[src/thorpej-futex2]: src/sys Cherry-pick this sys_futex.c revision and assoc...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c40f6f7f318f
branches:  thorpej-futex2
changeset: 991020:c40f6f7f318f
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Wed Nov 03 14:49:21 2021 +0000

description:
Cherry-pick this sys_futex.c revision and associated changes:

revision 1.13
date: 2021-09-28 08:05:42 -0700;  author: thorpej;  state: Exp;  lines: +11 -9;  commitid: FPndTp2ZDjYuyJaD;
futex_release_all_lwp(): No need to pass the "tid" argument separately; that
is a vestige of an older version of the code.  Also, move a KASSERT() that
both futex_release_all_lwp() call sites had inside of futex_release_all_lwp()
itself.

...so make this easier to test this sys_futex.c with trunk.

diffstat:

 sys/kern/kern_lwp.c  |   9 +++------
 sys/kern/sys_futex.c |  20 +++++++++++---------
 sys/sys/futex.h      |   4 ++--
 3 files changed, 16 insertions(+), 17 deletions(-)

diffs (128 lines):

diff -r f03c2d0b005a -r c40f6f7f318f sys/kern/kern_lwp.c
--- a/sys/kern/kern_lwp.c       Mon Nov 01 08:40:16 2021 +0000
+++ b/sys/kern/kern_lwp.c       Wed Nov 03 14:49:21 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_lwp.c,v 1.243 2021/01/13 07:36:56 skrll Exp $     */
+/*     $NetBSD: kern_lwp.c,v 1.243.12.1 2021/11/03 14:49:21 thorpej Exp $      */
 
 /*-
  * Copyright (c) 2001, 2006, 2007, 2008, 2009, 2019, 2020
@@ -217,7 +217,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.243 2021/01/13 07:36:56 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.243.12.1 2021/11/03 14:49:21 thorpej Exp $");
 
 #include "opt_ddb.h"
 #include "opt_lockdebug.h"
@@ -2060,11 +2060,8 @@
 void
 lwp_thread_cleanup(struct lwp *l)
 {
-       const lwpid_t tid = l->l_lid;
 
-       KASSERT((tid & FUTEX_TID_MASK) == tid);
        KASSERT(mutex_owned(l->l_proc->p_lock));
-
        mutex_exit(l->l_proc->p_lock);
 
        /*
@@ -2072,7 +2069,7 @@
         * now.
         */
        if (__predict_false(l->l_robust_head != 0)) {
-               futex_release_all_lwp(l, tid);
+               futex_release_all_lwp(l);
        }
 }
 
diff -r f03c2d0b005a -r c40f6f7f318f sys/kern/sys_futex.c
--- a/sys/kern/sys_futex.c      Mon Nov 01 08:40:16 2021 +0000
+++ b/sys/kern/sys_futex.c      Wed Nov 03 14:49:21 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_futex.c,v 1.12.4.6 2021/11/01 08:40:16 chs Exp $   */
+/*     $NetBSD: sys_futex.c,v 1.12.4.7 2021/11/03 14:49:21 thorpej Exp $       */
 
 /*-
  * Copyright (c) 2018, 2019, 2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_futex.c,v 1.12.4.6 2021/11/01 08:40:16 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_futex.c,v 1.12.4.7 2021/11/03 14:49:21 thorpej Exp $");
 
 /*
  * Futexes
@@ -2199,7 +2199,7 @@
  *     the i's and cross the t's.
  */
 void
-futex_release_all_lwp(struct lwp * const l, lwpid_t const tid)
+futex_release_all_lwp(struct lwp * const l)
 {
        u_long rhead[_FUTEX_ROBUST_HEAD_NWORDS];
        int limit = 1000000;
@@ -2209,13 +2209,15 @@
        if (l->l_robust_head == 0)
                return;
 
+       KASSERT((l->l_lid & FUTEX_TID_MASK) == l->l_lid);
+
        /* Read the final snapshot of the robust list head. */
        error = futex_fetch_robust_head(l->l_robust_head, rhead);
        if (error) {
-               printf("WARNING: pid %jd (%s) lwp %jd tid %jd:"
+               printf("WARNING: pid %jd (%s) lwp %jd:"
                    " unmapped robust futex list head\n",
                    (uintmax_t)l->l_proc->p_pid, l->l_proc->p_comm,
-                   (uintmax_t)l->l_lid, (uintmax_t)tid);
+                   (uintmax_t)l->l_lid);
                return;
        }
 
@@ -2237,21 +2239,21 @@
        while (next != l->l_robust_head && limit-- > 0) {
                /* pending handled below. */
                if (next != pending)
-                       release_futex(next + offset, tid, is_pi, false);
+                       release_futex(next + offset, l->l_lid, is_pi, false);
                error = futex_fetch_robust_entry(next, &next, &is_pi);
                if (error)
                        break;
                preempt_point();
        }
        if (limit <= 0) {
-               printf("WARNING: pid %jd (%s) lwp %jd tid %jd:"
+               printf("WARNING: pid %jd (%s) lwp %jd:"
                    " exhausted robust futex limit\n",
                    (uintmax_t)l->l_proc->p_pid, l->l_proc->p_comm,
-                   (uintmax_t)l->l_lid, (uintmax_t)tid);
+                   (uintmax_t)l->l_lid);
        }
 
        /* If there's a pending futex, it may need to be released too. */
        if (pending != 0) {
-               release_futex(pending + offset, tid, pending_is_pi, true);
+               release_futex(pending + offset, l->l_lid, pending_is_pi, true);
        }
 }
diff -r f03c2d0b005a -r c40f6f7f318f sys/sys/futex.h
--- a/sys/sys/futex.h   Mon Nov 01 08:40:16 2021 +0000
+++ b/sys/sys/futex.h   Wed Nov 03 14:49:21 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: futex.h,v 1.4 2020/05/05 15:25:18 riastradh Exp $      */
+/*     $NetBSD: futex.h,v 1.4.14.1 2021/11/03 14:49:21 thorpej Exp $   */
 
 /*-
  * Copyright (c) 2018, 2019 The NetBSD Foundation, Inc.
@@ -174,7 +174,7 @@
 struct lwp;
 
 int    futex_robust_head_lookup(struct lwp *, lwpid_t, void **);
-void   futex_release_all_lwp(struct lwp *, lwpid_t);
+void   futex_release_all_lwp(struct lwp *);
 int    do_futex(int *, int, int, const struct timespec *, int *, int,
            int, register_t *);
 void   futex_sys_init(void);