!48 [sync] PR-47: [PATCH] libbpf: Fix determine_ptr_size() guessing

From: @openeuler-sync-bot 
Reviewed-by: @bitcoffee 
Signed-off-by: @bitcoffee

backport-libbpf-Fix-determine_ptr_size-guessing.patch

@@ -0,0 +1,77 @@
+From a5d75daa8c467a863ecf297982b70ed284adc0e9 Mon Sep 17 00:00:00 2001
+From: Douglas Raillard <douglas.raillard@arm.com>
+Date: Tue, 24 May 2022 10:44:47 +0100
+Subject: [PATCH] libbpf: Fix determine_ptr_size() guessing
+
+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 names for integer types in debug info:
+
+    - clang uses "unsigned long"
+    - gcc uses "long unsigned int"
+
+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>
+Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
+Acked-by: Yonghong Song <yhs@fb.com>
+Link: https://lore.kernel.org/bpf/20220524094447.332186-1-douglas.raillard@arm.com
+---
+ src/btf.c | 26 ++++++++++++++++++++------
+ 1 file changed, 20 insertions(+), 6 deletions(-)
+
+diff --git a/src/btf.c b/src/btf.c
+index bb1e06eb1..3d6c30d9a 100644
+--- a/src/btf.c
++++ b/src/btf.c
+@@ -472,9 +472,22 @@ const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id)
+ 
+ static int determine_ptr_size(const struct btf *btf)
+ {
++	static const char * const long_aliases[] = {
++		"long",
++		"long int",
++		"int long",
++		"unsigned long",
++		"long unsigned",
++		"unsigned long int",
++		"unsigned int long",
++		"long unsigned int",
++		"long int unsigned",
++		"int unsigned long",
++		"int long unsigned",
++	};
+ 	const struct btf_type *t;
+ 	const char *name;
+-	int i, n;
++	int i, j, n;
+ 
+ 	if (btf->base_btf && btf->base_btf->ptr_sz > 0)
+ 		return btf->base_btf->ptr_sz;
+@@ -485,15 +498,16 @@ static int determine_ptr_size(const struct btf *btf)
+ 		if (!btf_is_int(t))
+ 			continue;
+ 
++		if (t->size != 4 && t->size != 8)
++			continue;
++
+ 		name = btf__name_by_offset(btf, t->name_off);
+ 		if (!name)
+ 			continue;
+ 
+-		if (strcmp(name, "long int") == 0 ||
+-		    strcmp(name, "long unsigned int") == 0) {
+-			if (t->size != 4 && t->size != 8)
+-				continue;
+-			return t->size;
++		for (j = 0; j < ARRAY_SIZE(long_aliases); j++) {
++			if (strcmp(name, long_aliases[j]) == 0)
++				return t->size;
+ 		}
+ 	}
+ 

libbpf.spec

@@ -4,7 +4,7 @@
 
 Name:           %{githubname}
 Version:        %{githubver}
-Release:        2
+Release:        3
 Summary:        Libbpf library
 
 License:        LGPLv2 or BSD
@@ -12,6 +12,9 @@ URL:            https://github.com/%{githubname}/%{githubname}
 Source:         https://github.com/%{githubname}/%{githubname}/archive/%{githubname}-%{githubver}.tar.gz
 BuildRequires:  gcc elfutils-libelf-devel elfutils-devel
 
+#patches
+Patch0000:      backport-libbpf-Fix-determine_ptr_size-guessing.patch
+
 # This package supersedes libbpf from kernel-tools,
 # which has default Epoch: 0. By having Epoch: 1
 # this libbpf will take over smoothly
@@ -42,7 +45,7 @@ developing applications that use %{name}
 %global make_flags DESTDIR=%{buildroot} OBJDIR=%{_builddir} CFLAGS="%{build_cflags} -fPIC" LDFLAGS="%{build_ldflags} -Wl,--no-as-needed" LIBDIR=/%{_libdir} NO_PKG_CONFIG=1
 
 %prep
-%autosetup -n %{githubfull}
+%autosetup -n %{githubfull} -p1
 
 %build
 %make_build -C ./src %{make_flags}
@@ -63,6 +66,9 @@ developing applications that use %{name}
 %{_libdir}/libbpf.a
 
 %changelog
+* Wed Oct 26 2022 zhangmingyi <zhangmingyi5@huawei.com> - 2:0.3-3
+- Fix determine_ptr_size() guessing
+
 * Mon Aug 22 2022 hujiawang <hujiawang1@huawei.com> - 2:0.3-2
 - change the package name