[Crash-utility] Re: [PATCH] Fix "log -c" option on Linux 6.14 and later kernels

Date: Wed, 23 Apr 2025 05:27:58 +0000 From: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com&gt; Subject: [Crash-utility] [PATCH] Fix "log -c" option on Linux 6.14 and later kernels To: &quot;devel(a)lists.crash-utility.osci.io&quot; <devel(a)lists.crash-utility.osci.io&gt; Message-ID: <1745386073-6196-1-git-send-email-k-hagio-ab(a)nec.com&gt; Content-Type: text/plain; charset="iso-2022-jp" From: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; Kernel commit 7863dcc72d0f ("pid: allow pid_max to be set per pid namespace") moved the pid_max variable into init_pid_ns. Without the patch, the "log -c" option fails with the following error: crash> log -c log: cannot resolve: "pid_max" While it is possible to track the pid_max value to init_pid_ns.pid_max, considering the option's availability, it might be better not to do so just for the sake of printing width. Furthermore, the current PID_MAX_LIMIT is 4194304, which does not exceed PID_CHARS_DEFAULT(8). Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; --- printk.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

index be842a759549..95db7e607e4c 100644 --- a/printk.c +++ b/printk.c @@ -285,8 +285,9 @@ dump_lockless_record_log(int msg_flags) if (msg_flags & SHOW_LOG_CALLER) { unsigned int pidmax; - get_symbol_data("pid_max", sizeof(pidmax), &pidmax); - if (pidmax <= 99999) + if (!try_get_symbol_data("pid_max", sizeof(pidmax), &pidmax)) + m.pid_max_chars = PID_CHARS_DEFAULT; + else if (pidmax <= 99999) m.pid_max_chars = 6; else if (pidmax <= 999999) m.pid_max_chars = 7; -- 2.31.1