diff options
| author | Randy Dunlap <rdunlap@infradead.org> | 2022-02-28 23:05:56 +0100 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2022-03-02 09:01:37 +0100 |
| commit | b665eae7a788c5e2bc10f9ac3c0137aa0ad1fc97 (patch) | |
| tree | 50d1de36aaef20c438ba3fb3418e926a07662b87 /kernel/printk | |
| parent | vsprintf: Fix %pK with kptr_restrict == 0 (diff) | |
| download | linux-b665eae7a788c5e2bc10f9ac3c0137aa0ad1fc97.tar.xz linux-b665eae7a788c5e2bc10f9ac3c0137aa0ad1fc97.zip | |
printk: fix return value of printk.devkmsg __setup handler
If an invalid option value is used with "printk.devkmsg=<value>",
it is silently ignored.
If a valid option value is used, it is honored but the wrong return
value (0) is used, indicating that the command line option had an
error and was not handled. This string is not added to init's
environment strings due to init/main.c::unknown_bootoption()
checking for a '.' in the boot option string and then considering
that string to be an "Unused module parameter".
Print a warning message if a bad option string is used.
Always return 1 from the __setup handler to indicate that the command
line option has been handled.
Fixes: 750afe7babd1 ("printk: add kernel parameter to control writes to /dev/kmsg")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220228220556.23484-1-rdunlap@infradead.org
Diffstat (limited to 'kernel/printk')
| -rw-r--r-- | kernel/printk/printk.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 266cc974b0e3..21fb4e1cd7db 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -146,8 +146,10 @@ static int __control_devkmsg(char *str) static int __init control_devkmsg(char *str) { - if (__control_devkmsg(str) < 0) + if (__control_devkmsg(str) < 0) { + pr_warn("printk.devkmsg: bad option string '%s'\n", str); return 1; + } /* * Set sysctl string accordingly: @@ -166,7 +168,7 @@ static int __init control_devkmsg(char *str) */ devkmsg_log |= DEVKMSG_LOG_MASK_LOCK; - return 0; + return 1; } __setup("printk.devkmsg=", control_devkmsg); |