It may be useful to add timestamp for Tx packets for continuous or cyclic
transmit operation. The timestamp and sequence ID of a Tx packet are
stored according to pktgen header format. To enable per-packet timestamp,
use -y|--tstamp option. If timestamp is off, pktgen header is not
included in the UDP payload. This means receiving side can use the magic
number for pktgen for differentiation.

The implementation supports both VLAN tagged and untagged option. By
default, the minimum packet size is set at 64B. However, if VLAN tagged
is on (-V), the minimum packet size is increased to 66B just so to fit
the pktgen_hdr size.

Added hex_dump() into the code path just for future cross-checking.
As before, simply change to "#define DEBUG_HEXDUMP 1" to inspect the
accuracy of TX packet.
Signed-off-by: NOng Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211230035447.523177-8-boon.leong.ong@intel.com

When user sets tx-pkt-count and in case where there are invalid Tx frame,
the complete_tx_only_all() process polls indefinitely. So, this patch
adds a time-out mechanism into the process so that the application
can terminate automatically after it retries 3*polling interval duration.

v1->v2:
 Thanks to Jesper's and Song Liu's suggestion.
 - clean-up git message to remove polling log
 - make the Tx time-out retries configurable with 1s granularity
Signed-off-by: NOng Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211230035447.523177-7-boon.leong.ong@intel.com

By default, TX schedule policy is SCHED_OTHER (round-robin time-sharing).
To improve TX cyclic scheduling, we add SCHED_FIFO policy and its priority
by using -W FIFO or --policy=FIFO and -U <PRIO> or --schpri=<PRIO>.

A) From xdpsock --app-stats, for SCHED_OTHER policy:
   $ xdpsock -i eth0 -t -N -z -T 1000 -b 16 -C 100000 -a

                      period     min        ave        max        cycle
   Cyclic TX          1000000    53507      75334      712642     6250

B) For SCHED_FIFO policy and schpri=50:
   $ xdpsock -i eth0 -t -N -z -T 1000 -b 16 -C 100000 -a -W FIFO -U 50

                      period     min        ave        max        cycle
   Cyclic TX          1000000    3699       24859      54397      6250
Signed-off-by: NOng Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211230035447.523177-6-boon.leong.ong@intel.com

Tx cycle time is in micro-seconds unit. By combining the batch size (-b M)
and Tx cycle time (-T|--tx-cycle N), xdpsock now can transmit batch-size of
packets every N-us periodically. Cyclic TX operation is not applicable if
--poll mode is used.

To transmit 16 packets every 1ms cycle time for total of 100000 packets
silently:
 $ xdpsock -i eth0 -T -N -z -T 1000 -b 16 -C 100000

To print cyclic TX schedule variance stats, use --app-stats|-a:
 $ xdpsock -i eth0 -T -N -z -T 1000 -b 16 -C 100000 -a

 sock0@eth0:0 txonly xdp-drv
                   pps            pkts           0.00
rx                 0              0
tx                 0              100000

                   calls/s        count
rx empty polls     0              0
fill fail polls    0              0
copy tx sendtos    0              0
tx wakeup sendtos  0              6254
opt polls          0              0

                   period     min        ave        max        cycle
Cyclic TX          1000000    53507      75334      712642     6250
Signed-off-by: NOng Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211230035447.523177-5-boon.leong.ong@intel.com

User specifies the clock selection by using -w CLOCK or --clock=CLOCK
where CLOCK=[REALTIME, TAI, BOOTTIME, MONOTONIC].

The default CLOCK selection is MONOTONIC.

The implementation of clock selection parsing is borrowed from
iproute2/tc/q_taprio.c
Signed-off-by: NOng Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211230035447.523177-4-boon.leong.ong@intel.com

To set Dest MAC address (-G|--tx-dmac) only:
 $ xdpsock -i eth0 -t -N -z -G aa:bb:cc:dd:ee:ff

To set Source MAC address (-H|--tx-smac) only:
 $ xdpsock -i eth0 -t -N -z -H 11:22:33:44:55:66

To set both Dest and Source MAC address:
 $ xdpsock -i eth0 -t -N -z -G aa:bb:cc:dd:ee:ff \
   -H 11:22:33:44:55:66

The default Dest and Source MAC address remain the same as before.
Signed-off-by: NOng Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/20211230035447.523177-3-boon.leong.ong@intel.com

In multi-queue environment testing, the support for VLAN-tag based
steering is useful. So, this patch adds the capability to add
VLAN tag (VLAN ID and Priority) to the generated Tx frame.

To set the VLAN ID=10 and Priority=2 for Tx only through TxQ=3:
 $ xdpsock -i eth0 -t -N -z -q 3 -V -J 10 -K 2

If VLAN ID (-J) and Priority (-K) is set, it default to
  VLAN ID = 1
  VLAN Priority = 0.

For example, VLAN-tagged Tx only, xdp copy mode through TxQ=1:
 $ xdpsock -i eth0 -t -N -c -q 1 -V
Signed-off-by: NOng Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211230035447.523177-2-boon.leong.ong@intel.com

bpf_object__find_program_by_title is going to be deprecated.
Replace use cases of bpf_object__find_program_by_title in samples/bpf/
with bpf_object__for_each_program.
Signed-off-by: NKui-Feng Lee <kuifeng@fb.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211214035931.1148209-3-kuifeng@fb.com

Adding ftrace-direct-multi-modify.ko kernel module that uses
modify_ftrace_direct_multi API. The core functionality is taken
from ftrace-direct-modify.ko kernel module and changed to fit
multi direct interface.

The init function creates kthread that periodically calls
modify_ftrace_direct_multi to change the trampoline address
for the direct ftrace_ops. The ftrace trace_pipe then shows
trace from both trampolines.

Link: https://lkml.kernel.org/r/20211206182032.87248-4-jolsa@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Reviewed-by: NHeiko Carstens <hca@linux.ibm.com>
Tested-by: NHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

Return value directly instead of taking this in another redundant variable.
Reported-by: NZeal Robot <zealci@zte.com.cm>
Signed-off-by: NMinghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211209080051.421844-1-chi.minghao@zte.com.cn

Clang doesn't have 'stringop-truncation' group like GCC does, and
complains about it when building samples which use xdp_sample_user
infra:

 samples/bpf/xdp_sample_user.h:48:32: warning: unknown warning group '-Wstringop-truncation', ignored [-Wunknown-warning-option]
 #pragma GCC diagnostic ignored "-Wstringop-truncation"
                                ^
[ repeat ]

Those are harmless, but avoidable when guarding it with ifdef.
I could guard push/pop as well, but this would require one more
ifdef cruft around a single line which I don't think is reasonable.

Fixes: 156f886c ("samples: bpf: Add basic infrastructure for XDP samples")
Signed-off-by: NAlexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20211203195004.5803-3-alexandr.lobakin@intel.com

Clang (13) doesn't get the jokes about specifying libraries to link in
cclags of individual .o objects:

clang-13: warning: -lm: 'linker' input unused [-Wunused-command-line-argument]
[ ... ]
  LD  samples/bpf/xdp_redirect_cpu
  LD  samples/bpf/xdp_redirect_map_multi
  LD  samples/bpf/xdp_redirect_map
  LD  samples/bpf/xdp_redirect
  LD  samples/bpf/xdp_monitor
/usr/bin/ld: samples/bpf/xdp_sample_user.o: in function `sample_summary_print':
xdp_sample_user.c:(.text+0x84c): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x870): undefined reference to `ceil'
/usr/bin/ld: xdp_sample_user.c:(.text+0x8cf): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x8f3): undefined reference to `ceil'
[ more ]

Specify '-lm' as ldflags for all xdp_sample_user.o users in the main
Makefile and remove it from ccflags of ^ in Makefile.target -- just
like it's done for all other samples. This works with all compilers.

Fixes: 6e1051a5 ("samples: bpf: Convert xdp_monitor to XDP samples helper")
Fixes: b926c55d ("samples: bpf: Convert xdp_redirect to XDP samples helper")
Fixes: e531a220 ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper")
Fixes: bbe65865 ("samples: bpf: Convert xdp_redirect_map to XDP samples helper")
Fixes: 594a116b ("samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper")
Signed-off-by: NAlexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20211203195004.5803-2-alexandr.lobakin@intel.com

Replace deprecated APIs with new ones. Also mute source code using
deprecated AF_XDP (xsk.h). Figuring out what to do with all the AF_XDP
stuff is a separate problem that should be solved with its own set of
changes.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211201232824.3166325-9-andrii@kernel.org

Remove xdp_samples_user.o rule redefinition which generates Makefile
warning and instead override TPROGS_CFLAGS. This seems to work fine when
building inside selftests/bpf.

That was one big head-scratcher before I found that generic
Makefile.target hid this surprising specialization for for xdp_samples_user.o.

Main change is to use actual locally installed libbpf headers.

Also drop printk macro re-definition (not even used!).
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211201232824.3166325-8-andrii@kernel.org

Fix the following samples/bpf build error appeared after the
introduction of bpf_map_create() in libbpf:

  CC  samples/bpf/fds_example.o
samples/bpf/fds_example.c:49:12: error: static declaration of 'bpf_map_create' follows non-static declaration
static int bpf_map_create(void)
           ^
samples/bpf/libbpf/include/bpf/bpf.h:55:16: note: previous declaration is here
LIBBPF_API int bpf_map_create(enum bpf_map_type map_type,
               ^
samples/bpf/fds_example.c:82:23: error: too few arguments to function call, expected 6, have 0
                fd = bpf_map_create();
                     ~~~~~~~~~~~~~~ ^
samples/bpf/libbpf/include/bpf/bpf.h:55:16: note: 'bpf_map_create' declared here
LIBBPF_API int bpf_map_create(enum bpf_map_type map_type,
               ^
2 errors generated.

fds_example by accident has a static function with the same name.
It's not worth it to separate a single call into its own function,
so just embed it.

Fixes: 992c4225 ("libbpf: Unify low-level map creation APIs w/ new bpf_map_create()")
Signed-off-by: NAlexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Reviewed-by: NMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: NToke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20211201164931.47357-1-alexandr.lobakin@intel.com

Add s390 architecture support for the ftrace direct multi sample.
See commit 5fae941b ("ftrace/samples: Add multi direct interface
test module") for further details.

Link: https://lore.kernel.org/r/20211115195614.3173346-3-hca@linux.ibm.comSigned-off-by: NHeiko Carstens <hca@linux.ibm.com>

Currently it is not possible to build the ftrace direct multi example
anymore due to broken config dependencies. Fix this by adding
SAMPLE_FTRACE_DIRECT_MULTI config option.

This broke when merging s390-5.16-1 due to an incorrect merge conflict
resolution proposed by me.

Also rename SAMPLE_FTRACE_MULTI_DIRECT to SAMPLE_FTRACE_DIRECT_MULTI
so it matches the module name.

Fixes: 0b707e57 ("Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux")
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211115195614.3173346-2-hca@linux.ibm.comSigned-off-by: NHeiko Carstens <hca@linux.ibm.com>

Since recent Kbuild updates we no longer include files from compiler
directories. However, samples/bpf/hbm_kern.h hasn't been tuned for
this (LLVM 13):

  CLANG-bpf  samples/bpf/hbm_out_kern.o
In file included from samples/bpf/hbm_out_kern.c:55:
samples/bpf/hbm_kern.h:12:10: fatal error: 'stddef.h' file not found
         ^~~~~~~~~~
1 error generated.
  CLANG-bpf  samples/bpf/hbm_edt_kern.o
In file included from samples/bpf/hbm_edt_kern.c:53:
samples/bpf/hbm_kern.h:12:10: fatal error: 'stddef.h' file not found
         ^~~~~~~~~~
1 error generated.

It is enough to just drop both stdbool.h and stddef.h from includes
to fix those.

Fixes: 04e85bbf ("isystem: delete global -isystem compile option")
Signed-off-by: NAlexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: NMichal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://lore.kernel.org/bpf/20211115130741.3584-1-alexandr.lobakin@intel.comSigned-off-by: NAlexei Starovoitov <ast@kernel.org>

Commit b599015f ("samples/bpf: Fix application of sizeof to pointer")
tried to fix a bug where sizeof was incorrectly applied to a pointer instead
of the array string was being copied to, to find the destination buffer size,
but ended up using strlen, which is still incorrect. However, on closer look
ifname_buf has no other use, hence directly use optarg.

Fixes: b599015f ("samples/bpf: Fix application of sizeof to pointer")
Fixes: e531a220 ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper")
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: NAlexander Lobakin <alexandr.lobakin@intel.com>
Tested-by: NAlexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20211112020301.528357-1-memxor@gmail.comSigned-off-by: NAlexei Starovoitov <ast@kernel.org>

sample_summary_print() uses accumulated period to calculate and display
per-sec averages. This period gets incremented by sampling interval each
time a new sample is formed, and thus equals to the number of samples
collected multiplied by this interval.

However, the totals are being calculated differently, they receive current
sample statistics already divided by the interval gotten as a difference
between sample timestamps for better precision -- in other words, they are
being incremented by the per-sec values each sample.

This leads to the excessive division of summary per-secs when interval != 1
sec. It is obvious pps couldn't become two times lower just from picking a
different sampling interval value:

  $ samples/bpf/xdp_redirect_cpu -p xdp_prognum_n1_inverse_qnum -c all
    -s -d 6 -i 1
  < snip >
    Packets received    : 2,197,230,321
    Average packets/s   : 22,887,816
    Packets redirected  : 2,197,230,472
    Average redir/s     : 22,887,817
  $ samples/bpf/xdp_redirect_cpu -p xdp_prognum_n1_inverse_qnum -c all
    -s -d 6 -i 2
  < snip >
    Packets received    : 159,566,498
    Average packets/s   : 11,397,607
    Packets redirected  : 159,566,995
    Average redir/s     : 11,397,642

This can be easily fixed by treating the divisor not as a period, but rather
as a total number of samples, and thus incrementing it by 1 instead of
interval. As a nice side effect, we can now remove so-named argument from a
couple of functions. Let us also create an "alias" for sample_output::rx_cnt::pps
named 'num' using a union since this field is used to store this number (period
previously) as well, and the resulting counter-intuitive code might've been a
reason for this bug.

Fixes: 156f886c ("samples: bpf: Add basic infrastructure for XDP samples")
Signed-off-by: NAlexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Reviewed-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20211111215703.690-1-alexandr.lobakin@intel.comSigned-off-by: NAlexei Starovoitov <ast@kernel.org>

Commit 54510930 ("samples: Add fs error monitoring example") added a
new sample program, but didn't teach git to ignore the new generated
files, causing unnecessary noise from 'git status' after a full build.

Add the 'fs-monitor' sample executable to the .gitignore for this
subdirectory to silence it all again.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's compilation fail reported kernel test robot for W=1 build:

  >> samples/ftrace/ftrace-direct-multi.c:8:6: warning: no previous
  prototype for function 'my_direct_func' [-Wmissing-prototypes]
     void my_direct_func(unsigned long ip)

The inlined assembly is used outside function, so we can't make
my_direct_func static and pass it as asm input argument.

However my_tramp is already extern so I think there's no problem
keeping my_direct_func extern as well and just add its prototype.

Link: https://lkml.kernel.org/r/20211101153907.377668-1-jolsa@kernel.orgReported-by: Nkernel test robot <lkp@intel.com>
Fixes: 5fae941b ("ftrace/samples: Add multi direct interface test module")
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

'sys/types.h' included in 'samples/fanotify/fs-monitor.c'
is duplicated.It is also included on 15 line.

Link: https://lore.kernel.org/r/20211101075152.35780-1-zhang.mingyu@zte.com.cnReported-by: NZeal Robot <zealci@zte.com.cn>
Signed-off-by: NZhang Mingyu <zhang.mingyu@zte.com.cn>
Signed-off-by: NJan Kara <jack@suse.cz>

The fsnotify sample code generates the following warning on powerpc:

samples/fanotify/fs-monitor.c: In function 'handle_notifications':
samples/fanotify/fs-monitor.c:68:36: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 2 has type '__u64' {aka 'long unsigned int'} [-Wformat=]
   68 |    printf("unexpected FAN MARK: %llx\n", event->mask);
      |                                 ~~~^     ~~~~~~~~~~~
      |                                    |          |
      |                                    |          __u64 {aka long unsigned int}
      |                                    long long unsigned int
      |                                 %lx

Fix the problem by explicitely typing the argument to proper type.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NJan Kara <jack@suse.cz>

Prevent build errors when headers or libc are not available, such as on
kernel build bots, like the below:

samples/fanotify/fs-monitor.c:7:10: fatal error: errno.h: No such file
or directory
  7 | #include <errno.h>
    |          ^~~~~~~~~

Link: https://lore.kernel.org/r/87fsslasgz.fsf@collabora.comSuggested-by: NGuenter Roeck <linux@roeck-us.net>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: NJan Kara <jack@suse.cz>

Introduce an example of a FAN_FS_ERROR fanotify user to track filesystem
errors.

Link: https://lore.kernel.org/r/20211025192746.66445-31-krisman@collabora.comReviewed-by: NAmir Goldstein <amir73il@gmail.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NGabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: NJan Kara <jack@suse.cz>

Use the actual return value instead of always -1 if register_kretprobe()
failed.

E.g. without this patch:

 # insmod samples/kprobes/kretprobe_example.ko func=no_such_func
 insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Operation not permitted

With this patch:

 # insmod samples/kprobes/kretprobe_example.ko func=no_such_func
 insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Unknown symbol in module

Link: https://lkml.kernel.org/r/1635213091-24387-2-git-send-email-yangtiezhu@loongson.cn

Fixes: 804defea ("Kprobes: move kprobe examples to samples/")
Signed-off-by: NTiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined
__BYTE_ORDER for consistency.
Signed-off-by: NIlya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-5-iii@linux.ibm.com

In order to better track where in the kernel the dma-buf code is used,
put the symbols in the namespace DMA_BUF and modify all users of the
symbols to properly import the namespace to not break the build at the
same time.

Now the output of modinfo shows the use of these symbols, making it
easier to watch for users over time:

$ modinfo drivers/misc/fastrpc.ko | grep import
import_ns:      DMA_BUF

Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NChristian König <christian.koenig@amd.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NSumit Semwal <sumit.semwal@linaro.org>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20211010124628.17691-1-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When compiling bpf samples, the following warning appears:

readelf: Error: Missing knowledge of 32-bit reloc types used in DWARF
sections of machine number 247
readelf: Warning: unable to apply unsupported reloc type 10 to section
.debug_info
readelf: Warning: unable to apply unsupported reloc type 1 to section
.debug_info
readelf: Warning: unable to apply unsupported reloc type 10 to section
.debug_info

Same problem was mentioned in commit 2f092126 ("selftests/bpf:
suppress readelf stderr when probing for BTF support"), let's use
readelf that supports btf.
Signed-off-by: NPu Lehui <pulehui@huawei.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20211021123913.48833-1-pulehui@huawei.com

Adding simple module that uses multi direct interface:

  register_ftrace_direct_multi
  unregister_ftrace_direct_multi

The init function registers trampoline for 2 functions,
and exit function unregisters them.

Link: https://lkml.kernel.org/r/20211008091336.33616-9-jolsa@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

The coccinelle check report:
"./samples/bpf/xdp_redirect_cpu_user.c:397:32-38:
ERROR: application of sizeof to pointer"
Using the "strlen" to fix it.
Reported-by: NZeal Robot <zealci@zte.com.cn>
Signed-off-by: NDavid Yang <davidcomponentone@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211012111649.983253-1-davidcomponentone@gmail.com

Add s390 support for ftrace direct call samples, which also enables
ftrace direct call selftests within ftrace selftests.
Acked-by: NIlya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: NSven Schnelle <svens@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211012133802.2460757-5-hca@linux.ibm.comSigned-off-by: NVasily Gorbik <gor@linux.ibm.com>

Add HAVE_SAMPLE_FTRACE_DIRECT config option which can be selected by
architectures which have support for ftrace direct call samples.
Acked-by: NIlya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: NSven Schnelle <svens@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20211012133802.2460757-4-hca@linux.ibm.comSigned-off-by: NVasily Gorbik <gor@linux.ibm.com>

The variables names read_lock and write_lock can clash with functions used for
read/writer locks.

Rename read_lock to read_access and write_lock to write_access to avoid a name
collision.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lkml.kernel.org/r/20210806152551.qio7c3ho6pexezup@linutronix.de
Link: https://lore.kernel.org/r/20210923172918.o22iwgvn3w7ilh44@linutronix.deAcked-by: NStefani Seibold <stefani@seibold.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In samples/bpf/Makefile, libbpf has a FORCE dependency that force it to
be rebuilt. I read this as a way to keep the library up-to-date, given
that we do not have, in samples/bpf, a list of the source files for
libbpf itself. However, a better approach would be to use the
"$(wildcard ...)" function from make, and to have libbpf depend on all
the .c and .h files in its directory. This is what samples/bpf/Makefile
does for bpftool, and also what the BPF selftests' Makefile does for
libbpf.

Let's update the Makefile to avoid rebuilding libbpf all the time (and
bpftool on top of it).
Signed-off-by: NQuentin Monnet <quentin@isovalent.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-11-quentin@isovalent.com

API headers from libbpf should not be accessed directly from the source
directory. Instead, they should be exported with "make install_headers".
Make sure that samples/bpf/Makefile installs the headers properly when
building.

The object compiled from and exported by libbpf are now placed into a
subdirectory of sample/bpf/ instead of remaining in tools/lib/bpf/. We
attempt to remove this directory on "make clean". However, the "clean"
target re-enters the samples/bpf/ directory from the root of the
repository ("$(MAKE) -C ../../ M=$(CURDIR) clean"), in such a way that
$(srctree) and $(src) are not defined, making it impossible to use
$(LIBBPF_OUTPUT) and $(LIBBPF_DESTDIR) in the recipe. So we only attempt
to clean $(CURDIR)/libbpf, which is the default value.

Add a dependency on libbpf's headers for the $(TRACE_HELPERS).

We also change the output directory for bpftool, to place the generated
objects under samples/bpf/bpftool/ instead of building in bpftool's
directory directly. Doing so, we make sure bpftool reuses the libbpf
library previously compiled and installed.
Signed-off-by: NQuentin Monnet <quentin@isovalent.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-10-quentin@isovalent.com

Update samples/bpf/.gitignore to ignore files generated when building
the samples. Add:

  - vmlinux.h
  - the generated skeleton files (*.skel.h)
  - the samples/bpf/libbpf/ and .../bpftool/ directories, in preparation
    of a future commit which introduces a local output directory for
    building libbpf and bpftool.
Signed-off-by: NQuentin Monnet <quentin@isovalent.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-9-quentin@isovalent.com

Replace deprecated bpf_{map,program}__next APIs with newly added
bpf_object__next_{map,program} APIs, so that no compilation warnings
emit.
Signed-off-by: NHengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211003165844.4054931-3-hengqi.chen@gmail.com

Recent-ish versions of make do no longer consider number signs ("#") as
comment symbols when they are inserted inside of a macro reference or in
a function invocation. In such cases, the symbols should not be escaped.

There are a few occurrences of "\#" in libbpf's and samples' Makefiles.
In the former, the backslash is harmless, because grep associates no
particular meaning to the escaped symbol and reads it as a regular "#".
In samples' Makefile, recent versions of make will pass the backslash
down to the compiler, making the probe fail all the time and resulting
in the display of a warning about "make headers_install" being required,
even after headers have been installed.

A similar issue has been addressed at some other locations by commit
9564a8cf ("Kbuild: fix # escaping in .cmd files for future Make").
Let's address it for libbpf's and samples' Makefiles in the same
fashion, by using a "$(pound)" variable (pulled from
tools/scripts/Makefile.include for libbpf, or re-defined for the
samples).

Reference for the change in make:
https://git.savannah.gnu.org/cgit/make.git/commit/?id=c6966b323811c37acedff05b57

Fixes: 2f383041 ("libbpf: Make libbpf_version.h non-auto-generated")
Fixes: 07c3bbdb ("samples: bpf: print a warning about headers_install")
Signed-off-by: NQuentin Monnet <quentin@isovalent.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211006111049.20708-1-quentin@isovalent.com