svn commit: r284215 - in head/sys: amd64/linux32 compat/linux compat/svr4 dev/drm2/i915 fs/fdescfs i386/ibcs2 i386/linux kern ofed/drivers/infiniband/core ofed/drivers/infiniband/hw/mthca sys vm

[Ivan Klymenko]

Wed, 10 Jun 2015 15:53:37 +0200
Mateusz Guzik <mjguzik at gmail.com> написав:

> On Wed, Jun 10, 2015 at 04:33:26PM +0300, Ivan Klymenko wrote:
> > Wed, 10 Jun 2015 10:48:13 +0000 (UTC)
> > Mateusz Guzik <mjg at FreeBSD.org> написав:
> > 
> > > Author: mjg
> > > Date: Wed Jun 10 10:48:12 2015
> > > New Revision: 284215
> > > URL: https://svnweb.freebsd.org/changeset/base/284215
> > > 
> > > Log:
> > >   Implement lockless resource limits.
> > >   
> > >   Use the same scheme implemented to manage credentials.
> > >   
> > >   Code needing to look at process's credentials (as opposed to
> > > thred's) is provided with *_proc variants of relevant functions.
> > >   
> > >   Places which possibly had to take the proc lock anyway still use
> > > the proc pointer to access limits.
> > > 
> > > 
> > 
> > I have panic.
> > I not sure that it refers to a specific commit.
> > 
> > Fatal trap 12: page fault while in kernel mode
> > cpuid = 0; apic id = 00
> > fault virtual address	= 0x80
> > fault code		= supervisor read data, page not present
> > instruction pointer	= 0x20:0xffffffff809cfbfa
> > stack pointer	        = 0x28:0xfffffe01aa4906c0
> > frame pointer	        = 0x28:0xfffffe01aa4906e0
> > code segment		= base 0x0, limit 0xfffff, type 0x1b
> > 			= DPL 0, pres 1, long 1, def32 0, gran 1
> > processor eflags	= interrupt enabled, resume, IOPL = 0
> > current process		= 4091 (npviewer.bin)
> > trap number		= 12
> > panic: page fault
> > cpuid = 0
> > KDB: stack backtrace:
> > #0 0xffffffff80a17c27 at kdb_backtrace+0x67
> > #1 0xffffffff809d3f79 at vpanic+0x189
> > #2 0xffffffff809d3de3 at panic+0x43
> > #3 0xffffffff80e73b35 at trap_fatal+0x355
> > #4 0xffffffff80e73e6e at trap_pfault+0x31e
> > #5 0xffffffff80e734d4 at trap+0x464
> > #6 0xffffffff80e57422 at calltrap+0x8
> > #7 0xffffffff8097c942 at fdalloc+0x32
> > #8 0xffffffff8097cf95 at finstall+0x95
> > #9 0xffffffff80a99844 at kern_openat+0x3c4
> > #10 0xffffffff8229fe93 at linux_common_open+0xc3
> > #11 0xffffffff822a0068 at linux_open+0x58
> > #12 0xffffffff80f7408b at ia32_syscall+0x41b
> > #13 0xffffffff80e57a05 at Xint0x80_syscall+0x95
> > Uptime: 29m1s
> > Dumping 854 out of 6047
> > MB:..2%..12%..21%..32%..42%..51%..62%..72%..81%..92%
> > 
> > 221	pcpu.h: No such file or directory.
> > 	in pcpu.h
> > (kgdb) #0  doadump (textdump=<value optimized out>) at pcpu.h:221
> > #1  0xffffffff809d3a7d in kern_reboot (howto=260)
> >     at /usr/src/sys/kern/kern_shutdown.c:447
> > #2  0xffffffff809d3fb8 in vpanic (fmt=<value optimized out>, 
> >     ap=<value optimized out>)
> > at /usr/src/sys/kern/kern_shutdown.c:744 #3  0xffffffff809d3de3 in
> > panic (fmt=0x0) at /usr/src/sys/kern/kern_shutdown.c:675
> > #4  0xffffffff80e73b35 in trap_fatal (frame=<value optimized out>, 
> >     eva=<value optimized out>)
> > at /usr/src/sys/amd64/amd64/trap.c:853 #5  0xffffffff80e73e6e in
> > trap_pfault (frame=0xfffffe01aa490610, usermode=<value optimized
> > out>) at /usr/src/sys/amd64/amd64/trap.c:676 #6  0xffffffff80e734d4
> > out>in trap (frame=0xfffffe01aa490610)
> >     at /usr/src/sys/amd64/amd64/trap.c:426
> > #7  0xffffffff80e57422 in calltrap ()
> >     at /usr/src/sys/amd64/amd64/exception.S:235
> > #8  0xffffffff809cfbfa in lim_cur (td=0xfffff8010185e4c0, which=8)
> >     at /usr/src/sys/kern/kern_resource.c:1209
> > #9  0xffffffff8097c942 in fdalloc (td=0xfffff8010185e4c0, 
> >     minfd=<value optimized out>, result=0xfffffe01aa4907dc)
> >     at /usr/src/sys/kern/kern_descrip.c:790
> > #10 0xffffffff8097cf95 in finstall (td=0xfffff8010185e4c0, 
> >     fp=0xfffff80139e89870, fd=0xfffffe01aa4907dc, flags=1,
> > fcaps=0x0) at /usr/src/sys/kern/kern_descrip.c:1768
> > #11 0xffffffff80a99844 in kern_openat (td=0xfffff8010185e4c0,
> > fd=-100, path=0xfffff80016832400 "/compat/linux/proc/stat",
> > pathseg=UIO_SYSSPACE, flags=<value optimized out>, mode=<value
> > optimized out>) at /usr/src/sys/kern/vfs_syscalls.c:1158
> > #12 0xffffffff8229fe93 in linux_common_open (td=0xfffff8010185e4c0,
> > dirfd=8, path=0xfffff80016832400 "/compat/linux/proc/stat", 
> >     l_flags=<value optimized out>, mode=51)
> >     at /usr/src/sys/modules/linux/../../compat/linux/linux_file.c:134
> > #13 0xffffffff822a0068 in linux_open (td=<value optimized out>, 
> >     args=<value optimized out>)
> >     at /usr/src/sys/modules/linux/../../compat/linux/linux_file.c:211
> > #14 0xffffffff80f7408b in ia32_syscall (frame=0xfffffe01aa490ac0)
> >     at subr_syscall.c:133
> > #15 0xffffffff80e57a05 in Xint0x80_syscall () at ia32_exception.S:73
> > #16 0x00000000ffffe452 in ?? ()
> > Previous frame inner to this frame (corrupt stack?)
> > Current language:  auto; currently minimal
> > (kgdb) 
> > 
> 
> The following should fix it:
> diff --git a/sys/compat/linux/linux_fork.c
> b/sys/compat/linux/linux_fork.c index 0fd47fd..394c26f 100644
> --- a/sys/compat/linux/linux_fork.c
> +++ b/sys/compat/linux/linux_fork.c
> @@ -298,7 +298,7 @@ linux_clone_thread(struct thread *td, struct
> linux_clone_args *args) __rangeof(struct thread, td_startcopy,
> td_endcopy)); 
>         newtd->td_proc = p;
> -       newtd->td_ucred = crhold(td->td_ucred);
> +       thread_cow_get(newtd, td);
>  
>         /* create the emuldata */
>         linux_proc_init(td, newtd, args->flags);
> 
> Still, it seems a bug that linux_clone_thread replicates so much of
> create_thread.
> 

Seems it helps to solve this problem.
Panic more not reproduced.
Thank you.