Date: Fri, 9 Feb 2024 17:03:30 -0500 From: Zaphod Beeblebrox <zbeeble@gmail.com> To: Mark Johnston <markj@freebsd.org> Cc: "Matthew L. Dailey" <Matthew.L.Dailey@dartmouth.edu>, "freebsd-current@freebsd.org" <freebsd-current@freebsd.org> Subject: Re: FreeBSD panics possibly caused by nfs clients Message-ID: <CACpH0MfvdizKo%2BRA0E6jnMVZSayotA2Vn2znZG8qD1K18dsF6g@mail.gmail.com> In-Reply-To: <ZcaWkUwMlBCZCUhg@nuc> References: <c5d44484-8660-4b8b-a379-79423cb208f6@dartmouth.edu> <ZcZNDtN1nNJmo8cS@nuc> <c9eca81a-9eff-4b17-9928-bee2c79cef8f@dartmouth.edu> <b3243928-4d66-4c5e-9745-254d57f1cc5e@dartmouth.edu> <ZcaWkUwMlBCZCUhg@nuc>
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--000000000000f273500610fa199d Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Just in case it's relevant, I'm carrying around this patch on my fairly busy little RISC-V machine. diff --git a/sys/fs/nfsclient/nfs_clvnops.c b/sys/fs/nfsclient/nfs_clvnops.= c index 0b8c587a542c..85c0ebd7a10f 100644 --- a/sys/fs/nfsclient/nfs_clvnops.c +++ b/sys/fs/nfsclient/nfs_clvnops.c @@ -2459,6 +2459,16 @@ nfs_readdir(struct vop_readdir_args *ap) return (EINVAL); uio->uio_resid -=3D left; + /* + * For readdirplus, if starting to read the directory, + * purge the name cache, since it will be reloaded by + * this directory read. + * This removes potentially stale name cache entries. + */ + if (uio->uio_offset =3D=3D 0 && + (VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_RDIRPLUS) !=3D 0) + cache_purge(vp); + /* * Call ncl_bioread() to do the real work. */ ... without it, I can panic. On Fri, Feb 9, 2024 at 4:18=E2=80=AFPM Mark Johnston <markj@freebsd.org> wr= ote: > On Fri, Feb 09, 2024 at 06:23:08PM +0000, Matthew L. Dailey wrote: > > I had my first kernel panic with a KASAN kernel after only 01:27. This > > first panic was a "double fault," which isn't anything we've seen > > previously - usually we've seen trap 9 or trap 12, but sometimes others= . > > Based on the backtrace, it definitely looks like KASAN caught something= , > > but I don't have the expertise to know if this points to anything > > specific. From the backtrace, it looks like this might have originated > > in ipfw code. > > A double fault is rather unexpected. I presume you're running > releng/14.0? Is it at all possible to test with FreeBSD-CURRENT? > > Did you add INVARIANTS etc. to the kernel configuration used here, or > just KASAN? > > > Please let me know what other info I can provide or what I can do to di= g > > deeper. > > If you could repeat the test several times, I'd be interested in seeing > if you always get the same result. If you're willing to share the > vmcore (or several), I'd be willing to take a look at it. > > > Thanks!! > > > > Panic message: > > [5674] Fatal double fault > > [5674] rip 0xffffffff812f6e32 rsp 0xfffffe014677afe0 rbp > 0xfffffe014677b430 > > [5674] rax 0x1fffffc028cef620 rdx 0xf2f2f2f8f2f2f2f2 rbx 0x1 > > [5674] rcx 0xdffff7c000000000 rsi 0xfffffe004086a4a0 rdi > 0xf8f8f8f8f2f2f2f8 > > [5674] r8 0xf8f8f8f8f8f8f8f8 r9 0x162a r10 0x835003002d3a64e1 > > [5674] r11 0 r12 0xfffff78028cef620 r13 0xfffffe004086a440 > > [5674] r14 0xfffffe01488c0560 r15 0x26f40 rflags 0x10006 > > [5674] cs 0x20 ss 0x28 ds 0x3b es 0x3b fs 0x13 gs 0x1b > > [5674] fsbase 0x95d1d81a130 gsbase 0xffffffff84a14000 kgsbase 0 > > [5674] cpuid =3D 4; apic id =3D 08 > > [5674] panic: double fault > > [5674] cpuid =3D 4 > > [5674] time =3D 1707498420 > > [5674] KDB: stack backtrace: > > [5674] Uptime: 1h34m34s > > > > Backtrace: > > #0 __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:57 > > #1 doadump (textdump=3D<optimized out>) at > > /usr/src/sys/kern/kern_shutdown.c:405 > > #2 0xffffffff8128b7dc in kern_reboot (howto=3Dhowto@entry=3D260) > > at /usr/src/sys/kern/kern_shutdown.c:526 > > #3 0xffffffff8128c000 in vpanic ( > > fmt=3Dfmt@entry=3D0xffffffff82589a00 <str> "double fault", > > ap=3Dap@entry=3D0xfffffe0040866de0) at > > /usr/src/sys/kern/kern_shutdown.c:970 > > #4 0xffffffff8128bd75 in panic (fmt=3D0xffffffff82589a00 <str> "double > > fault") > > at /usr/src/sys/kern/kern_shutdown.c:894 > > #5 0xffffffff81c4b335 in dblfault_handler (frame=3D<optimized out>) > > at /usr/src/sys/amd64/amd64/trap.c:1012 > > #6 <signal handler called> > > #7 0xffffffff812f6e32 in sched_clock (td=3Dtd@entry=3D0xfffffe01488c05= 60, > > cnt=3Dcnt@entry=3D1) at /usr/src/sys/kern/sched_ule.c:2601 > > #8 0xffffffff8119e2a7 in statclock (cnt=3Dcnt@entry=3D1, > > usermode=3Dusermode@entry=3D0) at /usr/src/sys/kern/kern_clock.c:7= 60 > > #9 0xffffffff8119fb67 in handleevents (now=3Dnow@entry=3D2437185569983= 2, > > fake=3Dfake@entry=3D0) at /usr/src/sys/kern/kern_clocksource.c:195 > > #10 0xffffffff811a10cc in timercb (et=3D<optimized out>, arg=3D<optimiz= ed > out>) > > at /usr/src/sys/kern/kern_clocksource.c:353 > > #11 0xffffffff81dcd280 in lapic_handle_timer (frame=3D0xfffffe014677b75= 0) > > at /usr/src/sys/x86/x86/local_apic.c:1343 > > #12 <signal handler called> > > #13 __asan_load8_noabort (addr=3D18446741880219689232) > > at /usr/src/sys/kern/subr_asan.c:1113 > > #14 0xffffffff851488b8 in ?? () from /boot/thayer/ipfw.ko > > #15 0xfffffe0100000000 in ?? () > > #16 0xffffffff8134dcd5 in pcpu_find (cpuid=3D1238425856) > > at /usr/src/sys/kern/subr_pcpu.c:286 > > #17 0xffffffff85151f6f in ?? () from /boot/thayer/ipfw.ko > > #18 0x0000000000000000 in ?? () > > --000000000000f273500610fa199d Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div>Just in case it's relevant, I'm carrying arou= nd this patch on my fairly busy little RISC-V machine.</div><div><br></div>= <div>diff --git a/sys/fs/nfsclient/nfs_clvnops.c b/sys/fs/nfsclient/nfs_clv= nops.c<br>index 0b8c587a542c..85c0ebd7a10f 100644<br>--- a/sys/fs/nfsclient= /nfs_clvnops.c<br>+++ b/sys/fs/nfsclient/nfs_clvnops.c<br>@@ -2459,6 +2459,= 16 @@ nfs_readdir(struct vop_readdir_args *ap)<br>=C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 return (EINVAL);<br>=C2=A0 =C2=A0 =C2=A0 = =C2=A0 uio->uio_resid -=3D left;<br><br>+ =C2=A0 =C2=A0 =C2=A0 /*<br>+ = =C2=A0 =C2=A0 =C2=A0 =C2=A0* For readdirplus, if starting to read the direc= tory,<br>+ =C2=A0 =C2=A0 =C2=A0 =C2=A0* purge the name cache, since it will= be reloaded by<br>+ =C2=A0 =C2=A0 =C2=A0 =C2=A0* this directory read.<br>+= =C2=A0 =C2=A0 =C2=A0 =C2=A0* This removes potentially stale name cache ent= ries.<br>+ =C2=A0 =C2=A0 =C2=A0 =C2=A0*/<br>+ =C2=A0 =C2=A0 =C2=A0 if (uio-= >uio_offset =3D=3D 0 &&<br>+ =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = (VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_RDIRPLUS) !=3D 0)<br>+ = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 cache_purge(vp);<br>+<br>= =C2=A0 =C2=A0 =C2=A0 =C2=A0 /*<br>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0* Call = ncl_bioread() to do the real work.<br>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0*/<= /div><div>... without it, I can panic.</div><div><br></div></div><br><div c= lass=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Fri, Feb 9, 2= 024 at 4:18=E2=80=AFPM Mark Johnston <<a href=3D"mailto:markj@freebsd.or= g">markj@freebsd.org</a>> wrote:<br></div><blockquote class=3D"gmail_quo= te" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204= );padding-left:1ex">On Fri, Feb 09, 2024 at 06:23:08PM +0000, Matthew L. Da= iley wrote:<br> > I had my first kernel panic with a KASAN kernel after only 01:27. This= <br> > first panic was a "double fault," which isn't anything w= e've seen <br> > previously - usually we've seen trap 9 or trap 12, but sometimes o= thers. <br> > Based on the backtrace, it definitely looks like KASAN caught somethin= g, <br> > but I don't have the expertise to know if this points to anything = <br> > specific. From the backtrace, it looks like this might have originated= <br> > in ipfw code.<br> <br> A double fault is rather unexpected.=C2=A0 I presume you're running<br> releng/14.0?=C2=A0 Is it at all possible to test with FreeBSD-CURRENT?<br> <br> Did you add INVARIANTS etc. to the kernel configuration used here, or<br> just KASAN?<br> <br> > Please let me know what other info I can provide or what I can do to d= ig <br> > deeper.<br> <br> If you could repeat the test several times, I'd be interested in seeing= <br> if you always get the same result.=C2=A0 If you're willing to share the= <br> vmcore (or several), I'd be willing to take a look at it.<br> <br> > Thanks!!<br> > <br> > Panic message:<br> > [5674] Fatal double fault<br> > [5674] rip 0xffffffff812f6e32 rsp 0xfffffe014677afe0 rbp 0xfffffe01467= 7b430<br> > [5674] rax 0x1fffffc028cef620 rdx 0xf2f2f2f8f2f2f2f2 rbx 0x1<br> > [5674] rcx 0xdffff7c000000000 rsi 0xfffffe004086a4a0 rdi 0xf8f8f8f8f2f= 2f2f8<br> > [5674] r8 0xf8f8f8f8f8f8f8f8 r9 0x162a r10 0x835003002d3a64e1<br> > [5674] r11 0 r12 0xfffff78028cef620 r13 0xfffffe004086a440<br> > [5674] r14 0xfffffe01488c0560 r15 0x26f40 rflags 0x10006<br> > [5674] cs 0x20 ss 0x28 ds 0x3b es 0x3b fs 0x13 gs 0x1b<br> > [5674] fsbase 0x95d1d81a130 gsbase 0xffffffff84a14000 kgsbase 0<br> > [5674] cpuid =3D 4; apic id =3D 08<br> > [5674] panic: double fault<br> > [5674] cpuid =3D 4<br> > [5674] time =3D 1707498420<br> > [5674] KDB: stack backtrace:<br> > [5674] Uptime: 1h34m34s<br> > <br> > Backtrace:<br> > #0=C2=A0 __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:57<br= > > #1=C2=A0 doadump (textdump=3D<optimized out>) at <br> > /usr/src/sys/kern/kern_shutdown.c:405<br> > #2=C2=A0 0xffffffff8128b7dc in kern_reboot (howto=3Dhowto@entry=3D260)= <br> >=C2=A0 =C2=A0 =C2=A0 at /usr/src/sys/kern/kern_shutdown.c:526<br> > #3=C2=A0 0xffffffff8128c000 in vpanic (<br> >=C2=A0 =C2=A0 =C2=A0 fmt=3Dfmt@entry=3D0xffffffff82589a00 <str> &= quot;double fault",<br> >=C2=A0 =C2=A0 =C2=A0 ap=3Dap@entry=3D0xfffffe0040866de0) at <br> > /usr/src/sys/kern/kern_shutdown.c:970<br> > #4=C2=A0 0xffffffff8128bd75 in panic (fmt=3D0xffffffff82589a00 <str= > "double <br> > fault")<br> >=C2=A0 =C2=A0 =C2=A0 at /usr/src/sys/kern/kern_shutdown.c:894<br> > #5=C2=A0 0xffffffff81c4b335 in dblfault_handler (frame=3D<optimized= out>)<br> >=C2=A0 =C2=A0 =C2=A0 at /usr/src/sys/amd64/amd64/trap.c:1012<br> > #6=C2=A0 <signal handler called><br> > #7=C2=A0 0xffffffff812f6e32 in sched_clock (td=3Dtd@entry=3D0xfffffe01= 488c0560,<br> >=C2=A0 =C2=A0 =C2=A0 cnt=3Dcnt@entry=3D1) at /usr/src/sys/kern/sched_ul= e.c:2601<br> > #8=C2=A0 0xffffffff8119e2a7 in statclock (cnt=3Dcnt@entry=3D1,<br> >=C2=A0 =C2=A0 =C2=A0 usermode=3Dusermode@entry=3D0) at /usr/src/sys/ker= n/kern_clock.c:760<br> > #9=C2=A0 0xffffffff8119fb67 in handleevents (now=3Dnow@entry=3D2437185= 5699832,<br> >=C2=A0 =C2=A0 =C2=A0 fake=3Dfake@entry=3D0) at /usr/src/sys/kern/kern_c= locksource.c:195<br> > #10 0xffffffff811a10cc in timercb (et=3D<optimized out>, arg=3D&= lt;optimized out>)<br> >=C2=A0 =C2=A0 =C2=A0 at /usr/src/sys/kern/kern_clocksource.c:353<br> > #11 0xffffffff81dcd280 in lapic_handle_timer (frame=3D0xfffffe014677b7= 50)<br> >=C2=A0 =C2=A0 =C2=A0 at /usr/src/sys/x86/x86/local_apic.c:1343<br> > #12 <signal handler called><br> > #13 __asan_load8_noabort (addr=3D18446741880219689232)<br> >=C2=A0 =C2=A0 =C2=A0 at /usr/src/sys/kern/subr_asan.c:1113<br> > #14 0xffffffff851488b8 in ?? () from /boot/thayer/ipfw.ko<br> > #15 0xfffffe0100000000 in ?? ()<br> > #16 0xffffffff8134dcd5 in pcpu_find (cpuid=3D1238425856)<br> >=C2=A0 =C2=A0 =C2=A0 at /usr/src/sys/kern/subr_pcpu.c:286<br> > #17 0xffffffff85151f6f in ?? () from /boot/thayer/ipfw.ko<br> > #18 0x0000000000000000 in ?? ()<br> <br> </blockquote></div> --000000000000f273500610fa199d--
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