On Thu, Oct 24, 2019 at 03:23:41PM +0200, Jiri Olsa wrote: > The bpftool interface stays the same, but now it's possible > to run it over BTF raw data, like: > > $ bpftool btf dump file /sys/kernel/btf/vmlinux > [1] INT '(anon)' size=4 bits_offset=0 nr_bits=32 encoding=(none) > [2] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none) > [3] CONST '(anon)' type_id=2 > > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx> > --- ugh, wrong title.. I sent v3 :-\ sry jirka > v2 changes: > - added is_btf_raw to find out which btf__parse_* function to call > - changed labels and error propagation in btf__parse_raw > - drop the err initialization, which is not needed under this change > > tools/bpf/bpftool/btf.c | 57 ++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 56 insertions(+), 1 deletion(-) > > diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c > index 9a9376d1d3df..a7b8bf233cf5 100644 > --- a/tools/bpf/bpftool/btf.c > +++ b/tools/bpf/bpftool/btf.c > @@ -12,6 +12,9 @@ > #include <libbpf.h> > #include <linux/btf.h> > #include <linux/hashtable.h> > +#include <sys/types.h> > +#include <sys/stat.h> > +#include <unistd.h> > > #include "btf.h" > #include "json_writer.h" > @@ -388,6 +391,54 @@ static int dump_btf_c(const struct btf *btf, > return err; > } > > +static struct btf *btf__parse_raw(const char *file) > +{ > + struct btf *btf; > + struct stat st; > + __u8 *buf; > + FILE *f; > + > + if (stat(file, &st)) > + return NULL; > + > + f = fopen(file, "rb"); > + if (!f) > + return NULL; > + > + buf = malloc(st.st_size); > + if (!buf) { > + btf = ERR_PTR(-ENOMEM); > + goto exit_close; > + } > + > + if ((size_t) st.st_size != fread(buf, 1, st.st_size, f)) { > + btf = ERR_PTR(-EINVAL); > + goto exit_free; > + } > + > + btf = btf__new(buf, st.st_size); > + > +exit_free: > + free(buf); > +exit_close: > + fclose(f); > + return btf; > +} > + > +static bool is_btf_raw(const char *file) > +{ > + __u16 magic = 0; > + int fd; > + > + fd = open(file, O_RDONLY); > + if (fd < 0) > + return false; > + > + read(fd, &magic, sizeof(magic)); > + close(fd); > + return magic == BTF_MAGIC; > +} > + > static int do_dump(int argc, char **argv) > { > struct btf *btf = NULL; > @@ -465,7 +516,11 @@ static int do_dump(int argc, char **argv) > } > NEXT_ARG(); > } else if (is_prefix(src, "file")) { > - btf = btf__parse_elf(*argv, NULL); > + if (is_btf_raw(*argv)) > + btf = btf__parse_raw(*argv); > + else > + btf = btf__parse_elf(*argv, NULL); > + > if (IS_ERR(btf)) { > err = PTR_ERR(btf); > btf = NULL; > -- > 2.21.0 >