| Message ID | b239588581c1a1367b3ae901a9e3058bbb7a9eb7.1647382072.git.delyank@fb.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | Subskeleton support for BPF libraries | expand |
On Tue, Mar 15, 2022 at 3:15 PM Delyan Kratunov <delyank@fb.com> wrote: > > Currently, libbpf considers a single routine in .text to be a program. This > is particularly confusing when it comes to library objects - a single routine > meant to be used as an extern will instead be considered a bpf_program. > > This patch hides this compatibility behavior behind the pre-existing > SEC_NAME strict mode flag. > > Signed-off-by: Delyan Kratunov <delyank@fb.com> > --- > tools/lib/bpf/libbpf.c | 7 +++++++ > tools/lib/bpf/libbpf_legacy.h | 4 +++- > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index 43161fdd44bb..aa26163e4ca1 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -3832,7 +3832,14 @@ static bool prog_is_subprog(const struct bpf_object *obj, > * .text programs are subprograms (even if they are not called from > * other programs), because libbpf never explicitly supported mixing > * SEC()-designated BPF programs and .text entry-point BPF programs. > + * > + * In libbpf 1.0 strict mode, we always consider .text > + * programs to be subprograms. > */ > + > + if (libbpf_mode & LIBBPF_STRICT_SEC_NAME) > + return prog->sec_idx == obj->efile.text_shndx; > + > return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1; > } > > diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h > index a283cf031665..8d2e632aec79 100644 > --- a/tools/lib/bpf/libbpf_legacy.h > +++ b/tools/lib/bpf/libbpf_legacy.h > @@ -53,7 +53,9 @@ enum libbpf_strict_mode { > * SEC("xdp") and SEC("perf_event"). > * > * Note, in this mode the program pin path will be based on the > - * function name instead of section name. > + * function name instead of section name. Additionally, routines in the > + * .text section are always considered sub-programs. (Legacy behavior > + * allows for a single routine in .text to be a program.) nit: pinning doesn't have much in common with this, so please put the new text on a separate paragraph > */ > LIBBPF_STRICT_SEC_NAME = 0x04, > /* > -- > 2.34.1
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 43161fdd44bb..aa26163e4ca1 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3832,7 +3832,14 @@ static bool prog_is_subprog(const struct bpf_object *obj, * .text programs are subprograms (even if they are not called from * other programs), because libbpf never explicitly supported mixing * SEC()-designated BPF programs and .text entry-point BPF programs. + * + * In libbpf 1.0 strict mode, we always consider .text + * programs to be subprograms. */ + + if (libbpf_mode & LIBBPF_STRICT_SEC_NAME) + return prog->sec_idx == obj->efile.text_shndx; + return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1; } diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h index a283cf031665..8d2e632aec79 100644 --- a/tools/lib/bpf/libbpf_legacy.h +++ b/tools/lib/bpf/libbpf_legacy.h @@ -53,7 +53,9 @@ enum libbpf_strict_mode { * SEC("xdp") and SEC("perf_event"). * * Note, in this mode the program pin path will be based on the - * function name instead of section name. + * function name instead of section name. Additionally, routines in the + * .text section are always considered sub-programs. (Legacy behavior + * allows for a single routine in .text to be a program.) */ LIBBPF_STRICT_SEC_NAME = 0x04, /*
Currently, libbpf considers a single routine in .text to be a program. This is particularly confusing when it comes to library objects - a single routine meant to be used as an extern will instead be considered a bpf_program. This patch hides this compatibility behavior behind the pre-existing SEC_NAME strict mode flag. Signed-off-by: Delyan Kratunov <delyank@fb.com> --- tools/lib/bpf/libbpf.c | 7 +++++++ tools/lib/bpf/libbpf_legacy.h | 4 +++- 2 files changed, 10 insertions(+), 1 deletion(-)