From 01f2e36c959c813a532ae836db49b2ac9de46de4 Mon Sep 17 00:00:00 2001
From: Tao Chen <chentao.kernel@linux.alibaba.com>
Date: Tue, 13 Sep 2022 00:43:00 +0800
Subject: [PATCH] libbpf: Support raw BTF placed in the default search path
Currently, the default vmlinux files at '/boot/vmlinux-*',
'/lib/modules/*/vmlinux-*' etc. are parsed with 'btf__parse_elf()' to
extract BTF. It is possible that these files are actually raw BTF files
similar to /sys/kernel/btf/vmlinux. So parse these files with
'btf__parse' which tries both raw format and ELF format.
This might be useful in some scenarios where users put their custom BTF
into known locations and don't want to specify btf_custom_path option.
Signed-off-by: Tao Chen <chentao.kernel@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/3f59fb5a345d2e4f10e16fe9e35fbc4c03ecaa3e.1662999860.git.chentao.kernel@linux.alibaba.com
---
tools/lib/bpf/btf.c | 30 ++++++++++++------------------
1 file changed, 12 insertions(+), 18 deletions(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 361131518d63..b4d9a96c3c1b 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -4642,20 +4642,17 @@ static int btf_dedup_remap_types(struct btf_dedup *d)
*/
struct btf *btf__load_vmlinux_btf(void)
{
- struct {
- const char *path_fmt;
- bool raw_btf;
- } locations[] = {
+ const char *locations[] = {
/* try canonical vmlinux BTF through sysfs first */
- { "/sys/kernel/btf/vmlinux", true /* raw BTF */ },
- /* fall back to trying to find vmlinux ELF on disk otherwise */
- { "/boot/vmlinux-%1$s" },
- { "/lib/modules/%1$s/vmlinux-%1$s" },
- { "/lib/modules/%1$s/build/vmlinux" },
- { "/usr/lib/modules/%1$s/kernel/vmlinux" },
- { "/usr/lib/debug/boot/vmlinux-%1$s" },
- { "/usr/lib/debug/boot/vmlinux-%1$s.debug" },
- { "/usr/lib/debug/lib/modules/%1$s/vmlinux" },
+ "/sys/kernel/btf/vmlinux",
+ /* fall back to trying to find vmlinux on disk otherwise */
+ "/boot/vmlinux-%1$s",
+ "/lib/modules/%1$s/vmlinux-%1$s",
+ "/lib/modules/%1$s/build/vmlinux",
+ "/usr/lib/modules/%1$s/kernel/vmlinux",
+ "/usr/lib/debug/boot/vmlinux-%1$s",
+ "/usr/lib/debug/boot/vmlinux-%1$s.debug",
+ "/usr/lib/debug/lib/modules/%1$s/vmlinux",
};
char path[PATH_MAX + 1];
struct utsname buf;
@@ -4665,15 +4662,12 @@ struct btf *btf__load_vmlinux_btf(void)
uname(&buf);
for (i = 0; i < ARRAY_SIZE(locations); i++) {
- snprintf(path, PATH_MAX, locations[i].path_fmt, buf.release);
+ snprintf(path, PATH_MAX, locations[i], buf.release);
if (access(path, R_OK))
continue;
- if (locations[i].raw_btf)
- btf = btf__parse_raw(path);
- else
- btf = btf__parse_elf(path, NULL);
+ btf = btf__parse(path, NULL);
err = libbpf_get_error(btf);
pr_debug("loading kernel BTF '%s': %d\n", path, err);
if (err)