The rseq registration and unregistration expect a fixed-size length
(32 bytes). In preparation to extend struct rseq, pass a fixed value
rather than the size of the rseq structure.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
---
include/uapi/linux/rseq.h | 5 +++++
tools/testing/selftests/rseq/rseq.c | 5 ++---
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
index 9a402fdb60e9..e11d9df5e564 100644
--- a/include/uapi/linux/rseq.h
+++ b/include/uapi/linux/rseq.h
@@ -37,6 +37,11 @@ enum rseq_cs_flags {
(1U << RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT),
};
+/* The rseq_len expected by rseq registration is always 32 bytes. */
+enum rseq_len_expected {
+ RSEQ_LEN_EXPECTED = 32,
+};
+
/*
* struct rseq_cs is aligned on 4 * 8 bytes to ensure it is always
* contained within a single cache-line. It is usually declared as
diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index 7159eb777fd3..da2264c679b9 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -87,7 +87,7 @@ int rseq_register_current_thread(void)
}
if (__rseq_refcount++)
goto end;
- rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), 0, RSEQ_SIG);
+ rc = sys_rseq(&__rseq_abi, RSEQ_LEN_EXPECTED, 0, RSEQ_SIG);
if (!rc) {
assert(rseq_current_cpu_raw() >= 0);
goto end;
@@ -115,8 +115,7 @@ int rseq_unregister_current_thread(void)
}
if (--__rseq_refcount)
goto end;
- rc = sys_rseq(&__rseq_abi, sizeof(struct rseq),
- RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
+ rc = sys_rseq(&__rseq_abi, RSEQ_LEN_EXPECTED, RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
if (!rc)
goto end;
__rseq_refcount = 1;
--
2.17.1
