sys: expose new syscall numbers programmatically

This will be required for reproduction tool.

1 files changed, 67 insertions, 29 deletions

diff --git a/sysgen/sysgen.go b/sysgen/sysgen.go
index b3496d004..82e31f349 100644
--- a/sysgen/sysgen.go
+++ b/sysgen/sysgen.go
@@ -15,6 +15,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"text/template"
 )
 
 func main() {
@@ -453,47 +454,84 @@ func generateConsts(flags map[string]string, out io.Writer) {
 		fmt.Fprintf(out, "	%v = %v\n", f.name, f.val)
 	}
 	fmt.Fprintf(out, ")\n")
+	fmt.Fprintf(out, "\n")
+
+	fmt.Fprintf(out, "var NewSyscalls = map[string]int {\n")
+	for call, nr := range NewSyscalls {
+		fmt.Fprintf(out, "	\"%v\": %v,\n", call, nr)
+	}
+	fmt.Fprintf(out, "}\n")
 }
 
-func generateHeader(syscalls []Syscall, out io.Writer) {
-	fmt.Fprint(out, `// AUTOGENERATED FILE
+// Note: this is x86_64 numbers
+var NewSyscalls = map[string]int{
+	"getrandom":    318,
+	"memfd_create": 319,
+	"bpf":          321,
+	"userfaultfd":  323,
+	"membarrier":   324,
+	"mlock2":       325,
+
+	"syz_openpts":       1000001,
+	"syz_dri_open":      1000002,
+	"syz_fuse_mount":    1000003,
+	"syz_fuseblk_mount": 1000004,
+}
+
+var syscallsTempl = template.Must(template.New("").Parse(
+	`// AUTOGENERATED FILE
+
+// Note: this is x86_64 numbers
+{{range $c := $.Defines}}
+#ifndef __NR_{{$c.Name}}
+#define __NR_{{$c.Name}} {{$c.Val}}
+#endif
+{{end}}
 
 struct call_t {
 	const char*	name;
 	int		sys_nr;
 };
 
-// Note: this is x86_64 number
-#ifndef __NR_getrandom
-#define __NR_getrandom 318
-#endif
-#ifndef __NR_memfd_create
-#define __NR_memfd_create 319
-#endif
-#ifndef __NR_bpf
-#define __NR_bpf 321
-#endif
-#ifndef __NR_userfaultfd
-#define __NR_userfaultfd 323
-#endif
-#ifndef __NR_membarrier
-#define __NR_membarrier 324
-#endif
-#ifndef __NR_mlock2
-#define __NR_mlock2 325
-#endif
+call_t syscalls[] = {
+{{range $c := $.Syscalls}}
+	{"{{$c.Name}}", __NR_{{$c.CallName}}},{{end}}
+};
+`))
 
-#define __NR_syz_openpts	1000001
-#define __NR_syz_dri_open	1000002
-#define __NR_syz_fuse_mount	1000003
-#define __NR_syz_fuseblk_mount	1000004
+type TemplData struct {
+	Syscalls []SyscallData
+	Defines  []DefineData
+}
 
-call_t syscalls[] = {
-`)
+type SyscallData struct {
+	Name     string
+	CallName string
+}
+
+type DefineData struct {
+	Name string
+	Val  int
+}
+
+func generateHeader(syscalls []Syscall, out io.Writer) {
+	var data TemplData
+	present := make(map[string]bool)
 	for _, s := range syscalls {
-		fmt.Fprintf(out, "\t{\"%v\", __NR_%v},\n", s.Name, s.CallName)
+		data.Syscalls = append(data.Syscalls, SyscallData{Name: s.Name, CallName: s.CallName})
+		if !present[s.CallName] {
+			present[s.CallName] = true
+			nr, ok := NewSyscalls[s.CallName]
+			if !ok {
+				nr = -1
+			}
+			data.Defines = append(data.Defines, DefineData{Name: s.CallName, Val: nr})
+		}
+	}
+
+	if err := syscallsTempl.Execute(out, data); err != nil {
+		panic(err)
 	}
-	fmt.Fprintf(out, "};\n")
 }
 
 func compileFlags(includes []string, defines map[string]string, flags map[string][]string) (map[string][]string, map[string]string) {