----- On Sep 24, 2020, at 9:33 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote:
----- On Sep 23, 2020, at 7:36 PM, Peter Oskolkov posk@google.com wrote:
The patch title should state that it only adds rseq_offset_deref_addv to x86-64. Considering that other architecture maintainers will look at it as inspiration for other architectures, we should also state in the commit message that architectures implementing it should define "RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV".
With those changes applied, you can also add my:
Acked-by: Mathieu Desnoyers mathieu.desnoyers@efficios.com
Thanks,
Mathieu
Thanks,
Mathieu
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.
v7->v8: this patch split out of the v7 selftest patch.
Signed-off-by: Peter Oskolkov posk@google.com
tools/testing/selftests/rseq/rseq-x86.h | 57 +++++++++++++++++++++++++ 1 file changed, 57 insertions(+)
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h index b2da6004fe30..640411518e46 100644 --- a/tools/testing/selftests/rseq/rseq-x86.h +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -279,6 +279,63 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) #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, -- 2.28.0.709.gb0816b6eb0-goog
-- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com