Re: [RFC PATCH bpf-next 1/2] bpf: share BTF "show" implementation between kernel and libbpf

Re: [RFC PATCH bpf-next 1/2] bpf: share BTF "show" implementation between kernel and libbpf

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 1207 bytes --]

CC: kbuild-all(a)lists.01.org
In-Reply-To: <1610386373-24162-2-git-send-email-alan.maguire@oracle.com>
References: <1610386373-24162-2-git-send-email-alan.maguire@oracle.com>
TO: Alan Maguire <alan.maguire@oracle.com>

Hi Alan,

[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on bpf-next/master]

url:    https://github.com/0day-ci/linux/commits/Alan-Maguire/bpf-libbpf-share-BTF-data-show-functionality/20210112-013917
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
:::::: branch date: 4 hours ago
:::::: commit date: 4 hours ago
config: riscv-randconfig-c003-20210111 (attached as .config)
compiler: riscv64-linux-gcc (GCC) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>


"coccinelle warnings: (new ones prefixed by >>)"
>> kernel/bpf/btf_show_common.c:1111:6-7: ERROR: iterator variable bound on line 1109 cannot be NULL

Please review and possibly fold the followup patch.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 40259 bytes --]

[PATCH] bpf: fix itnull.cocci warnings

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 1793 bytes --]

CC: kbuild-all(a)lists.01.org
In-Reply-To: <1610386373-24162-2-git-send-email-alan.maguire@oracle.com>
References: <1610386373-24162-2-git-send-email-alan.maguire@oracle.com>
TO: Alan Maguire <alan.maguire@oracle.com>

From: kernel test robot <lkp@intel.com>

kernel/bpf/btf_show_common.c:1111:6-7: ERROR: iterator variable bound on line 1109 cannot be NULL

 Many iterators have the property that the first argument is always bound
 to a real list element, never NULL.

Semantic patch information:
 False positives arise for some iterators that do not have this property,
 or in cases when the loop cursor is reassigned.  The latter should only
 happen when the matched code is on the way to a loop exit (break, goto,
 or return).

Generated by: scripts/coccinelle/iterators/itnull.cocci

CC: Alan Maguire <alan.maguire@oracle.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
---

url:    https://github.com/0day-ci/linux/commits/Alan-Maguire/bpf-libbpf-share-BTF-data-show-functionality/20210112-013917
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
:::::: branch date: 4 hours ago
:::::: commit date: 4 hours ago

Please take the patch only if it's a positive warning. Thanks!

 btf_show_common.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/kernel/bpf/btf_show_common.c
+++ b/kernel/bpf/btf_show_common.c
@@ -1108,8 +1108,7 @@ void btf_datasec_show(const struct btf *
 			    __btf_name_by_offset(btf, t->name_off));
 	for_each_vsi(i, t, vsi) {
 		var = btf_type_by_id(btf, vsi->type);
-		if (i)
-			btf_show(show, ",");
+		btf_show(show, ",");
 		btf_type_ops_show(btf, var, vsi->type,
 				  data + vsi->offset, bits_offset, show);
 	}