----- On Sep 24, 2020, at 9:33 AM, Mathieu Desnoyers mathieu.desnoyers@xxxxxxxxxxxx wrote:
> ----- On Sep 23, 2020, at 7:36 PM, Peter Oskolkov posk@xxxxxxxxxx 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@xxxxxxxxxxxx>
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@xxxxxxxxxx>
>> ---
>> 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
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
