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Currently old compile rule (CLANG-bpf) doesn't contains VMLINUX_H define
flag which is essential for the bpf program that includes "vmlinux.h".
Also old compile rule doesn't directly specify the compile target as bpf,
instead it uses bunch of extra options with clang followed by long chain
of commands. (e.g. clang | opt | llvm-dis | llc)
In Makefile, there is already new compile rule which is more simple and
neat. And it also has -D__VMLINUX_H__ option. By just changing the _kern
suffix to .bpf will inherit the benefit of the new CLANG-BPF compile
target.
Also, this commit adds dummy gnu/stub.h to the samples/bpf directory.
As commit 1c2dd16add7e ("selftests/bpf: get rid of -D__x86_64__") noted,
compiling with 'clang -target bpf' will raise an error with stubs.h
unless workaround (-D__x86_64) is used. This commit solves this problem
by adding dummy stub.h to make /usr/include/features.h to follow the
expected path as the same way selftests/bpf dealt with.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-4-danieltimlee@gmail.com
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program
This commit applies vmlinux.h to syscall tracing program. This change
allows the bpf program to refer to the internal structure as a single
"vmlinux.h" instead of including each header referenced by the bpf
program.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-3-danieltimlee@gmail.com
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Syscall tracing using kprobe is quite unstable. Since it uses the exact
name of the kernel function, the program might broke due to the rename
of a function. The problem can also be caused by a changes in the
arguments of the function to which the kprobe connects.
In this commit, ksyscall is used instead of kprobe. By using ksyscall,
libbpf will detect the appropriate kernel function name.
(e.g. sys_write -> __s390_sys_write). This eliminates the need to worry
about which wrapper function to attach in order to parse arguments.
In addition, ksyscall provides more fine method with attaching system
call, the coarse SYSCALL helper at trace_common.h can be removed.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-2-danieltimlee@gmail.com
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since commit c504e5c2f964("net: skb: introduce kfree_skb_reason()")
kfree_skb() is replaced by kfree_skb_reason() and kfree_skb() is set to
the inline function. So, we replace kprobe/kfree_skb with
kprobe/kfree_skb_reason to solve the tracex2 error.
$ cd samples/bpf
$ sudo ./tracex2
libbpf: prog 'bpf_prog2': failed to create kprobe 'kfree_skb+0x0' perf event: No such file or directory
ERROR: bpf_program__attach failed
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_0F0DAE84C0B3C42E0B550E5E9F47A9114D09@qq.com
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Because the previous two commit replaced the bpf_load implementation of
the user program with libbpf, the corresponding kernel program's MAP
definition can be replaced with new BTF-defined map syntax.
This commit only updates the samples which uses libbpf API for loading
bpf program not with bpf_load.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200516040608.1377876-6-danieltimlee@gmail.com
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Currently, the kprobe BPF program attachment method for bpf_load is
quite old. The implementation of bpf_load "directly" controls and
manages(create, delete) the kprobe events of DEBUGFS. On the other hand,
using using the libbpf automatically manages the kprobe event.
(under bpf_link interface)
By calling bpf_program__attach(_kprobe) in libbpf, the corresponding
kprobe is created and the BPF program will be attached to this kprobe.
To remove this, by simply invoking bpf_link__destroy will clean up the
event.
This commit refactors kprobe tracing programs (tracex{1~7}_user.c) with
libbpf using bpf_link interface and bpf_program__attach.
tracex2_kern.c, which tracks system calls (sys_*), has been modified to
append prefix depending on architecture.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200516040608.1377876-3-danieltimlee@gmail.com
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Fix all files in samples/bpf to include libbpf header files with the bpf/
prefix, to be consistent with external users of the library. Also ensure
that all includes of exported libbpf header files (those that are exported
on 'make install' of the library) use bracketed includes instead of quoted.
To make sure no new files are introduced that doesn't include the bpf/
prefix in its include, remove tools/lib/bpf from the include path entirely,
and use tools/lib instead.
Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
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Split-off PT_REGS-related helpers into bpf_tracing.h header. Adjust
selftests and samples to include it where necessary.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-5-andriin@fb.com
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Remove the zero initialization in the sample programs where appropriate.
Note that this is an optimization which is now possible, old programs
still doing the zero initialization are just fine as well. Also, make
sure we don't have padding issues when we don't memset() the entire
struct anymore.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add the necessary definitions for building bpf samples on ppc.
Since ppc doesn't store function return address on the stack, modify how
PT_REGS_RET() and PT_REGS_FP() work.
Also, introduce PT_REGS_IP() to access the instruction pointer.
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The trace bpf samples do not compile on s390x because they use x86
specific fields from the "pt_regs" structure.
Fix this and access the fields via new PT_REGS macros.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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eBPF programs attached to kprobes need to filter based on
current->pid, uid and other fields, so introduce helper functions:
u64 bpf_get_current_pid_tgid(void)
Return: current->tgid << 32 | current->pid
u64 bpf_get_current_uid_gid(void)
Return: current_gid << 32 | current_uid
bpf_get_current_comm(char *buf, int size_of_buf)
stores current->comm into buf
They can be used from the programs attached to TC as well to classify packets
based on current task fields.
Update tracex2 example to print histogram of write syscalls for each process
instead of aggregated for all.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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write() syscall
this example has two probes in one C file that attach to
different kprove events and use two different maps.
1st probe is x64 specific equivalent of dropmon. It attaches to
kfree_skb, retrevies 'ip' address of kfree_skb() caller and
counts number of packet drops at that 'ip' address. User space
prints 'location - count' map every second.
2nd probe attaches to kprobe:sys_write and computes a histogram
of different write sizes
Usage:
$ sudo tracex2
location 0xffffffff81695995 count 1
location 0xffffffff816d0da9 count 2
location 0xffffffff81695995 count 2
location 0xffffffff816d0da9 count 2
location 0xffffffff81695995 count 3
location 0xffffffff816d0da9 count 2
557145+0 records in
557145+0 records out
285258240 bytes (285 MB) copied, 1.02379 s, 279 MB/s
syscall write() stats
byte_size : count distribution
1 -> 1 : 3 | |
2 -> 3 : 0 | |
4 -> 7 : 0 | |
8 -> 15 : 0 | |
16 -> 31 : 2 | |
32 -> 63 : 3 | |
64 -> 127 : 1 | |
128 -> 255 : 1 | |
256 -> 511 : 0 | |
512 -> 1023 : 1118968 |************************************* |
Ctrl-C at any time. Kernel will auto cleanup maps and programs
$ addr2line -ape ./bld_x64/vmlinux 0xffffffff81695995
0xffffffff816d0da9 0xffffffff81695995:
./bld_x64/../net/ipv4/icmp.c:1038 0xffffffff816d0da9:
./bld_x64/../net/unix/af_unix.c:1231
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1427312966-8434-8-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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