Commit graph

14 commits

Author SHA1 Message Date
Lorenz Bauer
4a638d581a libbpf: Fail compilation if target arch is missing
bpf2go is the Go equivalent of libbpf skeleton. The convention is that
the compiled BPF is checked into the repository to facilitate distributing
BPF as part of Go packages. To make this portable, bpf2go by default
generates both bpfel and bpfeb variants of the C.

Using bpf_tracing.h is inherently non-portable since the fields of
struct pt_regs differ between platforms, so CO-RE can't help us here.
The only way of working around this is to compile for each target
platform independently. bpf2go can't do this by default since there
are too many platforms.

Define the various PT_... macros when no target can be determined and
turn them into compilation failures. This works because bpf2go always
compiles for bpf targets, so the compiler fallback doesn't kick in.
Conditionally define __BPF_MISSING_TARGET so that we can inject a
more appropriate error message at build time. The user can then
choose which platform to target explicitly.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210616083635.11434-1-lmb@cloudflare.com
2021-06-16 20:15:30 -07:00
Florent Revest
d6a6a55518 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 <andrii@kernel.org>
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210526164643.2881368-1-revest@chromium.org
2021-05-26 10:45:41 -07:00
Florent Revest
58c2b1f5e0 libbpf: Introduce a BPF_SNPRINTF helper macro
Similarly to BPF_SEQ_PRINTF, this macro turns variadic arguments into an
array of u64, making it more natural to call the bpf_snprintf helper.

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210419155243.1632274-6-revest@chromium.org
2021-04-19 15:27:37 -07:00
Florent Revest
83cd92b464 libbpf: Initialize the bpf_seq_printf parameters array field by field
When initializing the __param array with a one liner, if all args are
const, the initial array value will be placed in the rodata section but
because libbpf does not support relocation in the rodata section, any
pointer in this array will stay NULL.

Fixes: c09add2fbc ("tools/libbpf: Add bpf_iter support")
Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210419155243.1632274-5-revest@chromium.org
2021-04-19 15:27:37 -07:00
Andrii Nakryiko
70785cfb19 libbpf: Switch tracing and CO-RE helper macros to bpf_probe_read_kernel()
Now that libbpf can automatically fallback to bpf_probe_read() on old kernels
not yet supporting bpf_probe_read_kernel(), switch libbpf BPF-side helper
macros to use appropriate BPF helper for reading kernel data.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20200818213356.2629020-7-andriin@fb.com
2020-08-18 17:16:15 -07:00
Jerry Crunchtime
1acf8f90ea libbpf: Fix register in PT_REGS MIPS macros
The o32, n32 and n64 calling conventions require the return
value to be stored in $v0 which maps to $2 register, i.e.,
the register 2.

Fixes: c1932cd ("bpf: Add MIPS support to samples/bpf.")
Signed-off-by: Jerry Crunchtime <jerry.c.t@web.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/43707d31-0210-e8f0-9226-1af140907641@web.de
2020-07-31 17:20:49 +02:00
David S. Miller
da07f52d3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Move the bpf verifier trace check into the new switch statement in
HEAD.

Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15 13:48:59 -07:00
Sumanth Korikkar
516d8d497c libbpf: Fix register naming in PT_REGS s390 macros
Fix register naming in PT_REGS s390 macros

Fixes: b8ebce86ff ("libbpf: Provide CO-RE variants of PT_REGS macros")
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200513154414.29972-1-sumanthk@linux.ibm.com
2020-05-14 12:44:17 -07:00
Yonghong Song
c09add2fbc tools/libbpf: Add bpf_iter support
Two new libbpf APIs are added to support bpf_iter:
  - bpf_program__attach_iter
    Given a bpf program and additional parameters, which is
    none now, returns a bpf_link.
  - bpf_iter_create
    syscall level API to create a bpf iterator.

The macro BPF_SEQ_PRINTF are also introduced. The format
looks like:
  BPF_SEQ_PRINTF(seq, "task id %d\n", pid);

This macro can help bpf program writers with
nicer bpf_seq_printf syntax similar to the kernel one.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175917.2476936-1-yhs@fb.com
2020-05-09 17:05:27 -07:00
Wenbo Zhang
483d7a30f5 bpf, libbpf: Fix ___bpf_kretprobe_args1(x) macro definition
Use PT_REGS_RC instead of PT_REGS_RET to get ret correctly.

Fixes: df8ff35311 ("libbpf: Merge selftests' bpf_trace_helpers.h into libbpf's bpf_tracing.h")
Signed-off-by: Wenbo Zhang <ethercflow@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200315083252.22274-1-ethercflow@gmail.com
2020-03-17 19:33:40 +01:00
Andrii Nakryiko
b8ebce86ff libbpf: Provide CO-RE variants of PT_REGS macros
Syscall raw tracepoints have struct pt_regs pointer as tracepoint's first
argument. After that, reading any of pt_regs fields requires bpf_probe_read(),
even for tp_btf programs. Due to that, PT_REGS_PARMx macros are not usable as
is. This patch adds CO-RE variants of those macros that use BPF_CORE_READ() to
read necessary fields. This provides relocatable architecture-agnostic pt_regs
field accesses.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200313172336.1879637-4-andriin@fb.com
2020-03-13 23:30:53 +01:00
Andrii Nakryiko
df8ff35311 libbpf: Merge selftests' bpf_trace_helpers.h into libbpf's bpf_tracing.h
Move BPF_PROG, BPF_KPROBE, and BPF_KRETPROBE macro into libbpf's bpf_tracing.h
header to make it available for non-selftests users.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200229231112.1240137-5-andriin@fb.com
2020-03-02 16:25:14 -08:00
Andrii Nakryiko
fd56e00584 libbpf: Fix use of PT_REGS_PARM macros with vmlinux.h
Add detection of vmlinux.h to bpf_tracing.h header for PT_REGS macro.
Currently, BPF applications have to define __KERNEL__ symbol to use correct
definition of struct pt_regs on x86 arch. This is due to different field names
under internal kernel vs UAPI conditions. To make this more transparent for
users, detect vmlinux.h by checking __VMLINUX_H__ symbol.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200229231112.1240137-3-andriin@fb.com
2020-03-02 16:25:14 -08:00
Andrii Nakryiko
e01a75c159 libbpf: Move bpf_{helpers, helper_defs, endian, tracing}.h into libbpf
Move bpf_helpers.h, bpf_tracing.h, and bpf_endian.h into libbpf. Move
bpf_helper_defs.h generation into libbpf's Makefile. Ensure all those
headers are installed along the other libbpf headers. Also, adjust
selftests and samples include path to include libbpf now.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-6-andriin@fb.com
2019-10-08 23:16:03 +02:00
Renamed from tools/testing/selftests/bpf/bpf_tracing.h (Browse further)