feat: read full program name from function info

info.go

@@ -305,6 +305,7 @@ type ProgramInfo struct {
 
 	maps                 []MapID
 	insns                []byte
+	numInsns             uint32
 	jitedSize            uint32
 	verifiedInstructions uint32
 
@@ -372,6 +373,7 @@ func newProgramInfoFromFd(fd *sys.FD) (*ProgramInfo, error) {
 		jitedSize:            info.JitedProgLen,
 		loadTime:             time.Duration(info.LoadTime),
 		verifiedInstructions: info.VerifiedInsns,
+		numInsns:             info.XlatedProgLen,
 	}
 
 	// Supplement OBJ_INFO with data from /proc/self/fdinfo. It contains fields
@@ -416,9 +418,20 @@ func newProgramInfoFromFd(fd *sys.FD) (*ProgramInfo, error) {
 
 	if info.XlatedProgLen > 0 {
 		pi.insns = make([]byte, info.XlatedProgLen)
-		info2.XlatedProgLen = info.XlatedProgLen
-		info2.XlatedProgInsns = sys.SlicePointer(pi.insns)
-		makeSecondCall = true
+		var info3 sys.ProgInfo
+		info3.XlatedProgLen = info.XlatedProgLen
+		info3.XlatedProgInsns = sys.SlicePointer(pi.insns)
+
+		// When kernel.kptr_restrict and net.core.bpf_jit_harden are both set, it causes the
+		// syscall to abort when trying to readback xlated instructions, skipping other info
+		// as well. So request xlated instructions separately.
+		if err := sys.ObjInfo(fd, &info3); err != nil {
+			return nil, err
+		}
+		if info3.XlatedProgInsns.IsNil() {
+			pi.restricted = true
+			pi.insns = nil
+		}
 	}
 
 	if info.NrLineInfo > 0 {
@@ -477,19 +490,53 @@ func newProgramInfoFromFd(fd *sys.FD) (*ProgramInfo, error) {
 		if err := sys.ObjInfo(fd, &info2); err != nil {
 			return nil, err
 		}
+		if info.JitedProgLen > 0 && info2.JitedProgInsns.IsNil() {
+			// JIT information is not available due to kernel.kptr_restrict
+			pi.jitedInfo.lineInfos = nil
+			pi.jitedInfo.ksyms = nil
+			pi.jitedInfo.insns = nil
+			pi.jitedInfo.funcLens = nil
+		}
 	}
 
-	if info.XlatedProgLen > 0 && info2.XlatedProgInsns.IsNil() {
-		pi.restricted = true
-		pi.insns = nil
-		pi.lineInfos = nil
-		pi.funcInfos = nil
-		pi.jitedInfo = programJitedInfo{}
+	if len(pi.Name) == len(info.Name)-1 { // Possibly truncated, check BTF info for full name
+		name, err := readNameFromFunc(&pi)
+		if err == nil {
+			pi.Name = name
+		} // If an error occurs, keep the truncated name, which is better than none
 	}
 
 	return &pi, nil
 }
 
+func readNameFromFunc(pi *ProgramInfo) (string, error) {
+	if pi.numFuncInfos == 0 {
+		return "", errors.New("no function info")
+	}
+
+	spec, err := pi.btfSpec()
+	if err != nil {
+		return "", err
+	}
+
+	funcInfos, err := btf.LoadFuncInfos(
+		bytes.NewReader(pi.funcInfos),
+		internal.NativeEndian,
+		pi.numFuncInfos,
+		spec,
+	)
+	if err != nil {
+		return "", err
+	}
+
+	for _, funcInfo := range funcInfos {
+		if funcInfo.Offset == 0 { // Information about the whole program
+			return funcInfo.Func.Name, nil
+		}
+	}
+	return "", errors.New("no function info about program")
+}
+
 func readProgramInfoFromProc(fd *sys.FD, pi *ProgramInfo) error {
 	var progType uint32
 	err := scanFdInfo(fd, map[string]interface{}{
@@ -581,10 +628,6 @@ var ErrRestrictedKernel = internal.ErrRestrictedKernel
 // 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 pi.restricted {
-		return nil, fmt.Errorf("line infos: %w", ErrRestrictedKernel)
-	}
-
 	if len(pi.lineInfos) == 0 {
 		return nil, fmt.Errorf("insufficient permissions or unsupported kernel: %w", ErrNotSupported)
 	}
@@ -708,10 +751,6 @@ func (pi *ProgramInfo) Instructions() (asm.Instructions, error) {
 //
 // Available from 4.13. Reading this metadata requires CAP_BPF or equivalent.
 func (pi *ProgramInfo) JitedSize() (uint32, error) {
-	if pi.restricted {
-		return 0, fmt.Errorf("jited size: %w", ErrRestrictedKernel)
-	}
-
 	if pi.jitedSize == 0 {
 		return 0, fmt.Errorf("insufficient permissions, unsupported kernel, or JIT compiler disabled: %w", ErrNotSupported)
 	}
@@ -721,20 +760,12 @@ func (pi *ProgramInfo) JitedSize() (uint32, error) {
 // TranslatedSize returns the size of the program's translated instructions in
 // bytes, after it has been verified and rewritten by the kernel.
 //
-// Returns an error wrapping [ErrRestrictedKernel] if translated instructions
-// are restricted by sysctls.
-//
 // Available from 4.13. Reading this metadata requires CAP_BPF or equivalent.
 func (pi *ProgramInfo) TranslatedSize() (int, error) {
-	if pi.restricted {
-		return 0, fmt.Errorf("xlated size: %w", ErrRestrictedKernel)
-	}
-
-	insns := len(pi.insns)
-	if insns == 0 {
+	if pi.numInsns == 0 {
 		return 0, fmt.Errorf("insufficient permissions or unsupported kernel: %w", ErrNotSupported)
 	}
-	return insns, nil
+	return int(pi.numInsns), nil
 }
 
 // MapIDs returns the maps related to the program.
@@ -832,10 +863,6 @@ func (pi *ProgramInfo) JitedFuncLens() ([]uint32, 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) {
-	if pi.restricted {
-		return nil, fmt.Errorf("func infos: %w", ErrRestrictedKernel)
-	}
-
 	if len(pi.funcInfos) == 0 {
 		return nil, fmt.Errorf("insufficient permissions or unsupported kernel: %w", ErrNotSupported)
 	}