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authorAlexander Sverdlin <alexander.sverdlin@sysgo.com>2011-09-21 09:51:40 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2011-09-21 13:18:52 -0700
commit808bf29b9195c52239b9aaeda7c6082a0ddf07c6 (patch)
treeeabb672d84cf00b13225b44fdf2482b6900b5a14
parent32ef43848f283e0ef945d3c67e851c143fea3970 (diff)
downloadlinux-sh-808bf29b9195c52239b9aaeda7c6082a0ddf07c6.tar.gz
init: carefully handle loglevel option on kernel cmdline.
When a malformed loglevel value (for example "${abc}") is passed on the kernel cmdline, the loglevel itself is being set to 0. That then suppresses all following messages, including all the errors and crashes caused by other malformed cmdline options. This could make debugging process quite tricky. This patch leaves the previous value of loglevel if the new value is incorrect and reports an error code in this case. Signed-off-by: Alexander Sverdlin <alexander.sverdlin@sysgo.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--init/main.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/init/main.c b/init/main.c
index 9c51ee7adf3d..2a9b88aa5e76 100644
--- a/init/main.c
+++ b/init/main.c
@@ -209,8 +209,19 @@ early_param("quiet", quiet_kernel);
static int __init loglevel(char *str)
{
- get_option(&str, &console_loglevel);
- return 0;
+ int newlevel;
+
+ /*
+ * Only update loglevel value when a correct setting was passed,
+ * to prevent blind crashes (when loglevel being set to 0) that
+ * are quite hard to debug
+ */
+ if (get_option(&str, &newlevel)) {
+ console_loglevel = newlevel;
+ return 0;
+ }
+
+ return -EINVAL;
}
early_param("loglevel", loglevel);