| Message ID | 20210707214751.159713-5-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf, x86: Add bpf_get_func_ip helper | expand |
On Wed, 7 Jul 2021 23:47:48 +0200 Jiri Olsa <jolsa@redhat.com> wrote: > Adding bpf_get_func_ip helper for BPF_PROG_TYPE_KPROBE programs, > so it's now possible to call bpf_get_func_ip from both kprobe and > kretprobe programs. > > Taking the caller's address from 'struct kprobe::addr', which is > defined for both kprobe and kretprobe. > Note that the kp->addr of kretprobe will be the callee function address, even if the handler is called when the end of the callee. Anyway, this looks good to me. Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Thank you, > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > include/uapi/linux/bpf.h | 2 +- > kernel/bpf/verifier.c | 2 ++ > kernel/trace/bpf_trace.c | 17 +++++++++++++++++ > tools/include/uapi/linux/bpf.h | 2 +- > 4 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 83e87ffdbb6e..4894f99a1993 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -4783,7 +4783,7 @@ union bpf_attr { > * > * u64 bpf_get_func_ip(void *ctx) > * Description > - * Get address of the traced function (for tracing programs). > + * Get address of the traced function (for tracing and kprobe programs). > * Return > * Address of the traced function. > */ > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index f975a3aa9368..79eb9d81a198 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -5979,6 +5979,8 @@ static int has_get_func_ip(struct bpf_verifier_env *env) > return -ENOTSUPP; > } > return 0; > + } else if (type == BPF_PROG_TYPE_KPROBE) { > + return 0; > } > > verbose(env, "func %s#%d not supported for program type %d\n", > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index 9edd3b1a00ad..55acf56b0c3a 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -17,6 +17,7 @@ > #include <linux/error-injection.h> > #include <linux/btf_ids.h> > #include <linux/bpf_lsm.h> > +#include <linux/kprobes.h> > > #include <net/bpf_sk_storage.h> > > @@ -961,6 +962,20 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { > .arg1_type = ARG_PTR_TO_CTX, > }; > > +BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) > +{ > + struct kprobe *kp = kprobe_running(); > + > + return kp ? (u64) kp->addr : 0; > +} > + > +static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { > + .func = bpf_get_func_ip_kprobe, > + .gpl_only = true, > + .ret_type = RET_INTEGER, > + .arg1_type = ARG_PTR_TO_CTX, > +}; > + > const struct bpf_func_proto * > bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > { > @@ -1092,6 +1107,8 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > case BPF_FUNC_override_return: > return &bpf_override_return_proto; > #endif > + case BPF_FUNC_get_func_ip: > + return &bpf_get_func_ip_proto_kprobe; > default: > return bpf_tracing_func_proto(func_id, prog); > } > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h > index 83e87ffdbb6e..4894f99a1993 100644 > --- a/tools/include/uapi/linux/bpf.h > +++ b/tools/include/uapi/linux/bpf.h > @@ -4783,7 +4783,7 @@ union bpf_attr { > * > * u64 bpf_get_func_ip(void *ctx) > * Description > - * Get address of the traced function (for tracing programs). > + * Get address of the traced function (for tracing and kprobe programs). > * Return > * Address of the traced function. > */ > -- > 2.31.1 >
On Sat, Jul 10, 2021 at 04:55:12PM +0900, Masami Hiramatsu wrote: > On Wed, 7 Jul 2021 23:47:48 +0200 > Jiri Olsa <jolsa@redhat.com> wrote: > > > Adding bpf_get_func_ip helper for BPF_PROG_TYPE_KPROBE programs, > > so it's now possible to call bpf_get_func_ip from both kprobe and > > kretprobe programs. > > > > Taking the caller's address from 'struct kprobe::addr', which is > > defined for both kprobe and kretprobe. > > > > Note that the kp->addr of kretprobe will be the callee function > address, even if the handler is called when the end of the callee. yes, that's what we need > > Anyway, this looks good to me. > > Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> thanks, jirka > > Thank you, > > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > > --- > > include/uapi/linux/bpf.h | 2 +- > > kernel/bpf/verifier.c | 2 ++ > > kernel/trace/bpf_trace.c | 17 +++++++++++++++++ > > tools/include/uapi/linux/bpf.h | 2 +- > > 4 files changed, 21 insertions(+), 2 deletions(-) > > > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > > index 83e87ffdbb6e..4894f99a1993 100644 > > --- a/include/uapi/linux/bpf.h > > +++ b/include/uapi/linux/bpf.h > > @@ -4783,7 +4783,7 @@ union bpf_attr { > > * > > * u64 bpf_get_func_ip(void *ctx) > > * Description > > - * Get address of the traced function (for tracing programs). > > + * Get address of the traced function (for tracing and kprobe programs). > > * Return > > * Address of the traced function. > > */ > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > > index f975a3aa9368..79eb9d81a198 100644 > > --- a/kernel/bpf/verifier.c > > +++ b/kernel/bpf/verifier.c > > @@ -5979,6 +5979,8 @@ static int has_get_func_ip(struct bpf_verifier_env *env) > > return -ENOTSUPP; > > } > > return 0; > > + } else if (type == BPF_PROG_TYPE_KPROBE) { > > + return 0; > > } > > > > verbose(env, "func %s#%d not supported for program type %d\n", > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > > index 9edd3b1a00ad..55acf56b0c3a 100644 > > --- a/kernel/trace/bpf_trace.c > > +++ b/kernel/trace/bpf_trace.c > > @@ -17,6 +17,7 @@ > > #include <linux/error-injection.h> > > #include <linux/btf_ids.h> > > #include <linux/bpf_lsm.h> > > +#include <linux/kprobes.h> > > > > #include <net/bpf_sk_storage.h> > > > > @@ -961,6 +962,20 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { > > .arg1_type = ARG_PTR_TO_CTX, > > }; > > > > +BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) > > +{ > > + struct kprobe *kp = kprobe_running(); > > + > > + return kp ? (u64) kp->addr : 0; > > +} > > + > > +static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { > > + .func = bpf_get_func_ip_kprobe, > > + .gpl_only = true, > > + .ret_type = RET_INTEGER, > > + .arg1_type = ARG_PTR_TO_CTX, > > +}; > > + > > const struct bpf_func_proto * > > bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > > { > > @@ -1092,6 +1107,8 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > > case BPF_FUNC_override_return: > > return &bpf_override_return_proto; > > #endif > > + case BPF_FUNC_get_func_ip: > > + return &bpf_get_func_ip_proto_kprobe; > > default: > > return bpf_tracing_func_proto(func_id, prog); > > } > > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h > > index 83e87ffdbb6e..4894f99a1993 100644 > > --- a/tools/include/uapi/linux/bpf.h > > +++ b/tools/include/uapi/linux/bpf.h > > @@ -4783,7 +4783,7 @@ union bpf_attr { > > * > > * u64 bpf_get_func_ip(void *ctx) > > * Description > > - * Get address of the traced function (for tracing programs). > > + * Get address of the traced function (for tracing and kprobe programs). > > * Return > > * Address of the traced function. > > */ > > -- > > 2.31.1 > > > > > -- > Masami Hiramatsu <mhiramat@kernel.org> >
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 83e87ffdbb6e..4894f99a1993 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4783,7 +4783,7 @@ union bpf_attr { * * u64 bpf_get_func_ip(void *ctx) * Description - * Get address of the traced function (for tracing programs). + * Get address of the traced function (for tracing and kprobe programs). * Return * Address of the traced function. */ diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index f975a3aa9368..79eb9d81a198 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5979,6 +5979,8 @@ static int has_get_func_ip(struct bpf_verifier_env *env) return -ENOTSUPP; } return 0; + } else if (type == BPF_PROG_TYPE_KPROBE) { + return 0; } verbose(env, "func %s#%d not supported for program type %d\n", diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 9edd3b1a00ad..55acf56b0c3a 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -17,6 +17,7 @@ #include <linux/error-injection.h> #include <linux/btf_ids.h> #include <linux/bpf_lsm.h> +#include <linux/kprobes.h> #include <net/bpf_sk_storage.h> @@ -961,6 +962,20 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) +{ + struct kprobe *kp = kprobe_running(); + + return kp ? (u64) kp->addr : 0; +} + +static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { + .func = bpf_get_func_ip_kprobe, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -1092,6 +1107,8 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_override_return: return &bpf_override_return_proto; #endif + case BPF_FUNC_get_func_ip: + return &bpf_get_func_ip_proto_kprobe; default: return bpf_tracing_func_proto(func_id, prog); } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 83e87ffdbb6e..4894f99a1993 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4783,7 +4783,7 @@ union bpf_attr { * * u64 bpf_get_func_ip(void *ctx) * Description - * Get address of the traced function (for tracing programs). + * Get address of the traced function (for tracing and kprobe programs). * Return * Address of the traced function. */
Adding bpf_get_func_ip helper for BPF_PROG_TYPE_KPROBE programs, so it's now possible to call bpf_get_func_ip from both kprobe and kretprobe programs. Taking the caller's address from 'struct kprobe::addr', which is defined for both kprobe and kretprobe. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- include/uapi/linux/bpf.h | 2 +- kernel/bpf/verifier.c | 2 ++ kernel/trace/bpf_trace.c | 17 +++++++++++++++++ tools/include/uapi/linux/bpf.h | 2 +- 4 files changed, 21 insertions(+), 2 deletions(-)