CVS commit: [netbsd-10] src/sys

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Sun Oct 25 11:02:59 UTC 2026

Modified Files:
        src/sys/kern [netbsd-10]: kern_proc.c
        src/sys/sys [netbsd-10]: proc.h
        src/sys/uvm [netbsd-10]: uvm_map.c

Log Message:
Pull up following revision(s) (requested by riastradh in ticket #1397):

        sys/uvm/uvm_map.c: revision 1.432
        sys/sys/proc.h: revision 1.374
        sys/kern/kern_proc.c: revision 1.284
        sys/kern/kern_proc.c: revision 1.285
        sys/kern/kern_proc.c: revision 1.286
        (all via patch)

kern: New function proc_find_reflocked.

This is like proc_find_locked but returns with p_reflock held rather
than p_lock.  Will be used to replace proc_find_locked in order to
fix:

PR kern/60568: panic locking against myself (p->p_lock) in NFS from
sysctl_vmproc

No modules currently use proc_find_locked or proc_find_reflocked, so
there should be no module ABI compatibility issues here.

sysctl vm.proc.*: Use p_reflock, not p_lock.
- Avoid holding p_lock across copyout; this risks deadlock or panic
  if memory is exhausted and the uvm fault handler during copyout
  tries to deliver SIGKILL, which requires p_lock.
- Avoid holding p_lock across vnode_to_path: this risks deadlock or
  panic if the file system, such as nfs, tries to check for pending
  signals, which requires p_lock.

PR kern/60568: panic locking against myself (p->p_lock) in NFS from
sysctl_vmproc

sysctl kern.proc_args.*.cwd/pathname: Use p_reflock, not p_lock.
- Avoid holding p_lock across copyout; this risks deadlock or panic
  if memory is exhausted and the uvm fault handler during copyout
  tries to deliver SIGKILL, which requires p_lock.
- Avoid holding p_lock across vnode_to_path: this risks deadlock or
  panic if the file system, such as nfs, tries to check for pending
  signals, which requires p_lock.

PR kern/60568: panic locking against myself (p->p_lock) in NFS from
sysctl_vmproc

proc_vmspace_getref: Take p->p_lock around p->p_sflag access.
Prompted by reviewing the locking rules in;

PR kern/60568: panic locking against myself (p->p_lock) in NFS from
sysctl_vmproc


To generate a diff of this commit:
cvs rdiff -u -r1.269.2.1 -r1.269.2.2 src/sys/kern/kern_proc.c
cvs rdiff -u -r1.370.4.2 -r1.370.4.3 src/sys/sys/proc.h
cvs rdiff -u -r1.403.2.4 -r1.403.2.5 src/sys/uvm/uvm_map.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.