info: expose more prog jited info

Expose these prog jited info: 1. JITed machine native instructions torvalds/linux@1e2709769086 ("bpf: Add BPF_OBJ_GET_INFO_BY_FD") 2. JITed line info torvalds/linux@c454a46b5efd ("bpf: Add bpf_line_info support") 3. JITed image lengths torvalds/linux@815581c11cc2 ("bpf: get JITed image lengths of functions via syscall") Signed-off-by: Leon Hwang <[email protected]>
cilium · Nov 25, 2024 · a34ec46 · a34ec46
1 parent ab9722b
commit a34ec46
Show file tree

Hide file tree

Showing 3 changed files with 149 additions and 24 deletions.
diff --git a/info.go b/info.go
@@ -179,6 +179,40 @@ type programStats struct {
 	recursionMisses uint64
 }
 
+// programJitedInfo holds information about JITed info of a program.
+type programJitedInfo struct {
+	// ksyms holds the ksym addresses of the BPF program, including those of its
+	// subprograms.
+	//
+	// Available from 4.18.
+	ksyms    []uintptr
+	numKsyms uint32
+
+	// insns holds the JITed machine native instructions of the program,
+	// including those of its subprograms.
+	//
+	// Available from 4.13.
+	insns    []byte
+	numInsns uint32
+
+	// lineInfos holds the JITed line infos, which are kernel addresses.
+	//
+	// Available from 5.0.
+	lineInfos    []uint64
+	numLineInfos uint32
+
+	// lineInfoRecSize is the size of a single line info record.
+	//
+	// Available from 5.0.
+	lineInfoRecSize uint32
+
+	// funcLens holds the insns length of each function.
+	//
+	// Available from 4.18.
+	funcLens    []uint32
+	numFuncLens uint32
+}
+
 // ProgramInfo describes a program.
 type ProgramInfo struct {
 	Type ProgramType
@@ -199,12 +233,12 @@ type ProgramInfo struct {
 	jitedSize            uint32
 	verifiedInstructions uint32
 
+	jitedInfo programJitedInfo
+
 	lineInfos    []byte
 	numLineInfos uint32
 	funcInfos    []byte
 	numFuncInfos uint32
-	ksymInfos    []uint64
-	numKsymInfos uint32
 }
 
 func newProgramInfoFromFd(fd *sys.FD) (*ProgramInfo, error) {
@@ -282,11 +316,37 @@ func newProgramInfoFromFd(fd *sys.FD) (*ProgramInfo, error) {
 		makeSecondCall = true
 	}
 
+	pi.jitedInfo.lineInfoRecSize = info.JitedLineInfoRecSize
+	if info.JitedProgLen > 0 {
+		pi.jitedInfo.numInsns = info.JitedProgLen
+		pi.jitedInfo.insns = make([]byte, info.JitedProgLen)
+		info2.JitedProgLen = info.JitedProgLen
+		info2.JitedProgInsns = sys.NewSlicePointer(pi.jitedInfo.insns)
+		makeSecondCall = true
+	}
+
+	if info.NrJitedFuncLens > 0 {
+		pi.jitedInfo.numFuncLens = info.NrJitedFuncLens
+		pi.jitedInfo.funcLens = make([]uint32, info.NrJitedFuncLens)
+		info2.NrJitedFuncLens = info.NrJitedFuncLens
+		info2.JitedFuncLens = sys.NewSlicePointer(pi.jitedInfo.funcLens)
+		makeSecondCall = true
+	}
+
+	if info.NrJitedLineInfo > 0 {
+		pi.jitedInfo.numLineInfos = info.NrJitedLineInfo
+		pi.jitedInfo.lineInfos = make([]uint64, info.NrJitedLineInfo)
+		info2.NrJitedLineInfo = info.NrJitedLineInfo
+		info2.JitedLineInfo = sys.NewSlicePointer(pi.jitedInfo.lineInfos)
+		info2.JitedLineInfoRecSize = info.JitedLineInfoRecSize
+		makeSecondCall = true
+	}
+
 	if info.NrJitedKsyms > 0 {
-		pi.ksymInfos = make([]uint64, info.NrJitedKsyms)
-		info2.JitedKsyms = sys.NewSlicePointer(pi.ksymInfos)
+		pi.jitedInfo.numKsyms = info.NrJitedKsyms
+		pi.jitedInfo.ksyms = make([]uintptr, info.NrJitedKsyms)
+		info2.JitedKsyms = sys.NewSlicePointer(pi.jitedInfo.ksyms)
 		info2.NrJitedKsyms = info.NrJitedKsyms
-		pi.numKsymInfos = info.NrJitedKsyms
 		makeSecondCall = true
 	}
 
@@ -380,6 +440,52 @@ func (pi *ProgramInfo) RecursionMisses() (uint64, bool) {
 	return 0, false
 }
 
+// btfSpec returns the BTF spec associated with the program.
+func (pi *ProgramInfo) btfSpec() (*btf.Spec, error) {
+	id, ok := pi.BTFID()
+	if !ok {
+		return nil, fmt.Errorf("program created without BTF or unsupported kernel: %w", ErrNotSupported)
+	}
+
+	h, err := btf.NewHandleFromID(id)
+	if err != nil {
+		return nil, fmt.Errorf("get BTF handle: %w", err)
+	}
+	defer h.Close()
+
+	spec, err := h.Spec(nil)
+	if err != nil {
+		return nil, fmt.Errorf("get BTF spec: %w", err)
+	}
+
+	return spec, nil
+}
+
+// LineInfos returns the BTF line information of the program.
+//
+// Available from 5.0.
+//
+// Requires CAP_SYS_ADMIN or equivalent for reading BTF information. Returns
+// ErrNotSupported if the program was created without BTF or if the kernel
+// doesn't support the field.
+func (pi *ProgramInfo) LineInfos() (btf.LineOffsets, error) {
+	if len(pi.lineInfos) == 0 {
+		return nil, fmt.Errorf("insufficient permissions or unsupported kernel: %w", ErrNotSupported)
+	}
+
+	spec, err := pi.btfSpec()
+	if err != nil {
+		return nil, err
+	}
+
+	return btf.LoadLineInfos(
+		bytes.NewReader(pi.lineInfos),
+		internal.NativeEndian,
+		pi.numLineInfos,
+		spec,
+	)
+}
+
 // Instructions returns the 'xlated' instruction stream of the program
 // after it has been verified and rewritten by the kernel. These instructions
 // cannot be loaded back into the kernel as-is, this is mainly used for
@@ -524,11 +630,34 @@ func (pi *ProgramInfo) VerifiedInstructions() (uint32, bool) {
 //
 // The bool return value indicates whether this optional field is available.
 func (pi *ProgramInfo) KsymAddrs() ([]uintptr, bool) {
-	addrs := make([]uintptr, 0, len(pi.ksymInfos))
-	for _, addr := range pi.ksymInfos {
-		addrs = append(addrs, uintptr(addr))
-	}
-	return addrs, pi.numKsymInfos > 0
+	return pi.jitedInfo.ksyms, len(pi.jitedInfo.ksyms) > 0
+}
+
+// JitedInsns returns the JITed machine native instructions of the program.
+//
+// Available from 4.13.
+//
+// The bool return value indicates whether this optional field is available.
+func (pi *ProgramInfo) JitedInsns() ([]byte, bool) {
+	return pi.jitedInfo.insns, len(pi.jitedInfo.insns) > 0
+}
+
+// JitedLineInfos returns the JITed line infos of the program.
+//
+// Available from 5.0.
+//
+// The bool return value indicates whether this optional field is available.
+func (pi *ProgramInfo) JitedLineInfos() ([]uint64, bool) {
+	return pi.jitedInfo.lineInfos, len(pi.jitedInfo.lineInfos) > 0
+}
+
+// JitedFuncLens returns the insns length of each function in the JITed program.
+//
+// Available from 4.18.
+//
+// The bool return value indicates whether this optional field is available.
+func (pi *ProgramInfo) JitedFuncLens() ([]uint32, bool) {
+	return pi.jitedInfo.funcLens, len(pi.jitedInfo.funcLens) > 0
 }
 
 // FuncInfos returns the offset and function information of all (sub)programs in
@@ -540,20 +669,13 @@ func (pi *ProgramInfo) KsymAddrs() ([]uintptr, bool) {
 // ErrNotSupported if the program was created without BTF or if the kernel
 // doesn't support the field.
 func (pi *ProgramInfo) FuncInfos() (btf.FuncOffsets, error) {
-	id, ok := pi.BTFID()
-	if pi.numFuncInfos == 0 || !ok {
-		return nil, fmt.Errorf("program created without BTF or unsupported kernel: %w", ErrNotSupported)
-	}
-
-	h, err := btf.NewHandleFromID(id)
-	if err != nil {
-		return nil, fmt.Errorf("get BTF handle: %w", err)
+	if len(pi.funcInfos) == 0 {
+		return nil, fmt.Errorf("insufficient permissions or unsupported kernel: %w", ErrNotSupported)
 	}
-	defer h.Close()
 
-	spec, err := h.Spec(nil)
+	spec, err := pi.btfSpec()
 	if err != nil {
-		return nil, fmt.Errorf("get BTF spec: %w", err)
+		return nil, err
 	}
 
 	return btf.LoadFuncInfos(

diff --git a/internal/cmd/gentypes/main.go b/internal/cmd/gentypes/main.go
@@ -197,10 +197,13 @@ import (
 			"ProgInfo", "bpf_prog_info",
 			[]patch{
 				replace(objName, "name"),
+				replace(pointer, "jited_prog_insns"),
 				replace(pointer, "xlated_prog_insns"),
 				replace(pointer, "map_ids"),
 				replace(pointer, "line_info"),
+				replace(pointer, "jited_line_info"),
 				replace(pointer, "jited_ksyms"),
+				replace(pointer, "jited_func_lens"),
 				replace(pointer, "func_info"),
 				replace(btfID, "btf_id", "attach_btf_obj_id"),
 				replace(typeID, "attach_btf_id"),

diff --git a/internal/sys/types.go b/internal/sys/types.go
@@ -720,7 +720,7 @@ type ProgInfo struct {
 	Tag                  [8]uint8
 	JitedProgLen         uint32
 	XlatedProgLen        uint32
-	JitedProgInsns       uint64
+	JitedProgInsns       Pointer
 	XlatedProgInsns      Pointer
 	LoadTime             uint64
 	CreatedByUid         uint32
@@ -734,14 +734,14 @@ type ProgInfo struct {
 	NrJitedKsyms         uint32
 	NrJitedFuncLens      uint32
 	JitedKsyms           Pointer
-	JitedFuncLens        uint64
+	JitedFuncLens        Pointer
 	BtfId                BTFID
 	FuncInfoRecSize      uint32
 	FuncInfo             Pointer
 	NrFuncInfo           uint32
 	NrLineInfo           uint32
 	LineInfo             Pointer
-	JitedLineInfo        uint64
+	JitedLineInfo        Pointer
 	NrJitedLineInfo      uint32
 	LineInfoRecSize      uint32
 	JitedLineInfoRecSize uint32