On Fri, Sep 07, 2018 at 06:08:56AM -0400, Prarit Bhargava wrote: > gcc 8.1.0 warns with: > > kernel/debug/kdb/kdb_support.c: In function ‘kallsyms_symbol_next’: > kernel/debug/kdb/kdb_support.c:239:4: warning: ‘strncpy’ specified bound > depends on the length of the source argument [-Wstringop-overflow=] > strncpy(prefix_name, name, strlen(name)+1); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > kernel/debug/kdb/kdb_support.c:239:31: note: length computed here > > The strings do not need to be zero padded so use strlcpy() instead. > > Signed-off-by: Prarit Bhargava <[email protected]> > Cc: Jonathan Toppins <[email protected]> > Cc: Jason Wessel <[email protected]> > Cc: Daniel Thompson <[email protected]> > --- > kernel/debug/kdb/kdb_support.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c > index 990b3cc526c8..1ad4370ccbf0 100644 > --- a/kernel/debug/kdb/kdb_support.c > +++ b/kernel/debug/kdb/kdb_support.c > @@ -236,7 +236,7 @@ int kallsyms_symbol_next(char *prefix_name, int flag) > > while ((name = kdb_walk_kallsyms(&pos))) { > if (strncmp(name, prefix_name, prefix_len) == 0) { > - strncpy(prefix_name, name, strlen(name)+1); > + strlcpy(prefix_name, name, strlen(name)+1);
How does this *fix* the warning? The warning occurs because a "safe" string copy function is incorrectly using the length of the second argument as the length (i.e. it is simply an inefficient implementation of strcpy). The code is still bogus whether you use strncpy, strlcpy or strscpy. All we are doing here is kicking the ball down the road until someone teaches gcc 9+ about strlcpy()! Daniel. _______________________________________________ Kgdb-bugreport mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
