drm: remove the newline for CRC source name.

[ Upstream commit 72a848f5c46bab4c921edc9cbffd1ab273b2be17 ]

userspace may transfer a newline, and this terminating newline
is replaced by a '\0' to avoid followup issues.

'len-1' is the index to replace the newline of CRC source name.

v3: typo fix (Sam)

v2: update patch subject, body and format. (Sam)

Cc: Leo Li <sunpeng.li@amd.com>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Dingchen Zhang <dingchen.zhang@amd.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190610134751.14356-1-dingchen.zhang@amd.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c
index be1b7ba92ffe1e5e041c4d794edc0c0972da5ae4..6a626c82e264b011304cd72cd3f225f16ae45b17 100644 (file)
--- a/drivers/gpu/drm/drm_debugfs_crc.c
+++ b/drivers/gpu/drm/drm_debugfs_crc.c
@@ -140,8 +140,8 @@ static ssize_t crc_control_write(struct file *file, const char __user *ubuf,
        if (IS_ERR(source))
                return PTR_ERR(source);
 
-       if (source[len] == '\n')
-               source[len] = '\0';
+       if (source[len - 1] == '\n')
+               source[len - 1] = '\0';
 
        ret = crtc->funcs->verify_crc_source(crtc, source, &values_cnt);
        if (ret)