> -----Original Message----- > From: Taneja, Archit > Sent: Thursday, July 29, 2010 9:16 AM > To: Premi, Sanjeev; tomi.valkeinen@xxxxxxxxx > Cc: linux-omap@xxxxxxxxxxxxxxx > Subject: RE: [PATCH resend] OMAP: DSS2: Replace strncmp() > with sysfs_streq() in overlay_manager_store() > > > > > > > -----Original Message----- > > > > > From: linux-omap-owner@xxxxxxxxxxxxxxx > > > > > [mailto:linux-omap-owner@xxxxxxxxxxxxxxx] On Behalf Of > > > > Taneja, Archit > > > > > Sent: Wednesday, July 28, 2010 11:52 AM > > > > > To: tomi.valkeinen@xxxxxxxxx > > > > > Cc: linux-omap@xxxxxxxxxxxxxxx; Taneja, Archit > > > > > Subject: [PATCH resend] OMAP: DSS2: Replace strncmp() with > > > > > sysfs_streq() in overlay_manager_store() > > > > > > > > > > In the function overlay_manager_store, the length of the > > > > string buf is > > > > > used to comapre the 2 strings, there is a possibility > of false > > > > > positive match if buf is a prefix string of another manager. > > > > > > > > > > The use of sysfs_streq() fixes this. > > > > > > > > > > Signed-off-by: Archit Taneja <archit@xxxxxx> > > > > > --- > > > > > drivers/video/omap2/dss/overlay.c | 2 +- > > > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > > > > > diff --git a/drivers/video/omap2/dss/overlay.c > > > > > b/drivers/video/omap2/dss/overlay.c > > > > > index 8233658..244dca8 > > > > > --- a/drivers/video/omap2/dss/overlay.c > > > > > +++ b/drivers/video/omap2/dss/overlay.c > > > > > @@ -65,7 +65,7 @@ static ssize_t overlay_manager_store(struct > > > > > omap_overlay *ovl, const char *buf, > > > > > for (i = 0; i < > > > > > omap_dss_get_num_overlay_managers(); ++i) { > > > > > mgr = omap_dss_get_overlay_manager(i); > > > > > > > > > > - if (strncmp(buf, mgr->name, len) == 0) > > > > > + if (sysfs_streq(buf, mgr->name)) > > > > > > > > [sp] sysfs_streq() ignores trailing newlines during > > comparison. So, > > > > the possibility mentioned in the description still stays. > > > > > > The aim is to compare one string which is a sysfs input and > > the other > > > which is in the kernel. > > > > > > > > > > > I am not familiar with overall context; but > wouldn't srtcmp() > > > > be the right choice? unless, of course, either of strings > > > > being compared are not null terminated. > > > > > > The sysfs input will have a newline and null at the end > whereas the > > > other string will only have null, strcmp will fail when > we want the > > > two strings to match. > > > > > > Eg. Sysfs input "lcd\n\0" > > > Kernel string "lcd\0" > > > > > > strcmp will fail here > > > > [sp] If the patch is intending to fix this condition, then it isn't > > evident from the description. You should consider updating the > > description. > > The patch isn't intending to fix this condition, this > condition doesn't > occur at all in the existing code. I explained this to tell > you why strcmp > is a bad choice, the patch description tells why sysfs_streq > is a better > choice over strncmp. [sp] Can you explain the real condition and how/why it can't be handled by strcmp() > > > > > > > > > > > > > > > break; > > > > > > > > > > mgr = NULL; > > > > > -- > > > > > 1.5.4.7 > > > > > > > > > > -- > > > > > To unsubscribe from this list: send the line "unsubscribe > > > > linux-omap" > > > > > in the body of a message to majordomo@xxxxxxxxxxxxxxx More > > > > majordomo > > > > > info at http://vger.kernel.org/majordomo-info.html > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
