On Mon, Dec 28, 2020 at 11:47:44AM -0800, Andrii Nakryiko wrote:
On Mon, Dec 28, 2020 at 7:49 AM Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> wrote:Perf build failed on stable-rc 5.4 branch due to this patch. On Mon, 28 Dec 2020 at 19:15, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > From: Andrii Nakryiko <andrii@xxxxxxxxxx> > > [ Upstream commit d8123624506cd62730c9cd9c7672c698e462703d ] > > Make data section layout checks stricter, disallowing overlap of types and > strings data. > > Additionally, allow BTFs with no type data. There is nothing inherently wrong > with having BTF with no types (put potentially with some strings). This could > be a situation with kernel module BTFs, if module doesn't introduce any new > type information. > > Also fix invalid offset alignment check for btf->hdr->type_off. > > Fixes: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf") > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> > Link: https://lore.kernel.org/bpf/20201105043402.2530976-8-andrii@xxxxxxxxxx > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > tools/lib/bpf/btf.c | 16 ++++++---------- > 1 file changed, 6 insertions(+), 10 deletions(-) > > diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c > index d606a358480da..3380aadb74655 100644 > --- a/tools/lib/bpf/btf.c > +++ b/tools/lib/bpf/btf.c > @@ -100,22 +100,18 @@ static int btf_parse_hdr(struct btf *btf) > return -EINVAL; > } > > - if (meta_left < hdr->type_off) { > - pr_debug("Invalid BTF type section offset:%u\n", hdr->type_off); > + if (meta_left < hdr->str_off + hdr->str_len) { > + pr_debug("Invalid BTF total size:%u\n", btf->raw_size); In file included from btf.c:17:0: btf.c: In function 'btf_parse_hdr': btf.c:104:48: error: 'struct btf' has no member named 'raw_size'; did you mean 'data_size'? pr_debug("Invalid BTF total size:%u\n", btf->raw_size); ^ libbpf_internal.h:59:40: note: in definition of macro '__pr' libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \ ^~~~~~~~~~~ btf.c:104:3: note: in expansion of macro 'pr_debug' pr_debug("Invalid BTF total size:%u\n", btf->raw_size); ^~~~~~~~This patch fixes the bug introduced back in 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf"), but a bunch of other refactorings happened since then, adding/renaming struct btf internals. The fix here is not that critical, so it's probably best to just drop this patch from the stable, if possible. Would it be ok, Greg?
I'll drop it, thanks. -- Thanks, Sasha
