Messages in this thread | | | Date | Tue, 11 Feb 2020 13:43:17 +0100 | From | Petr Mladek <> | Subject | Re: [PATCH v1] printk: Declare log_wait as external variable |
| |
On Mon 2020-02-03 15:15:28, Andy Shevchenko wrote: > Static analyzer is not happy: > > kernel/printk/printk.c:421:1: warning: symbol 'log_wait' was not declared. Should it be static? > > This is due to usage of log_wait in the other module without announcing > its declaration to the world. I wasn't able to dug into deep history of > reasons why it is so, and thus decide to make less invasive change, i.e. > declaring log_wait as external variable to make static analyzer happy. > > Note the above is done if and only if the CONFIG_PROC_FS is enabled, > otherwise we fallback to static variable. > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > --- > kernel/printk/printk.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index 633f41a11d75..43b5cb88c607 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -418,7 +418,14 @@ DEFINE_RAW_SPINLOCK(logbuf_lock); > } while (0) > > #ifdef CONFIG_PRINTK > + > +#ifdef CONFIG_PROC_FS > +extern wait_queue_head_t log_wait; /* Used in fs/proc/kmsg.c */ > DECLARE_WAIT_QUEUE_HEAD(log_wait); > +#else > +static DECLARE_WAIT_QUEUE_HEAD(log_wait); > +#endif /* CONFIG_PROC_FS */
This looks too complicated as a workaround for a warning.
I got really confused. Probably also because the macro DECLARE_*() does a definition instead of a declaration.
As a minimal fix, I suggest to rename log_wait -> printk_log_wait and declare it in include/linux/printk.h.
Even better solution might be to move fs/proc/kmsg.c to kernel/printk/proc_kmsg.c and declare printk_log_wait only in kernel/printk/internal.h. I think that this is what Sergey suggested.
Another great thing would be to extract devkmsg stuff from kernel/printk/printk.c and put it into kernel/printk/dev_kmsg.c.
I am not sure but it might help people to realize that there are actually two different interfaces (old in /proc dmesg-like, and in /dev new for systemd). Sigh.
I am not sure how deep and far you would like to go ;-)
Best Regards, Petr
| |