bpflbr: Add verbose log when --verbose

Signed-off-by: Leon Hwang <[email protected]>

internal/bpflbr/disasm.go

@@ -60,6 +60,7 @@ func readKcore(kaddr uint64, bytes uint) ([]byte, bool) {
 }
 
 func dumpKfunc(kfunc string, bytes uint) {
+	VerboseLog("Reading /proc/kallsyms ..")
 	kallsyms, err := NewKallsyms()
 	assert.NoErr(err, "Failed to read /proc/kallsyms: %v")
 
@@ -82,11 +83,15 @@ func dumpKfunc(kfunc string, bytes uint) {
 
 	vmlinux, err := FindVmlinux()
 	assert.NoErr(err, "Failed to find vmlinux: %v")
+	VerboseLog("Found vmlinux: %s", vmlinux)
 
 	textAddr, err := ReadTextAddrFromVmlinux(vmlinux)
 	assert.NoErr(err, "Failed to read .text address from vmlinux: %v")
 
 	kaslrOffset := textAddr - kallsyms.Stext()
+	VerboseLog("KASLR offset: %#x", kaslrOffset)
+
+	VerboseLog("Creating addr2line from vmlinux ..")
 	addr2line, err := NewAddr2Line(vmlinux, kaslrOffset, kallsyms.SysBPF())
 	assert.NoErr(err, "Failed to create addr2line: %v")
 
@@ -99,6 +104,7 @@ func dumpKfunc(kfunc string, bytes uint) {
 		assert.NoErr(err, "Failed to set syntax: %v")
 	}
 
+	VerboseLog("Disassembling bpf progs ..")
 	bpfProgs, err := NewBPFProgs(engine, nil, false)
 	assert.NoErr(err, "Failed to get bpf progs: %v")
 	defer bpfProgs.Close()

internal/bpflbr/dump.go

@@ -31,23 +31,29 @@ func DumpProg(pf []ProgFlag) {
 		log.Fatalf("No prog found")
 	}
 
+	VerboseLog("Reading /proc/kallsyms ..")
 	kallsyms, err := NewKallsyms()
 	assert.NoErr(err, "Failed to read /proc/kallsyms: %v")
 
 	vmlinux, err := FindVmlinux()
 	assert.NoErr(err, "Failed to find vmlinux: %v")
+	VerboseLog("Found vmlinux: %s", vmlinux)
 
 	textAddr, err := ReadTextAddrFromVmlinux(vmlinux)
 	assert.NoErr(err, "Failed to read .text address from vmlinux: %v")
 
 	kaslrOffset := textAddr - kallsyms.Stext()
+	VerboseLog("KASLR offset: %#x", kaslrOffset)
+
+	VerboseLog("Creating addr2line from vmlinux ..")
 	addr2line, err := NewAddr2Line(vmlinux, kaslrOffset, kallsyms.SysBPF())
 	assert.NoErr(err, "Failed to create addr2line: %v")
 
 	engine, err := gapstone.New(int(gapstone.CS_ARCH_X86), int(gapstone.CS_MODE_64))
 	assert.NoErr(err, "Failed to create engine: %v")
 	defer engine.Close()
 
+	VerboseLog("Disassembling bpf progs ..")
 	bpfProgs, err := NewBPFProgs(engine, nil, false)
 	assert.NoErr(err, "Failed to get bpf progs: %v")
 	defer bpfProgs.Close()

internal/bpflbr/log.go

@@ -0,0 +1,12 @@
+// Copyright 2024 Leon Hwang.
+// SPDX-License-Identifier: Apache-2.0
+
+package bpflbr
+
+import "log"
+
+func VerboseLog(format string, args ...interface{}) {
+	if verbose {
+		log.Printf(format, args...)
+	}
+}

main.go

@@ -54,30 +54,37 @@ func main() {
 	assert.NoErr(err, "Failed to open LBR perf event: %v")
 	defer lbrPerfEvents.Close()
 
+	bpflbr.VerboseLog("Reading /proc/kallsyms ..")
 	kallsyms, err := bpflbr.NewKallsyms()
 	assert.NoErr(err, "Failed to read /proc/kallsyms: %v")
 
 	vmlinux, err := bpflbr.FindVmlinux()
 	assert.NoErr(err, "Failed to find vmlinux: %v")
+	bpflbr.VerboseLog("Found vmlinux: %s", vmlinux)
 
 	textAddr, err := bpflbr.ReadTextAddrFromVmlinux(vmlinux)
 	assert.NoErr(err, "Failed to read .text address from vmlinux: %v")
 
 	kaslrOffset := textAddr - kallsyms.Stext()
+	bpflbr.VerboseLog("KASLR offset: 0x%x", kaslrOffset)
+
+	bpflbr.VerboseLog("Creating addr2line from vmlinux ..")
 	addr2line, err := bpflbr.NewAddr2Line(vmlinux, kaslrOffset, kallsyms.SysBPF())
 	assert.NoErr(err, "Failed to create addr2line: %v")
 
 	engine, err := gapstone.New(int(gapstone.CS_ARCH_X86), int(gapstone.CS_MODE_64))
 	assert.NoErr(err, "Failed to create capstone engine: %v")
 	defer engine.Close()
 
+	bpflbr.VerboseLog("Disassembling bpf progs ..")
 	bpfProgs, err := bpflbr.NewBPFProgs(engine, progs, false)
 	assert.NoErr(err, "Failed to get bpf progs: %v")
 	defer bpfProgs.Close()
 
 	tracingTargets := bpfProgs.Tracings()
 	assert.True(len(tracingTargets)+len(flags.Kfuncs()) != 0, "No tracing target")
 
+	bpflbr.VerboseLog("Tracing bpf progs or kernel functions ..")
 	bpfSpec, err := loadLbr()
 	assert.NoErr(err, "Failed to load bpf spec: %v")
 	delete(bpfSpec.Programs, bpflbr.TracingProgName(flags.OtherMode()))