Re: Kernel panic related to pipe

[Martin Husemann <martin%duskware.de@localhost>]

On Mon, Oct 05, 2026 at 11:51:53AM +0200, Martin Husemann wrote:
> On Mon, Oct 05, 2026 at 06:35:15PM +0900, Ryo ONODERA wrote:
> > Hi,
> > 
> > The kernel build from the latest src gets kernel panic as follows:
> > 
> > uvm_fault(0xffff808a5adb4680, 0x0, 1) -> e
> > fatal page fault in supervisor mode
> > trap type 6 code 0 rip 0xffffffff80dd1c62 cs 0x8 rflags 0x10286 cr2 0x70 ilevel
> > 0 rsp 0xffff84892121be50
> > curlwp 0xffff808a38fbe000 pid 9260.9260 lowest kstack 0xffff8489212172c0
> > panic: trap
> > cpu8: Begin traceback...
> 
> I have the same problem.

Taylor: it crashes in the

	KASSERT(mutex_owned(pipe->pipe_lock));

with a NULL deref as apparently "pipe" is NULL.

[ 1791.9954315] uvm_fault(0xffff82fd6dde1c80, 0x0, 1) -> e
[ 1792.0554307] fatal page fault in supervisor mode
[ 1792.1054306] trap type 6 code 0 rip 0xffffffff80ed0d8f cs 0x8 rflags 0x10286$
[ 1792.2354293] curlwp 0xffff82fc97ee3400 pid 10053.10053 lowest kstack 0xffffa$
[uvermn_efla:u ltp(ag0xef ffafuf8l2tf ct3raccp,f4 c90od0,e =00
 Stopped in pid 10053.10053 (nbmake) at  netbsd:pipeselwakeup+0x13:      movq  $
0(%rdi),%rdi
pipeselwakeup() at netbsd:pipeselwakeup+0x13  
pipe_read() at netbsd:pipe_read+0x253
dofileread() at netbsd:dofileread+0xad
sys_read() at netbsd:sys_read+0x49
syscall() at netbsd:syscall+0xaf
--- syscall (number 3) ---
netbsd:syscall+0xaf:
ds          0
es          3400
fs          3400
gs          9dd0
rdi         0
rsi         2
rbp         ffffac0958544e80
rbx         0
rdx         20
rcx         ffff82fc97ee3400
rax         ffffffff8162893e    ostype+0x6c03e
r8          1
r9          1
db{1}> x/i pipeselwakeup
netbsd:pipeselwakeup:   pushq   %rbp
netbsd:pipeselwakeup+0x1:       movq    %rsp,%rbp
netbsd:pipeselwakeup+0x4:       pushq   %r13
netbsd:pipeselwakeup+0x6:       pushq   %r12
netbsd:pipeselwakeup+0x8:       pushq   %rbx
netbsd:pipeselwakeup+0x9:       subq    $0x8,%rsp
netbsd:pipeselwakeup+0xd:       movq    %rdi,%rbx
netbsd:pipeselwakeup+0x10:      movl    %esi,%r12d
netbsd:pipeselwakeup+0x13:      movq    0(%rdi),%rdi


Martin