Commit b4b638c3 authored by Yonghong Song's avatar Yonghong Song Committed by Daniel Borkmann
Browse files

selftests/bpf: Add a test for ptr_to_map_value on stack for helper access 



Change bpf_iter_task.c such that pointer to map_value may appear
on the stack for bpf_seq_printf() to access. Without previous
verifier patch, the bpf_iter test will fail.

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201210013350.943985-1-yhs@fb.com
parent cd17d38f

tools/testing/selftests/bpf/progs/bpf_iter_task.c

+2 −1
Original line number Diff line number Diff line
@@ -11,9 +11,10 @@ int dump_task(struct bpf_iter__task *ctx) 
{

	struct seq_file *seq = ctx->meta->seq;

	struct task_struct *task = ctx->task;

	static char info[] = "    === END ===";



	if (task == (void *)0) {

		BPF_SEQ_PRINTF(seq, "    === END ===\n");

		BPF_SEQ_PRINTF(seq, "%s\n", info);

		return 0;

	}

tools/testing/selftests/bpf/verifier/unpriv.c

+3 −2
Original line number Diff line number Diff line
@@ -108,8 +108,9 @@ 
	BPF_EXIT_INSN(),

	},

	.fixup_map_hash_8b = { 3 },

	.errstr = "invalid indirect read from stack off -8+0 size 8",

	.result = REJECT,

	.errstr_unpriv = "invalid indirect read from stack off -8+0 size 8",

	.result_unpriv = REJECT,

	.result = ACCEPT,

},

{

	"unpriv: mangle pointer on stack 1",

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