user/sven/linux.git/kernel/trace/bpf_trace.c, branch v6.7.3

bpf: Limit the number of kprobes when attaching program to multiple kprobes

2024-01-25T23:44:53Z

[ Upstream commit d6d1e6c17cab2dcb7b8530c599f00e7de906d380 ] An abnormally big cnt may also be assigned to kprobe_multi.cnt when attaching multiple kprobes. It will trigger the following warning in kvmalloc_node(): if (unlikely(size > INT_MAX)) { WARN_ON_ONCE(!(flags & __GFP_NOWARN)); return NULL; } Fix the warning by limiting the maximal number of kprobes in bpf_kprobe_multi_link_attach(). If the number of kprobes is greater than MAX_KPROBE_MULTI_CNT, the attachment will fail and return -E2BIG. Fixes: 0dcac2725406 ("bpf: Add multi kprobe link") Signed-off-by: Hou Tao Signed-off-by: Daniel Borkmann Acked-by: Jiri Olsa Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20231215100708.2265609-3-houtao@huaweicloud.com Signed-off-by: Sasha Levin

bpf: Limit the number of uprobes when attaching program to multiple uprobes

2024-01-25T23:44:53Z

[ Upstream commit 8b2efe51ba85ca83460941672afac6fca4199df6 ] An abnormally big cnt may be passed to link_create.uprobe_multi.cnt, and it will trigger the following warning in kvmalloc_node(): if (unlikely(size > INT_MAX)) { WARN_ON_ONCE(!(flags & __GFP_NOWARN)); return NULL; } Fix the warning by limiting the maximal number of uprobes in bpf_uprobe_multi_link_attach(). If the number of uprobes is greater than MAX_UPROBE_MULTI_CNT, the attachment will return -E2BIG. Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link") Reported-by: Xingwei Lee Signed-off-by: Hou Tao Signed-off-by: Daniel Borkmann Acked-by: Jiri Olsa Acked-by: Andrii Nakryiko Closes: https://lore.kernel.org/bpf/CABOYnLwwJY=yFAGie59LFsUsBAgHfroVqbzZ5edAXbFE3YiNVA@mail.gmail.com Link: https://lore.kernel.org/bpf/20231215100708.2265609-2-houtao@huaweicloud.com Signed-off-by: Sasha Levin

bpf: Add __bpf_kfunc_{start,end}_defs macros

2023-11-02T05:33:53Z

BPF kfuncs are meant to be called from BPF programs. Accordingly, most kfuncs are not called from anywhere in the kernel, which the -Wmissing-prototypes warning is unhappy about. We've peppered __diag_ignore_all("-Wmissing-prototypes", ... everywhere kfuncs are defined in the codebase to suppress this warning. This patch adds two macros meant to bound one or many kfunc definitions. All existing kfunc definitions which use these __diag calls to suppress -Wmissing-prototypes are migrated to use the newly-introduced macros. A new __diag_ignore_all - for "-Wmissing-declarations" - is added to the __bpf_kfunc_start_defs macro based on feedback from Andrii on an earlier version of this patch [0] and another recent mailing list thread [1]. In the future we might need to ignore different warnings or do other kfunc-specific things. This change will make it easier to make such modifications for all kfunc defs. [0]: https://lore.kernel.org/bpf/CAEf4BzaE5dRWtK6RPLnjTW-MW9sx9K3Fn6uwqCTChK2Dcb1Xig@mail.gmail.com/ [1]: https://lore.kernel.org/bpf/ZT+2qCc%2FaXep0%2FLf@krava/ Signed-off-by: Dave Marchevsky Suggested-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Cc: Jiri Olsa Acked-by: Jiri Olsa Acked-by: David Vernet Acked-by: Yafang Shao Link: https://lore.kernel.org/r/20231031215625.2343848-1-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov

bpf: Count missed stats in trace_call_bpf

2023-09-25T23:37:44Z

Increase misses stats in case bpf array execution is skipped because of recursion check in trace_call_bpf. Adding bpf_prog_inc_misses_counters that increase misses counts for all bpf programs in bpf_prog_array. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Tested-by: Song Liu Reviewed-by: Song Liu Link: https://lore.kernel.org/bpf/20230920213145.1941596-5-jolsa@kernel.org

bpf: Add missed value to kprobe perf link info

2023-09-25T23:37:44Z

Add missed value to kprobe attached through perf link info to hold the stats of missed kprobe handler execution. The kprobe's missed counter gets incremented when kprobe handler is not executed due to another kprobe running on the same cpu. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230920213145.1941596-4-jolsa@kernel.org

bpf: Add missed value to kprobe_multi link info

2023-09-25T23:37:44Z

Add missed value to kprobe_multi link info to hold the stats of missed kprobe_multi probe. The missed counter gets incremented when fprobe fails the recursion check or there's no rethook available for return probe. In either case the attached bpf program is not executed. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Tested-by: Song Liu Reviewed-by: Song Liu Acked-by: Hou Tao Link: https://lore.kernel.org/bpf/20230920213145.1941596-3-jolsa@kernel.org

bpf: Count stats for kprobe_multi programs

2023-09-25T23:37:44Z

Adding support to gather missed stats for kprobe_multi programs due to bpf_prog_active protection. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Tested-by: Song Liu Reviewed-by: Song Liu Link: https://lore.kernel.org/bpf/20230920213145.1941596-2-jolsa@kernel.org

bpf: Fix uprobe_multi get_pid_task error path

2023-09-15T17:32:40Z

Dan reported Smatch static checker warning due to missing error value set in uprobe multi link's get_pid_task error path. Reported-by: Dan Carpenter Closes: https://lore.kernel.org/bpf/c5ffa7c0-6b06-40d5-aca2-63833b5cd9af@moroto.mountain/ Signed-off-by: Jiri Olsa Reviewed-by: Song Liu Link: https://lore.kernel.org/r/20230915101420.1193800-1-jolsa@kernel.org Signed-off-by: Alexei Starovoitov

bpf: Add override check to kprobe multi link attach

2023-09-08T23:53:10Z

Currently the multi_kprobe link attach does not check error injection list for programs with bpf_override_return helper and allows them to attach anywhere. Adding the missing check. Fixes: 0dcac2725406 ("bpf: Add multi kprobe link") Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Reviewed-by: Alan Maguire Cc: stable@vger.kernel.org Link: https://lore.kernel.org/bpf/20230907200652.926951-1-jolsa@kernel.org

bpf: Add bpf_get_func_ip helper support for uprobe link

2023-08-21T22:51:25Z

Adding support for bpf_get_func_ip helper being called from ebpf program attached by uprobe_multi link. It returns the ip of the uprobe. Acked-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230809083440.3209381-7-jolsa@kernel.org Signed-off-by: Alexei Starovoitov