bpf: Add multi uprobe link #5232
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Adding new multi uprobe link that allows to attach bpf program
to multiple uprobes.
Uprobes to attach are specified via new link_create uprobe_multi
union:
struct {
__u32 flags;
__u32 cnt;
__aligned_u64 path;
__aligned_u64 offsets;
__aligned_u64 ref_ctr_offsets;
} uprobe_multi;
Uprobes are defined for single binary specified in path and multiple
calling sites specified in offsets array with optional reference
counters specified in ref_ctr_offsets array. All specified arrays
have length of 'cnt'.
The 'flags' supports single bit for now that marks the uprobe as
return probe.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding support to specify cookies array for uprobe_multi link. The cookies array share indexes and length with other uprobe_multi arrays (offsets/ref_ctr_offsets). The cookies[i] value defines cookie for i-the uprobe and will be returned by bpf_get_attach_cookie helper when called from ebpf program hooked to that specific uprobe. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding support to specify pid for uprobe_multi link and the uprobes are created only for task with given pid value. Using the consumer.filter filter callback for that, so the task gets filtered during the uprobe installation. We still need to check the task during runtime in the uprobe handler, because the handler could get executed if there's another system wide consumer on the same uprobe (thanks Oleg for the insight). Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
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 <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding new uprobe_multi attach type and link names, so the functions can resolve the new values. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding elf symbol iterator object (and some functions) that follow
open-coded iterator pattern and some functions to ease up iterating
elf object symbols.
The idea is to iterate single symbol section with:
struct elf_symbol_iter iter;
struct elf_symbol *sym;
if (elf_symbol_iter_new(&iter, elf, binary_path, SHT_DYNSYM))
goto error;
while ((sym = elf_symbol_iter_next(&iter))) {
...
}
I considered opening the elf inside the iterator and iterate all symbol
sections, but then it gets more complicated wrt user checks for when
the next section is processed.
Plus side is the we don't need 'exit' function, because caller/user is
in charge of that.
The returned iterated symbol object from elf_symbol_iter_next function
is placed inside the struct elf_symbol_iter, so no extra allocation or
argument is needed.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding open_elf/close_elf functions and using it in elf_find_func_offset_from_file function. It will be used in following changes to save some code. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding elf_find_multi_func_offset function that looks up offsets for symbols specified in syms array argument. Offsets are returned in allocated array with the 'cnt' size, that needs to be released by the caller. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding elf_find_pattern_func_offset function that looks up offsets for symbols specified by pattern argument. The 'pattern' argument allows wildcards (*?' supported). Offsets are returned in allocated array together with its size and needs to be released by the caller. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding new uprobe_multi struct to bpf_link_create_opts object to pass multiple uprobe data to link_create attr uapi. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding bpf_program__attach_uprobe_multi_opts function that
allows to attach multiple uprobes with uprobe_multi link.
The user can specify uprobes with direct arguments:
binary_path/func_pattern
or with struct bpf_uprobe_multi_opts opts argument fields:
const char *path;
const char **syms;
const unsigned long *offsets;
const unsigned long *ref_ctr_offsets;
User can specify 3 mutually exclusive set of incputs:
1) use only binary_path/func_pattern aruments
2) use only opts argument with allowed combinations of:
path/offsets/ref_ctr_offsets/cookies/cnt
3) use binary_path with allowed combinations of:
syms/offsets/ref_ctr_offsets/cookies/cnt
Any other usage results in error.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding support for several uprobe_multi program sections to allow auto attach of multi_uprobe programs. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding uprobe-multi link detection. It will be used later in bpf_program__attach_usdt function to check and use uprobe_multi link over standard uprobe links. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding support for usdt_manager_attach_usdt to use uprobe_multi link to attach to usdt probes. The uprobe_multi support is detected before the usdt program is loaded and its expected_attach_type is set accordingly. If uprobe_multi support is detected the usdt_manager_attach_usdt gathers uprobes info and calls bpf_program__attach_uprobe_opts to create all needed uprobes. If uprobe_multi support is not detected the old behaviour stays. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding uprobe_multi test for skeleton load/attach functions, to test skeleton auto attach for uprobe_multi link. Test that bpf_get_func_ip works properly for uprobe_multi attachment. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding uprobe_multi test for bpf_program__attach_uprobe_multi_opts attach function. Testing attachment using glob patterns and via bpf_uprobe_multi_opts paths/syms fields. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding uprobe_multi test for bpf_link_create attach function. Testing attachment using the struct bpf_link_create_opts. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding uprobe_multi test program that defines 50k uprobe_multi_func_* functions and will serve as attach point for uprobe_multi bench test in following patch. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding test that attaches 50k uprobes in uprobe_multi binary. After the attach is done we run the binary and make sure we get proper amount of hits. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding usdt_multi test program that defines 50k usdts and will serve as attach point for uprobe_multi usdt bench test in following patch. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding test that attaches 50k usdt probes in usdt_multi binary. After the attach is done we run the binary and make sure we get proper amount of hits. With current uprobes: # perf stat --null ./test_progs -n 254/6 #254/6 uprobe_multi_test/bench_usdt:OK #254 uprobe_multi_test:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED Performance counter stats for './test_progs -n 254/6': 1353.659680562 seconds time elapsed With uprobe_multi link: # perf stat --null ./test_progs -n 254/6 #254/6 uprobe_multi_test/bench_usdt:OK #254 uprobe_multi_test:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED Performance counter stats for './test_progs -n 254/6': 0.322046364 seconds time elapsed Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Adding test for cookies setup/retrieval in uprobe_link uprobes and making sure bpf_get_attach_cookie works properly. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Running api and link tests also with pid filter and checking the probe gets executed only for specific pid. Spawning extra process to trigger attached uprobes and checking we get correct counts from executed programs. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Attaching extra program to same functions system wide for api and link tests. This way we can test the pid filter works properly when there's extra system wide consumer on the same uprobe that will trigger the original uprobe handler. We expect to have the same counts as before. Signed-off-by: Jiri Olsa <jolsa@kernel.org>
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Upstream branch: 970308a |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=758591 expired. Closing PR. |
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Pull request for series with
subject: bpf: Add multi uprobe link
version: 1
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=758591