[dm-devel] [PATCH 5/5] libmultipath: deal with dynamic PTHREAD_STACK_MIN

Benjamin Marzinski bmarzins at redhat.com
Thu Jul 29 21:46:05 UTC 2021


Starting in glibc-2.34 (commit 5d98a7da), PTHREAD_STACK_MIN is defined
as sysconf(_SC_THREAD_STACK_MIN) if _GNU_SOURCE is defined. sysconf()
returns a long and can, at least in theory, return -1.  This change
causes compilation to fail in setup_thread_attr() due to a comparision
with different signedness, since stacksize is a size_t.

Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
---
 libmultipath/util.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libmultipath/util.c b/libmultipath/util.c
index e2fafe85..ea858409 100644
--- a/libmultipath/util.c
+++ b/libmultipath/util.c
@@ -223,8 +223,8 @@ setup_thread_attr(pthread_attr_t *attr, size_t stacksize, int detached)
 
 	ret = pthread_attr_init(attr);
 	assert(ret == 0);
-	if (stacksize < PTHREAD_STACK_MIN)
-		stacksize = PTHREAD_STACK_MIN;
+	if (PTHREAD_STACK_MIN > 0 && stacksize < (size_t)PTHREAD_STACK_MIN)
+		stacksize = (size_t)PTHREAD_STACK_MIN;
 	ret = pthread_attr_setstacksize(attr, stacksize);
 	assert(ret == 0);
 	if (detached) {
-- 
2.17.2




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