Commit 1be84ca5 authored by Ian Rogers's avatar Ian Rogers Committed by Andrii Nakryiko
Browse files

bpftool: Align bpf_load_and_run_opts insns and data 



A C string lacks alignment so use aligned arrays to avoid potential
alignment problems. Switch to using sizeof (less 1 for the \0
terminator) rather than a hardcode size constant.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarQuentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20231007044439.25171-2-irogers@google.com
parent 23671f4d

tools/bpf/bpftool/gen.c

+23 −20
Original line number Diff line number Diff line
@@ -708,17 +708,22 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h 


		codegen("\

		\n\

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

		", ident);

			{						    \n\

				static const char data[] __attribute__((__aligned__(8))) = \"\\\n\

		");

		mmap_data = bpf_map__initial_value(map, &mmap_size);

		print_hex(mmap_data, mmap_size);

		codegen("\

		\n\

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

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

		\";							    \n\

									    \n\

				skel->%1$s = skel_prep_map_data((void *)data, %2$zd,\n\

								sizeof(data) - 1);\n\

				if (!skel->%1$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);

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

			}						    \n\

			", ident, bpf_map_mmap_sz(map));

	}

	codegen("\

		\n\
@@ -733,32 +738,30 @@ static int gen_trace(struct bpf_object *obj, const char *obj_name, const char *h 
		{							    \n\

			struct bpf_load_and_run_opts opts = {};		    \n\

			int err;					    \n\

									    \n\

			opts.ctx = (struct bpf_loader_ctx *)skel;	    \n\

			opts.data_sz = %2$d;				    \n\

			opts.data = (void *)\"\\			    \n\

			static const char opts_data[] __attribute__((__aligned__(8))) = \"\\\n\

		",

		obj_name, opts.data_sz);

		obj_name);

	print_hex(opts.data, opts.data_sz);

	codegen("\

		\n\

		\";							    \n\

			static const char opts_insn[] __attribute__((__aligned__(8))) = \"\\\n\

		");



	codegen("\

		\n\

			opts.insns_sz = %d;				    \n\

			opts.insns = (void *)\"\\			    \n\

		",

		opts.insns_sz);

	print_hex(opts.insns, opts.insns_sz);

	codegen("\

		\n\

		\";							    \n\

									    \n\

			opts.ctx = (struct bpf_loader_ctx *)skel;	    \n\

			opts.data_sz = sizeof(opts_data) - 1;		    \n\

			opts.data = (void *)opts_data;			    \n\

			opts.insns_sz = sizeof(opts_insn) - 1;		    \n\

			opts.insns = (void *)opts_insn;			    \n\

									    \n\

			err = bpf_load_and_run(&opts);			    \n\

			if (err < 0)					    \n\

				return err;				    \n\

		", obj_name);

		");

	bpf_object__for_each_map(map, obj) {

		const char *mmap_flags;