[RFC PATCH 1/4] selftests: rseq: Use fixed value as rseq_len parameter
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: 2020-07-14 03:03:58
Also in:
lkml
Subsystem:
kernel selftest framework, restartable sequences support, the rest · Maintainers:
Shuah Khan, Shuah Khan, Mathieu Desnoyers, Peter Zijlstra, "Paul E. McKenney", Boqun Feng, Linus Torvalds
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@efficios.com> --- 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