Hello, 2014-04-17 9:00 GMT+09:00 DaeSeok Youn <daeseok.y...@gmail.com>: > Hello, > > 2014-04-16 21:38 GMT+09:00 Jean-Christophe PLAGNIOL-VILLARD > <plagn...@jcrosoft.com>: >> >> On Apr 16, 2014, at 5:40 PM, Daeseok Youn <daeseok.y...@gmail.com> wrote: >> >>> >>> The spec->modedb can be NULL by fb_create_modedb(). >>> >>> And also smatch says: >>> drivers/video/fbdev/core/fbmon.c:975 fb_edid_to_monspecs() error: >>> potential null dereference 'specs->modedb'. >>> (fb_create_modedb returns null) >>> >>> Signed-off-by: Daeseok Youn <daeseok.y...@gmail.com> >>> --- >>> drivers/video/fbdev/core/fbmon.c | 3 +++ >>> 1 files changed, 3 insertions(+), 0 deletions(-) >>> >>> diff --git a/drivers/video/fbdev/core/fbmon.c >>> b/drivers/video/fbdev/core/fbmon.c >>> index c204ebe..db274ca 100644 >>> --- a/drivers/video/fbdev/core/fbmon.c >>> +++ b/drivers/video/fbdev/core/fbmon.c >>> @@ -966,6 +966,9 @@ void fb_edid_to_monspecs(unsigned char *edid, struct >>> fb_monspecs *specs) >>> >>> specs->modedb = fb_create_modedb(edid, &specs->modedb_len); >>> >>> + if (!specs->modedb) >>> + return; >>> + >> >> we need to return an error and trace it > Yes, you're right. I will change return type from void to int and add > to handle an error when this function(fb_edid_to_monspecs) is called. > I try to look at the fbdev code related with fb_edid_to_monspecs(). And the result, I think it doesn't need to return an error and trace it. My patch is also useless because modedb_len is zero when fb_create_modedb() returns NULL so It cannot be dereferenced.
And callers of this function seem to need a log but I think they don't need to handling an error. Some functions are handling error with checking NULL of modedb variable, they are just printing an error message. If I am wrong or you have reasons for handling an error on that function, please let me know. Regards, Daeseok Youn. > I will send this patch as your comment. > > Thanks for review. > > Daeseok Youn. >> >> Best Regards, >> J. >>> /* >>> * Workaround for buggy EDIDs that sets that the first >>> * detailed timing is preferred but has not detailed >>> -- >>> 1.7.4.4 >>> >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
