kexec: fix the unexpected kexec_dprintk() macro
authorBaoquan He <bhe@redhat.com>
Tue, 9 Apr 2024 04:22:38 +0000 (12:22 +0800)
committerAndrew Morton <akpm@linux-foundation.org>
Wed, 8 May 2024 15:41:26 +0000 (08:41 -0700)
commitf4af41bf177add167e39e4b0203460b1d0b531f6
treeb3d48e2ac7d508cf311fd4f626386d95bd674bad
parent4707c13de3e42a47f0d99fe5fb58fa9dd23b455e
kexec: fix the unexpected kexec_dprintk() macro

Jiri reported that the current kexec_dprintk() always prints out debugging
message whenever kexec/kdmmp loading is triggered.  That is not wanted.
The debugging message is supposed to be printed out when 'kexec -s -d' is
specified for kexec/kdump loading.

After investigating, the reason is the current kexec_dprintk() takes
printk(KERN_INFO) or printk(KERN_DEBUG) depending on whether '-d' is
specified.  However, distros usually have defaulg log level like below:

 [~]# cat /proc/sys/kernel/printk
 7       4      1       7

So, even though '-d' is not specified, printk(KERN_DEBUG) also always
prints out.  I thought printk(KERN_DEBUG) is equal to pr_debug(), it's
not.

Fix it by changing to use pr_info() instead which are expected to work.

Link: https://lkml.kernel.org/r/20240409042238.1240462-1-bhe@redhat.com
Fixes: cbc2fe9d9cb2 ("kexec_file: add kexec_file flag to control debug printing")
Signed-off-by: Baoquan He <bhe@redhat.com>
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Closes: https://lore.kernel.org/all/4c775fca-5def-4a2d-8437-7130b02722a2@kernel.org
Reviewed-by: Dave Young <dyoung@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
include/linux/kexec.h