commit 4356e9f841f7fbb945521cef3577ba394c65f3fc upstream.
We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c323 ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").
Then, much later, we ended up removing the workaround in commit
43c249ea0b ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.
Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround. But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.
It looks like there are at least two separate issues that all hit in
this area:
(a) some versions of gcc don't mark the asm goto as 'volatile' when it
has outputs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420
which is easy to work around by just adding the 'volatile' by hand.
(b) Internal compiler errors:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422
which are worked around by adding the extra empty 'asm' as a
barrier, as in the original workaround.
but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.
but the same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.
Reported-and-tested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9220c3ef6fefbf18f24aeedb1142a642b3de0596 ]
Commit 06744f2469 ("samples/bpf: Add openat2() enter/exit tracepoint
to syscall_tp sample") added two more eBPF programs to support the
openat2() syscall. However, it did not increase the size of the array
that holds the corresponding bpf_links. This leads to an out-of-bound
access on that array in the bpf_object__for_each_program loop and could
corrupt other variables on the stack. On our testing QEMU, it corrupts
the map1_fds array and causes the sample to fail:
# ./syscall_tp
prog #0: map ids 4 5
verify map:4 val: 5
map_lookup failed: Bad file descriptor
Dynamically allocate the array based on the number of programs reported
by libbpf to prevent similar inconsistencies in the future
Fixes: 06744f2469 ("samples/bpf: Add openat2() enter/exit tracepoint to syscall_tp sample")
Signed-off-by: Jinghao Jia <jinghao@linux.ibm.com>
Signed-off-by: Ruowen Qin <ruowenq2@illinois.edu>
Signed-off-by: Jinghao Jia <jinghao7@illinois.edu>
Link: https://lore.kernel.org/r/20230917214220.637721-4-jinghao7@illinois.edu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0ee352fe0d28015cab161b04d202fa3231c0ba3b ]
The variable name num_progs causes confusion because that variable
really controls the number of rounds the test should be executed.
Rename num_progs into nr_tests for the sake of clarity.
Signed-off-by: Jinghao Jia <jinghao@linux.ibm.com>
Signed-off-by: Ruowen Qin <ruowenq2@illinois.edu>
Signed-off-by: Jinghao Jia <jinghao7@illinois.edu>
Link: https://lore.kernel.org/r/20230917214220.637721-3-jinghao7@illinois.edu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 9220c3ef6fef ("samples/bpf: syscall_tp_user: Fix array out-of-bound access")
Signed-off-by: Sasha Levin <sashal@kernel.org>
To help users find the XDP utilities, add a note to the README about the
new location and the conversion documentation in the commit messages.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-8-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Remove no longer present XDP utilities from .gitignore. Apart from the
recently removed XDP utilities this also includes the previously removed
xdpsock and xsk utilities.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-7-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The functionality of this utility is covered by the xdpdump utility in
xdp-tools.
There's a slight difference in usage as the xdpdump utility's main focus is
to dump packets before or after they are processed by an existing XDP
program. However, xdpdump also has the --load-xdp-program switch, which
will make it attach its own program if no existing program is loaded. With
this, xdp_sample_pkts usage can be converted as:
xdp_sample_pkts eth0
--> xdpdump --load-xdp-program eth0
To get roughly equivalent behaviour.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-6-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The functionality of these utilities have been incorporated into the
xdp-bench utility in xdp-tools.
Equivalent functionality is:
xdp1 eth0
--> xdp-bench drop -p parse-ip -l load-bytes eth0
xdp2 eth0
--> xdp-bench drop -p swap-macs eth0
Note that there's a slight difference in behaviour of those examples: the
swap-macs operation of xdp-bench doesn't use the bpf_xdp_load_bytes()
helper to load the packet data, whereas the xdp2 utility did so
unconditionally. For the parse-ip action the use of bpf_xdp_load_bytes()
can be selected by the '-l load-bytes' switch, with the difference that the
xdp-bench utility will perform two separate calls to the helper, one to
load the ethernet header and another to load the IP header; where the xdp1
utility only performed one call always loading 60 bytes of data.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-5-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The functionality of this utility has been incorporated into the xdp-bench
utility in xdp-tools, by way of the --rxq-stats argument to the 'drop',
'pass' and 'tx' commands of xdp-bench.
Some examples of how to convert xdp_rxq_info invocations into equivalent
xdp-bench commands:
xdp_rxq_info -d eth0
--> xdp-bench pass --rxq-stats eth0
xdp_rxq_info -d eth0 -a XDP_DROP -m
--> xdp-bench drop --rxq-stats -p swap-macs eth0
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-4-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
These utilities have all been ported to xdp-tools as functions of the
xdp-bench utility. The four different utilities in samples are incorporated
as separate subcommands to xdp-bench, with most of the command line
parameters left intact, except that mandatory arguments are always
positional in xdp-bench. For full usage details see the --help output of
each command, or the xdp-bench man page.
Some examples of how to convert usage to xdp-bench are:
xdp_redirect eth0 eth1
--> xdp-bench redirect eth0 eth1
xdp_redirect_map eth0 eth1
--> xdp-bench redirect-map eth0 eth1
xdp_redirect_map_multi eth0 eth1 eth2 eth3
--> xdp-bench redirect-multi eth0 eth1 eth2 eth3
xdp_redirect_cpu -d eth0 -c 0 -c 1
--> xdp-bench redirect-cpu -c 0 -c 1 eth0
xdp_redirect_cpu -d eth0 -c 0 -c 1 -r eth1
--> xdp-bench redirect-cpu -c 0 -c 1 eth0 -r redirect -D eth1
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-3-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This utility has been ported as-is to xdp-tools as 'xdp-monitor'. The only
difference in usage between the samples and xdp-tools versions is that the
'-v' command line parameter has been changed to '-e' in the xdp-tools
version for consistency with the other utilities.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230824102255.1561885-2-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
With the introduction of kprobe.multi, it is now possible to attach
multiple kprobes to a single BPF program without the need for multiple
definitions. Additionally, this method supports wildcard-based
matching, allowing for further simplification of BPF programs. In here,
an asterisk (*) wildcard is used to map to all symbols relevant to
spin_{lock|unlock}.
Furthermore, since kprobe.multi handles symbol matching, this commit
eliminates the need for the previous logic of reading the ksym table to
verify the existence of symbols.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-10-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit refactors the syscall tracing programs by adopting the
BPF_KSYSCALL macro. This change aims to enhance the clarity and
simplicity of the BPF programs by reducing the complexity of argument
parsing from pt_regs.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-9-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In the commit 7c4cd051ad ("bpf: Fix syscall's stackmap lookup
potential deadlock"), a potential deadlock issue was addressed, which
resulted in *_map_lookup_elem not triggering BPF programs.
(prior to lookup, bpf_disable_instrumentation() is used)
To resolve the broken map lookup probe using "htab_map_lookup_elem",
this commit introduces an alternative approach. Instead, it utilize
"bpf_map_copy_value" and apply a filter specifically for the hash table
with map_type.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Fixes: 7c4cd051ad ("bpf: Fix syscall's stackmap lookup potential deadlock")
Link: https://lore.kernel.org/r/20230818090119.477441-8-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Recently, a new tracepoint for the block layer, specifically the
block_io_start/done tracepoints, was introduced in commit 5a80bd075f
("block: introduce block_io_start/block_io_done tracepoints").
Previously, the kprobe entry used for this purpose was quite unstable
and inherently broke relevant probes [1]. Now that a stable tracepoint
is available, this commit replaces the bio latency check with it.
One of the changes made during this replacement is the key used for the
hash table. Since 'struct request' cannot be used as a hash key, the
approach taken follows that which was implemented in bcc/biolatency [2].
(uses dev:sector for the key)
[1]: https://github.com/iovisor/bcc/issues/4261
[2]: https://github.com/iovisor/bcc/pull/4691
Fixes: 450b7879e3 ("block: move blk_account_io_{start,done} to blk-mq.c")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-7-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The existing tracing programs have been developed for a considerable
period of time and, as a result, do not properly incorporate the
features of the current libbpf, such as CO-RE. This is evident in
frequent usage of functions like PT_REGS* and the persistence of "hack"
methods using underscore-style bpf_probe_read_kernel from the past.
These programs are far behind the current level of libbpf and can
potentially confuse users. Therefore, this commit aims to convert the
outdated BPF programs to be more CO-RE centric.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-6-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, multiple kprobe programs are suffering from symbol mismatch
due to compiler optimization. These optimizations might induce
additional suffix to the symbol name such as '.isra' or '.constprop'.
# egrep ' finish_task_switch| __netif_receive_skb_core' /proc/kallsyms
ffffffff81135e50 t finish_task_switch.isra.0
ffffffff81dd36d0 t __netif_receive_skb_core.constprop.0
ffffffff8205cc0e t finish_task_switch.isra.0.cold
ffffffff820b1aba t __netif_receive_skb_core.constprop.0.cold
To avoid this, this commit replaces the original kprobe section to
kprobe.multi in order to match symbol with wildcard characters. Here,
asterisk is used for avoiding symbol mismatch.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-5-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, BPF programs typically have a suffix of .bpf.c. However,
some programs still utilize a mixture of _kern.c suffix alongside the
naming convention. In order to achieve consistency in the naming of
these programs, this commit unifies the inconsistency in the naming
convention of BPF kernel programs.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-4-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit replaces separate headers with a single vmlinux.h to
tracing programs. Thanks to that, we no longer need to define the
argument structure for tracing programs directly. For example, argument
for the sched_switch tracpepoint (sched_switch_args) can be replaced
with the vmlinux.h provided trace_event_raw_sched_switch.
Additional defines have been added to the BPF program either directly
or through the inclusion of net_shared.h. Defined values are
PERF_MAX_STACK_DEPTH, IFNAMSIZ constants and __stringify() macro. This
change enables the BPF program to access internal structures with BTF
generated "vmlinux.h" header.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-3-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, compiling the bpf programs will result the warning with the
ignored attribute as follows. This commit fixes the warning by adding
cf-protection option.
In file included from ./arch/x86/include/asm/linkage.h:6:
./arch/x86/include/asm/ibt.h:77:8: warning: 'nocf_check' attribute ignored; use -fcf-protection to enable the attribute [-Wignored-attributes]
extern __noendbr u64 ibt_save(bool disable);
^
./arch/x86/include/asm/ibt.h:32:34: note: expanded from macro '__noendbr'
^
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-2-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Update samples/bpf/README.rst to add pahole to the build dependencies
list. Add the reference to "Documentation/process/changes.rst" for
minimum version required so that the version required will not be
outdated in the future.
Signed-off-by: Anh Tuan Phan <tuananhlfc@gmail.com>
Link: https://lore.kernel.org/r/aecaf7a2-9100-cd5b-5cf4-91e5dbb2c90d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The -target option has been deprecated since clang 3.4 in 2013. Therefore, use
the preferred --target=bpf form instead. This also matches how we use --target=
in scripts/Makefile.clang.
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: 274b6f0c87
Link: https://lore.kernel.org/bpf/20230624001856.1903733-1-maskray@google.com
Default samples/pktgen scripts send 60 byte packets as hardware adds
4-bytes FCS checksum, which fulfils minimum Ethernet 64 bytes frame
size.
XDP layer will not necessary have access to the 4-bytes FCS checksum.
This leads to bpf_xdp_load_bytes() failing as it tries to copy 64-bytes
from an XDP packet that only have 60-bytes available.
Fixes: 7722517422 ("samples/bpf: fixup some tools to be able to support xdp multibuffer")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/bpf/168545704139.2996228.2516528552939485216.stgit@firesoul
Macro PAGE_OFFSET(0xffff880000000000) in sampleip_user.c is inaccurate,
for example, in aarch64 architecture, this value depends on the
CONFIG_ARM64_VA_BITS compilation configuration, this value defaults to 48,
the corresponding PAGE_OFFSET is 0xffff800000000000, if we use the value
defined in sampleip_user.c, then all KSYMs obtained by sampleip are (user)
Symbol error due to PAGE_OFFSET error:
$ sudo ./sampleip 1
Sampling at 99 Hertz for 1 seconds. Ctrl-C also ends.
ADDR KSYM COUNT
0xffff80000810ceb8 (user) 1
0xffffb28ec880 (user) 1
0xffff8000080c82b8 (user) 1
0xffffb23fed24 (user) 1
0xffffb28944fc (user) 1
0xffff8000084628bc (user) 1
0xffffb2a935c0 (user) 1
0xffff80000844677c (user) 1
0xffff80000857a3a4 (user) 1
...
A few examples of addresses in the CONFIG_ARM64_VA_BITS=48 environment in
the aarch64 environment:
$ sudo head /proc/kallsyms
ffff8000080a0000 T _text
ffff8000080b0000 t gic_handle_irq
ffff8000080b0000 T _stext
ffff8000080b0000 T __irqentry_text_start
ffff8000080b00b0 t gic_handle_irq
ffff8000080b0230 t gic_handle_irq
ffff8000080b03b4 T __irqentry_text_end
ffff8000080b03b8 T __softirqentry_text_start
ffff8000080b03c0 T __do_softirq
ffff8000080b0718 T __entry_text_start
We just need to replace the PAGE_OFFSET with the address _text in
/proc/kallsyms to solve this problem:
$ sudo ./sampleip 1
Sampling at 99 Hertz for 1 seconds. Ctrl-C also ends.
ADDR KSYM COUNT
0xffffb2892ab0 (user) 1
0xffffb2b1edfc (user) 1
0xffff800008462834 __arm64_sys_ppoll 1
0xffff8000084b87f4 eventfd_read 1
0xffffb28e6788 (user) 1
0xffff8000081e96d8 rcu_all_qs 1
0xffffb2ada878 (user) 1
...
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Link: https://lore.kernel.org/r/tencent_A0E82E0BEE925285F8156D540731DF805F05@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Fix fout being fopen'ed but then not subsequently fclose'd. In the affected
branch, fout is otherwise going out of scope.
Signed-off-by: Hao Zeng <zenghao@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230411084349.1999628-1-zenghao@kylinos.cn
The canonical location for the tracefs filesystem is at /sys/kernel/tracing.
But, from Documentation/trace/ftrace.rst:
Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:
/sys/kernel/debug/tracing
Many comments and samples in the bpf code still refer to this older
debugfs path, so let's update them to avoid confusion. There are a few
spots where the bpf code explicitly checks both tracefs and debugfs
(tools/bpf/bpftool/tracelog.c and tools/lib/api/fs/fs.c) and I've left
those alone so that the tools can continue to work with both paths.
Signed-off-by: Ross Zwisler <zwisler@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230313205628.1058720-2-zwisler@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit fe3300897cbf("samples: bpf: fix syscall_tp due to unused syscall")
added openat() syscall tracepoints. This patch adds support for
openat2() as well.
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_9381CB1A158ED7ADD12C4406034E21A3AC07@qq.com
This commit changes the _kern suffix to .bpf with the BPF test programs.
With this modification, test programs will inherit the benefit of the
new CLANG-BPF compile target.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-11-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit applies vmlinux.h to BPF functionality testing program.
Macros that were not defined despite migration to "vmlinux.h" were
defined separately in individual files.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-10-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit applies "net_shared.h" to BPF programs to remove existing
network related header dependencies. Also, this commit removes
unnecessary headers before applying "vmlinux.h" to the BPF programs.
Mostly, endianness conversion function has been applied to the source.
In addition, several macros have been defined to fulfill the INET,
TC-related constants.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-9-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, many programs under sample/bpf often include individual
macros by directly including the header under "linux/" rather than
using the "vmlinux.h" header.
However, there are some problems with migrating to "vmlinux.h" because
there is no definition for utility functions such as endianness
conversion (ntohs/htons). Fortunately, the xdp_sample program already
has a function that can be replaced to solve this problem.
Therefore, this commit attempts to separate these functions into a file
called net_shared.h to make them universally available. Additionally,
this file includes network-related macros that are not defined in
"vmlinux.h". (inspired by 'selftests' bpf_tracing_net.h)
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-8-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
With libbpf 1.0 release, support for legacy BPF map declaration syntax
had been dropped. If you run a program using legacy BPF in the latest
libbpf, the following error will be output.
libbpf: map 'lwt_len_hist_map' (legacy): legacy map definitions are deprecated, use BTF-defined maps instead
libbpf: Use of BPF_ANNOTATE_KV_PAIR is deprecated, use BTF-defined maps in .maps section instead
This commit replaces legacy map with the BTF-defined map.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-7-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The test_overhead bpf program is designed to compare performance
between tracepoint and kprobe. Initially it used task_rename and
urandom_read tracepoint.
However, commit 14c174633f ("random: remove unused tracepoints")
removed urandom_read tracepoint, and for this reason the test_overhead
got broken.
This commit introduces new microbenchmark using fib_table_lookup.
This microbenchmark sends UDP packets to localhost in order to invoke
fib_table_lookup.
In a nutshell:
fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
addr.sin_addr.s_addr = inet_addr(DUMMY_IP);
addr.sin_port = htons(DUMMY_PORT);
for() {
sendto(fd, buf, strlen(buf), 0,
(struct sockaddr *)&addr, sizeof(addr));
}
on 4 cpus in parallel:
lookup per sec
base (no tracepoints, no kprobes) 381k
with kprobe at fib_table_lookup() 325k
with tracepoint at fib:fib_table_lookup 330k
with raw_tracepoint at fib:fib_table_lookup 365k
Fixes: 14c174633f ("random: remove unused tracepoints")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-6-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, executing test_cgrp2_sock2 fails due to wrong section
header. This 'cgroup/sock1' style section is previously used at
'samples/bpf_load' (deprecated) BPF loader. Because this style isn't
supported in libbpf, this commit fixes this problem by correcting the
section header.
$ sudo ./test_cgrp2_sock2.sh
libbpf: prog 'bpf_prog1': missing BPF prog type, check ELF section name 'cgroup/sock1'
libbpf: prog 'bpf_prog1': failed to load: -22
libbpf: failed to load object './sock_flags_kern.o'
ERROR: loading BPF object file failed
In addition, this BPF program filters ping packets by comparing whether
the socket type uses SOCK_RAW. However, after the ICMP socket[1] was
developed, ping sends ICMP packets using SOCK_DGRAM. Therefore, in this
commit, the packet filtering is changed to use SOCK_DGRAM instead of
SOCK_RAW.
$ strace --trace socket ping -6 -c1 -w1 ::1
socket(AF_INET6, SOCK_DGRAM, IPPROTO_ICMPV6) = 3
[1]: https://lwn.net/Articles/422330/
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-5-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The test_lwt_bpf is a script that tests the functionality of BPF through
the output of the ftrace with bpf_trace_printk. Currently, this program
is not operating normally for several reasons.
First of all, this test script can't parse the ftrace results properly.
GNU sed tries to be as greedy as possible when attempting pattern
matching. Due to this, cutting metadata (such as timestamp) from the
log entry of ftrace doesn't work properly, and also desired log isn't
extracted properly. To make sed stripping clearer, 'nocontext-info'
option with the ftrace has been used to remove metadata from the log.
Also, instead of using unclear pattern matching, this commit specifies
an explicit parse pattern.
Also, unlike before when this test was introduced, the way
bpf_trace_printk behaves has changed[1]. The previous bpf_trace_printk
had to always have '\n' in order to print newline, but now that the
bpf_trace_printk call includes newline by default, so '\n' is no longer
needed.
Lastly with the lwt ENCAP_BPF out, the context information with the
sk_buff protocol is preserved. Therefore, this commit changes the
previous test result from 'protocol 0' to 'protocol 8', which means
ETH_P_IP.
[1]: commit ac5a72ea5c ("bpf: Use dedicated bpf_trace_printk event instead of trace_printk()")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-4-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, some test scripts are experiencing minor errors related to
executing tests.
$ sudo ./test_cgrp2_sock.sh
./test_cgrp2_sock.sh: 22: test_cgrp2_sock: not found
This problem occurs because the path to the execution target is not
properly specified. Therefore, this commit solves this problem by
specifying a relative path to its executables. This commit also makes
a concise refactoring of hard-coded BPF program names.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-3-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, a few of BPF tests use ipv6 functionality. The problem here
is that if ipv6 is disabled, these tests will fail, and even if the
test fails, it will not tell you why it failed.
$ sudo ./test_cgrp2_sock2.sh
RTNETLINK answers: Permission denied
In order to fix this, this commit ensures ipv6 is enabled prior to
running tests.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-2-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit enhances the syscall tracing programs by using the
BPF_SYSCALL macro to reduce the inconvenience of parsing arguments from
pt_regs. By simplifying argument extraction, bpf program will become
clear to understand.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-6-danieltimlee@gmail.com
Currently, there is a problem with tracex2, as it doesn't print the
histogram properly and the results are misleading. (all results report
as 0)
The problem is caused by a change in arguments of the function to which
the kprobe connects. This tracex2 bpf program uses kprobe (attached
to __x64_sys_write) to figure out the size of the write system call. In
order to achieve this, the third argument 'count' must be intact.
The following is a prototype of the sys_write variant. (checked with
pfunct)
~/git/linux$ pfunct -P fs/read_write.o | grep sys_write
ssize_t ksys_write(unsigned int fd, const char * buf, size_t count);
long int __x64_sys_write(const struct pt_regs * regs);
... cross compile with s390x ...
long int __s390_sys_write(struct pt_regs * regs);
Since the nature of SYSCALL_WRAPPER function wraps the argument once,
additional process of argument extraction is required to properly parse
the argument.
#define BPF_KSYSCALL(name, args...)
... snip ...
struct pt_regs *regs = LINUX_HAS_SYSCALL_WRAPPER \
? (struct pt_regs *)PT_REGS_PARM1(ctx) \
: ctx; \
In order to fix this problem, the BPF_SYSCALL macro has been used. This
reduces the hassle of parsing arguments from pt_regs. Since the macro
uses the CORE version of argument extraction, additional portability
comes too.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-5-danieltimlee@gmail.com
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 1c2dd16add ("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
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
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
Currently, compiling samples/bpf with LLVM warns about the uninitialized
use of variable with test_current_task_under_cgroup.
./samples/bpf/test_current_task_under_cgroup_user.c:57:6:
warning: variable 'cg2' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (setup_cgroup_environment())
^~~~~~~~~~~~~~~~~~~~~~~~~~
./samples/bpf/test_current_task_under_cgroup_user.c:106:8:
note: uninitialized use occurs here
close(cg2);
^~~
./samples/bpf/test_current_task_under_cgroup_user.c:57:2:
note: remove the 'if' if its condition is always false
if (setup_cgroup_environment())
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./samples/bpf/test_current_task_under_cgroup_user.c:19:9:
note: initialize the variable 'cg2' to silence this warning
int cg2, idx = 0, rc = 1;
^
= 0
1 warning generated.
This commit resolve this compiler warning by pre-initialize the variable
with error for safeguard.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221218061453.6287-4-danieltimlee@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Currently, compiling samples/bpf with LLVM warns about the unused but
set variable with tracex4_user.
./samples/bpf/tracex4_user.c:54:14:
warning: variable 'i' set but not used [-Wunused-but-set-variable]
int map_fd, i, j = 0;
^
1 warning generated.
This commit resolve this compiler warning by replacing the meaningless
counter.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221218061453.6287-3-danieltimlee@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Currently, compiling samples/bpf with LLVM warns about the unused
function with test_lru_dist.
./samples/bpf/test_lru_dist.c:45:19:
warning: unused function 'list_empty' [-Wunused-function]
static inline int list_empty(const struct list_head *head)
^
1 warning generated.
This commit resolve this compiler warning by removing the abandoned
function.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221218061453.6287-2-danieltimlee@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Linus Torvalds