Fix unresovled kernel symbols when /proc/kallsyms is not sorted

grafana · Sep 24, 2024 · 94ff4bc · 94ff4bc
1 parent 7439460
commit 94ff4bc
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/ebpf/symtab/kallsyms.go b/ebpf/symtab/kallsyms.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"runtime"
+	"sort"
 	"strconv"
 )
 
@@ -94,5 +95,9 @@ func NewKallsymsFromData(kallsyms []byte) (*SymbolTab, error) {
 	if allZeros {
 		return NewSymbolTab(nil), nil
 	}
+	// kallsyms maybe unsorted when bpf/modules are loaded from userspace after kernel boot.
+	sort.Slice(syms, func(i, j int) bool {
+		return syms[i].Start < syms[j].Start
+	})
 	return NewSymbolTab(syms), nil
 }
diff --git a/ebpf/symtab/kallsyms_test.go b/ebpf/symtab/kallsyms_test.go
@@ -25,7 +25,9 @@ ffffffff81001750 T memblock_find
 ffffffff81001780 T __memblock_alloc_base
 ffffffff810017d0 T memblock_alloc
 ffffffff81001820 T early_memtest
-ffffffff810018a0 T early_memtest_report`
+ffffffff810018a0 T early_memtest_report
+ffffffff81000800 T unordered_symbol_0
+ffffffff81000100 T unordered_symbol_1`
 
 func TestKallsyms(t *testing.T) {
 	kallsyms, err := NewKallsymsFromData([]byte(testdata))