Currently the rseq constructor, rseq_init(), assumes that glibc always
has the support for rseq symbols (__rseq_size for instance). However,
glibc supports rseq from version 2.35 onwards. As a result, for the
systems that run glibc less than 2.35, the global rseq_size remains
initialized to -1U. When a thread then tries to register for rseq,
get_rseq_min_alloc_size() would end up returning -1U, which is
incorrect. Hence, initialize rseq_size for the cases where glibc doesn't
have the support for rseq symbols.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 73a4f5a704a2 ("selftests/rseq: Fix mm_cid test failure")
Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
---
tools/testing/selftests/rseq/rseq.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index 5b9772cdf265..9eb5356f25fa 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -142,6 +142,16 @@ unsigned int get_rseq_kernel_feature_size(void)
return ORIG_RSEQ_FEATURE_SIZE;
}
+static void set_default_rseq_size(void)
+{
+ unsigned int rseq_kernel_feature_size = get_rseq_kernel_feature_size();
+
+ if (rseq_kernel_feature_size < ORIG_RSEQ_ALLOC_SIZE)
+ rseq_size = rseq_kernel_feature_size;
+ else
+ rseq_size = ORIG_RSEQ_ALLOC_SIZE;
+}
+
int rseq_register_current_thread(void)
{
int rc;
@@ -219,12 +229,7 @@ void rseq_init(void)
fallthrough;
case ORIG_RSEQ_ALLOC_SIZE:
{
- unsigned int rseq_kernel_feature_size = get_rseq_kernel_feature_size();
-
- if (rseq_kernel_feature_size < ORIG_RSEQ_ALLOC_SIZE)
- rseq_size = rseq_kernel_feature_size;
- else
- rseq_size = ORIG_RSEQ_ALLOC_SIZE;
+ set_default_rseq_size();
break;
}
default:
@@ -239,8 +244,10 @@ void rseq_init(void)
rseq_size = 0;
return;
}
+
rseq_offset = (void *)&__rseq_abi - rseq_thread_pointer();
rseq_flags = 0;
+ set_default_rseq_size();
}
static __attribute__((destructor))
base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37
--
2.47.0.338.g60cca15819-goog
