %%rbx\n\t"
"addq %[off], %%rbx\n\t"
/* get pv */
"movq (%%rbx), %%rcx\n\t"
/* *pv += inc */
"addq %[inc], (%%rcx)\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(4)
RSEQ_ASM_DEFINE_ABORT(4, "", abort)
: /* gcc asm goto does not allow outputs */
: [cpu_id] "r" (cpu),
[rseq_abi] "r" (&__rseq_abi),
/* final store input */
[ptr] "m" (*ptr),
[off] "er" (off),
[inc] "er" (inc)
: "memory", "cc", "rax", "rbx", "rcx"
RSEQ_INJECT_CLOBBER
: abort
#ifdef RSEQ_COMPARE_TWICE
, error1
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
intptr_t *v2, intptr_t newv2,