mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-19 02:52:53 +02:00
[bpf] allow direct and indirect calls
kernel verifier is becoming smarter and soon will support direct and indirect function calls. Remove obsolete error from BPF backend. Make call to use PCRel_4 fixup. 'bpf to bpf' calls are distinguished from 'bpf to kernel' calls by insn->src_reg == BPF_PSEUDO_CALL == 1 which is used as relocation indicator similar to ld_imm64->src_reg == BPF_PSEUDO_MAP_FD == 1 The actual 'call' instruction remains the same for both 'bpf to kernel' and 'bpf to bpf' calls. Signed-off-by: Alexei Starovoitov <ast@kernel.org> llvm-svn: 318614
This commit is contained in:
parent
329b3ccd40
commit
746f3d54fe
@ -330,13 +330,6 @@ SDValue BPFTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
|
||||
// Likewise ExternalSymbol -> TargetExternalSymbol.
|
||||
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
|
||||
auto GV = G->getGlobal();
|
||||
fail(CLI.DL, DAG,
|
||||
"A call to global function '" + StringRef(GV->getName())
|
||||
+ "' is not supported. "
|
||||
+ (GV->isDeclaration() ?
|
||||
"Only calls to predefined BPF helpers are allowed." :
|
||||
"Please use __attribute__((always_inline) to make sure"
|
||||
" this function is inlined."));
|
||||
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), CLI.DL, PtrVT,
|
||||
G->getOffset(), 0);
|
||||
} else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee)) {
|
||||
|
@ -400,6 +400,18 @@ class CALL<string OpcodeStr>
|
||||
let BPFClass = BPF_JMP;
|
||||
}
|
||||
|
||||
class CALLX<string OpcodeStr>
|
||||
: TYPE_ALU_JMP<BPF_CALL.Value, BPF_X.Value,
|
||||
(outs),
|
||||
(ins calltarget:$BrDst),
|
||||
!strconcat(OpcodeStr, " $BrDst"),
|
||||
[]> {
|
||||
bits<32> BrDst;
|
||||
|
||||
let Inst{31-0} = BrDst;
|
||||
let BPFClass = BPF_JMP;
|
||||
}
|
||||
|
||||
// Jump always
|
||||
let isBranch = 1, isTerminator = 1, hasDelaySlot=0, isBarrier = 1 in {
|
||||
def JMP : BRANCH<BPF_JA, "goto", [(br bb:$BrDst)]>;
|
||||
@ -410,6 +422,7 @@ let isCall=1, hasDelaySlot=0, Uses = [R11],
|
||||
// Potentially clobbered registers
|
||||
Defs = [R0, R1, R2, R3, R4, R5] in {
|
||||
def JAL : CALL<"call">;
|
||||
def JALX : CALLX<"callx">;
|
||||
}
|
||||
|
||||
class NOP_I<string OpcodeStr>
|
||||
@ -476,6 +489,7 @@ def : Pat<(i64 (and (i64 GPR:$src), 0xffffFFFF)),
|
||||
def : Pat<(BPFcall tglobaladdr:$dst), (JAL tglobaladdr:$dst)>;
|
||||
def : Pat<(BPFcall texternalsym:$dst), (JAL texternalsym:$dst)>;
|
||||
def : Pat<(BPFcall imm:$dst), (JAL imm:$dst)>;
|
||||
def : Pat<(BPFcall GPR:$dst), (JALX GPR:$dst)>;
|
||||
|
||||
// Loads
|
||||
def : Pat<(extloadi8 ADDRri:$src), (i64 (LDB ADDRri:$src))>;
|
||||
|
@ -76,6 +76,15 @@ void BPFAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
|
||||
unsigned Idx = IsLittleEndian ? i : Size - i - 1;
|
||||
Data[Fixup.getOffset() + Idx] = uint8_t(Value >> (i * 8));
|
||||
}
|
||||
} else if (Fixup.getKind() == FK_PCRel_4) {
|
||||
Value = (uint32_t)((Value - 8) / 8);
|
||||
if (IsLittleEndian) {
|
||||
Data[Fixup.getOffset() + 1] = 0x10;
|
||||
support::endian::write32le(&Data[Fixup.getOffset() + 4], Value);
|
||||
} else {
|
||||
Data[Fixup.getOffset() + 1] = 0x1;
|
||||
support::endian::write32be(&Data[Fixup.getOffset() + 4], Value);
|
||||
}
|
||||
} else {
|
||||
assert(Fixup.getKind() == FK_PCRel_2);
|
||||
Value = (uint16_t)((Value - 8) / 8);
|
||||
|
@ -44,6 +44,7 @@ unsigned BPFELFObjectWriter::getRelocType(MCContext &Ctx, const MCValue &Target,
|
||||
llvm_unreachable("invalid fixup kind!");
|
||||
case FK_SecRel_8:
|
||||
return ELF::R_BPF_64_64;
|
||||
case FK_PCRel_4:
|
||||
case FK_SecRel_4:
|
||||
return ELF::R_BPF_64_32;
|
||||
case FK_Data_8:
|
||||
|
@ -100,7 +100,7 @@ unsigned BPFMCCodeEmitter::getMachineOpValue(const MCInst &MI,
|
||||
|
||||
if (MI.getOpcode() == BPF::JAL)
|
||||
// func call name
|
||||
Fixups.push_back(MCFixup::create(0, Expr, FK_SecRel_4));
|
||||
Fixups.push_back(MCFixup::create(0, Expr, FK_PCRel_4));
|
||||
else if (MI.getOpcode() == BPF::LD_imm64)
|
||||
Fixups.push_back(MCFixup::create(0, Expr, FK_SecRel_8));
|
||||
else
|
||||
|
@ -1,4 +1,4 @@
|
||||
; RUN: not llc < %s -march=bpfel -show-mc-encoding | FileCheck %s
|
||||
; RUN: llc < %s -march=bpfel -show-mc-encoding | FileCheck %s
|
||||
|
||||
define void @test() #0 {
|
||||
entry:
|
||||
|
@ -1,4 +1,4 @@
|
||||
; RUN: not llc < %s -march=bpfeb -show-mc-encoding | FileCheck %s
|
||||
; RUN: llc < %s -march=bpfeb -show-mc-encoding | FileCheck %s
|
||||
; test big endian
|
||||
|
||||
define void @test() #0 {
|
||||
|
@ -1,4 +1,4 @@
|
||||
; RUN: not llc < %s -march=bpfel | FileCheck %s
|
||||
; RUN: llc < %s -march=bpfel | FileCheck %s
|
||||
|
||||
define void @test() #0 {
|
||||
entry:
|
||||
|
@ -1,4 +1,4 @@
|
||||
; RUN: not llc < %s -march=bpf | FileCheck %s
|
||||
; RUN: llc < %s -march=bpf | FileCheck %s
|
||||
|
||||
%struct.key_t = type { i32, [16 x i8] }
|
||||
|
||||
|
@ -1,4 +1,4 @@
|
||||
; RUN: not llc < %s -march=bpfel | FileCheck %s
|
||||
; RUN: llc < %s -march=bpfel | FileCheck %s
|
||||
|
||||
@foo_printf.fmt = private unnamed_addr constant [9 x i8] c"hello \0A\00", align 1
|
||||
|
||||
|
@ -1,5 +1,5 @@
|
||||
; RUN: not llc < %s -march=bpfel | FileCheck -check-prefixes=CHECK,EL %s
|
||||
; RUN: not llc < %s -march=bpfeb | FileCheck -check-prefixes=CHECK,EB %s
|
||||
; RUN: llc < %s -march=bpfel | FileCheck -check-prefixes=CHECK,EL %s
|
||||
; RUN: llc < %s -march=bpfeb | FileCheck -check-prefixes=CHECK,EB %s
|
||||
|
||||
%struct.bpf_map_def = type { i32, i32, i32, i32 }
|
||||
%struct.__sk_buff = type opaque
|
||||
|
@ -2,9 +2,6 @@
|
||||
|
||||
; CHECK: error: warn_call.c
|
||||
; CHECK: built-in function 'memcpy'
|
||||
; CHECK: error: warn_call.c
|
||||
; CHECK: global function 'foo'
|
||||
; CHECK: global function 'bar'
|
||||
define i8* @warn(i8* returned, i8*, i64) local_unnamed_addr #0 !dbg !6 {
|
||||
tail call void @llvm.dbg.value(metadata i8* %0, i64 0, metadata !14, metadata !17), !dbg !18
|
||||
tail call void @llvm.dbg.value(metadata i8* %1, i64 0, metadata !15, metadata !17), !dbg !19
|
||||
|
Loading…
Reference in New Issue
Block a user