linux.git/samples/bpf/bpf_load.c, branch v5.9

samples, bpf: Move read_trace_pipe to trace_helpers

2020-03-23T21:27:51+00:00

To reduce the reliance of trace samples (trace*_user) on bpf_load,
move read_trace_pipe to trace_helpers. By moving this bpf_loader helper
elsewhere, trace functions can be easily migrated to libbbpf.

Signed-off-by: Daniel T. Lee 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20200321100424.1593964-2-danieltimlee@gmail.com

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-06-18T03:20:36+00:00

Honestly all the conflicts were simple overlapping changes,
nothing really interesting to report.

Signed-off-by: David S. Miller

samples/bpf: fix a couple of style issues in bpf_load

2019-05-28T09:10:37+00:00

This commit fixes a few style problems in samples/bpf/bpf_load.c:

 - Magic string use of 'DEBUGFS'
 - Useless zero initialization of a global variable
 - Minor style fix with whitespace

Signed-off-by: Daniel T. Lee 
Acked-by: Yonghong Song 
Signed-off-by: Daniel Borkmann

samples, bpf: fix to change the buffer size for read()

2019-05-21T14:36:48+00:00

If the trace for read is larger than 4096, the return
value sz will be 4096. This results in off-by-one error
on buf:

    static char buf[4096];
    ssize_t sz;

    sz = read(trace_fd, buf, sizeof(buf));
    if (sz > 0) {
        buf[sz] = 0;
        puts(buf);
    }

Signed-off-by: Chang-Hsien Tsai 
Signed-off-by: Daniel Borkmann

samples: bpf: fix: seg fault with NULL pointer arg

2018-12-03T22:58:03+00:00

When NULL pointer accidentally passed to write_kprobe_events,
due to strlen(NULL), segmentation fault happens.
Changed code returns -1 to deal with this situation.

Bug issued with Smatch, static analysis.

Signed-off-by: Daniel T. Lee 
Acked-by: Song Liu 
Signed-off-by: Daniel Borkmann

samples: bpf: fix: error handling regarding kprobe_events

2018-11-23T21:39:09+00:00

Currently, kprobe_events failure won't be handled properly.
Due to calling system() indirectly to write to kprobe_events,
it can't be identified whether an error is derived from kprobe or system.

    // buf = "echo '%c:%s %s' >> /s/k/d/t/kprobe_events"
    err = system(buf);
    if (err < 0) {
        printf("failed to create kprobe ..");
        return -1;
    }

For example, running ./tracex7 sample in ext4 partition,
"echo p:open_ctree open_ctree >> /s/k/d/t/kprobe_events"
gets 256 error code system() failure.
=> The error comes from kprobe, but it's not handled correctly.

According to man of system(3), it's return value
just passes the termination status of the child shell
rather than treating the error as -1. (don't care success)

Which means, currently it's not working as desired.
(According to the upper code snippet)

    ex) running ./tracex7 with ext4 env.
    # Current Output
    sh: echo: I/O error
    failed to open event open_ctree

    # Desired Output
    failed to create kprobe 'open_ctree' error 'No such file or directory'

The problem is, error can't be verified whether from child ps
or system. But using write() directly can verify the command
failure, and it will treat all error as -1. So I suggest using
write() directly to 'kprobe_events' rather than calling system().

Signed-off-by: Daniel T. Lee 
Signed-off-by: Daniel Borkmann

bpf_load: add map name to load_maps error message

2018-11-07T21:34:54+00:00

To help when debugging bpf/xdp load issues, have the load_map()
error message include the number and name of the map that
failed.

Signed-off-by: Shannon Nelson 
Acked-by: John Fastabend 
Acked-by: Song Liu 
Signed-off-by: Daniel Borkmann

samples/bpf: remove duplicated includes

2018-09-18T15:49:33+00:00

Remove duplicated includes.

Signed-off-by: YueHaibing 
Acked-by: Yonghong Song 
Signed-off-by: Daniel Borkmann

samples: bpf: ensure that we don't load over MAX_PROGS programs

2018-07-16T22:00:56+00:00

I can't see that we check prog_cnt to ensure it doesn't go over
MAX_PROGS.

Signed-off-by: Dan Carpenter 
Signed-off-by: Alexei Starovoitov

samples: bpf: include bpf/bpf.h instead of local libbpf.h

2018-05-15T05:52:10+00:00

There are two files in the tree called libbpf.h which is becoming
problematic.  Most samples don't actually need the local libbpf.h
they simply include it to get to bpf/bpf.h.  Include bpf/bpf.h
directly instead.

Signed-off-by: Jakub Kicinski 
Acked-by: Jesper Dangaard Brouer 
Signed-off-by: Alexei Starovoitov