From 703ca45bb7ef43679d6bfc489a86baa74cf518cc Mon Sep 17 00:00:00 2001
From: Joey Jiao <quic_jiangenj@quicinc.com>
Date: Tue, 14 May 2024 14:08:15 +0800
Subject: pkg/vminfo: parse linux core kernel to get Addr and .text Size

---
 pkg/vminfo/linux.go | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

(limited to 'pkg')

diff --git a/pkg/vminfo/linux.go b/pkg/vminfo/linux.go
index 96f6bf47c..c8e81dd01 100644
--- a/pkg/vminfo/linux.go
+++ b/pkg/vminfo/linux.go
@@ -10,6 +10,7 @@ import (
 	"io"
 	"path"
 	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -70,6 +71,18 @@ func (linux) parseModules(files filesystem) ([]*cover.KernelModule, error) {
 			Size: modSize - offset,
 		})
 	}
+	_stext, _etext, err := linuxParseCoreKernel(files)
+	if err != nil {
+		return nil, err
+	}
+	modules = append(modules, cover.KernelModule{
+		Name: "",
+		Addr: _stext,
+		Size: _etext - _stext,
+	})
+	sort.Slice(modules, func(i, j int) bool {
+		return modules[i].Addr < modules[j].Addr
+	})
 	return modules, nil
 }
 
@@ -86,6 +99,29 @@ func linuxModuleTextAddr(files filesystem, module string) (uint64, error) {
 	return addr, nil
 }
 
+func linuxParseCoreKernel(files filesystem) (uint64, uint64, error) {
+	_Text, _ := files.ReadFile("/proc/kallsyms")
+	re := regexp.MustCompile(`([a-fA-F0-9]+) T _stext\n`)
+	m := re.FindSubmatch(_Text)
+	if m == nil {
+		return 0, 0, fmt.Errorf("failed to get _stext symbol")
+	}
+	_stext, err := strconv.ParseUint("0x"+string(m[1]), 0, 64)
+	if err != nil {
+		return 0, 0, fmt.Errorf("address parsing error in /proc/kallsyms for _stext: %w", err)
+	}
+	re = regexp.MustCompile(`([a-fA-F0-9]+) [DT] _etext\n`)
+	m = re.FindSubmatch(_Text)
+	if m == nil {
+		return 0, 0, fmt.Errorf("failed to get _etext symbol")
+	}
+	_etext, err := strconv.ParseUint("0x"+string(m[1]), 0, 64)
+	if err != nil {
+		return 0, 0, fmt.Errorf("address parsing error in /proc/kallsyms for _etext: %w", err)
+	}
+	return _stext, _etext, nil
+}
+
 func linuxReadCPUInfo(files filesystem, w io.Writer) (string, error) {
 	data, err := files.ReadFile("/proc/cpuinfo")
 	if err != nil {
-- 
cgit mrf-deployment