| Message ID | 20191016032505.2089704-5-ast@kernel.org |
|---|---|
| State | Accepted |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | bpf: revolutionize bpf tracing | expand |
On Wed, Oct 16, 2019 at 4:15 AM Alexei Starovoitov <ast@kernel.org> wrote: > > Add attach_btf_id attribute to prog_load command. > It's similar to existing expected_attach_type attribute which is > used in several cgroup based program types. > Unfortunately expected_attach_type is ignored for > tracing programs and cannot be reused for new purpose. > Hence introduce attach_btf_id to verify bpf programs against > given in-kernel BTF type id at load time. > It is strictly checked to be valid for raw_tp programs only. > In a later patches it will become: > btf_id == 0 semantics of existing raw_tp progs. > btd_id > 0 raw_tp with BTF and additional type safety. > > Signed-off-by: Alexei Starovoitov <ast@kernel.org> > Acked-by: Andrii Nakryiko <andriin@fb.com> > --- > include/linux/bpf.h | 1 + > include/uapi/linux/bpf.h | 1 + > kernel/bpf/syscall.c | 18 ++++++++++++++---- > tools/include/uapi/linux/bpf.h | 1 + > 4 files changed, 17 insertions(+), 4 deletions(-) > > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index 282e28bf41ec..f916380675dd 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -375,6 +375,7 @@ struct bpf_prog_aux { > u32 id; > u32 func_cnt; /* used by non-func prog as the number of func progs */ > u32 func_idx; /* 0 for non-func prog, the index in func array for func prog */ > + u32 attach_btf_id; /* in-kernel BTF type id to attach to */ > bool verifier_zext; /* Zero extensions has been inserted by verifier. */ > bool offload_requested; > struct bpf_prog **func; > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index a65c3b0c6935..3bb2cd1de341 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -420,6 +420,7 @@ union bpf_attr { > __u32 line_info_rec_size; /* userspace bpf_line_info size */ > __aligned_u64 line_info; /* line info */ > __u32 line_info_cnt; /* number of bpf_line_info records */ > + __u32 attach_btf_id; /* in-kernel BTF type id to attach to */ > }; > > struct { /* anonymous struct used by BPF_OBJ_* commands */ > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > index 82eabd4e38ad..b56c482c9760 100644 > --- a/kernel/bpf/syscall.c > +++ b/kernel/bpf/syscall.c > @@ -23,6 +23,7 @@ > #include <linux/timekeeping.h> > #include <linux/ctype.h> > #include <linux/nospec.h> > +#include <uapi/linux/btf.h> > > #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \ > (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ > @@ -1565,8 +1566,9 @@ static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) > } > > static int > -bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, > - enum bpf_attach_type expected_attach_type) > +bpf_prog_load_check_attach(enum bpf_prog_type prog_type, > + enum bpf_attach_type expected_attach_type, > + u32 btf_id) > { > switch (prog_type) { > case BPF_PROG_TYPE_CGROUP_SOCK: > @@ -1608,13 +1610,19 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, > default: > return -EINVAL; > } > + case BPF_PROG_TYPE_RAW_TRACEPOINT: > + if (btf_id > BTF_MAX_TYPE) > + return -EINVAL; > + return 0; > default: > + if (btf_id) > + return -EINVAL; this is minor issue, feel free to fix in a follow up patch, but this check should be done for all cases but BPF_PROG_TYPE_RAW_TRACEPOINT, not just for default (default will ignore a bunch of cgroup attach types). > return 0; > } > } >
On 10/16/19 12:45 PM, Andrii Nakryiko wrote: > On Wed, Oct 16, 2019 at 4:15 AM Alexei Starovoitov <ast@kernel.org> wrote: >> >> Add attach_btf_id attribute to prog_load command. >> It's similar to existing expected_attach_type attribute which is >> used in several cgroup based program types. >> Unfortunately expected_attach_type is ignored for >> tracing programs and cannot be reused for new purpose. >> Hence introduce attach_btf_id to verify bpf programs against >> given in-kernel BTF type id at load time. >> It is strictly checked to be valid for raw_tp programs only. >> In a later patches it will become: >> btf_id == 0 semantics of existing raw_tp progs. >> btd_id > 0 raw_tp with BTF and additional type safety. >> >> Signed-off-by: Alexei Starovoitov <ast@kernel.org> >> Acked-by: Andrii Nakryiko <andriin@fb.com> >> --- >> include/linux/bpf.h | 1 + >> include/uapi/linux/bpf.h | 1 + >> kernel/bpf/syscall.c | 18 ++++++++++++++---- >> tools/include/uapi/linux/bpf.h | 1 + >> 4 files changed, 17 insertions(+), 4 deletions(-) >> >> diff --git a/include/linux/bpf.h b/include/linux/bpf.h >> index 282e28bf41ec..f916380675dd 100644 >> --- a/include/linux/bpf.h >> +++ b/include/linux/bpf.h >> @@ -375,6 +375,7 @@ struct bpf_prog_aux { >> u32 id; >> u32 func_cnt; /* used by non-func prog as the number of func progs */ >> u32 func_idx; /* 0 for non-func prog, the index in func array for func prog */ >> + u32 attach_btf_id; /* in-kernel BTF type id to attach to */ >> bool verifier_zext; /* Zero extensions has been inserted by verifier. */ >> bool offload_requested; >> struct bpf_prog **func; >> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h >> index a65c3b0c6935..3bb2cd1de341 100644 >> --- a/include/uapi/linux/bpf.h >> +++ b/include/uapi/linux/bpf.h >> @@ -420,6 +420,7 @@ union bpf_attr { >> __u32 line_info_rec_size; /* userspace bpf_line_info size */ >> __aligned_u64 line_info; /* line info */ >> __u32 line_info_cnt; /* number of bpf_line_info records */ >> + __u32 attach_btf_id; /* in-kernel BTF type id to attach to */ >> }; >> >> struct { /* anonymous struct used by BPF_OBJ_* commands */ >> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c >> index 82eabd4e38ad..b56c482c9760 100644 >> --- a/kernel/bpf/syscall.c >> +++ b/kernel/bpf/syscall.c >> @@ -23,6 +23,7 @@ >> #include <linux/timekeeping.h> >> #include <linux/ctype.h> >> #include <linux/nospec.h> >> +#include <uapi/linux/btf.h> >> >> #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \ >> (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ >> @@ -1565,8 +1566,9 @@ static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) >> } >> >> static int >> -bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, >> - enum bpf_attach_type expected_attach_type) >> +bpf_prog_load_check_attach(enum bpf_prog_type prog_type, >> + enum bpf_attach_type expected_attach_type, >> + u32 btf_id) >> { >> switch (prog_type) { >> case BPF_PROG_TYPE_CGROUP_SOCK: >> @@ -1608,13 +1610,19 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, >> default: >> return -EINVAL; >> } >> + case BPF_PROG_TYPE_RAW_TRACEPOINT: >> + if (btf_id > BTF_MAX_TYPE) >> + return -EINVAL; >> + return 0; >> default: >> + if (btf_id) >> + return -EINVAL; > > this is minor issue, feel free to fix in a follow up patch, but this > check should be done for all cases but BPF_PROG_TYPE_RAW_TRACEPOINT, > not just for default (default will ignore a bunch of cgroup attach > types). right. good point. will fix in follow up if there are no issues in the rest of patches.
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 282e28bf41ec..f916380675dd 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -375,6 +375,7 @@ struct bpf_prog_aux { u32 id; u32 func_cnt; /* used by non-func prog as the number of func progs */ u32 func_idx; /* 0 for non-func prog, the index in func array for func prog */ + u32 attach_btf_id; /* in-kernel BTF type id to attach to */ bool verifier_zext; /* Zero extensions has been inserted by verifier. */ bool offload_requested; struct bpf_prog **func; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index a65c3b0c6935..3bb2cd1de341 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -420,6 +420,7 @@ union bpf_attr { __u32 line_info_rec_size; /* userspace bpf_line_info size */ __aligned_u64 line_info; /* line info */ __u32 line_info_cnt; /* number of bpf_line_info records */ + __u32 attach_btf_id; /* in-kernel BTF type id to attach to */ }; struct { /* anonymous struct used by BPF_OBJ_* commands */ diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 82eabd4e38ad..b56c482c9760 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -23,6 +23,7 @@ #include <linux/timekeeping.h> #include <linux/ctype.h> #include <linux/nospec.h> +#include <uapi/linux/btf.h> #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ @@ -1565,8 +1566,9 @@ static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) } static int -bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, - enum bpf_attach_type expected_attach_type) +bpf_prog_load_check_attach(enum bpf_prog_type prog_type, + enum bpf_attach_type expected_attach_type, + u32 btf_id) { switch (prog_type) { case BPF_PROG_TYPE_CGROUP_SOCK: @@ -1608,13 +1610,19 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, default: return -EINVAL; } + case BPF_PROG_TYPE_RAW_TRACEPOINT: + if (btf_id > BTF_MAX_TYPE) + return -EINVAL; + return 0; default: + if (btf_id) + return -EINVAL; return 0; } } /* last field in 'union bpf_attr' used by this command */ -#define BPF_PROG_LOAD_LAST_FIELD line_info_cnt +#define BPF_PROG_LOAD_LAST_FIELD attach_btf_id static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) { @@ -1656,7 +1664,8 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) return -EPERM; bpf_prog_load_fixup_attach_type(attr); - if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type)) + if (bpf_prog_load_check_attach(type, attr->expected_attach_type, + attr->attach_btf_id)) return -EINVAL; /* plain bpf_prog allocation */ @@ -1665,6 +1674,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) return -ENOMEM; prog->expected_attach_type = attr->expected_attach_type; + prog->aux->attach_btf_id = attr->attach_btf_id; prog->aux->offload_requested = !!attr->prog_ifindex; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index a65c3b0c6935..3bb2cd1de341 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -420,6 +420,7 @@ union bpf_attr { __u32 line_info_rec_size; /* userspace bpf_line_info size */ __aligned_u64 line_info; /* line info */ __u32 line_info_cnt; /* number of bpf_line_info records */ + __u32 attach_btf_id; /* in-kernel BTF type id to attach to */ }; struct { /* anonymous struct used by BPF_OBJ_* commands */