diff options
Diffstat (limited to 'guix/build/syscalls.scm')
| -rw-r--r-- | guix/build/syscalls.scm | 55 |
1 files changed, 39 insertions, 16 deletions
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm index b2871c3c10..39bcffd516 100644 --- a/guix/build/syscalls.scm +++ b/guix/build/syscalls.scm @@ -1,5 +1,5 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2014-2023 Ludovic Courtès <ludo@gnu.org> +;;; Copyright © 2014-2024 Ludovic Courtès <ludo@gnu.org> ;;; Copyright © 2015 David Thompson <davet@gnu.org> ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org> ;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com> @@ -765,27 +765,50 @@ current process." (list (strerror err)) (list err))))))) -(define (kernel? pid) - "Return #t if PID designates a \"kernel thread\" rather than a normal -user-land process." - (let ((stat (call-with-input-file (format #f "/proc/~a/stat" pid) - (compose string-tokenize read-string)))) - ;; See proc.txt in Linux's documentation for the list of fields. - (match stat - ((pid tcomm state ppid pgrp sid tty_nr tty_pgrp flags min_flt - cmin_flt maj_flt cmaj_flt utime stime cutime cstime - priority nice num_thread it_real_value start_time - vsize rss rsslim - (= string->number start_code) (= string->number end_code) _ ...) - ;; Got this obscure trick from sysvinit's 'killall5' program. - (and (zero? start_code) (zero? end_code)))))) +(define (linux-process-flags pid) ;copied from the Shepherd + "Return the process flags of @var{pid} (or'd @code{PF_} constants), assuming +the Linux /proc file system is mounted; raise a @code{system-error} exception +otherwise." + (call-with-input-file (string-append "/proc/" (number->string pid) + "/stat") + (lambda (port) + (define line + (read-string port)) + + ;; Parse like systemd's 'is_kernel_thread' function. + (let ((offset (string-index line #\)))) ;offset past 'tcomm' field + (match (and offset + (string-tokenize (string-drop line (+ offset 1)))) + ((state ppid pgrp sid tty-nr tty-pgrp flags . _) + (or (string->number flags) 0)) + (_ + 0)))))) + +;; Per-process flag defined in <linux/sched.h>. +(define PF_KTHREAD #x00200000) ;I am a kernel thread + +(define (linux-kernel-thread? pid) + "Return true if @var{pid} is a Linux kernel thread." + (= PF_KTHREAD (logand (linux-process-flags pid) PF_KTHREAD))) + +(define pseudo-process? + (if (string-contains %host-type "linux") + (lambda (pid) + "Return true if @var{pid} denotes a \"pseudo-process\" such as a Linux +kernel thread rather than a \"regular\" process. A pseudo-process is one that +may never terminate, even after sending it SIGKILL---e.g., kthreadd on Linux." + (catch 'system-error + (lambda () + (linux-kernel-thread? pid)) + (const #f))) + (const #f))) (define (processes) "Return the list of live processes." (sort (filter-map (lambda (file) (let ((pid (string->number file))) (and pid - (not (kernel? pid)) + (not (pseudo-process? pid)) pid))) (scandir "/proc")) <)) |