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
