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author | Alexei Starovoitov <ast@kernel.org> | 2021-05-14 03:36:19 +0300 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-05-19 01:41:31 +0300 |
commit | d510296d331accd4afaa13498220c93ae690628a (patch) | |
tree | 246ce79b5dd2a617efbe59a3890440c7be57074e /tools/bpf/bpftool/main.c | |
parent | 7723256bf2443d6bd7db3e583953d14107955233 (diff) | |
download | linux-d510296d331accd4afaa13498220c93ae690628a.tar.xz |
bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.
Add -L flag to bpftool to use libbpf gen_trace facility and syscall/loader program
for skeleton generation and program loading.
"bpftool gen skeleton -L" command will generate a "light skeleton" or "loader skeleton"
that is similar to existing skeleton, but has one major difference:
$ bpftool gen skeleton lsm.o > lsm.skel.h
$ bpftool gen skeleton -L lsm.o > lsm.lskel.h
$ diff lsm.skel.h lsm.lskel.h
@@ -5,34 +4,34 @@
#define __LSM_SKEL_H__
#include <stdlib.h>
-#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
The light skeleton does not use majority of libbpf infrastructure.
It doesn't need libelf. It doesn't parse .o file.
It only needs few sys_bpf wrappers. All of them are in bpf/bpf.h file.
In future libbpf/bpf.c can be inlined into bpf.h, so not even libbpf.a would be
needed to work with light skeleton.
"bpftool prog load -L file.o" command is introduced for debugging of syscall/loader
program generation. Just like the same command without -L it will try to load
the programs from file.o into the kernel. It won't even try to pin them.
"bpftool prog load -L -d file.o" command will provide additional debug messages
on how syscall/loader program was generated.
Also the execution of syscall/loader program will use bpf_trace_printk() for
each step of loading BTF, creating maps, and loading programs.
The user can do "cat /.../trace_pipe" for further debug.
An example of fexit_sleep.lskel.h generated from progs/fexit_sleep.c:
struct fexit_sleep {
struct bpf_loader_ctx ctx;
struct {
struct bpf_map_desc bss;
} maps;
struct {
struct bpf_prog_desc nanosleep_fentry;
struct bpf_prog_desc nanosleep_fexit;
} progs;
struct {
int nanosleep_fentry_fd;
int nanosleep_fexit_fd;
} links;
struct fexit_sleep__bss {
int pid;
int fentry_cnt;
int fexit_cnt;
} *bss;
};
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-18-alexei.starovoitov@gmail.com
Diffstat (limited to 'tools/bpf/bpftool/main.c')
-rw-r--r-- | tools/bpf/bpftool/main.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index d9afb730136a..7f2817d97079 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -29,6 +29,7 @@ bool show_pinned; bool block_mount; bool verifier_logs; bool relaxed_maps; +bool use_loader; struct btf *base_btf; struct pinned_obj_table prog_table; struct pinned_obj_table map_table; @@ -392,6 +393,7 @@ int main(int argc, char **argv) { "mapcompat", no_argument, NULL, 'm' }, { "nomount", no_argument, NULL, 'n' }, { "debug", no_argument, NULL, 'd' }, + { "use-loader", no_argument, NULL, 'L' }, { "base-btf", required_argument, NULL, 'B' }, { 0 } }; @@ -409,7 +411,7 @@ int main(int argc, char **argv) hash_init(link_table.table); opterr = 0; - while ((opt = getopt_long(argc, argv, "VhpjfmndB:", + while ((opt = getopt_long(argc, argv, "VhpjfLmndB:", options, NULL)) >= 0) { switch (opt) { case 'V': @@ -452,6 +454,9 @@ int main(int argc, char **argv) return -1; } break; + case 'L': + use_loader = true; + break; default: p_err("unrecognized option '%s'", argv[optind - 1]); if (json_output) |