Age | Commit message (Collapse) | Author | Files | Lines |
|
When the error code is EAGAIN, the kernel signals the user
space should retry the read() operation for bpf iterators.
Let us do it.
Signed-off-by: Yonghong Song <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
|
|
Don't emit warning that bpftool was built without PID iterator support. This
error garbles JSON output of otherwise perfectly valid show commands.
Reported-by: Andrey Ignatov <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
|
|
emit_obj_refs_json needs to added the same as with emit_obj_refs_plain
to prevent segfaults, similar to Commit "8ae4121bd89e bpf: Fix bpftool
without skeleton code enabled"). See the error below:
# ./bpftool -p prog
{
"error": "bpftool built without PID iterator support"
},[{
"id": 2,
"type": "cgroup_skb",
"tag": "7be49e3934a125ba",
"gpl_compatible": true,
"loaded_at": 1594052789,
"uid": 0,
"bytes_xlated": 296,
"jited": true,
"bytes_jited": 203,
"bytes_memlock": 4096,
"map_ids": [2,3
Segmentation fault (core dumped)
The same happens for ./bpftool -p map, as well as ./bpftool -j prog/map.
Fixes: d53dee3fe013 ("tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDs")
Signed-off-by: Louis Peens <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Reviewed-by: Quentin Monnet <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
|
|
Fix segfault from bpftool by adding emit_obj_refs_plain when skeleton
code is disabled.
Tested by deleting BUILD_BPF_SKELS in Makefile. We found this doing
backports for Cilium when a testing image pulled in latest bpf-next
bpftool, but kept using an older clang-7.
# ./bpftool prog show
Error: bpftool built without PID iterator support
3: cgroup_skb tag 7be49e3934a125ba gpl
loaded_at 2020-07-01T08:01:29-0700 uid 0
Segmentation fault
Fixes: d53dee3fe013 ("tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDs")
Reported-by: Joe Stringer <[email protected]>
Signed-off-by: John Fastabend <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/bpf/159375071997.14984.17404504293832961401.stgit@john-XPS-13-9370
|
|
Building bpftool yields the following complaint:
pids.c: In function 'emit_obj_refs_json':
pids.c:175:80: warning: declaration of 'json_wtr' shadows a global declaration [-Wshadow]
175 | void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr)
| ~~~~~~~~~~~~~~~^~~~~~~~
In file included from pids.c:11:
main.h:141:23: note: shadowed declaration is here
141 | extern json_writer_t *json_wtr;
| ^~~~~~~~
Let's rename the variable.
v2:
- Rename the variable instead of calling the global json_wtr directly.
Signed-off-by: Quentin Monnet <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
|
|
Add bpf_iter-based way to find all the processes that hold open FDs against
BPF object (map, prog, link, btf). bpftool always attempts to discover this,
but will silently give up if kernel doesn't yet support bpf_iter BPF programs.
Process name and PID are emitted for each process (task group).
Sample output for each of 4 BPF objects:
$ sudo ./bpftool prog show
2694: cgroup_device tag 8c42dee26e8cd4c2 gpl
loaded_at 2020-06-16T15:34:32-0700 uid 0
xlated 648B jited 409B memlock 4096B
pids systemd(1)
2907: cgroup_skb name egress tag 9ad187367cf2b9e8 gpl
loaded_at 2020-06-16T18:06:54-0700 uid 0
xlated 48B jited 59B memlock 4096B map_ids 2436
btf_id 1202
pids test_progs(2238417), test_progs(2238445)
$ sudo ./bpftool map show
2436: array name test_cgr.bss flags 0x400
key 4B value 8B max_entries 1 memlock 8192B
btf_id 1202
pids test_progs(2238417), test_progs(2238445)
2445: array name pid_iter.rodata flags 0x480
key 4B value 4B max_entries 1 memlock 8192B
btf_id 1214 frozen
pids bpftool(2239612)
$ sudo ./bpftool link show
61: cgroup prog 2908
cgroup_id 375301 attach_type egress
pids test_progs(2238417), test_progs(2238445)
62: cgroup prog 2908
cgroup_id 375344 attach_type egress
pids test_progs(2238417), test_progs(2238445)
$ sudo ./bpftool btf show
1202: size 1527B prog_ids 2908,2907 map_ids 2436
pids test_progs(2238417), test_progs(2238445)
1242: size 34684B
pids bpftool(2258892)
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Reviewed-by: Quentin Monnet <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
|