Messages in this thread | | | Subject | Re: [PATCH V2] auxdisplay: use correct string length | From | Xiongfeng Wang <> | Date | Tue, 13 Feb 2018 09:19:21 +0800 |
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On 2018/2/12 20:53, Miguel Ojeda wrote: > On Tue, Jan 16, 2018 at 10:38 AM, Xiongfeng Wang > <wangxiongfeng2@huawei.com> wrote: >> From: Xiongfeng Wang <xiongfeng.wang@linaro.org> >> >> gcc-8 reports >> >> drivers/auxdisplay/panel.c: In function 'panel_attach': >> ./include/linux/string.h:245:9: warning: '__builtin_strncpy' specified >> bound 12 equals destination size [-Wstringop-truncation] >> >> We need one less byte or call strlcpy() to make it a nul-terminated >> string. >> >> Signed-off-by: Xiongfeng Wang <xiongfeng.wang@linaro.org> >> --- >> drivers/auxdisplay/panel.c | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c >> index ea7869c..d288900 100644 >> --- a/drivers/auxdisplay/panel.c >> +++ b/drivers/auxdisplay/panel.c >> @@ -1506,10 +1506,10 @@ static struct logical_input *panel_bind_key(const char *name, const char *press, >> key->rise_time = 1; >> key->fall_time = 1; >> >> - strncpy(key->u.kbd.press_str, press, sizeof(key->u.kbd.press_str)); >> - strncpy(key->u.kbd.repeat_str, repeat, sizeof(key->u.kbd.repeat_str)); >> + strncpy(key->u.kbd.press_str, press, sizeof(key->u.kbd.press_str) - 1); >> + strncpy(key->u.kbd.repeat_str, repeat, sizeof(key->u.kbd.repeat_str) - 1); >> strncpy(key->u.kbd.release_str, release, >> - sizeof(key->u.kbd.release_str)); >> + sizeof(key->u.kbd.release_str) - 1); > > Are you sure about this patch? `kbd` says "strings can be non null-terminated". > > Willy, maybe those should just be memcpy()s? (unless the remaining > bytes, if any, must be 0). Sorry, my apologies. I think I made a mistake. I meant to use strlcpy(), but this also decrease the destination storage size by one. I think, if the strings can be non null-terminated, we can just use memcpy(). This may suppress the gcc warning.
Thanks, Xiongfeng
> > Thanks, > Miguel > >> list_add(&key->list, &logical_inputs); >> return key; >> } >> -- >> 1.8.3.1 >> > > . >
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