git: 323226829ae7 - stable/14 - rtld-elf: Avoid unnecessary lock_restart_for_upgrade() calls

The branch stable/14 has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=323226829ae79094a29198efcc6913a7b48c05ca

commit 323226829ae79094a29198efcc6913a7b48c05ca
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2024-02-01 22:43:05 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2024-02-09 14:55:56 +0000

    rtld-elf: Avoid unnecessary lock_restart_for_upgrade() calls
    
    In order to atomically upgrade the rtld bind lock, load_filtees() may
    trigger a longjmp back to _rtld_bind() so that the binding can be done
    with the write lock held.  However, the write lock is only needed when
    filtee objects haven't already been loaded, so move the
    lock_restart_for_upgrade() call to avoid unnecessary lock upgrades when
    a filtee is defined.
    
    Reviewed by:    kib
    Tested by:      brooks
    MFC after:      1 week
    Sponsored by:   Innovate UK
    
    (cherry picked from commit e7951d0b04e6464b37264b8166b1e9ce368a9f1d)
---
 libexec/rtld-elf/rtld.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 0bbd8104e11b..37c016299a66 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -2573,8 +2573,8 @@ static void
 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
 {
 
-    lock_restart_for_upgrade(lockstate);
     if (!obj->filtees_loaded) {
+	lock_restart_for_upgrade(lockstate);
 	load_filtee1(obj, obj->needed_filtees, flags, lockstate);
 	load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate);
 	obj->filtees_loaded = true;