selftests/bpf: drop unnecessary bpf_iter.h type duplication

Drop bpf_iter.h header which uses vmlinux.h but re-defines a bunch of
iterator structures and some of BPF constants for use in BPF iterato

selftests/bpf: drop unnecessary bpf_iter.h type duplication

Drop bpf_iter.h header which uses vmlinux.h but re-defines a bunch of
iterator structures and some of BPF constants for use in BPF iterator
selftests.

None of that is necessary when fresh vmlinux.h header is generated for
vmlinux image that matches latest selftests. So drop ugly hacks and have
a nice plain vmlinux.h usage everywhere.

We could do the same with all the kfunc __ksym redefinitions, but that
has dependency on very fresh pahole, so I'm not addressing that here.

Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

show more ...

selftests/bpf: Add assert for user stacks in test_task_stack

This is a follow up to:
commit b8e3a87a627b ("bpf: Add crosstask check to __bpf_get_stack").

This test ensures that the task iterator on

selftests/bpf: Add assert for user stacks in test_task_stack

This is a follow up to:
commit b8e3a87a627b ("bpf: Add crosstask check to __bpf_get_stack").

This test ensures that the task iterator only gets a single
user stack (for the current task).

Signed-off-by: Jordan Rome <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Stanislav Fomichev <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

show more ...

libbpf: Move BPF_SEQ_PRINTF and BPF_SNPRINTF to bpf_helpers.h

These macros are convenient wrappers around the bpf_seq_printf and
bpf_snprintf helpers. They are currently provided by bpf_tracing.h wh

libbpf: Move BPF_SEQ_PRINTF and BPF_SNPRINTF to bpf_helpers.h

These macros are convenient wrappers around the bpf_seq_printf and
bpf_snprintf helpers. They are currently provided by bpf_tracing.h which
targets low level tracing primitives. bpf_helpers.h is a better fit.

The __bpf_narg and __bpf_apply are needed in both files and provided
twice. __bpf_empty isn't used anywhere and is removed from bpf_tracing.h

Reported-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Florent Revest <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

show more ...

bpf/selftests: Add bpf_get_task_stack retval bounds test_prog

Add a libbpf test prog which feeds bpf_get_task_stack's return value
into seq_write after confirming it's positive. No attempt to bound

bpf/selftests: Add bpf_get_task_stack retval bounds test_prog

Add a libbpf test prog which feeds bpf_get_task_stack's return value
into seq_write after confirming it's positive. No attempt to bound the
value from above is made.

Load will fail if verifier does not refine retval range based on buf sz
input to bpf_get_task_stack.

Signed-off-by: Dave Marchevsky <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Song Liu <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

show more ...

selftests/bpf: Fix compilation error of bpf_iter_task_stack.c

BPF selftests show a compilation error as follows:

libbpf: invalid relo for 'entries' in special section 0xfff2; forgot to
initiali

selftests/bpf: Fix compilation error of bpf_iter_task_stack.c

BPF selftests show a compilation error as follows:

libbpf: invalid relo for 'entries' in special section 0xfff2; forgot to
initialize global var?..

Fix it by initializing 'entries' to zeros.

Fixes: c7568114bc56 ("selftests/bpf: Add bpf_iter test with bpf_get_task_stack()")
Reported-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

show more ...

selftests/bpf: Add bpf_iter test with bpf_get_task_stack()

The new test is similar to other bpf_iter tests. It dumps all
/proc/<pid>/stack to a seq_file. Here is some example output:

pid: 2873

selftests/bpf: Add bpf_iter test with bpf_get_task_stack()

The new test is similar to other bpf_iter tests. It dumps all
/proc/<pid>/stack to a seq_file. Here is some example output:

pid: 2873 num_entries: 3
[<0>] worker_thread+0xc6/0x380
[<0>] kthread+0x135/0x150
[<0>] ret_from_fork+0x22/0x30

pid: 2874 num_entries: 9
[<0>] __bpf_get_stack+0x15e/0x250
[<0>] bpf_prog_22a400774977bb30_dump_task_stack+0x4a/0xb3c
[<0>] bpf_iter_run_prog+0x81/0x170
[<0>] __task_seq_show+0x58/0x80
[<0>] bpf_seq_read+0x1c3/0x3b0
[<0>] vfs_read+0x9e/0x170
[<0>] ksys_read+0xa7/0xe0
[<0>] do_syscall_64+0x4c/0xa0
[<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Note: bpf_iter test as-is doesn't print the contents of the seq_file. To
see the example above, it is necessary to add printf() to do_dummy_read.

Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

show more ...