[ksyms] Do not cache ksyms to reduce memory consumption

We use ksyms for checking the proper exit hooks when loading the base
sensor. Furthermore, we use it when we add a kprobe policy for a
function that is part of a kernel module.

Having that always in memory, uses a lot of memory. This patch makes the
read of ksyms when we need that.

Signed-off-by: Anastasios Papagiannis <tasos.papagiannnis@gmail.com>

pkg/ksyms/ksyms.go

@@ -11,25 +11,15 @@ import (
 	"sort"
 	"strconv"
 	"strings"
-	"sync"
 
 	"github.com/cilium/tetragon/pkg/logger"
 	"github.com/cilium/tetragon/pkg/option"
 
 	lru "github.com/hashicorp/golang-lru/v2"
 )
 
-var (
-	kernelSymbols    *Ksyms
-	setKernelSymbols sync.Once
-)
-
 func KernelSymbols() (*Ksyms, error) {
-	var err error
-	setKernelSymbols.Do(func() {
-		kernelSymbols, err = NewKsyms(option.Config.ProcFS)
-	})
-	return kernelSymbols, err
+	return NewKsyms(option.Config.ProcFS)
 }
 
 type ksym struct {