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  1. 24 Apr, 2024 20 commits
  3. 22 Apr, 2024 2 commits
  5. 21 Apr, 2024 2 commits
  7. 20 Apr, 2024 7 commits
  9. 18 Apr, 2024 1 commit
  11. 17 Apr, 2024 2 commits
    • Quentin Deslandes's avatar
      libbpf: Fix dump of subsequent char arrays · e739e01d
      Quentin Deslandes authored 
      When dumping a character array, libbpf will watch for a '\0' and set
is_array_terminated=true if found. This prevents libbpf from printing
the remaining characters of the array, treating it as a nul-terminated
string.

However, once this flag is set, it's never reset, leading to subsequent
characters array not being printed properly:

.str_multi = (__u8[2][16])[
    [
        'H',
        'e',
        'l',
    ],
],

This patch saves the is_array_terminated flag and restores its
default (false) value before looping over the elements of an array,
then restores it afterward. This way, libbpf's behavior is unchanged
when dumping the characters of an array, but subsequent arrays are
printed properly:

.str_multi = (__u8[2][16])[
    [
        'H',
        'e',
        'l',
    ],
    [
        'l',
        'o',
    ],
],
Signed-off-by: default avatarQuentin Deslandes <qde@naccy.de>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240413211258.134421-3-qde@naccy.de
      e739e01d
    • Quentin Deslandes's avatar
      libbpf: Fix misaligned array closing bracket · 9213e529
      Quentin Deslandes authored 
      In btf_dump_array_data(), libbpf will call btf_dump_dump_type_data() for
each element. For an array of characters, each element will be
processed the following way:

- btf_dump_dump_type_data() is called to print the character
- btf_dump_data_pfx() prefixes the current line with the proper number
  of indentations
- btf_dump_int_data() is called to print the character
- After the last character is printed, btf_dump_dump_type_data() calls
  btf_dump_data_pfx() before writing the closing bracket

However, for an array containing characters, btf_dump_int_data() won't
print any '\0' and subsequent characters. This leads to situations where
the line prefix is written, no character is added, then the prefix is
written again before adding the closing bracket:

(struct sk_metadata){
    .str_array = (__u8[14])[
        'H',
        'e',
        'l',
        'l',
        'o',
                ],

This change solves this issue by printing the '\0' character, which
has two benefits:

- The bracket closing the array is properly aligned
- It's clear from a user point of view that libbpf uses '\0' as a
  terminator for arrays of characters.
Signed-off-by: default avatarQuentin Deslandes <qde@naccy.de>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240413211258.134421-2-qde@naccy.de
      9213e529
  13. 16 Apr, 2024 5 commits
  15. 12 Apr, 2024 1 commit
    • Jiri Olsa's avatar
      selftests/bpf: Add read_trace_pipe_iter function · 4d4992ff
      Jiri Olsa authored 
      We have two printk tests reading trace_pipe in non blocking way,
with the very same code. Moving that in new read_trace_pipe_iter
function.

Current read_trace_pipe is used from samples/bpf and needs to
do blocking read and printf of the trace_pipe data, using new
read_trace_pipe_iter to implement that.

Both printk tests do early checks for the number of found messages
and can bail earlier, but I did not find any speed difference w/o
that condition, so I did not complicate the change more for that.

Some of the samples/bpf programs use read_trace_pipe function,
so I kept that interface untouched. I did not see any issues with
affected samples/bpf programs other than there's slight change in
read_trace_pipe output. The current code uses puts that adds new
line after the printed string, so we would occasionally see extra
new line. With this patch we read output per lines, so there's no
need to use puts and we can use just printf instead without extra
new line.
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240410140952.292261-1-jolsa@kernel.org
      4d4992ff
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