Commit:     1f2b69f9bdce8461341e5fb864568a2ee90079c8
Parent:     69f7c0a1be84b10a81b6edcce2dbee0cdec26eba
Author:     Paul Mundt <[EMAIL PROTECTED]>
AuthorDate: Mon Mar 5 00:30:31 2007 -0800
Committer:  Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Mon Mar 5 07:57:51 2007 -0800

    [PATCH] fb: sm501fb off-by-1 sysfs store
    Currently sm501fb_crtsrc_store() won't allow the routing to be changed via
    echos from userspace in to the sysfs file.  The reason for this is that the
    strnicmp() for both heads uses a sizeof() for the string length, which ends
    up being strlen() + 1 (\0 in the normal case, but the echo gives a newline,
    which is where the issue occurs), this then causes a mismatch and
    subsequently bails with the -EINVAL.
    In addition to this, the hardcoded lengths were then used for the store
    length that was returned, which ended up being erroneous and resulting in a
    write error.  There's also no point in returning anything but the full
    length since it will -EINVAL out on a mismatch well before then anyways.
    sizeof("string") is great for making sure you have space in your buffer,
    but rather less so for string comparisons :-)
    Signed-off-by: Paul Mundt <[EMAIL PROTECTED]>
    Acked-by: Ben Dooks <[EMAIL PROTECTED]>
    Cc: "Antonino A. Daplas" <[EMAIL PROTECTED]>
    Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
    Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
 drivers/video/sm501fb.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c
index 58c0ac7..0a44c44 100644
--- a/drivers/video/sm501fb.c
+++ b/drivers/video/sm501fb.c
@@ -1074,9 +1074,9 @@ static ssize_t sm501fb_crtsrc_store(struct device *dev,
        if (len < 1)
                return -EINVAL;
-       if (strnicmp(buf, "crt", sizeof("crt")) == 0)
+       if (strnicmp(buf, "crt", 3) == 0)
                head = HEAD_CRT;
-       else if (strnicmp(buf, "panel", sizeof("panel")) == 0)
+       else if (strnicmp(buf, "panel", 5) == 0)
                head = HEAD_PANEL;
                return -EINVAL;
@@ -1098,7 +1098,7 @@ static ssize_t sm501fb_crtsrc_store(struct device *dev,
        writel(ctrl, info->regs + SM501_DC_CRT_CONTROL);
-       return (head == HEAD_CRT) ? 3 : 5;
+       return len;
 /* Prepare the device_attr for registration with sysfs later */
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