lkml.org 
[lkml]   [2022]   [Oct]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRE: [PATCH bpf-next] selftests/bpf: Fix strncpy() fortify warning
    Date
    From: Rong Tao
    > Sent: 29 October 2022 04:00
    >
    > From: Rong Tao <rongtao@cestc.cn>
    >
    > Replace strncpy() with strncat(), strncat() leaves the dst string zero
    > terminated. Compile samples/bpf warning:

    This only makes a difference because tests for strncat() have not been added.
    srtncat() really is never the string function you are looking for.

    David


    >
    > $ cd samples/bpf
    > $ make
    > ...
    > In function ‘__enable_controllers’:
    > samples/bpf/../../tools/testing/selftests/bpf/cgroup_helpers.c:80:17: warning: ‘strncpy’ specified
    > bound 4097 equals destination size [-Wstringop-truncation]
    > 80 | strncpy(enable, controllers, sizeof(enable));
    > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    >
    > Signed-off-by: Rong Tao <rongtao@cestc.cn>
    > ---
    > tools/testing/selftests/bpf/cgroup_helpers.c | 3 ++-
    > 1 file changed, 2 insertions(+), 1 deletion(-)
    >
    > diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c
    > b/tools/testing/selftests/bpf/cgroup_helpers.c
    > index a70e873b267e..912e6522c7c5 100644
    > --- a/tools/testing/selftests/bpf/cgroup_helpers.c
    > +++ b/tools/testing/selftests/bpf/cgroup_helpers.c
    > @@ -77,7 +77,8 @@ static int __enable_controllers(const char *cgroup_path, const char *controllers
    > enable[len] = 0;
    > close(fd);
    > } else {
    > - strncpy(enable, controllers, sizeof(enable) - 1);
    > + enable[0] = '\0';
    > + strncat(enable, controllers, sizeof(enable) - 1);
    > }
    >
    > snprintf(path, sizeof(path), "%s/cgroup.subtree_control", cgroup_path);
    > --
    > 2.31.1

    -
    Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
    Registration No: 1397386 (Wales)
    \
     
     \ /
      Last update: 2022-10-29 14:24    [W:3.180 / U:0.172 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site