git: 1fa6daaafd74 - main - ipfilter: Avoid stopping with a lock held

From: Jose Luis Duran <jlduran_at_FreeBSD.org>
Date: Tue, 12 Nov 2024 03:47:25 UTC
The branch main has been updated by jlduran:

URL: https://cgit.FreeBSD.org/src/commit/?id=1fa6daaafd74c1a457dcfe26e0a5943b5441dc9d

commit 1fa6daaafd74c1a457dcfe26e0a5943b5441dc9d
Author:     Jose Luis Duran <jlduran@FreeBSD.org>
AuthorDate: 2024-11-02 17:58:59 +0000
Commit:     Jose Luis Duran <jlduran@FreeBSD.org>
CommitDate: 2024-11-12 03:46:15 +0000

    ipfilter: Avoid stopping with a lock held
    
    Avoid calling _callout_stop_safe with a non-sleepable lock held when
    detaching by initializing callout_init_rw() with CALLOUT_SHAREDLOCK.
    
    It avoids the following WITNESS warning when stopping the service:
    
        # service ipfilter stop
        calling _callout_stop_safe with the following non-sleepable locks held:
        shared rw ipf filter load/unload mutex (ipf filter load/unload mutex) r = 0 (0xffff0000417c7530) locked @ /usr/src/sys/netpfil/ipfilter/netinet/fil.c:7926
        stack backtrace:
        #0 0xffff00000052d394 at witness_debugger+0x60
        #1 0xffff00000052e620 at witness_warn+0x404
        #2 0xffff0000004d4ffc at _callout_stop_safe+0x8c
        #3 0xffff0000f7236674 at ipfdetach+0x3c
        #4 0xffff0000f723fa4c at ipf_ipf_ioctl+0x788
        #5 0xffff0000f72367e0 at ipfioctl+0x144
        #6 0xffff00000034abd8 at devfs_ioctl+0x100
        #7 0xffff0000005c66a0 at vn_ioctl+0xbc
        #8 0xffff00000034b2cc at devfs_ioctl_f+0x24
        #9 0xffff0000005331ec at kern_ioctl+0x2e0
        #10 0xffff000000532eb4 at sys_ioctl+0x140
        #11 0xffff000000880480 at do_el0_sync+0x604
        #12 0xffff0000008579ac at handle_el0_sync+0x4c
    
    PR:             282478
    Suggested by:   markj
    Reviewed by:    cy
    Approved by:    emaste (mentor)
    MFC after:      1 week
---
 sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c b/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c
index bcde0d2c7323..b3dea40c3d8c 100644
--- a/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c
+++ b/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c
@@ -181,7 +181,7 @@ ipf_timer_func(void *arg)
 #if 0
 		softc->ipf_slow_ch = timeout(ipf_timer_func, softc, hz/2);
 #endif
-		callout_init(&softc->ipf_slow_ch, 1);
+		callout_init_rw(&softc->ipf_slow_ch, &softc->ipf_global.ipf_lk, CALLOUT_SHAREDLOCK);
 		callout_reset(&softc->ipf_slow_ch,
 			(hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
 			ipf_timer_func, softc);
@@ -221,7 +221,7 @@ ipfattach(ipf_main_softc_t *softc)
 	softc->ipf_slow_ch = timeout(ipf_timer_func, softc,
 				     (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT);
 #endif
-	callout_init(&softc->ipf_slow_ch, 1);
+	callout_init_rw(&softc->ipf_slow_ch, &softc->ipf_global.ipf_lk, CALLOUT_SHAREDLOCK);
 	callout_reset(&softc->ipf_slow_ch, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
 		ipf_timer_func, softc);
 	return (0);