From: Douglas RAILLARD <douglas.raillard@arm.com>
To: bpf@vger.kernel.org
Cc: beata.michalska@arm.com,
Douglas Raillard <douglas.raillard@arm.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Tom Rix <trix@redhat.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
llvm@lists.linux.dev
Subject: [PATCH v2] libbpf: Fix determine_ptr_size() guessing
Date: Mon, 23 May 2022 11:29:55 +0100 [thread overview]
Message-ID: <20220523102955.43844-1-douglas.raillard@arm.com> (raw)
From: Douglas Raillard <douglas.raillard@arm.com>
One strategy employed by libbpf to guess the pointer size is by finding
the size of "unsigned long" type. This is achieved by looking for a type
of with the expected name and checking its size.
Unfortunately, the C syntax is friendlier to humans than to computers
as there is some variety in how such a type can be named. Specifically,
gcc and clang do not use the same name in debug info.
Lookup all the names for such a type so that libbpf can hope to find the
information it wants.
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
---
tools/lib/bpf/btf.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
CHANGELOG
v2:
* Added missing case for "long"
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 1383e26c5d1f..ab92b3bc2724 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -489,8 +489,19 @@ static int determine_ptr_size(const struct btf *btf)
if (!name)
continue;
- if (strcmp(name, "long int") == 0 ||
- strcmp(name, "long unsigned int") == 0) {
+ if (
+ strcmp(name, "long") == 0 ||
+ strcmp(name, "long int") == 0 ||
+ strcmp(name, "int long") == 0 ||
+ strcmp(name, "unsigned long") == 0 ||
+ strcmp(name, "long unsigned") == 0 ||
+ strcmp(name, "unsigned long int") == 0 ||
+ strcmp(name, "unsigned int long") == 0 ||
+ strcmp(name, "long unsigned int") == 0 ||
+ strcmp(name, "long int unsigned") == 0 ||
+ strcmp(name, "int unsigned long") == 0 ||
+ strcmp(name, "int long unsigned") == 0
+ ) {
if (t->size != 4 && t->size != 8)
continue;
return t->size;
--
2.25.1
next reply other threads:[~2022-05-23 10:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-23 10:29 Douglas RAILLARD [this message]
2022-05-23 15:45 ` Yonghong Song
2022-05-23 21:00 ` Daniel Borkmann
2022-05-23 22:07 ` Andrii Nakryiko
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