Date: Thu, 19 Dec 2013 10:59:35 -0800 From: Peter Wemm <peter@wemm.org> To: Sean Bruno <sbruno@freebsd.org> Cc: Konstantin Belousov <kostikbel@gmail.com>, "freebsd-stable@freebsd.org" <freebsd-stable@freebsd.org> Subject: Re: 10.0 BETA 3 with redports kernel panic Message-ID: <CAGE5yCqhmRSM6oyw=FRZq59LniLsYaN%2BEog=GEPn3-ruuQk9EQ@mail.gmail.com> In-Reply-To: <1387479064.2494.5.camel@powernoodle.corp.yahoo.com> References: <1384029731.1819.7.camel@powernoodle.corp.yahoo.com> <20131109205030.GF59496@kib.kiev.ua> <1387217065.1407.3.camel@powernoodle.corp.yahoo.com> <1387219558.1407.6.camel@powernoodle.corp.yahoo.com> <20131217120019.GD59496@kib.kiev.ua> <1387285472.2372.2.camel@powernoodle.corp.yahoo.com> <1387473915.2494.0.camel@powernoodle.corp.yahoo.com> <20131219180833.GN59496@kib.kiev.ua> <1387479064.2494.5.camel@powernoodle.corp.yahoo.com>
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On Thu, Dec 19, 2013 at 10:51 AM, Sean Bruno <sean_bruno@yahoo.com> wrote: > On Thu, 2013-12-19 at 20:08 +0200, Konstantin Belousov wrote: >> On Thu, Dec 19, 2013 at 09:25:15AM -0800, Sean Bruno wrote: >> > On Tue, 2013-12-17 at 05:04 -0800, Sean Bruno wrote: >> > > On Tue, 2013-12-17 at 14:00 +0200, Konstantin Belousov wrote: >> > > > On Mon, Dec 16, 2013 at 10:45:58AM -0800, Sean Bruno wrote: >> > > > > On Mon, 2013-12-16 at 10:04 -0800, Sean Bruno wrote: >> > > > > > > What is the source line for memrw+0x195 ? >> > > > > > >> > > > > > My apologies for the delay on this. Its been frustrating getting a >> > > > > > crashdump on these machines due to their very large tmpfs usage. >> > > > > > Currently, I am dumping a crash of 13+GB to a third HD that we had >> > > > > > installed for this purpose. >> > > > > > >> > > > > > The machines are still running RC3 of 10.0r. >> > > > > > >> > > > > > I will attempt to get the requested information shortly. >> > > > > > >> > > > > > sean >> > > > > > >> > > > > > >> > > > > >> > > > > I've updated http://people.freebsd.org/~sbruno/redbuild_panic.txt >> > > > > >> > > > > It looks like its dying in uiomove() ? >> > > > >> > > > I believe I already posted the following patch, with no feedback. >> > > > >> > > > diff --git a/sys/amd64/amd64/mem.c b/sys/amd64/amd64/mem.c >> > > > index abbbb21..e371499 100644 >> > > > --- a/sys/amd64/amd64/mem.c >> > > > +++ b/sys/amd64/amd64/mem.c >> > > > @@ -98,7 +98,11 @@ memrw(struct cdev *dev, struct uio *uio, int flags) >> > > > kmemphys: >> > > > o = v & PAGE_MASK; >> > > > c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o)); >> > > > - error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio); >> > > > + v = PHYS_TO_DMAP(v); >> > > > + if (v < DMAP_MIN_ADDRESS || v >= DMAP_MAX_ADDRESS || >> > > > + pmap_kextract(v) == 0) >> > > > + return (EFAULT); >> > > > + error = uiomove((void *)v, (int)c, uio); >> > > > continue; >> > > > } >> > > > else if (dev2unit(dev) == CDEV_MINOR_KMEM) { >> > > >> > > Will begin testing immediately >> > > >> > > sean >> > >> > >> > Huh ... both machines panic'd this morning. It'll take 30 minutes or so >> > to get a crash dump, but it looks like its still in the same place. >> > >> > db> whe >> > Tracing pid 489 tid 101801 td 0xfffff80322946490 >> > kdb_enter() at kdb_enter+0x3e/frame 0xfffffe1839d26220 >> > panic() at panic+0x175/frame 0xfffffe1839d262a0 >> > vm_fault_hold() at vm_fault_hold+0x14ed/frame 0xfffffe1839d26500 >> > vm_fault() at vm_fault+0x77/frame 0xfffffe1839d26540 >> > trap_pfault() at trap_pfault+0x19b/frame 0xfffffe1839d265f0 >> > trap() at trap+0x5e6/frame 0xfffffe1839d26810 >> > calltrap() at calltrap+0x8/frame 0xfffffe1839d26810 >> > --- trap 0xc, rip = 0xffffffff80cae47b, rsp = 0xfffffe1839d268d0, rbp = >> > 0xfffffe1839d26920 --- >> > copyout() at copyout+0x3b/frame 0xfffffe1839d26920 >> > memrw() at memrw+0x1b6/frame 0xfffffe1839d26960 >> > giant_read() at giant_read+0x7a/frame 0xfffffe1839d269a0 >> > devfs_read_f() at devfs_read_f+0xea/frame 0xfffffe1839d26a00 >> > dofileread() at dofileread+0x7b/frame 0xfffffe1839d26a40 >> > kern_readv() at kern_readv+0x65/frame 0xfffffe1839d26a90 >> > sys_read() at sys_read+0x63/frame 0xfffffe1839d26ae0 >> > amd64_syscall() at amd64_syscall+0x357/frame 0xfffffe1839d26bf0 >> > Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe1839d26bf0 >> > --- syscall (3, FreeBSD ELF64, sys_read), rip = 0x800b750aa, rsp = >> > 0x7fffffffd068, rbp = 0x7fffffffd0b0 --- >> > db> call doadump >> > >> >> I need to see exact panic and trap messages, as well as I need to know >> the source line for memrw+0x1b6 in the patched kernel. > > Here is the panic/trap and the requested display. Peter suspects that > part of the failure is the use of DMAP_MAX_ADDR and not dmaplimit in > this and other comparisons. Patch attached that contains your > modifications and his. > > bcc peter@ > > > panic: vm_fault: fault on nofault entry, addr: fffffe0327240000 > cpuid = 16 > KDB: stack backtrace: > db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame > 0xfffffe1839d26170 > kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe1839d26220 > panic() at panic+0x155/frame 0xfffffe1839d262a0 > vm_fault_hold() at vm_fault_hold+0x14ed/frame 0xfffffe1839d26500 > vm_fault() at vm_fault+0x77/frame 0xfffffe1839d26540 > trap_pfault() at trap_pfault+0x19b/frame 0xfffffe1839d265f0 > trap() at trap+0x5e6/frame 0xfffffe1839d26810 > calltrap() at calltrap+0x8/frame 0xfffffe1839d26810 > --- trap 0xc, rip = 0xffffffff80cae47b, rsp = 0xfffffe1839d268d0, rbp = > 0xfffffe1839d26920 --- > copyout() at copyout+0x3b/frame 0xfffffe1839d26920 > memrw() at memrw+0x1b6/frame 0xfffffe1839d26960 > giant_read() at giant_read+0x7a/frame 0xfffffe1839d269a0 > devfs_read_f() at devfs_read_f+0xea/frame 0xfffffe1839d26a00 > dofileread() at dofileread+0x7b/frame 0xfffffe1839d26a40 > kern_readv() at kern_readv+0x65/frame 0xfffffe1839d26a90 > sys_read() at sys_read+0x63/frame 0xfffffe1839d26ae0 > amd64_syscall() at amd64_syscall+0x357/frame 0xfffffe1839d26bf0 > Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe1839d26bf0 > --- syscall (3, FreeBSD ELF64, sys_read), rip = 0x800b750aa, rsp = > 0x7fffffffd068, rbp = 0x7fffffffd0b0 --- > KDB: enter: panic > > > (kgdb) whe > #0 doadump (textdump=-2127435168) at pcpu.h:219 > #1 0xffffffff80342e25 in db_fncall (dummy1=<value optimized out>, dummy2=<value optimized out>, dummy3=<value optimized out>, dummy4=<value optimized out>) > at /usr/src/sys/ddb/db_command.c:578 > #2 0xffffffff80342b0d in db_command (cmd_table=<value optimized out>) at /usr/src/sys/ddb/db_command.c:449 > #3 0xffffffff80342884 in db_command_loop () at /usr/src/sys/ddb/db_command.c:502 > #4 0xffffffff803451f0 in db_trap (type=<value optimized out>, code=0) at /usr/src/sys/ddb/db_main.c:231 > #5 0xffffffff808fad33 in kdb_trap (type=3, code=0, tf=<value optimized out>) at /usr/src/sys/kern/subr_kdb.c:656 > #6 0xffffffff80cb0277 in trap (frame=0xfffffe1839d26150) at /usr/src/sys/amd64/amd64/trap.c:579 > #7 0xffffffff80c96ef2 in calltrap () at /usr/src/sys/amd64/amd64/exception.S:232 > #8 0xffffffff808fa4ee in kdb_enter (why=0xffffffff80f07ff2 "panic", msg=<value optimized out>) at cpufunc.h:63 > #9 0xffffffff808c1eb5 in panic (fmt=<value optimized out>) at /usr/src/sys/kern/kern_shutdown.c:747 > #10 0xffffffff80b299ed in vm_fault_hold (map=0xfffff80002000000, vaddr=<value optimized out>, fault_type=1 '\001', fault_flags=0, m_hold=0x0) at /usr/src/sys/vm/vm_fault.c:279 > #11 0xffffffff80b284b7 in vm_fault (map=0xfffff80002000000, vaddr=<value optimized out>, fault_type=1 '\001', fault_flags=0) at /usr/src/sys/vm/vm_fault.c:224 > #12 0xffffffff80cb08cb in trap_pfault (frame=0xfffffe1839d26820, usermode=0) at /usr/src/sys/amd64/amd64/trap.c:775 > #17 0xffffffff80c9e746 in memrw (dev=<value optimized out>, uio=<value optimized out>, flags=<value optimized out>) at /usr/src/sys/amd64/amd64/mem.c:105 > #18 0xffffffff8087323a in giant_read (dev=0xfffff80011302e00, uio=0xfffffe1839d26ab0, ioflag=0) at /usr/src/sys/kern/kern_conf.c:444 > #19 0xffffffff807b670a in devfs_read_f (fp=0xfffff80033711a50, uio=0xfffffe1839d26ab0, cred=<value optimized out>, flags=0, td=0xfffff80322946490) > at /usr/src/sys/fs/devfs/devfs_vnops.c:1193 > #20 0xffffffff809117eb in dofileread (td=0xfffff80322946490, fd=4, fp=0xfffff80033711a50, auio=0xfffffe1839d26ab0, offset=<value optimized out>, flags=0) at file.h:295 > #21 0xffffffff80911525 in kern_readv (td=0xfffff80322946490, fd=4, auio=0xfffffe1839d26ab0) at /usr/src/sys/kern/sys_generic.c:256 > #22 0xffffffff809114b3 in sys_read (td=<value optimized out>, uap=<value optimized out>) at /usr/src/sys/kern/sys_generic.c:171 > #23 0xffffffff80cb1017 in amd64_syscall (td=0xfffff80322946490, traced=0) at subr_syscall.c:134 > #24 0xffffffff80c971db in Xfast_syscall () at /usr/src/sys/amd64/amd64/exception.S:391 > #25 0x0000000800b750aa in ?? () > Previous frame inner to this frame (corrupt stack?) > Current language: auto; currently minimal > (kgdb) p memrw+0x1b6 > $1 = (int (*)(struct cdev *, struct uio *, int)) 0xffffffff80c9e746 <memrw+438> > (kgdb) f 17 > #17 0xffffffff80c9e746 in memrw (dev=<value optimized out>, uio=<value optimized out>, flags=<value optimized out>) at /usr/src/sys/amd64/amd64/mem.c:105 > 105 error = uiomove((void *)v, (int)c, uio); > (kgdb) list > 100 c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o)); > 101 v = PHYS_TO_DMAP(v); > 102 if (v < DMAP_MIN_ADDRESS || v >= DMAP_MAX_ADDRESS || > 103 pmap_kextract(v) == 0) > 104 return (EFAULT); > 105 error = uiomove((void *)v, (int)c, uio); > 106 continue; > 107 } > 108 else if (dev2unit(dev) == CDEV_MINOR_KMEM) { > 109 v = uio->uio_offset; > > > > Index: sys/amd64/amd64/mem.c > =================================================================== > --- sys/amd64/amd64/mem.c (revision 258554) > +++ sys/amd64/amd64/mem.c (working copy) > @@ -98,7 +98,11 @@ > kmemphys: > o = v & PAGE_MASK; > c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o)); > - error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, > uio); > + v = PHYS_TO_DMAP(v); > + if (v < DMAP_MIN_ADDRESS || v >= > DMAP_MAX_ADDRESS || > + pmap_kextract(v) == 0) > + return (EFAULT); > + error = uiomove((void *)v, (int)c, uio); > continue; > } > else if (dev2unit(dev) == CDEV_MINOR_KMEM) { > Index: sys/amd64/amd64/pmap.c > =================================================================== > --- sys/amd64/amd64/pmap.c (revision 258554) > +++ sys/amd64/amd64/pmap.c (working copy) > @@ -1870,7 +1870,7 @@ > pd_entry_t pde; > vm_paddr_t pa; > > - if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS) { > + if (va >= DMAP_MIN_ADDRESS && va < dmaplimit) { > pa = DMAP_TO_PHYS(va); > } else { > pde = *vtopde(va); > @@ -3308,7 +3308,7 @@ > */ > if ((oldpde & PG_A) == 0 || (mpte = vm_page_alloc(NULL, > pmap_pde_pindex(va), (va >= DMAP_MIN_ADDRESS && va < > - DMAP_MAX_ADDRESS ? VM_ALLOC_INTERRUPT : > VM_ALLOC_NORMAL) | > + dmaplimit ? VM_ALLOC_INTERRUPT : VM_ALLOC_NORMAL) | > VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) { > SLIST_INIT(&free); > pmap_remove_pde(pmap, pde, trunc_2mpage(va), > &free, > @@ -6117,7 +6117,7 @@ > vm_offset_t base, offset; > > /* If we gave a direct map region in pmap_mapdev, do nothing */ > - if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS) > + if (va >= DMAP_MIN_ADDRESS && va < dmaplimit) > return; > base = trunc_page(va); > offset = va & PAGE_MASK; > > Specifically, pmap_kextract(v) is nothing more than a repeat of the if() that kib added to mem.c. pmap_kextract() doesn't check to see if it is attempting to access beyond the end of the instantiated part of the direct map region. pmap_kextract(invalid_address) returns a value even between dmaplimit and DMAP_MAX_ADDRESS - and that'll lead to a fault. -Peter -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com; KI6FJV Yes, I know, gmail sucks now. If you see this then I forgot. Habits are hard to break.
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