From 004dfc5fce1f461d74862293edfa19bd6e2283ae Mon Sep 17 00:00:00 2001
From: Taylor R Campbell <riastradh@NetBSD.org>
Date: Thu, 31 Mar 2022 02:02:03 +0000
Subject: [PATCH 24/49] rtld: Convert membar_exit/enter to
membar_release/acquire.
These are basic CAS-based locking primitives needing release and
acquire semantics, nothing fancy here -- except the membar_sync parts
which are questionable but not relevant to the present audit.
---
libexec/ld.elf_so/rtld.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/libexec/ld.elf_so/rtld.c b/libexec/ld.elf_so/rtld.c
index 59ed3c4530b2..f08664529bb8 100644
--- a/libexec/ld.elf_so/rtld.c
+++ b/libexec/ld.elf_so/rtld.c
@@ -1682,7 +1682,7 @@ _rtld_shared_enter(void)
/* Yes, so increment use counter */
if (atomic_cas_uint(&_rtld_mutex, cur, cur + 1) != cur)
continue;
- membar_enter();
+ membar_acquire();
return;
}
/*
@@ -1728,7 +1728,7 @@ _rtld_shared_exit(void)
* Wakeup LWPs waiting for an exclusive lock if this is the last
* LWP on the shared lock.
*/
- membar_exit();
+ membar_release();
if (atomic_dec_uint_nv(&_rtld_mutex))
return;
membar_sync();
@@ -1750,7 +1750,7 @@ _rtld_exclusive_enter(sigset_t *mask)
for (;;) {
if (atomic_cas_uint(&_rtld_mutex, 0, locked_value) == 0) {
- membar_enter();
+ membar_acquire();
break;
}
waiter = atomic_swap_uint(&_rtld_waiter_exclusive, self);
@@ -1774,7 +1774,7 @@ _rtld_exclusive_exit(sigset_t *mask)
{
lwpid_t waiter;
- membar_exit();
+ membar_release();
_rtld_mutex = 0;
membar_sync();
if ((waiter = _rtld_waiter_exclusive) != 0)
--
2.33.0