Hi
Am 01.11.20 um 10:50 schrieb Sam Ravnborg:
On Wed, Oct 21, 2020 at 02:12:41PM +0200, Thomas Zimmermann wrote:
Trying to copy into the string fields with strncpy() gives a warning from gcc. Both fields are part of a packed HDMI header and do not require a terminating \0 character.
../drivers/video/hdmi.c: In function 'hdmi_spd_infoframe_init': ../drivers/video/hdmi.c:230:2: warning: 'strncpy' specified bound 8 equals destination size [-Wstringop-truncation] 230 | strncpy(frame->vendor, vendor, sizeof(frame->vendor)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../drivers/video/hdmi.c:231:2: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation] 231 | strncpy(frame->product, product, sizeof(frame->product)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Just use memcpy() instead.
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de
I assume vendor is guaranteed to be 0-termindated.
It's a fixed-length field in the protocol. There's similar code in radeon IIRC. So it would be nice to disable the warning in these cases. But that's probably to much fiddling.
Reviewed-by: Sam Ravnborg sam@ravnborg.org
Thanks.
Best regards Thomas
drivers/video/hdmi.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c index b7a1d6fae90d..1e4cb63d0d11 100644 --- a/drivers/video/hdmi.c +++ b/drivers/video/hdmi.c @@ -221,14 +221,18 @@ EXPORT_SYMBOL(hdmi_avi_infoframe_pack); int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame, const char *vendor, const char *product) {
size_t len;
memset(frame, 0, sizeof(*frame));
frame->type = HDMI_INFOFRAME_TYPE_SPD; frame->version = 1; frame->length = HDMI_SPD_INFOFRAME_SIZE;
- strncpy(frame->vendor, vendor, sizeof(frame->vendor));
- strncpy(frame->product, product, sizeof(frame->product));
len = strlen(vendor);
memcpy(frame->vendor, vendor, min(len, sizeof(frame->vendor)));
len = strlen(product);
memcpy(frame->product, product, min(len, sizeof(frame->product)));
return 0;
}
2.28.0
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