[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
diff --git a/llvm/lib/Target/BPF/BPFISelLowering.cpp b/llvm/lib/Target/BPF/BPFISelLowering.cpp
index 995f206..f9078fa 100644
--- a/llvm/lib/Target/BPF/BPFISelLowering.cpp
+++ b/llvm/lib/Target/BPF/BPFISelLowering.cpp
@@ -330,13 +330,6 @@
// 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)) {
diff --git a/llvm/lib/Target/BPF/BPFInstrInfo.td b/llvm/lib/Target/BPF/BPFInstrInfo.td
index 27b26b9..126d55f 100644
--- a/llvm/lib/Target/BPF/BPFInstrInfo.td
+++ b/llvm/lib/Target/BPF/BPFInstrInfo.td
@@ -400,6 +400,18 @@
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 @@
// 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<(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))>;
diff --git a/llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp b/llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
index 800700d..e6ea92e 100644
--- a/llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
+++ b/llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
@@ -76,6 +76,15 @@
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);
diff --git a/llvm/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp b/llvm/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp
index 144ea2b..f7de612 100644
--- a/llvm/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp
+++ b/llvm/lib/Target/BPF/MCTargetDesc/BPFELFObjectWriter.cpp
@@ -44,6 +44,7 @@
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:
diff --git a/llvm/lib/Target/BPF/MCTargetDesc/BPFMCCodeEmitter.cpp b/llvm/lib/Target/BPF/MCTargetDesc/BPFMCCodeEmitter.cpp
index e8c9744..b4ecfde 100644
--- a/llvm/lib/Target/BPF/MCTargetDesc/BPFMCCodeEmitter.cpp
+++ b/llvm/lib/Target/BPF/MCTargetDesc/BPFMCCodeEmitter.cpp
@@ -100,7 +100,7 @@
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
diff --git a/llvm/test/CodeGen/BPF/cc_args.ll b/llvm/test/CodeGen/BPF/cc_args.ll
index 6a0a07a..020992a 100644
--- a/llvm/test/CodeGen/BPF/cc_args.ll
+++ b/llvm/test/CodeGen/BPF/cc_args.ll
@@ -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:
diff --git a/llvm/test/CodeGen/BPF/cc_args_be.ll b/llvm/test/CodeGen/BPF/cc_args_be.ll
index a2f1956..469556f 100644
--- a/llvm/test/CodeGen/BPF/cc_args_be.ll
+++ b/llvm/test/CodeGen/BPF/cc_args_be.ll
@@ -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 {
diff --git a/llvm/test/CodeGen/BPF/cc_ret.ll b/llvm/test/CodeGen/BPF/cc_ret.ll
index be198f5..73e3556 100644
--- a/llvm/test/CodeGen/BPF/cc_ret.ll
+++ b/llvm/test/CodeGen/BPF/cc_ret.ll
@@ -1,4 +1,4 @@
-; RUN: not llc < %s -march=bpfel | FileCheck %s
+; RUN: llc < %s -march=bpfel | FileCheck %s
define void @test() #0 {
entry:
diff --git a/llvm/test/CodeGen/BPF/fi_ri.ll b/llvm/test/CodeGen/BPF/fi_ri.ll
index 6ecc826..1245298 100644
--- a/llvm/test/CodeGen/BPF/fi_ri.ll
+++ b/llvm/test/CodeGen/BPF/fi_ri.ll
@@ -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] }
diff --git a/llvm/test/CodeGen/BPF/sanity.ll b/llvm/test/CodeGen/BPF/sanity.ll
index ebee851..33cfc2f 100644
--- a/llvm/test/CodeGen/BPF/sanity.ll
+++ b/llvm/test/CodeGen/BPF/sanity.ll
@@ -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
diff --git a/llvm/test/CodeGen/BPF/undef.ll b/llvm/test/CodeGen/BPF/undef.ll
index 6b99486..11bc9eb 100644
--- a/llvm/test/CodeGen/BPF/undef.ll
+++ b/llvm/test/CodeGen/BPF/undef.ll
@@ -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
diff --git a/llvm/test/CodeGen/BPF/warn-call.ll b/llvm/test/CodeGen/BPF/warn-call.ll
index ae7f78a..6dadb35 100644
--- a/llvm/test/CodeGen/BPF/warn-call.ll
+++ b/llvm/test/CodeGen/BPF/warn-call.ll
@@ -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