kernel/linux.git/samples, branch v5.15.38

samples/bpf, xdpsock: Fix race when running for fix duration of time

2022-04-08T12:23:40+00:00

[ Upstream commit 8fa42d78f6354bb96ad3a079dcbef528ca9fa9e0 ] When running xdpsock for a fix duration of time before terminating using --duration=, there is a race condition that may cause xdpsock to terminate immediately. When running for a fixed duration of time the check to determine when to terminate execution is in is_benchmark_done() and is being executed in the context of the poller thread, if (opt_duration > 0) { unsigned long dt = (get_nsecs() - start_time); if (dt >= opt_duration) benchmark_done = true; } However start_time is only set after the poller thread have been created. This leaves a small window when the poller thread is starting and calls is_benchmark_done() for the first time that start_time is not yet set. In that case start_time have its initial value of 0 and the duration check fails as it do not correlate correctly for the applications start time and immediately sets benchmark_done which in turn terminates the xdpsock application. Fix this by setting start_time before creating the poller thread. Fixes: d3f11b018f6c ("samples/bpf: xdpsock: Add duration option to specify how long to run") Signed-off-by: Niklas Söderlund Signed-off-by: Simon Horman Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220315102948.466436-1-niklas.soderlund@corigine.com Signed-off-by: Sasha Levin

samples/landlock: Fix path_list memory leak

2022-04-08T12:22:59+00:00

commit 66b513b7c64a7290c1fbb88e657f7cece992e131 upstream. Clang static analysis reports this error sandboxer.c:134:8: warning: Potential leak of memory pointed to by 'path_list' ret = 0; ^ path_list is allocated in parse_path() but never freed. Signed-off-by: Tom Rix Link: https://lore.kernel.org/r/20210428213852.2874324-1-trix@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün Signed-off-by: Greg Kroah-Hartman

samples: bpf: Fix 'unknown warning group' build warning on Clang

2022-01-27T10:03:29+00:00

[ Upstream commit 6f670d06e47c774bc065aaa84a527a4838f34bd8 ] 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: 156f886cf697 ("samples: bpf: Add basic infrastructure for XDP samples") Signed-off-by: Alexander Lobakin Signed-off-by: Andrii Nakryiko Acked-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/bpf/20211203195004.5803-3-alexandr.lobakin@intel.com Signed-off-by: Sasha Levin

samples: bpf: Fix xdp_sample_user.o linking with Clang

2022-01-27T10:03:29+00:00

[ Upstream commit e64fbcaa7a666f16329b1c67af15ea501bc84586 ] 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: 6e1051a54e31 ("samples: bpf: Convert xdp_monitor to XDP samples helper") Fixes: b926c55d856c ("samples: bpf: Convert xdp_redirect to XDP samples helper") Fixes: e531a220cc59 ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper") Fixes: bbe65865aa05 ("samples: bpf: Convert xdp_redirect_map to XDP samples helper") Fixes: 594a116b2aa1 ("samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper") Signed-off-by: Alexander Lobakin Signed-off-by: Andrii Nakryiko Acked-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/bpf/20211203195004.5803-2-alexandr.lobakin@intel.com Signed-off-by: Sasha Levin

samples/bpf: Clean up samples/bpf build failes

2022-01-27T10:03:29+00:00

[ Upstream commit 527024f7aeb683ce7ef49b07ef7ce9ecf015288d ] 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: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211201232824.3166325-8-andrii@kernel.org Signed-off-by: Sasha Levin

samples/bpf: Install libbpf headers when building

2022-01-27T10:03:28+00:00

[ Upstream commit 3f7a3318a7c60947e27be372950840a5eab976d0 ] 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: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211007194438.34443-10-quentin@isovalent.com Signed-off-by: Sasha Levin

ftrace/samples: Add missing prototypes direct functions

2022-01-11T14:35:13+00:00

commit 0daf5cb217a9ca8ae91b8f966ddae322699fb71d upstream. There's another compilation fail (first here [1]) reported by kernel test robot for W=1 clang build: >> samples/ftrace/ftrace-direct-multi-modify.c:7:6: warning: no previous prototype for function 'my_direct_func1' [-Wmissing-prototypes] void my_direct_func1(unsigned long ip) Direct functions in ftrace direct sample modules need to have prototypes defined. They are already global in order to be visible for the inline assembly, so there's no problem. The kernel test robot reported just error for ftrace-direct-multi-modify, but I got same errors also for the rest of the modules touched by this patch. [1] 67d4f6e3bf5d ftrace/samples: Add missing prototype for my_direct_func Link: https://lkml.kernel.org/r/20211219135317.212430-1-jolsa@kernel.org Reported-by: kernel test robot Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface") Fixes: ae0cc3b7e7f5 ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()") Fixes: 156473a0ff4f ("ftrace: Add another example of register_ftrace_direct() use case") Fixes: b06457c83af6 ("ftrace: Add sample module that uses register_ftrace_direct()") Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

samples/bpf: Fix incorrect use of strlen in xdp_redirect_cpu

2021-11-25T08:48:33+00:00

[ Upstream commit 2453afe3845523d9dfe89dbfb3d71abfa095e260 ] Commit b599015f044d ("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: b599015f044d ("samples/bpf: Fix application of sizeof to pointer") Fixes: e531a220cc59 ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper") Signed-off-by: Kumar Kartikeya Dwivedi Signed-off-by: Daniel Borkmann Reviewed-by: Alexander Lobakin Tested-by: Alexander Lobakin Link: https://lore.kernel.org/bpf/20211112020301.528357-1-memxor@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

samples/bpf: Fix summary per-sec stats in xdp_sample_user

2021-11-25T08:48:33+00:00

[ Upstream commit dc14ca4644f48b1cfa93631e35c28bdc011ad109 ] 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: 156f886cf697 ("samples: bpf: Add basic infrastructure for XDP samples") Signed-off-by: Alexander Lobakin Signed-off-by: Daniel Borkmann Reviewed-by: Jesse Brandeburg Reviewed-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/bpf/20211111215703.690-1-alexandr.lobakin@intel.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

samples/kretprobes: Fix return value if register_kretprobe() failed

2021-11-18T18:16:42+00:00

[ Upstream commit f76fbbbb5061fe14824ba5807c44bd7400a6b4e1 ] 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: 804defea1c02 ("Kprobes: move kprobe examples to samples/") Signed-off-by: Tiezhu Yang Acked-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin