Commit 28d743f6 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

bpftool: Generalize light skeleton generation. 



Generealize light skeleton by hiding mmap details in skel_internal.h
In this form generated lskel.h is usable both by user space and by the kernel.

Note that previously #include <bpf/bpf.h> was in *.lskel.h file.
To avoid #ifdef-s in a generated lskel.h the include of bpf.h is moved
to skel_internal.h, but skel_internal.h is also used by gen_loader.c
which is part of libbpf. Therefore skel_internal.h does #include "bpf.h"
in case of user space, so gen_loader.c and lskel.h have necessary definitions.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209232001.27490-4-alexei.starovoitov@gmail.com
parent 6fe65f1b

tools/bpf/bpftool/gen.c

+20 −19
Original line number Diff line number Diff line
@@ -472,7 +472,7 @@ static void codegen_destroy(struct bpf_object *obj, const char *obj_name) 
			continue;

		if (bpf_map__is_internal(map) &&

		    (bpf_map__map_flags(map) & BPF_F_MMAPABLE))

			printf("\tmunmap(skel->%1$s, %2$zd);\n",

			printf("\tskel_free_map_data(skel->%1$s, skel->maps.%1$s.initial_value, %2$zd);\n",

			       ident, bpf_map_mmap_sz(map));

		codegen("\

			\n\
@@ -481,7 +481,7 @@ static void codegen_destroy(struct bpf_object *obj, const char *obj_name) 
	}

	codegen("\

		\n\

			free(skel);					    \n\

			skel_free(skel);				    \n\

		}							    \n\

		",

		obj_name);
@@ -525,7 +525,7 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h 
		{							    \n\

			struct %1$s *skel;				    \n\

									    \n\

			skel = calloc(sizeof(*skel), 1);		    \n\

			skel = skel_alloc(sizeof(*skel));		    \n\

			if (!skel)					    \n\

				goto cleanup;				    \n\

			skel->ctx.sz = (void *)&skel->links - (void *)skel; \n\
@@ -544,18 +544,17 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h 


		codegen("\

		\n\

				skel->%1$s =					 \n\

					mmap(NULL, %2$zd, PROT_READ | PROT_WRITE,\n\

					     MAP_SHARED | MAP_ANONYMOUS, -1, 0); \n\

				if (skel->%1$s == (void *) -1)			 \n\

					goto cleanup;				 \n\

				memcpy(skel->%1$s, (void *)\"\\			 \n\

			", ident, bpf_map_mmap_sz(map));

			skel->%1$s = skel_prep_map_data((void *)\"\\	    \n\

		", ident);

		mmap_data = bpf_map__initial_value(map, &mmap_size);

		print_hex(mmap_data, mmap_size);

		printf("\", %2$zd);\n"

		       "\tskel->maps.%1$s.initial_value = (__u64)(long)skel->%1$s;\n",

		       ident, mmap_size);

		codegen("\

		\n\

		\", %1$zd, %2$zd);					    \n\

			if (!skel->%3$s)				    \n\

				goto cleanup;				    \n\

			skel->maps.%3$s.initial_value = (__u64) (long) skel->%3$s;\n\

		", bpf_map_mmap_sz(map), mmap_size, ident);

	}

	codegen("\

		\n\
@@ -611,9 +610,13 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h 
		else

			mmap_flags = "PROT_READ | PROT_WRITE";



		printf("\tskel->%1$s =\n"

		       "\t\tmmap(skel->%1$s, %2$zd, %3$s, MAP_SHARED | MAP_FIXED,\n"

		       "\t\t\tskel->maps.%1$s.map_fd, 0);\n",

		codegen("\

		\n\

			skel->%1$s = skel_finalize_map_data(&skel->maps.%1$s.initial_value,  \n\

							%2$zd, %3$s, skel->maps.%1$s.map_fd);\n\

			if (!skel->%1$s)				    \n\

				return -ENOMEM;				    \n\

			",

		       ident, bpf_map_mmap_sz(map), mmap_flags);

	}

	codegen("\
@@ -751,8 +754,6 @@ static int do_skeleton(int argc, char **argv) 
		#ifndef %2$s						    \n\

		#define %2$s						    \n\

									    \n\

		#include <stdlib.h>					    \n\

		#include <bpf/bpf.h>					    \n\

		#include <bpf/skel_internal.h>				    \n\

									    \n\

		struct %1$s {						    \n\