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Diffstat (limited to 'llvm/lib/Target/BPF/BTFDebug.cpp')
-rw-r--r--llvm/lib/Target/BPF/BTFDebug.cpp157
1 files changed, 106 insertions, 51 deletions
diff --git a/llvm/lib/Target/BPF/BTFDebug.cpp b/llvm/lib/Target/BPF/BTFDebug.cpp
index db551e739bd7..a9fb04f20d1c 100644
--- a/llvm/lib/Target/BPF/BTFDebug.cpp
+++ b/llvm/lib/Target/BPF/BTFDebug.cpp
@@ -308,10 +308,11 @@ void BTFTypeFuncProto::emitType(MCStreamer &OS) {
}
}
-BTFTypeFunc::BTFTypeFunc(StringRef FuncName, uint32_t ProtoTypeId)
+BTFTypeFunc::BTFTypeFunc(StringRef FuncName, uint32_t ProtoTypeId,
+ uint32_t Scope)
: Name(FuncName) {
Kind = BTF::BTF_KIND_FUNC;
- BTFType.Info = Kind << 24;
+ BTFType.Info = (Kind << 24) | Scope;
BTFType.Type = ProtoTypeId;
}
@@ -897,8 +898,9 @@ void BTFDebug::beginFunctionImpl(const MachineFunction *MF) {
visitSubroutineType(SP->getType(), true, FuncArgNames, ProtoTypeId);
// Construct subprogram func type
+ uint8_t Scope = SP->isLocalToUnit() ? BTF::FUNC_STATIC : BTF::FUNC_GLOBAL;
auto FuncTypeEntry =
- std::make_unique<BTFTypeFunc>(SP->getName(), ProtoTypeId);
+ std::make_unique<BTFTypeFunc>(SP->getName(), ProtoTypeId, Scope);
uint32_t FuncTypeId = addType(std::move(FuncTypeEntry));
for (const auto &TypeEntry : TypeEntries)
@@ -937,9 +939,8 @@ unsigned BTFDebug::populateStructType(const DIType *Ty) {
}
/// Generate a struct member field relocation.
-void BTFDebug::generateFieldReloc(const MachineInstr *MI,
- const MCSymbol *ORSym, DIType *RootTy,
- StringRef AccessPattern) {
+void BTFDebug::generateFieldReloc(const MCSymbol *ORSym, DIType *RootTy,
+ StringRef AccessPattern) {
unsigned RootId = populateStructType(RootTy);
size_t FirstDollar = AccessPattern.find_first_of('$');
size_t FirstColon = AccessPattern.find_first_of(':');
@@ -959,33 +960,8 @@ void BTFDebug::generateFieldReloc(const MachineInstr *MI,
FieldRelocTable[SecNameOff].push_back(FieldReloc);
}
-void BTFDebug::processLDimm64(const MachineInstr *MI) {
- // If the insn is an LD_imm64, the following two cases
- // will generate an .BTF.ext record.
- //
- // If the insn is "r2 = LD_imm64 @__BTF_...",
- // add this insn into the .BTF.ext FieldReloc subsection.
- // Relocation looks like:
- // . SecName:
- // . InstOffset
- // . TypeID
- // . OffSetNameOff
- // Later, the insn is replaced with "r2 = <offset>"
- // where "<offset>" equals to the offset based on current
- // type definitions.
- //
- // If the insn is "r2 = LD_imm64 @VAR" and VAR is
- // a patchable external global, add this insn into the .BTF.ext
- // ExternReloc subsection.
- // Relocation looks like:
- // . SecName:
- // . InstOffset
- // . ExternNameOff
- // Later, the insn is replaced with "r2 = <value>" or
- // "LD_imm64 r2, <value>" where "<value>" = 0.
-
+void BTFDebug::processReloc(const MachineOperand &MO) {
// check whether this is a candidate or not
- const MachineOperand &MO = MI->getOperand(1);
if (MO.isGlobal()) {
const GlobalValue *GVal = MO.getGlobal();
auto *GVar = dyn_cast<GlobalVariable>(GVal);
@@ -995,7 +971,7 @@ void BTFDebug::processLDimm64(const MachineInstr *MI) {
MDNode *MDN = GVar->getMetadata(LLVMContext::MD_preserve_access_index);
DIType *Ty = dyn_cast<DIType>(MDN);
- generateFieldReloc(MI, ORSym, Ty, GVar->getName());
+ generateFieldReloc(ORSym, Ty, GVar->getName());
}
}
}
@@ -1020,8 +996,31 @@ void BTFDebug::beginInstruction(const MachineInstr *MI) {
return;
}
- if (MI->getOpcode() == BPF::LD_imm64)
- processLDimm64(MI);
+ if (MI->getOpcode() == BPF::LD_imm64) {
+ // If the insn is "r2 = LD_imm64 @<an AmaAttr global>",
+ // add this insn into the .BTF.ext FieldReloc subsection.
+ // Relocation looks like:
+ // . SecName:
+ // . InstOffset
+ // . TypeID
+ // . OffSetNameOff
+ // . RelocType
+ // Later, the insn is replaced with "r2 = <offset>"
+ // where "<offset>" equals to the offset based on current
+ // type definitions.
+ processReloc(MI->getOperand(1));
+ } else if (MI->getOpcode() == BPF::CORE_MEM ||
+ MI->getOpcode() == BPF::CORE_ALU32_MEM ||
+ MI->getOpcode() == BPF::CORE_SHIFT) {
+ // relocation insn is a load, store or shift insn.
+ processReloc(MI->getOperand(3));
+ } else if (MI->getOpcode() == BPF::JAL) {
+ // check extern function references
+ const MachineOperand &MO = MI->getOperand(0);
+ if (MO.isGlobal()) {
+ processFuncPrototypes(dyn_cast<Function>(MO.getGlobal()));
+ }
+ }
// Skip this instruction if no DebugLoc or the DebugLoc
// is the same as the previous instruction.
@@ -1055,20 +1054,20 @@ void BTFDebug::processGlobals(bool ProcessingMapDef) {
// Collect all types referenced by globals.
const Module *M = MMI->getModule();
for (const GlobalVariable &Global : M->globals()) {
- // Ignore external globals for now.
- if (!Global.hasInitializer() && Global.hasExternalLinkage())
- continue;
-
// Decide the section name.
StringRef SecName;
if (Global.hasSection()) {
SecName = Global.getSection();
- } else {
+ } else if (Global.hasInitializer()) {
// data, bss, or readonly sections
if (Global.isConstant())
SecName = ".rodata";
else
SecName = Global.getInitializer()->isZeroValue() ? ".bss" : ".data";
+ } else {
+ // extern variables without explicit section,
+ // put them into ".extern" section.
+ SecName = ".extern";
}
if (ProcessingMapDef != SecName.startswith(".maps"))
@@ -1076,6 +1075,11 @@ void BTFDebug::processGlobals(bool ProcessingMapDef) {
SmallVector<DIGlobalVariableExpression *, 1> GVs;
Global.getDebugInfo(GVs);
+
+ // No type information, mostly internal, skip it.
+ if (GVs.size() == 0)
+ continue;
+
uint32_t GVTypeId = 0;
for (auto *GVE : GVs) {
if (SecName.startswith(".maps"))
@@ -1087,25 +1091,33 @@ void BTFDebug::processGlobals(bool ProcessingMapDef) {
// Only support the following globals:
// . static variables
- // . non-static global variables with section attributes
- // Essentially means:
- // . .bcc/.data/.rodata DataSec entities only contain static data
- // . Other DataSec entities contain static or initialized global data.
- // Initialized global data are mostly used for finding map key/value type
- // id's. Whether DataSec is readonly or not can be found from
- // corresponding ELF section flags.
+ // . non-static weak or non-weak global variables
+ // . weak or non-weak extern global variables
+ // Whether DataSec is readonly or not can be found from corresponding ELF
+ // section flags. Whether a BTF_KIND_VAR is a weak symbol or not
+ // can be found from the corresponding ELF symbol table.
auto Linkage = Global.getLinkage();
if (Linkage != GlobalValue::InternalLinkage &&
- (Linkage != GlobalValue::ExternalLinkage || !Global.hasSection()))
+ Linkage != GlobalValue::ExternalLinkage &&
+ Linkage != GlobalValue::WeakAnyLinkage &&
+ Linkage != GlobalValue::ExternalWeakLinkage)
continue;
- uint32_t GVarInfo = Linkage == GlobalValue::ExternalLinkage
- ? BTF::VAR_GLOBAL_ALLOCATED
- : BTF::VAR_STATIC;
+ uint32_t GVarInfo;
+ if (Linkage == GlobalValue::InternalLinkage) {
+ GVarInfo = BTF::VAR_STATIC;
+ } else if (Global.hasInitializer()) {
+ GVarInfo = BTF::VAR_GLOBAL_ALLOCATED;
+ } else {
+ GVarInfo = BTF::VAR_GLOBAL_EXTERNAL;
+ }
+
auto VarEntry =
std::make_unique<BTFKindVar>(Global.getName(), GVTypeId, GVarInfo);
uint32_t VarId = addType(std::move(VarEntry));
+ assert(!SecName.empty());
+
// Find or create a DataSec
if (DataSecEntries.find(SecName) == DataSecEntries.end()) {
DataSecEntries[SecName] = std::make_unique<BTFKindDataSec>(Asm, SecName);
@@ -1135,10 +1147,52 @@ bool BTFDebug::InstLower(const MachineInstr *MI, MCInst &OutMI) {
return true;
}
}
+ } else if (MI->getOpcode() == BPF::CORE_MEM ||
+ MI->getOpcode() == BPF::CORE_ALU32_MEM ||
+ MI->getOpcode() == BPF::CORE_SHIFT) {
+ const MachineOperand &MO = MI->getOperand(3);
+ if (MO.isGlobal()) {
+ const GlobalValue *GVal = MO.getGlobal();
+ auto *GVar = dyn_cast<GlobalVariable>(GVal);
+ if (GVar && GVar->hasAttribute(BPFCoreSharedInfo::AmaAttr)) {
+ uint32_t Imm = PatchImms[GVar->getName().str()];
+ OutMI.setOpcode(MI->getOperand(1).getImm());
+ if (MI->getOperand(0).isImm())
+ OutMI.addOperand(MCOperand::createImm(MI->getOperand(0).getImm()));
+ else
+ OutMI.addOperand(MCOperand::createReg(MI->getOperand(0).getReg()));
+ OutMI.addOperand(MCOperand::createReg(MI->getOperand(2).getReg()));
+ OutMI.addOperand(MCOperand::createImm(Imm));
+ return true;
+ }
+ }
}
return false;
}
+void BTFDebug::processFuncPrototypes(const Function *F) {
+ if (!F)
+ return;
+
+ const DISubprogram *SP = F->getSubprogram();
+ if (!SP || SP->isDefinition())
+ return;
+
+ // Do not emit again if already emitted.
+ if (ProtoFunctions.find(F) != ProtoFunctions.end())
+ return;
+ ProtoFunctions.insert(F);
+
+ uint32_t ProtoTypeId;
+ const std::unordered_map<uint32_t, StringRef> FuncArgNames;
+ visitSubroutineType(SP->getType(), false, FuncArgNames, ProtoTypeId);
+
+ uint8_t Scope = BTF::FUNC_EXTERN;
+ auto FuncTypeEntry =
+ std::make_unique<BTFTypeFunc>(SP->getName(), ProtoTypeId, Scope);
+ addType(std::move(FuncTypeEntry));
+}
+
void BTFDebug::endModule() {
// Collect MapDef globals if not collected yet.
if (MapDefNotCollected) {
@@ -1148,6 +1202,7 @@ void BTFDebug::endModule() {
// Collect global types/variables except MapDef globals.
processGlobals(false);
+
for (auto &DataSec : DataSecEntries)
addType(std::move(DataSec.second));
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-06 14:36:45 +0000