Message ID | 20230526021047.368833-1-liu.yun@linux.dev (mailing list archive) |
---|---|
State | Superseded |
Delegated to: | BPF |
Headers | show |
Series | [v5] libbpf: kprobe.multi: Filter with available_filter_functions | expand |
Context | Check | Description |
---|---|---|
netdev/tree_selection | success | Not a local patch |
bpf/vmtest-bpf-next-PR | success | PR summary |
bpf/vmtest-bpf-next-VM_Test-1 | success | Logs for ShellCheck |
bpf/vmtest-bpf-next-VM_Test-6 | success | Logs for set-matrix |
bpf/vmtest-bpf-next-VM_Test-2 | success | Logs for build for aarch64 with gcc |
bpf/vmtest-bpf-next-VM_Test-4 | success | Logs for build for x86_64 with gcc |
bpf/vmtest-bpf-next-VM_Test-5 | success | Logs for build for x86_64 with llvm-16 |
bpf/vmtest-bpf-next-VM_Test-3 | success | Logs for build for s390x with gcc |
bpf/vmtest-bpf-next-VM_Test-7 | success | Logs for test_maps on aarch64 with gcc |
bpf/vmtest-bpf-next-VM_Test-9 | success | Logs for test_maps on x86_64 with gcc |
bpf/vmtest-bpf-next-VM_Test-10 | success | Logs for test_maps on x86_64 with llvm-16 |
bpf/vmtest-bpf-next-VM_Test-17 | fail | Logs for test_progs_no_alu32 on x86_64 with gcc |
bpf/vmtest-bpf-next-VM_Test-18 | success | Logs for test_progs_no_alu32 on x86_64 with llvm-16 |
bpf/vmtest-bpf-next-VM_Test-19 | success | Logs for test_progs_no_alu32_parallel on aarch64 with gcc |
bpf/vmtest-bpf-next-VM_Test-20 | success | Logs for test_progs_no_alu32_parallel on x86_64 with gcc |
bpf/vmtest-bpf-next-VM_Test-21 | success | Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16 |
bpf/vmtest-bpf-next-VM_Test-22 | success | Logs for test_progs_parallel on aarch64 with gcc |
bpf/vmtest-bpf-next-VM_Test-23 | success | Logs for test_progs_parallel on x86_64 with gcc |
bpf/vmtest-bpf-next-VM_Test-24 | success | Logs for test_progs_parallel on x86_64 with llvm-16 |
bpf/vmtest-bpf-next-VM_Test-25 | success | Logs for test_verifier on aarch64 with gcc |
bpf/vmtest-bpf-next-VM_Test-27 | success | Logs for test_verifier on x86_64 with gcc |
bpf/vmtest-bpf-next-VM_Test-28 | success | Logs for test_verifier on x86_64 with llvm-16 |
bpf/vmtest-bpf-next-VM_Test-29 | success | Logs for veristat |
bpf/vmtest-bpf-next-VM_Test-11 | success | Logs for test_progs on aarch64 with gcc |
bpf/vmtest-bpf-next-VM_Test-13 | success | Logs for test_progs on x86_64 with gcc |
bpf/vmtest-bpf-next-VM_Test-14 | success | Logs for test_progs on x86_64 with llvm-16 |
bpf/vmtest-bpf-next-VM_Test-15 | success | Logs for test_progs_no_alu32 on aarch64 with gcc |
bpf/vmtest-bpf-next-VM_Test-26 | success | Logs for test_verifier on s390x with gcc |
bpf/vmtest-bpf-next-VM_Test-16 | success | Logs for test_progs_no_alu32 on s390x with gcc |
bpf/vmtest-bpf-next-VM_Test-12 | success | Logs for test_progs on s390x with gcc |
bpf/vmtest-bpf-next-VM_Test-8 | success | Logs for test_maps on s390x with gcc |
On Fri, May 26, 2023 at 10:10:47AM +0800, Jackie Liu wrote: SNIP > -resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, > - const char *sym_name, void *ctx) > +kallsyms_resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, > + const char *sym_name, void *ctx) > { > struct kprobe_multi_resolve *res = ctx; > int err; > @@ -10431,8 +10438,8 @@ resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, > if (!glob_match(sym_name, res->pattern)) > return 0; > > - err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(unsigned long), > - res->cnt + 1); > + err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, > + sizeof(unsigned long), res->cnt + 1); hum, looks like this is just formatting change, AFAICS we don't need that > if (err) > return err; > > @@ -10440,6 +10447,75 @@ resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, > return 0; > } > SNIP > + > +static void kprobe_multi_resolve_free(struct kprobe_multi_resolve *res) > +{ > + while (res->syms && res->cnt) > + free((char *)res->syms[--res->cnt]); > + > + free(res->syms); > + free(res->addrs); we should set cnt and cap to zero for the fallback sake > +} > + > struct bpf_link * > bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, > const char *pattern, > @@ -10476,13 +10552,20 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, > return libbpf_err_ptr(-EINVAL); > > if (pattern) { > - err = libbpf_kallsyms_parse(resolve_kprobe_multi_cb, &res); > - if (err) > - goto error; > + err = libbpf_available_kprobes_parse(ftrace_resolve_kprobe_multi_cb, > + &res); > + if (err) { > + /* fallback to kallsyms */ we need to call kprobe_multi_resolve_free in here and set cnt/cap to zero in kprobe_multi_resolve_free jirka > + err = libbpf_kallsyms_parse(kallsyms_resolve_kprobe_multi_cb, > + &res); > + if (err) > + goto error; > + } > if (!res.cnt) { > err = -ENOENT; > goto error; > } > + syms = res.syms; > addrs = res.addrs; > cnt = res.cnt; > } > @@ -10511,12 +10594,12 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, > goto error; > } > link->fd = link_fd; > - free(res.addrs); > + kprobe_multi_resolve_free(&res); > return link; > > error: > free(link); > - free(res.addrs); > + kprobe_multi_resolve_free(&res); > return libbpf_err_ptr(err); > } > > -- > 2.25.1 >
在 2023/5/26 17:53, Jiri Olsa 写道: > On Fri, May 26, 2023 at 10:10:47AM +0800, Jackie Liu wrote: > > SNIP > >> -resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, >> - const char *sym_name, void *ctx) >> +kallsyms_resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, >> + const char *sym_name, void *ctx) >> { >> struct kprobe_multi_resolve *res = ctx; >> int err; >> @@ -10431,8 +10438,8 @@ resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, >> if (!glob_match(sym_name, res->pattern)) >> return 0; >> >> - err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(unsigned long), >> - res->cnt + 1); >> + err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, >> + sizeof(unsigned long), res->cnt + 1); > > hum, looks like this is just formatting change, AFAICS we don't need that > >> if (err) >> return err; >> >> @@ -10440,6 +10447,75 @@ resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, >> return 0; >> } >> > > SNIP > >> + >> +static void kprobe_multi_resolve_free(struct kprobe_multi_resolve *res) >> +{ >> + while (res->syms && res->cnt) >> + free((char *)res->syms[--res->cnt]); >> + >> + free(res->syms); >> + free(res->addrs); > > we should set cnt and cap to zero for the fallback sake It is necessary to set cap to 0, cnt is already 0, if syms exists. > >> +} >> + >> struct bpf_link * >> bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, >> const char *pattern, >> @@ -10476,13 +10552,20 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, >> return libbpf_err_ptr(-EINVAL); >> >> if (pattern) { >> - err = libbpf_kallsyms_parse(resolve_kprobe_multi_cb, &res); >> - if (err) >> - goto error; >> + err = libbpf_available_kprobes_parse(ftrace_resolve_kprobe_multi_cb, >> + &res); >> + if (err) { >> + /* fallback to kallsyms */ > > we need to call kprobe_multi_resolve_free in here and set > cnt/cap to zero in kprobe_multi_resolve_free Yes. > > jirka > >> + err = libbpf_kallsyms_parse(kallsyms_resolve_kprobe_multi_cb, >> + &res); >> + if (err) >> + goto error; >> + } >> if (!res.cnt) { >> err = -ENOENT; >> goto error; >> } >> + syms = res.syms; >> addrs = res.addrs; >> cnt = res.cnt; >> } >> @@ -10511,12 +10594,12 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, >> goto error; >> } >> link->fd = link_fd; >> - free(res.addrs); >> + kprobe_multi_resolve_free(&res); >> return link; >> >> error: >> free(link); >> - free(res.addrs); >> + kprobe_multi_resolve_free(&res); >> return libbpf_err_ptr(err); >> } >> >> -- >> 2.25.1 >>
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ad1ec893b41b..5aac8fe76c0a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10106,6 +10106,12 @@ static const char *tracefs_uprobe_events(void) return use_debugfs() ? DEBUGFS"/uprobe_events" : TRACEFS"/uprobe_events"; } +static const char *tracefs_available_filter_functions(void) +{ + return use_debugfs() ? DEBUGFS"/available_filter_functions" : + TRACEFS"/available_filter_functions"; +} + static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz, const char *kfunc_name, size_t offset) { @@ -10417,13 +10423,14 @@ static bool glob_match(const char *str, const char *pat) struct kprobe_multi_resolve { const char *pattern; unsigned long *addrs; + const char **syms; size_t cap; size_t cnt; }; static int -resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, - const char *sym_name, void *ctx) +kallsyms_resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, + const char *sym_name, void *ctx) { struct kprobe_multi_resolve *res = ctx; int err; @@ -10431,8 +10438,8 @@ resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, if (!glob_match(sym_name, res->pattern)) return 0; - err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(unsigned long), - res->cnt + 1); + err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, + sizeof(unsigned long), res->cnt + 1); if (err) return err; @@ -10440,6 +10447,75 @@ resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, return 0; } +static int ftrace_resolve_kprobe_multi_cb(const char *sym_name, void *ctx) +{ + struct kprobe_multi_resolve *res = ctx; + int err; + char *name; + + if (!glob_match(sym_name, res->pattern)) + return 0; + + err = libbpf_ensure_mem((void **) &res->syms, &res->cap, + sizeof(const char *), res->cnt + 1); + if (err) + return err; + + name = strdup(sym_name); + if (!name) + return -errno; + + res->syms[res->cnt++] = name; + return 0; +} + +typedef int (*available_kprobe_cb_t)(const char *sym_name, void *ctx); + +static int +libbpf_available_kprobes_parse(available_kprobe_cb_t cb, void *ctx) +{ + char sym_name[256]; + FILE *f; + int ret, err = 0; + const char *available_path = tracefs_available_filter_functions(); + + f = fopen(available_path, "r"); + if (!f) { + err = -errno; + pr_warn("failed to open %s, fallback to /proc/kallsyms.\n", + available_path); + return err; + } + + while (true) { + ret = fscanf(f, "%255s%*[^\n]\n", sym_name); + if (ret == EOF && feof(f)) + break; + if (ret != 1) { + pr_warn("failed to read available kprobe entry: %d\n", + ret); + err = -EINVAL; + break; + } + + err = cb(sym_name, ctx); + if (err) + break; + } + + fclose(f); + return err; +} + +static void kprobe_multi_resolve_free(struct kprobe_multi_resolve *res) +{ + while (res->syms && res->cnt) + free((char *)res->syms[--res->cnt]); + + free(res->syms); + free(res->addrs); +} + struct bpf_link * bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, const char *pattern, @@ -10476,13 +10552,20 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, return libbpf_err_ptr(-EINVAL); if (pattern) { - err = libbpf_kallsyms_parse(resolve_kprobe_multi_cb, &res); - if (err) - goto error; + err = libbpf_available_kprobes_parse(ftrace_resolve_kprobe_multi_cb, + &res); + if (err) { + /* fallback to kallsyms */ + err = libbpf_kallsyms_parse(kallsyms_resolve_kprobe_multi_cb, + &res); + if (err) + goto error; + } if (!res.cnt) { err = -ENOENT; goto error; } + syms = res.syms; addrs = res.addrs; cnt = res.cnt; } @@ -10511,12 +10594,12 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, goto error; } link->fd = link_fd; - free(res.addrs); + kprobe_multi_resolve_free(&res); return link; error: free(link); - free(res.addrs); + kprobe_multi_resolve_free(&res); return libbpf_err_ptr(err); }