[PATCH AUTOSEL 5.10 03/76] selftests/bpf: Fix vfs_link kprobe definition

[PATCH AUTOSEL 5.10 03/76] selftests/bpf: Fix vfs_link kprobe definition

[Sasha Levin]

From: Nikolay Borisov <nborisov@suse.com>

[ Upstream commit e299bcd4d16ff86f46c48df1062c8aae0eca1ed8 ]

Since commit 6521f8917082 ("namei: prepare for idmapped mounts")
vfs_link's prototype was changed, the kprobe definition in
profiler selftest in turn wasn't updated. The result is that all
argument after the first are now stored in different registers. This
means that self-test has been broken ever since. Fix it by updating the
kprobe definition accordingly.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220331140949.1410056-1-nborisov@suse.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/progs/profiler.inc.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h b/tools/testing/selftests/bpf/progs/profiler.inc.h
index 4896fdf816f7..92331053dba3 100644
--- a/tools/testing/selftests/bpf/progs/profiler.inc.h
+++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
@@ -826,8 +826,9 @@ int kprobe_ret__do_filp_open(struct pt_regs* ctx)
 
 SEC("kprobe/vfs_link")
 int BPF_KPROBE(kprobe__vfs_link,
-	       struct dentry* old_dentry, struct inode* dir,
-	       struct dentry* new_dentry, struct inode** delegated_inode)
+	       struct dentry* old_dentry, struct user_namespace *mnt_userns,
+	       struct inode* dir, struct dentry* new_dentry,
+	       struct inode** delegated_inode)
 {
 	struct bpf_func_stats_ctx stats_ctx;
 	bpf_stats_enter(&stats_ctx, profiler_bpf_vfs_link);
-- 
2.35.1

[PATCH AUTOSEL 5.10 75/76] selftests/bpf: fix btf_dump/btf_dump due to recent clang change

[Sasha Levin]

From: Yonghong Song <yhs@fb.com>

[ Upstream commit 4050764cbaa25760aab40857f723393c07898474 ]

Latest llvm-project upstream had a change of behavior
related to qualifiers on function return type ([1]).
This caused selftests btf_dump/btf_dump failure.
The following example shows what changed.

  $ cat t.c
  typedef const char * const (* const (* const fn_ptr_arr2_t[5])())(char * (*)(int));
  struct t {
    int a;
    fn_ptr_arr2_t l;
  };
  int foo(struct t *arg) {
    return arg->a;
  }

Compiled with latest upstream llvm15,
  $ clang -O2 -g -target bpf -S -emit-llvm t.c
The related generated debuginfo IR looks like:
  !16 = !DIDerivedType(tag: DW_TAG_typedef, name: "fn_ptr_arr2_t", file: !1, line: 1, baseType: !17)
  !17 = !DICompositeType(tag: DW_TAG_array_type, baseType: !18, size: 320, elements: !32)
  !18 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !19)
  !19 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !20, size: 64)
  !20 = !DISubroutineType(types: !21)
  !21 = !{!22, null}
  !22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !23, size: 64)
  !23 = !DISubroutineType(types: !24)
  !24 = !{!25, !28}
  !25 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !26, size: 64)
  !26 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !27)
  !27 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
You can see two intermediate const qualifier to pointer are dropped in debuginfo IR.

With llvm14, we have following debuginfo IR:
  !16 = !DIDerivedType(tag: DW_TAG_typedef, name: "fn_ptr_arr2_t", file: !1, line: 1, baseType: !17)
  !17 = !DICompositeType(tag: DW_TAG_array_type, baseType: !18, size: 320, elements: !34)
  !18 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !19)
  !19 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !20, size: 64)
  !20 = !DISubroutineType(types: !21)
  !21 = !{!22, null}
  !22 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !23)
  !23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !24, size: 64)
  !24 = !DISubroutineType(types: !25)
  !25 = !{!26, !30}
  !26 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !27)
  !27 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !28, size: 64)
  !28 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !29)
  !29 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
All const qualifiers are preserved.

To adapt the selftest to both old and new llvm, this patch removed
the intermediate const qualifier in const-to-ptr types, to make the
test succeed again.

  [1] https://reviews.llvm.org/D125919

Reported-by: Mykola Lysenko <mykolal@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220523152044.3905809-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
index 31975c96e2c9..fe43556e1a61 100644
--- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
+++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c
@@ -94,7 +94,7 @@ typedef void (* (*signal_t)(int, void (*)(int)))(int);
 
 typedef char * (*fn_ptr_arr1_t[10])(int **);
 
-typedef char * (* const (* const fn_ptr_arr2_t[5])())(char * (*)(int));
+typedef char * (* (* const fn_ptr_arr2_t[5])())(char * (*)(int));
 
 struct struct_w_typedefs {
 	int_t a;
-- 
2.35.1