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| author | Daniel Borkmann <daniel@iogearbox.net> | 2018-11-02 21:39:02 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-11-02 21:39:03 +0100 |
| commit | b0970f235f1ff68a49fd36fdbd8a80dd92bb7b04 (patch) | |
| tree | 83330b3be066e445313c856462efc8e11cdb71b8 /kernel/bpf/syscall.c | |
| parent | 7de414a9dd91426318df7b63da024b2b07e53df5 (diff) | |
| parent | ff1889fc531f582f902175c0acc80321af540b24 (diff) | |
Merge branch 'bpf-accurate-prog-addr'
Song Liu says:
====================
Changes v1 -> v2:
1. Added main program length to bpf_prog_info->jited_fun_lens (3/3).
2. Updated commit message of 1/3 and 2/3 with more background about the
address masking, and why it is still save after the changes.
3. Replace "ulong" with "unsigned long".
This set improves bpf program address showed in /proc/kallsyms and in
bpf_prog_info. First, real program address is showed instead of page
address. Second, when there is no subprogram, bpf_prog_info->jited_ksyms
and bpf_prog_info->jited_fun_lens returns the main prog address and
length.
====================
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index ccb93277aae2..9418174c276c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2158,11 +2158,11 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, } ulen = info.nr_jited_ksyms; - info.nr_jited_ksyms = prog->aux->func_cnt; + info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; if (info.nr_jited_ksyms && ulen) { if (bpf_dump_raw_ok()) { + unsigned long ksym_addr; u64 __user *user_ksyms; - ulong ksym_addr; u32 i; /* copy the address of the kernel symbol @@ -2170,10 +2170,17 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, */ ulen = min_t(u32, info.nr_jited_ksyms, ulen); user_ksyms = u64_to_user_ptr(info.jited_ksyms); - for (i = 0; i < ulen; i++) { - ksym_addr = (ulong) prog->aux->func[i]->bpf_func; - ksym_addr &= PAGE_MASK; - if (put_user((u64) ksym_addr, &user_ksyms[i])) + if (prog->aux->func_cnt) { + for (i = 0; i < ulen; i++) { + ksym_addr = (unsigned long) + prog->aux->func[i]->bpf_func; + if (put_user((u64) ksym_addr, + &user_ksyms[i])) + return -EFAULT; + } + } else { + ksym_addr = (unsigned long) prog->bpf_func; + if (put_user((u64) ksym_addr, &user_ksyms[0])) return -EFAULT; } } else { @@ -2182,7 +2189,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, } ulen = info.nr_jited_func_lens; - info.nr_jited_func_lens = prog->aux->func_cnt; + info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; if (info.nr_jited_func_lens && ulen) { if (bpf_dump_raw_ok()) { u32 __user *user_lens; @@ -2191,9 +2198,16 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, /* copy the JITed image lengths for each function */ ulen = min_t(u32, info.nr_jited_func_lens, ulen); user_lens = u64_to_user_ptr(info.jited_func_lens); - for (i = 0; i < ulen; i++) { - func_len = prog->aux->func[i]->jited_len; - if (put_user(func_len, &user_lens[i])) + if (prog->aux->func_cnt) { + for (i = 0; i < ulen; i++) { + func_len = + prog->aux->func[i]->jited_len; + if (put_user(func_len, &user_lens[i])) + return -EFAULT; + } + } else { + func_len = prog->jited_len; + if (put_user(func_len, &user_lens[0])) return -EFAULT; } } else { |