| Message ID | 20211007080952.1255615-2-davemarchevsky@fb.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: keep track of verifier insn_processed | expand |
On 10/7/21 10:09 AM, Dave Marchevsky wrote: > This stat is currently printed in the verifier log and not stored > anywhere. To ease consumption of this data, add a field to bpf_prog_aux > so it can be exposed via BPF_OBJ_GET_INFO_BY_FD and fdinfo. > > Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> > --- > include/linux/bpf.h | 1 + > include/uapi/linux/bpf.h | 1 + > kernel/bpf/syscall.c | 8 ++++++-- > kernel/bpf/verifier.c | 1 + > tools/include/uapi/linux/bpf.h | 1 + > 5 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index d604c8251d88..921ad62b892c 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -887,6 +887,7 @@ struct bpf_prog_aux { > struct bpf_prog *prog; > struct user_struct *user; > u64 load_time; /* ns since boottime */ > + u64 verif_insn_processed; nit: why u64 and not u32? > struct bpf_map *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]; > char name[BPF_OBJ_NAME_LEN]; > #ifdef CONFIG_SECURITY > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 6fc59d61937a..89be6ecf9204 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -5613,6 +5613,7 @@ struct bpf_prog_info { > __u64 run_time_ns; > __u64 run_cnt; > __u64 recursion_misses; > + __u64 verif_insn_processed; There's a '__u32 :31; /* alignment pad */' which could be reused. Given this is uapi, I'd probably just name it 'insn_processed' or 'verified_insns' (maybe the latter is more appropriate) to avoid abbreviation on verif_ which may not be obvious. > } __attribute__((aligned(8))); > > struct bpf_map_info { > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > index 4e50c0bfdb7d..ea452ced2296 100644 > --- a/kernel/bpf/syscall.c > +++ b/kernel/bpf/syscall.c > @@ -1848,7 +1848,8 @@ static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) > "prog_id:\t%u\n" > "run_time_ns:\t%llu\n" > "run_cnt:\t%llu\n" > - "recursion_misses:\t%llu\n", > + "recursion_misses:\t%llu\n" > + "verif_insn_processed:\t%llu\n", > prog->type, > prog->jited, > prog_tag, > @@ -1856,7 +1857,8 @@ static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) > prog->aux->id, > stats.nsecs, > stats.cnt, > - stats.misses); > + stats.misses, > + prog->aux->verif_insn_processed); > } > #endif > > @@ -3625,6 +3627,8 @@ static int bpf_prog_get_info_by_fd(struct file *file, > info.run_cnt = stats.cnt; > info.recursion_misses = stats.misses; > > + info.verif_insn_processed = prog->aux->verif_insn_processed; Bit off-topic, but stack depth might be useful as well. > + > if (!bpf_capable()) { > info.jited_prog_len = 0; > info.xlated_prog_len = 0; > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index 20900a1bac12..9ca301191d78 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -14038,6 +14038,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr) > > env->verification_time = ktime_get_ns() - start_time; > print_verification_stats(env); > + env->prog->aux->verif_insn_processed = env->insn_processed; > > if (log->level && bpf_verifier_log_full(log)) > ret = -ENOSPC; > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h > index 6fc59d61937a..89be6ecf9204 100644 > --- a/tools/include/uapi/linux/bpf.h > +++ b/tools/include/uapi/linux/bpf.h > @@ -5613,6 +5613,7 @@ struct bpf_prog_info { > __u64 run_time_ns; > __u64 run_cnt; > __u64 recursion_misses; > + __u64 verif_insn_processed; > } __attribute__((aligned(8))); > > struct bpf_map_info { >
On 10/7/21 5:46 PM, Daniel Borkmann wrote: > On 10/7/21 10:09 AM, Dave Marchevsky wrote: >> This stat is currently printed in the verifier log and not stored >> anywhere. To ease consumption of this data, add a field to bpf_prog_aux >> so it can be exposed via BPF_OBJ_GET_INFO_BY_FD and fdinfo. >> >> Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> >> --- >> include/linux/bpf.h | 1 + >> include/uapi/linux/bpf.h | 1 + >> kernel/bpf/syscall.c | 8 ++++++-- >> kernel/bpf/verifier.c | 1 + >> tools/include/uapi/linux/bpf.h | 1 + >> 5 files changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/bpf.h b/include/linux/bpf.h >> index d604c8251d88..921ad62b892c 100644 >> --- a/include/linux/bpf.h >> +++ b/include/linux/bpf.h >> @@ -887,6 +887,7 @@ struct bpf_prog_aux { >> struct bpf_prog *prog; >> struct user_struct *user; >> u64 load_time; /* ns since boottime */ >> + u64 verif_insn_processed; > > nit: why u64 and not u32? This was an attempt to future-proof, with this comment from Alexei on the RFC patchset in mind: "So it feels to me that insn_processed alone will be enough to address the monitoring goal. It can be exposed to fd_info and printed by bpftool. If/when it changes with some future verifier algorithm we should be able to approximate it." My thinking was that, if the scenario in the last sentence of the comment were to happen, a verifier putting an approximation of 'how hard did I have to work to verify all the insns' in this field might have use for the extra bytes. That seems pretty tenuous though, as does the current verifier needing the full u64 anytime soon, so happy to change. >> struct bpf_map *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]; >> char name[BPF_OBJ_NAME_LEN]; >> #ifdef CONFIG_SECURITY >> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h >> index 6fc59d61937a..89be6ecf9204 100644 >> --- a/include/uapi/linux/bpf.h >> +++ b/include/uapi/linux/bpf.h >> @@ -5613,6 +5613,7 @@ struct bpf_prog_info { >> __u64 run_time_ns; >> __u64 run_cnt; >> __u64 recursion_misses; >> + __u64 verif_insn_processed; > > There's a '__u32 :31; /* alignment pad */' which could be reused. Given this > is uapi, I'd probably just name it 'insn_processed' or 'verified_insns' (maybe > the latter is more appropriate) to avoid abbreviation on verif_ which may not > be obvious. Meaning, just use those 31 bits for insn_processed? re: your naming suggestions, I prefer 'verified_insns'. Main concern for me is making it obvious that this field is a property of the verification of the prog, not the prog itself like most other fields in bpf_prog_info. >> } __attribute__((aligned(8))); >> struct bpf_map_info { >> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c >> index 4e50c0bfdb7d..ea452ced2296 100644 >> --- a/kernel/bpf/syscall.c >> +++ b/kernel/bpf/syscall.c >> @@ -1848,7 +1848,8 @@ static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) >> "prog_id:\t%u\n" >> "run_time_ns:\t%llu\n" >> "run_cnt:\t%llu\n" >> - "recursion_misses:\t%llu\n", >> + "recursion_misses:\t%llu\n" >> + "verif_insn_processed:\t%llu\n", >> prog->type, >> prog->jited, >> prog_tag, >> @@ -1856,7 +1857,8 @@ static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) >> prog->aux->id, >> stats.nsecs, >> stats.cnt, >> - stats.misses); >> + stats.misses, >> + prog->aux->verif_insn_processed); >> } >> #endif >> @@ -3625,6 +3627,8 @@ static int bpf_prog_get_info_by_fd(struct file *file, >> info.run_cnt = stats.cnt; >> info.recursion_misses = stats.misses; >> + info.verif_insn_processed = prog->aux->verif_insn_processed; > > Bit off-topic, but stack depth might be useful as well. Agreed. Since there's a stack_depth per subprog it would require handling similar to other dynamic-size bpf_prog_info fields, so I didn't add it to the RFC patchset either, thinking it would be better to start with simple stats and see if anyone uses. Feedback there was to avoid adding too many verifier stats fields to bpf_prog_info, instead relying on a post-verification bare tracepoint (Andrii) or other BPF hook (John, Alexei) for extraction of other verifier stats. >> + >> if (!bpf_capable()) { >> info.jited_prog_len = 0; >> info.xlated_prog_len = 0; >> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c >> index 20900a1bac12..9ca301191d78 100644 >> --- a/kernel/bpf/verifier.c >> +++ b/kernel/bpf/verifier.c >> @@ -14038,6 +14038,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr) >> env->verification_time = ktime_get_ns() - start_time; >> print_verification_stats(env); >> + env->prog->aux->verif_insn_processed = env->insn_processed; >> if (log->level && bpf_verifier_log_full(log)) >> ret = -ENOSPC; >> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h >> index 6fc59d61937a..89be6ecf9204 100644 >> --- a/tools/include/uapi/linux/bpf.h >> +++ b/tools/include/uapi/linux/bpf.h >> @@ -5613,6 +5613,7 @@ struct bpf_prog_info { >> __u64 run_time_ns; >> __u64 run_cnt; >> __u64 recursion_misses; >> + __u64 verif_insn_processed; >> } __attribute__((aligned(8))); >> struct bpf_map_info { >> >
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index d604c8251d88..921ad62b892c 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -887,6 +887,7 @@ struct bpf_prog_aux { struct bpf_prog *prog; struct user_struct *user; u64 load_time; /* ns since boottime */ + u64 verif_insn_processed; struct bpf_map *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]; char name[BPF_OBJ_NAME_LEN]; #ifdef CONFIG_SECURITY diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 6fc59d61937a..89be6ecf9204 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5613,6 +5613,7 @@ struct bpf_prog_info { __u64 run_time_ns; __u64 run_cnt; __u64 recursion_misses; + __u64 verif_insn_processed; } __attribute__((aligned(8))); struct bpf_map_info { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4e50c0bfdb7d..ea452ced2296 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1848,7 +1848,8 @@ static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) "prog_id:\t%u\n" "run_time_ns:\t%llu\n" "run_cnt:\t%llu\n" - "recursion_misses:\t%llu\n", + "recursion_misses:\t%llu\n" + "verif_insn_processed:\t%llu\n", prog->type, prog->jited, prog_tag, @@ -1856,7 +1857,8 @@ static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) prog->aux->id, stats.nsecs, stats.cnt, - stats.misses); + stats.misses, + prog->aux->verif_insn_processed); } #endif @@ -3625,6 +3627,8 @@ static int bpf_prog_get_info_by_fd(struct file *file, info.run_cnt = stats.cnt; info.recursion_misses = stats.misses; + info.verif_insn_processed = prog->aux->verif_insn_processed; + if (!bpf_capable()) { info.jited_prog_len = 0; info.xlated_prog_len = 0; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 20900a1bac12..9ca301191d78 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -14038,6 +14038,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr) env->verification_time = ktime_get_ns() - start_time; print_verification_stats(env); + env->prog->aux->verif_insn_processed = env->insn_processed; if (log->level && bpf_verifier_log_full(log)) ret = -ENOSPC; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 6fc59d61937a..89be6ecf9204 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5613,6 +5613,7 @@ struct bpf_prog_info { __u64 run_time_ns; __u64 run_cnt; __u64 recursion_misses; + __u64 verif_insn_processed; } __attribute__((aligned(8))); struct bpf_map_info {
This stat is currently printed in the verifier log and not stored anywhere. To ease consumption of this data, add a field to bpf_prog_aux so it can be exposed via BPF_OBJ_GET_INFO_BY_FD and fdinfo. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 1 + kernel/bpf/syscall.c | 8 ++++++-- kernel/bpf/verifier.c | 1 + tools/include/uapi/linux/bpf.h | 1 + 5 files changed, 10 insertions(+), 2 deletions(-)