Accepting request 896646 from home:michals
- Handle zero sized per-cpu veriables in Linux BTF. + btf_encoder-fix-and-complete-filtering-out-zero-sized-per-CPU-variables.patch OBS-URL: https://build.opensuse.org/request/show/896646 OBS-URL: https://build.opensuse.org/package/show/devel:tools/dwarves?expand=0&rev=65
This commit is contained in:
parent
f2236ad99a
commit
9aca74399e
@ -0,0 +1,84 @@
|
||||
From 0d17503db0580a6635d103fed030724b38ba1364 Mon Sep 17 00:00:00 2001
|
||||
From: Andrii Nakryiko <andrii@kernel.org>
|
||||
Date: Mon, 24 May 2021 16:42:22 -0700
|
||||
Subject: [PATCH] btf_encoder: fix and complete filtering out zero-sized
|
||||
per-CPU variables
|
||||
MIME-Version: 1.0
|
||||
Content-Type: text/plain; charset=UTF-8
|
||||
Content-Transfer-Encoding: 8bit
|
||||
|
||||
Upstram: accepted - expected version 1.22
|
||||
Git-commit: 0d17503db0580a6635d103fed030724b38ba1364
|
||||
|
||||
btf_encoder is ignoring zero-sized per-CPU ELF symbols, but the same has to be
|
||||
done for DWARF variables when matching them with ELF symbols. This is due to
|
||||
zero-sized DWARF variables matching unrelated (non-zero-sized) variable that
|
||||
happens to be allocated at the exact same address, leading to a lot of
|
||||
confusion in BTF.
|
||||
|
||||
See [0] for when this causes big problems.
|
||||
|
||||
[0] https://lore.kernel.org/bpf/CAEf4BzZ0-sihSL-UAm21JcaCCY92CqfNxycHRZYXcoj8OYb=wA@mail.gmail.com/
|
||||
|
||||
Committer notes:
|
||||
|
||||
Kept the {} around the if block with more than one line, which
|
||||
simplifies the original patch by just removing that assignment
|
||||
to the 'dwarf_name' variable.
|
||||
|
||||
Reported-by: Michal Suchánek <msuchanek@suse.de>
|
||||
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
|
||||
Cc: Jiri Olsa <jolsa@kernel.org>
|
||||
Cc: bpf@vger.kernel.org
|
||||
Cc: dwarves@vger.kernel.org
|
||||
Cc: kernel-team@fb.com
|
||||
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
||||
---
|
||||
btf_encoder.c | 10 +++++++++-
|
||||
1 file changed, 9 insertions(+), 1 deletion(-)
|
||||
|
||||
diff --git a/btf_encoder.c b/btf_encoder.c
|
||||
index c711f12..033c927 100644
|
||||
--- a/btf_encoder.c
|
||||
+++ b/btf_encoder.c
|
||||
@@ -538,6 +538,7 @@ int cu__encode_btf(struct cu *cu, int verbose, bool force,
|
||||
cu__for_each_variable(cu, core_id, pos) {
|
||||
uint32_t size, type, linkage;
|
||||
const char *name, *dwarf_name;
|
||||
+ const struct tag *tag;
|
||||
uint64_t addr;
|
||||
int id;
|
||||
|
||||
@@ -550,6 +551,7 @@ int cu__encode_btf(struct cu *cu, int verbose, bool force,
|
||||
|
||||
/* addr has to be recorded before we follow spec */
|
||||
addr = var->ip.addr;
|
||||
+ dwarf_name = variable__name(var, cu);
|
||||
|
||||
/* DWARF takes into account .data..percpu section offset
|
||||
* within its segment, which for vmlinux is 0, but for kernel
|
||||
@@ -583,7 +585,6 @@ int cu__encode_btf(struct cu *cu, int verbose, bool force,
|
||||
* per-CPU symbols have non-zero values.
|
||||
*/
|
||||
if (var->ip.addr == 0) {
|
||||
- dwarf_name = variable__name(var, cu);
|
||||
if (!dwarf_name || strcmp(dwarf_name, name))
|
||||
continue;
|
||||
}
|
||||
@@ -600,6 +601,13 @@ int cu__encode_btf(struct cu *cu, int verbose, bool force,
|
||||
break;
|
||||
}
|
||||
|
||||
+ tag = cu__type(cu, var->ip.tag.type);
|
||||
+ if (tag__size(tag, cu) == 0) {
|
||||
+ if (btf_elf__verbose)
|
||||
+ fprintf(stderr, "Ignoring zero-sized per-CPU variable '%s'...\n", dwarf_name ?: "<missing name>");
|
||||
+ continue;
|
||||
+ }
|
||||
+
|
||||
type = var->ip.tag.type + type_id_off;
|
||||
linkage = var->external ? BTF_VAR_GLOBAL_ALLOCATED : BTF_VAR_STATIC;
|
||||
|
||||
--
|
||||
2.31.1
|
||||
|
@ -1,3 +1,9 @@
|
||||
-------------------------------------------------------------------
|
||||
Tue Jun 1 10:28:25 UTC 2021 - Michal Suchanek <msuchanek@suse.com>
|
||||
|
||||
- Handle zero sized per-cpu veriables in Linux BTF.
|
||||
+ btf_encoder-fix-and-complete-filtering-out-zero-sized-per-CPU-variables.patch
|
||||
|
||||
-------------------------------------------------------------------
|
||||
Mon May 3 08:45:43 UTC 2021 - Jiri Slaby <jslaby@suse.cz>
|
||||
|
||||
|
@ -29,6 +29,7 @@ Source: https://fedorapeople.org/~acme/dwarves/dwarves-%version.tar.xz
|
||||
Source2: https://fedorapeople.org/~acme/dwarves/dwarves-%version.tar.sign
|
||||
Source9: baselibs.conf
|
||||
Patch0: remove-ftrace-filter.patch
|
||||
Patch1: btf_encoder-fix-and-complete-filtering-out-zero-sized-per-CPU-variables.patch
|
||||
BuildRequires: cmake
|
||||
BuildRequires: libdw-devel >= 0.171
|
||||
%if 0%{?suse_version} < 1550
|
||||
|
Loading…
Reference in New Issue
Block a user