From 9e794163a69c103633fefb10a3879408d4e4e2c8 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 12 Dec 2018 10:18:21 -0800 Subject: [PATCH 1/2] bpf: Remove bpf_dump_raw_ok() check for func_info and line_info The func_info and line_info have the bpf insn offset but they do not contain kernel address. They will still be useful for the userspace tool to annotate the xlated insn. This patch removes the bpf_dump_raw_ok() guard for the func_info and line_info during bpf_prog_get_info_by_fd(). The guard stays for jited_line_info which contains the kernel address. Although this bpf_dump_raw_ok() guard behavior has started since the earlier func_info patch series, I marked the Fixes tag to the latest line_info patch series which contains both func_info and line_info and this patch is fixing for both of them. Fixes: c454a46b5efd ("bpf: Add bpf_line_info support") Signed-off-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann --- kernel/bpf/syscall.c | 32 ++++++++++++-------------------- 1 file changed, 12 insertions(+), 20 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 70fb11106fc2..b7c585838c72 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2272,33 +2272,25 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, ulen = info.nr_func_info; info.nr_func_info = prog->aux->func_info_cnt; if (info.nr_func_info && ulen) { - if (bpf_dump_raw_ok()) { - char __user *user_finfo; + char __user *user_finfo; - user_finfo = u64_to_user_ptr(info.func_info); - ulen = min_t(u32, info.nr_func_info, ulen); - if (copy_to_user(user_finfo, prog->aux->func_info, - info.func_info_rec_size * ulen)) - return -EFAULT; - } else { - info.func_info = 0; - } + user_finfo = u64_to_user_ptr(info.func_info); + ulen = min_t(u32, info.nr_func_info, ulen); + if (copy_to_user(user_finfo, prog->aux->func_info, + info.func_info_rec_size * ulen)) + return -EFAULT; } ulen = info.nr_line_info; info.nr_line_info = prog->aux->nr_linfo; if (info.nr_line_info && ulen) { - if (bpf_dump_raw_ok()) { - __u8 __user *user_linfo; + __u8 __user *user_linfo; - user_linfo = u64_to_user_ptr(info.line_info); - ulen = min_t(u32, info.nr_line_info, ulen); - if (copy_to_user(user_linfo, prog->aux->linfo, - info.line_info_rec_size * ulen)) - return -EFAULT; - } else { - info.line_info = 0; - } + user_linfo = u64_to_user_ptr(info.line_info); + ulen = min_t(u32, info.nr_line_info, ulen); + if (copy_to_user(user_linfo, prog->aux->linfo, + info.line_info_rec_size * ulen)) + return -EFAULT; } ulen = info.nr_jited_line_info; From 177e77169b0b71587c74382d5f2207a16da34790 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 12 Dec 2018 10:18:22 -0800 Subject: [PATCH 2/2] bpf: Remove !func_info and !line_info check from test_btf and bpftool kernel can provide the func_info and line_info even it fails the btf_dump_raw_ok() test because they don't contain kernel address. This patch removes the corresponding '== 0' test. Signed-off-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/prog.c | 7 ------- tools/lib/bpf/bpf_prog_linfo.c | 6 +----- tools/testing/selftests/bpf/test_btf.c | 7 ------- 3 files changed, 1 insertion(+), 19 deletions(-) diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index eddf7fba41c6..ee51279be9c7 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -596,13 +596,6 @@ static int do_dump(int argc, char **argv) goto err_free; } - if (func_info && !info.func_info) { - /* kernel.kptr_restrict is set. No func_info available. */ - free(func_info); - func_info = NULL; - nr_finfo = 0; - } - if (linfo && info.nr_line_info != nr_linfo) { p_err("incorrect nr_line_info %u vs. expected %u", info.nr_line_info, nr_linfo); diff --git a/tools/lib/bpf/bpf_prog_linfo.c b/tools/lib/bpf/bpf_prog_linfo.c index addd6e9971cc..6978314ea7f6 100644 --- a/tools/lib/bpf/bpf_prog_linfo.c +++ b/tools/lib/bpf/bpf_prog_linfo.c @@ -107,11 +107,7 @@ struct bpf_prog_linfo *bpf_prog_linfo__new(const struct bpf_prog_info *info) nr_linfo = info->nr_line_info; - /* - * Test !info->line_info because the kernel may NULL - * the ptr if kernel.kptr_restrict is set. - */ - if (!nr_linfo || !info->line_info) + if (!nr_linfo) return NULL; /* diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index f570e0a39959..8478316aaf9a 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -3948,12 +3948,6 @@ static int test_get_finfo(const struct prog_info_raw_test *test, goto done; } - if (CHECK(!info.func_info, - "info.func_info == 0. kernel.kptr_restrict is set?")) { - err = -1; - goto done; - } - finfo = func_info; for (i = 0; i < test->func_info_cnt; i++) { if (CHECK(finfo->type_id != test->func_info[i][1], @@ -4077,7 +4071,6 @@ static int test_get_linfo(const struct prog_info_raw_test *test, * Other fields are not the concern of this test. */ if (CHECK(err == -1 || - !info.line_info || info.nr_line_info != cnt || (jited_cnt && !info.jited_line_info) || info.nr_jited_line_info != jited_cnt ||