Hi, On Mon, Jun 27, 2022 at 4:06 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote: > > Hi, > > On Thu, May 19, 2022 at 12:33 AM Krzysztof Kozlowski > <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > > > The use of strncpy() is considered deprecated for NUL-terminated > > strings[1]. Replace strncpy() with strscpy_pad(), to keep existing > > pad-behavior of strncpy. This fixes W=1 warning: > > > > drivers/soc/qcom/cmd-db.c: In function ‘cmd_db_get_header.part.0’: > > drivers/soc/qcom/cmd-db.c:151:9: warning: ‘strncpy’ specified bound 8 equals destination size [-Wstringop-truncation] > > 151 | strncpy(query, id, sizeof(query)); > > > > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings > > > > Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> > > Reviewed-by: Stephen Boyd <sboyd@xxxxxxxxxx> > > > > --- > > > > Changes since v1: > > 1. Split series per subsystem. > > 2. Add tag. > > --- > > drivers/soc/qcom/cmd-db.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/soc/qcom/cmd-db.c b/drivers/soc/qcom/cmd-db.c > > index dd872017f345..c5137c25d819 100644 > > --- a/drivers/soc/qcom/cmd-db.c > > +++ b/drivers/soc/qcom/cmd-db.c > > @@ -148,7 +148,7 @@ static int cmd_db_get_header(const char *id, const struct entry_header **eh, > > return ret; > > > > /* Pad out query string to same length as in DB */ > > - strncpy(query, id, sizeof(query)); > > + strscpy_pad(query, id, sizeof(query)); > > Sorry to report that this breaks booting on > sc7280-herobrine-herobrine-r1. I believe that the function was > actually _relying_ on the "unsafe" behavior of strncpy(). Specifically > I think: > * The source string (id) was a '\0' terminated string. > * The destination (query) was a fixed 8-byte string and doesn't need > to be '\0' terminated. > > So before your change we could actually support 8-byte strings. Now we > can't because you'll only copy 7 bytes to the destination to leave > room for the '\0' termination... > > Looking at printouts, I see, for instance at least one ID that looks > like "lnbclka2". > > Given the requirements of this function(), the old strncpy() is > actually _exactly_ what we want. Is there any way to disable the > warning? If not, I guess we could make "query" be 9 bytes bit, or > "sizeof(ent->id) + 1" bytes big... Happy to post a patch, but it's > basically a bikeshed for how you want it fixed (there are dozens of > ways) and I'd rather you just tell me instead of me guessing. Actually, I followed the link on the error message and found that the right solution is probably '__nonstring' so I've posted that. If someone wants the bikeshed a different color I can do it a different way. https://lore.kernel.org/r/20220627161642.1.Ie7b480cd99e2c13319220cbc108caf2bcd41286b@changeid
