kernel/linux.git/samples/bpf/task_fd_query_user.c, branch v6.6.131

bpf: use canonical ftrace path

2023-03-14T04:51:30+00:00

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 Acked-by: Michael S. Tsirkin Reviewed-by: Steven Rostedt (Google) Link: https://lore.kernel.org/r/20230313205628.1058720-2-zwisler@kernel.org Signed-off-by: Alexei Starovoitov

samples/bpf: Replace blk_account_io_done() with __blk_account_io_done()

2022-09-21T00:25:59+00:00

Since commit be6bfe36db17 ("block: inline hot paths of blk_account_io_*()") blk_account_io_*() become inline functions. Signed-off-by: Rong Tao Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/tencent_1CC476835C219FACD84B6715F0D785517E07@qq.com

samples/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK

2022-04-11T03:17:15+00:00

We have switched to memcg-based memory accouting and thus the rlimit is not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduced in libbpf for backward compatibility, so we can use it instead now. This patch also removes the useless header sys/resource.h from many files in samples/bpf. Signed-off-by: Yafang Shao Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220409125958.92629-2-laoar.shao@gmail.com

samples, bpf: Suppress compiler warning

2021-05-12T19:29:43+00:00

While cross compiling on ARM32 , the casting from pointer to __u64 will cause warnings: samples/bpf/task_fd_query_user.c: In function 'main': samples/bpf/task_fd_query_user.c:399:23: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] 399 | uprobe_file_offset = (__u64)main - (__u64)&__executable_start; | ^ samples/bpf/task_fd_query_user.c:399:37: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] 399 | uprobe_file_offset = (__u64)main - (__u64)&__executable_start; Workaround this by using "unsigned long" to adapt to different ARCHs. Signed-off-by: Hailong Liu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210511140429.89426-1-liuhailongg6@163.com

bpf: samples: Do not touch RLIMIT_MEMLOCK

2020-12-03T02:32:47+00:00

Since bpf is not using rlimit memlock for the memory accounting and control, do not change the limit in sample applications. Signed-off-by: Roman Gushchin Signed-off-by: Alexei Starovoitov Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20201201215900.3569844-35-guro@fb.com

samples: bpf: Refactor task_fd_query program with libbpf

2020-11-27T03:33:35+00:00

This commit refactors the existing kprobe program with libbpf bpf loader. To attach bpf program, this uses generic bpf_program__attach() approach rather than using bpf_load's load_bpf_file(). To attach bpf to perf_event, instead of using previous ioctl method, this commit uses bpf_program__attach_perf_event since it manages the enable of perf_event and attach of BPF programs to it, which is much more intuitive way to achieve. Also, explicit close(fd) has been removed since event will be closed inside bpf_link__destroy() automatically. Furthermore, to prevent conflict of same named uprobe events, O_TRUNC flag has been used to clear 'uprobe_events' interface. Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-4-danieltimlee@gmail.com

samples/bpf: Set rlimit for memlock to infinity in all samples

2020-10-27T21:46:17+00:00

The memlock rlimit is a notorious source of failure for BPF programs. Most of the samples just set it to infinity, but a few used a lower limit. The problem with unconditionally setting a lower limit is that this will also override the limit if the system-wide setting is *higher* than the limit being set, which can lead to failures on systems that lock a lot of memory, but set 'ulimit -l' to unlimited before running a sample. One fix for this is to only conditionally set the limit if the current limit is lower, but it is simpler to just unify all the samples and have them all set the limit to infinity. Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/20201026233623.91728-1-toke@redhat.com

samples: bpf: Fix broken bpf programs due to removed symbol

2020-08-19T00:10:03+00:00

>From commit f1394b798814 ("block: mark blk_account_io_completion static") symbol blk_account_io_completion() has been marked as static, which makes it no longer possible to attach kprobe to this event. Currently, there are broken samples due to this reason. As a solution to this, attach kprobe events to blk_account_io_done() to modify them to perform the same behavior as before. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200818051641.21724-1-danieltimlee@gmail.com

samples/bpf: Use consistent include paths for libbpf

2020-01-21T00:37:45+00:00

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 Signed-off-by: Alexei Starovoitov Acked-by: Jesper Dangaard Brouer Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk

samples/bpf: Fix build for task_fd_query_user.c

2019-10-03T14:27:03+00:00

Add missing include for which was removed from perf-sys.h in commit 91854f9a077e ("perf tools: Move everything related to sys_perf_event_open() to perf-sys.h"). Fixes: 91854f9a077e ("perf tools: Move everything related to sys_perf_event_open() to perf-sys.h") Reported-by: KP Singh Reported-by: Florent Revest Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Tested-by: KP Singh Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20191001112249.27341-1-bjorn.topel@gmail.com