namei() returns EISDIR for "/" (Re: svn commit: r203990 - head/lib/libc/sys)

[Alexander Best]

Jaakko Heinonen schrieb am 2010-03-05:
> On 2010-02-28, Jaakko Heinonen wrote:
> > > >   http://people.freebsd.org/~jh/patches/lookup-root.diff

> I have updated the patch taking some of bde's comments into account.
> The
> new version also includes updates for namei(9) manual page.

could this panic have been triggered by the patch?

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x12
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff8048af0f
stack pointer           = 0x28:0xffffff8040495000
frame pointer           = 0x28:0xffffff8040495020
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         = 1402 (sh)

Tracing pid 1402 tid 100092 td 0xffffff000729d000
strlen() at strlen+0x1f
kvprintf() at kvprintf+0x1027
vsnprintf() at vsnprintf+0x48
panic() at panic+0x15f
_mtx_lock_flags() at _mtx_lock_flags+0xc5
fdesc_allocvp() at fdesc_allocvp+0xbf
fdesc_lookup() at fdesc_lookup+0x15c
VOP_LOOKUP_APV() at VOP_LOOKUP_APV+0x11c
VOP_LOOKUP() at VOP_LOOKUP+0x45
lookup() at lookup+0x8cf
namei() at namei+0x730
vn_open_cred() at vn_open_cred+0x114
vn_open() at vn_open+0x55
kern_openat() at kern_openat+0x178
kern_open() at kern_open+0x3e
open() at open+0x26
syscall() at syscall+0x2a7
Xfast_syscall() at Xfast_syscall+0xe1
--- syscall (5, FreeBSD ELF64, open), rip = 0x8009a3bec, rsp = 0x7fffffffd3c8,
rbp = 0x800e143b0 ---

this was 100% reducible when doing `portsnap fetch` though i changed a lot of
stuff in my kernel config and reverted a lot of src patches to resolve the
issue so i'm not sure what exactly was causing it.

cheers.
alex


> The patch is attached to this mail and also found at:

>         http://people.freebsd.org/~jh/patches/lookup-root.2.diff