[llvm] 152a9fe - BPF: permit .maps section variables with typedef type
Yonghong Song via llvm-commits
llvm-commits at lists.llvm.org
Sun Jul 12 09:46:58 PDT 2020
Author: Yonghong Song
Date: 2020-07-12T09:42:25-07:00
New Revision: 152a9fef1b3b44f2c224cb8096b3d649279f2578
URL: https://github.com/llvm/llvm-project/commit/152a9fef1b3b44f2c224cb8096b3d649279f2578
DIFF: https://github.com/llvm/llvm-project/commit/152a9fef1b3b44f2c224cb8096b3d649279f2578.diff
LOG: BPF: permit .maps section variables with typedef type
Currently, llvm when see a global variable in .maps section,
it ensures its type must be a struct type. Then pointee
will be further evaluated for the structure members.
In normal cases, the pointee type will be skipped.
Although this is what current all bpf programs are doing,
but it is a little bit restrictive. For example, it is legitimate
for users to have:
typedef struct { int key_size; int value_size; } __map_t;
__map_t map __attribute__((section(".maps")));
This patch lifts this restriction and typedef of
a struct type is also allowed for .maps section variables.
To avoid create unnecessary fixup entries when traversal
started with typedef/struct type, the new implementation
first traverse all map struct members and then traverse
the typedef/struct type. This way, in internal BTFDebug
implementation, no fixup entries are generated.
Two new unit tests are added for typedef and const
struct in .maps section. Also tested with kernel bpf selftests.
Differential Revision: https://reviews.llvm.org/D83638
Added:
llvm/test/CodeGen/BPF/BTF/map-def-2.ll
llvm/test/CodeGen/BPF/BTF/map-def-3.ll
Modified:
llvm/lib/Target/BPF/BTFDebug.cpp
llvm/test/CodeGen/BPF/BTF/map-def.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/BPF/BTFDebug.cpp b/llvm/lib/Target/BPF/BTFDebug.cpp
index 6ada75adba96..4510e9357489 100644
--- a/llvm/lib/Target/BPF/BTFDebug.cpp
+++ b/llvm/lib/Target/BPF/BTFDebug.cpp
@@ -664,7 +664,17 @@ void BTFDebug::visitMapDefType(const DIType *Ty, uint32_t &TypeId) {
return;
}
- // MapDef type is a struct type
+ // MapDef type may be a struct type or a non-pointer derived type
+ const DIType *OrigTy = Ty;
+ while (auto *DTy = dyn_cast<DIDerivedType>(Ty)) {
+ auto Tag = DTy->getTag();
+ if (Tag != dwarf::DW_TAG_typedef && Tag != dwarf::DW_TAG_const_type &&
+ Tag != dwarf::DW_TAG_volatile_type &&
+ Tag != dwarf::DW_TAG_restrict_type)
+ break;
+ Ty = DTy->getBaseType();
+ }
+
const auto *CTy = dyn_cast<DICompositeType>(Ty);
if (!CTy)
return;
@@ -673,27 +683,15 @@ void BTFDebug::visitMapDefType(const DIType *Ty, uint32_t &TypeId) {
if (Tag != dwarf::DW_TAG_structure_type || CTy->isForwardDecl())
return;
- // Record this type
+ // Visit all struct members to ensure pointee type is visited
const DINodeArray Elements = CTy->getElements();
- bool HasBitField = false;
- for (const auto *Element : Elements) {
- auto E = cast<DIDerivedType>(Element);
- if (E->isBitField()) {
- HasBitField = true;
- break;
- }
- }
-
- auto TypeEntry =
- std::make_unique<BTFTypeStruct>(CTy, true, HasBitField, Elements.size());
- StructTypes.push_back(TypeEntry.get());
- TypeId = addType(std::move(TypeEntry), CTy);
-
- // Visit all struct members
for (const auto *Element : Elements) {
const auto *MemberType = cast<DIDerivedType>(Element);
visitTypeEntry(MemberType->getBaseType());
}
+
+ // Visit this type, struct or a const/typedef/volatile/restrict type
+ visitTypeEntry(OrigTy, TypeId, false, false);
}
/// Read file contents from the actual file or from the source
diff --git a/llvm/test/CodeGen/BPF/BTF/map-def-2.ll b/llvm/test/CodeGen/BPF/BTF/map-def-2.ll
new file mode 100644
index 000000000000..bf3c4a7961fb
--- /dev/null
+++ b/llvm/test/CodeGen/BPF/BTF/map-def-2.ll
@@ -0,0 +1,90 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+;
+; Source code:
+; struct key_type {
+; int a1;
+; };
+; typedef struct map_type {
+; struct key_type *key;
+; } _map_type;
+; typedef _map_type __map_type;
+; __map_type __attribute__((section(".maps"))) hash_map;
+; Compilation flag:
+; clang -target bpf -O2 -g -S -emit-llvm t2.c
+
+%struct.map_type = type { %struct.key_type* }
+%struct.key_type = type { i32 }
+
+ at hash_map = dso_local local_unnamed_addr global %struct.map_type zeroinitializer, section ".maps", align 8, !dbg !0
+
+; CHECK: .long 0 # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT: .long 33554432 # 0x2000000
+; CHECK-NEXT: .long 2
+; CHECK-NEXT: .long 1 # BTF_KIND_STRUCT(id = 2)
+; CHECK-NEXT: .long 67108865 # 0x4000001
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 10
+; CHECK-NEXT: .long 3
+; CHECK-NEXT: .long 0 # 0x0
+; CHECK-NEXT: .long 13 # BTF_KIND_INT(id = 3)
+; CHECK-NEXT: .long 16777216 # 0x1000000
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 16777248 # 0x1000020
+; CHECK-NEXT: .long 17 # BTF_KIND_TYPEDEF(id = 4)
+; CHECK-NEXT: .long 134217728 # 0x8000000
+; CHECK-NEXT: .long 5
+; CHECK-NEXT: .long 28 # BTF_KIND_TYPEDEF(id = 5)
+; CHECK-NEXT: .long 134217728 # 0x8000000
+; CHECK-NEXT: .long 6
+; CHECK-NEXT: .long 38 # BTF_KIND_STRUCT(id = 6)
+; CHECK-NEXT: .long 67108865 # 0x4000001
+; CHECK-NEXT: .long 8
+; CHECK-NEXT: .long 47
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 0 # 0x0
+; CHECK-NEXT: .long 51 # BTF_KIND_VAR(id = 7)
+; CHECK-NEXT: .long 234881024 # 0xe000000
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 60 # BTF_KIND_DATASEC(id = 8)
+; CHECK-NEXT: .long 251658241 # 0xf000001
+; CHECK-NEXT: .long 0
+; CHECK-NEXT: .long 7
+; CHECK-NEXT: .long hash_map
+; CHECK-NEXT: .long 8
+
+; CHECK: .ascii "key_type" # string offset=1
+; CHECK: .ascii "a1" # string offset=10
+; CHECK: .ascii "int" # string offset=13
+; CHECK: .ascii "__map_type" # string offset=17
+; CHECK: .ascii "_map_type" # string offset=28
+; CHECK: .ascii "map_type" # string offset=38
+; CHECK: .ascii "key" # string offset=47
+; CHECK: .ascii "hash_map" # string offset=51
+; CHECK: .ascii ".maps" # string offset=60
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!16, !17, !18}
+!llvm.ident = !{!19}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "hash_map", scope: !2, file: !3, line: 8, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 11.0.0 (https://github.com/llvm/llvm-project.git b8409c03ed90807f3d49c7d98dceea98cf461f7a)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "t2.c", directory: "/tmp/home/yhs/tmp1")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_typedef, name: "__map_type", file: !3, line: 7, baseType: !7)
+!7 = !DIDerivedType(tag: DW_TAG_typedef, name: "_map_type", file: !3, line: 6, baseType: !8)
+!8 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "map_type", file: !3, line: 4, size: 64, elements: !9)
+!9 = !{!10}
+!10 = !DIDerivedType(tag: DW_TAG_member, name: "key", scope: !8, file: !3, line: 5, baseType: !11, size: 64)
+!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
+!12 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "key_type", file: !3, line: 1, size: 32, elements: !13)
+!13 = !{!14}
+!14 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !12, file: !3, line: 2, baseType: !15, size: 32)
+!15 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!16 = !{i32 7, !"Dwarf Version", i32 4}
+!17 = !{i32 2, !"Debug Info Version", i32 3}
+!18 = !{i32 1, !"wchar_size", i32 4}
+!19 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project.git b8409c03ed90807f3d49c7d98dceea98cf461f7a)"}
diff --git a/llvm/test/CodeGen/BPF/BTF/map-def-3.ll b/llvm/test/CodeGen/BPF/BTF/map-def-3.ll
new file mode 100644
index 000000000000..e05470782ec2
--- /dev/null
+++ b/llvm/test/CodeGen/BPF/BTF/map-def-3.ll
@@ -0,0 +1,65 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+;
+; Source code:
+; struct key_type {
+; int a1;
+; };
+; const struct key_type __attribute__((section(".maps"))) hash_map;
+; Compilation flag:
+; clang -target bpf -O2 -g -S -emit-llvm t3.c
+
+%struct.key_type = type { i32 }
+
+ at hash_map = dso_local local_unnamed_addr constant %struct.key_type zeroinitializer, section ".maps", align 4, !dbg !0
+
+; CHECK: .long 1 # BTF_KIND_INT(id = 1)
+; CHECK-NEXT: .long 16777216 # 0x1000000
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 16777248 # 0x1000020
+; CHECK-NEXT: .long 0 # BTF_KIND_CONST(id = 2)
+; CHECK-NEXT: .long 167772160 # 0xa000000
+; CHECK-NEXT: .long 3
+; CHECK-NEXT: .long 5 # BTF_KIND_STRUCT(id = 3)
+; CHECK-NEXT: .long 67108865 # 0x4000001
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 14
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 0 # 0x0
+; CHECK-NEXT: .long 17 # BTF_KIND_VAR(id = 4)
+; CHECK-NEXT: .long 234881024 # 0xe000000
+; CHECK-NEXT: .long 2
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 26 # BTF_KIND_DATASEC(id = 5)
+; CHECK-NEXT: .long 251658241 # 0xf000001
+; CHECK-NEXT: .long 0
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long hash_map
+; CHECK-NEXT: .long 4
+
+; CHECK: .ascii "int" # string offset=1
+; CHECK: .ascii "key_type" # string offset=5
+; CHECK: .ascii "a1" # string offset=14
+; CHECK: .ascii "hash_map" # string offset=17
+; CHECK: .ascii ".maps" # string offset=26
+
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "hash_map", scope: !2, file: !3, line: 4, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 11.0.0 (https://github.com/llvm/llvm-project.git 5bd074629f00d4798674b411cf00216f38016483)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "t3.c", directory: "/tmp/home/yhs/tmp1")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !7)
+!7 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "key_type", file: !3, line: 1, size: 32, elements: !8)
+!8 = !{!9}
+!9 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !7, file: !3, line: 2, baseType: !10, size: 32)
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{i32 7, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project.git 5bd074629f00d4798674b411cf00216f38016483)"}
diff --git a/llvm/test/CodeGen/BPF/BTF/map-def.ll b/llvm/test/CodeGen/BPF/BTF/map-def.ll
index cf777880efa1..e12cde3ef98a 100644
--- a/llvm/test/CodeGen/BPF/BTF/map-def.ll
+++ b/llvm/test/CodeGen/BPF/BTF/map-def.ll
@@ -28,41 +28,41 @@
; CHECK-NEXT: .long 168
; CHECK-NEXT: .long 168
; CHECK-NEXT: .long 65
-; CHECK-NEXT: .long 1 # BTF_KIND_STRUCT(id = 1)
-; CHECK-NEXT: .long 67108866 # 0x4000002
-; CHECK-NEXT: .long 16
-; CHECK-NEXT: .long 10
-; CHECK-NEXT: .long 2
-; CHECK-NEXT: .long 0 # 0x0
-; CHECK-NEXT: .long 14
-; CHECK-NEXT: .long 5
-; CHECK-NEXT: .long 64 # 0x40
-; CHECK-NEXT: .long 0 # BTF_KIND_PTR(id = 2)
+; CHECK-NEXT: .long 0 # BTF_KIND_PTR(id = 1)
; CHECK-NEXT: .long 33554432 # 0x2000000
-; CHECK-NEXT: .long 3
-; CHECK-NEXT: .long 20 # BTF_KIND_STRUCT(id = 3)
+; CHECK-NEXT: .long 2
+; CHECK-NEXT: .long 1 # BTF_KIND_STRUCT(id = 2)
; CHECK-NEXT: .long 67108866 # 0x4000002
; CHECK-NEXT: .long 8
-; CHECK-NEXT: .long 29
-; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 10
+; CHECK-NEXT: .long 3
; CHECK-NEXT: .long 0 # 0x0
-; CHECK-NEXT: .long 31
-; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 12
+; CHECK-NEXT: .long 3
; CHECK-NEXT: .long 32 # 0x20
-; CHECK-NEXT: .long 33 # BTF_KIND_INT(id = 4)
+; CHECK-NEXT: .long 14 # BTF_KIND_INT(id = 3)
; CHECK-NEXT: .long 16777216 # 0x1000000
; CHECK-NEXT: .long 4
; CHECK-NEXT: .long 16777248 # 0x1000020
-; CHECK-NEXT: .long 0 # BTF_KIND_PTR(id = 5)
+; CHECK-NEXT: .long 0 # BTF_KIND_PTR(id = 4)
; CHECK-NEXT: .long 33554432 # 0x2000000
-; CHECK-NEXT: .long 6
-; CHECK-NEXT: .long 37 # BTF_KIND_INT(id = 6)
+; CHECK-NEXT: .long 5
+; CHECK-NEXT: .long 18 # BTF_KIND_INT(id = 5)
; CHECK-NEXT: .long 16777216 # 0x1000000
; CHECK-NEXT: .long 4
; CHECK-NEXT: .long 32 # 0x20
+; CHECK-NEXT: .long 31 # BTF_KIND_STRUCT(id = 6)
+; CHECK-NEXT: .long 67108866 # 0x4000002
+; CHECK-NEXT: .long 16
+; CHECK-NEXT: .long 40
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 0 # 0x0
+; CHECK-NEXT: .long 44
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 64 # 0x40
; CHECK-NEXT: .long 50 # BTF_KIND_VAR(id = 7)
; CHECK-NEXT: .long 234881024 # 0xe000000
-; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 6
; CHECK-NEXT: .long 1
; CHECK-NEXT: .long 59 # BTF_KIND_DATASEC(id = 8)
; CHECK-NEXT: .long 251658241 # 0xf000001
@@ -71,21 +71,21 @@
; CHECK-NEXT: .long hash_map
; CHECK-NEXT: .long 16
; CHECK-NEXT: .byte 0 # string offset=0
-; CHECK-NEXT: .ascii "map_type" # string offset=1
+; CHECK-NEXT: .ascii "key_type" # string offset=1
; CHECK-NEXT: .byte 0
-; CHECK-NEXT: .ascii "key" # string offset=10
+; CHECK-NEXT: .byte 97 # string offset=10
; CHECK-NEXT: .byte 0
-; CHECK-NEXT: .ascii "value" # string offset=14
+; CHECK-NEXT: .byte 98 # string offset=12
; CHECK-NEXT: .byte 0
-; CHECK-NEXT: .ascii "key_type" # string offset=20
+; CHECK-NEXT: .ascii "int" # string offset=14
; CHECK-NEXT: .byte 0
-; CHECK-NEXT: .byte 97 # string offset=29
+; CHECK-NEXT: .ascii "unsigned int" # string offset=18
; CHECK-NEXT: .byte 0
-; CHECK-NEXT: .byte 98 # string offset=31
+; CHECK-NEXT: .ascii "map_type" # string offset=31
; CHECK-NEXT: .byte 0
-; CHECK-NEXT: .ascii "int" # string offset=33
+; CHECK-NEXT: .ascii "key" # string offset=40
; CHECK-NEXT: .byte 0
-; CHECK-NEXT: .ascii "unsigned int" # string offset=37
+; CHECK-NEXT: .ascii "value" # string offset=44
; CHECK-NEXT: .byte 0
; CHECK-NEXT: .ascii "hash_map" # string offset=50
; CHECK-NEXT: .byte 0
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