diff options
| -rw-r--r-- | README.md | 3 | ||||
| -rw-r--r-- | sysgen/fetch.go | 4 | ||||
| -rw-r--r-- | sysgen/syscallnr.go | 8 | ||||
| -rw-r--r-- | sysgen/sysgen.go | 29 |
4 files changed, 40 insertions, 4 deletions
@@ -230,6 +230,9 @@ This will re-create the following source code files: (per-architecture) kernel syscall numbers. - `executor/syscalls.h`: Constant definitions (in C) for all system call numbers. +If there are problems with this step, run `bin/syz-sysgen` directly and add +the use `-v=5` flag to show more details of the generation process. + Rebuild syzkaller (`make clean all`) to force use of the new system call definitions. Finally, adjust the `enable_syscalls` configuration value for syzkaller to specifically target the diff --git a/sysgen/fetch.go b/sysgen/fetch.go index 0c43d3d7d..941c6d587 100644 --- a/sysgen/fetch.go +++ b/sysgen/fetch.go @@ -16,6 +16,7 @@ import ( // into their respective numeric values. It does so by builting and executing a C program // that prints values of the provided expressions. func fetchValues(arch string, vals []string, includes []string, defines map[string]string) []string { + logf(1, "Use C compiler to fetch constant values for arch=%v", arch) includeText := "" for _, inc := range includes { includeText += fmt.Sprintf("#include <%v>\n", inc) @@ -33,6 +34,7 @@ func fetchValues(arch string, vals []string, includes []string, defines map[stri } bin.Close() defer os.Remove(bin.Name()) + logf(2, " Build C program into temp file %v", bin.Name()) args := []string{"-x", "c", "-", "-o", bin.Name()} args = append(args, []string{ @@ -55,6 +57,8 @@ func fetchValues(arch string, vals []string, includes []string, defines map[stri "-include", *flagLinux + "/include/linux/kconfig.h", }...) + logf(4, " Source code:\n%v", src) + logf(2, " Execute gcc with: %v", args) cmd := exec.Command("gcc", args...) cmd.Stdin = strings.NewReader(src) out, err := cmd.CombinedOutput() diff --git a/sysgen/syscallnr.go b/sysgen/syscallnr.go index 7e8131762..124ccc697 100644 --- a/sysgen/syscallnr.go +++ b/sysgen/syscallnr.go @@ -61,11 +61,13 @@ func fetchSyscallsNumbers(arch *Arch, syscalls []Syscall) { } func generateSyscallsNumbersArch(arch *Arch, syscalls []Syscall) { + var archcode string = "sys/sys_"+arch.GOARCH+".go" + logf(1, "Generate code with syscall numbers for arch=%v in %v", arch.GOARCH, archcode) buf := new(bytes.Buffer) if err := archTempl.Execute(buf, arch); err != nil { failf("failed to execute arch template: %v", err) } - writeSource("sys/sys_"+arch.GOARCH+".go", buf.Bytes()) + writeSource(archcode, buf.Bytes()) } func generateExecutorSyscalls(syscalls []Syscall) { @@ -82,11 +84,13 @@ func generateExecutorSyscalls(syscalls []Syscall) { } sort.Sort(SyscallArray(data.FakeCalls)) + var hdrcode string = "executor/syscalls.h" + logf(1, "Generate header with syscall numbers in %v", hdrcode) buf := new(bytes.Buffer) if err := syscallsTempl.Execute(buf, data); err != nil { failf("failed to execute syscalls template: %v", err) } - writeFile("executor/syscalls.h", buf.Bytes()) + writeFile(hdrcode, buf.Bytes()) } type SyscallsData struct { diff --git a/sysgen/sysgen.go b/sysgen/sysgen.go index f52e12ab7..4fbb31755 100644 --- a/sysgen/sysgen.go +++ b/sysgen/sysgen.go @@ -10,6 +10,7 @@ import ( "fmt" "go/format" "io" + "log" "os" "sort" "strconv" @@ -19,6 +20,7 @@ import ( var ( flagLinux = flag.String("linux", "", "path to linux kernel source checkout") flagLinuxBld = flag.String("linuxbld", "", "path to linux kernel build directory") + flagV = flag.Int("v", 0, "verbosity") ) func main() { @@ -27,6 +29,7 @@ func main() { failf("provide path to linux kernel checkout via -linux flag (or make generate LINUX= flag)") } if *flagLinuxBld == "" { + logf(1, "No kernel build directory provided, assuming in-place build") flagLinuxBld = flagLinux } if len(flag.Args()) == 0 { @@ -36,6 +39,7 @@ func main() { var r io.Reader for i, f := range flag.Args() { inf, err := os.Open(f) + logf(1, "Load descriptions from file %v", f) if err != nil { failf("failed to open input file: %v", err) } @@ -47,16 +51,22 @@ func main() { } } + logf(1, "Parse system call descriptions") includes, defines, syscalls, structs, unnamed, flags := parse(r) + logf(1, "Build flag definitions") intFlags, flagVals := compileFlags(includes, defines, flags) + var initcode string = "sys/sys.go" + logf(1, "Generate code to init system call data in %v", initcode) out := new(bytes.Buffer) generate(syscalls, structs, unnamed, intFlags, flagVals, out) - writeSource("sys/sys.go", out.Bytes()) + writeSource(initcode, out.Bytes()) + var constcode string = "prog/consts.go" + logf(1, "Generate code for constant values in %v", constcode) out = new(bytes.Buffer) generateConsts(flagVals, out) - writeSource("prog/consts.go", out.Bytes()) + writeSource(constcode, out.Bytes()) generateSyscallsNumbers(syscalls) } @@ -84,6 +94,7 @@ func generate(syscalls []Syscall, structs map[string]Struct, unnamed map[string] fmt.Fprintf(out, "var Calls []*Call\n") fmt.Fprintf(out, "func initCalls() {\n") for i, s := range syscalls { + logf(4, " generate population code for %v", s.Name) fmt.Fprintf(out, "func() { Calls = append(Calls, &Call{ID: %v, Name: \"%v\", CallName: \"%v\"", i, s.Name, s.CallName) if len(s.Ret) != 0 { fmt.Fprintf(out, ", Ret: ") @@ -94,6 +105,7 @@ func generate(syscalls []Syscall, structs map[string]Struct, unnamed map[string] if i != 0 { fmt.Fprintf(out, ", ") } + logf(5, " generate description for arg %v", i) generateArg(a[0], a[1], a[2:], structs, unnamed, flags, flagVals, false, out) } fmt.Fprintf(out, "}})}()\n") @@ -627,11 +639,13 @@ func parse(in io.Reader) (includes []string, defines map[string]string, syscalls } } } + logf(2, " Add struct %v", str.Name) structs[str.Name] = *str str = nil } else { p.SkipWs() fld := []string{p.Ident()} + logf(3, " Add field %f to struct %v", fld, str.Name) fld = append(fld, parseType(p, unnamed, flags)...) str.Flds = append(str.Flds, fld) } @@ -649,6 +663,7 @@ func parse(in io.Reader) (includes []string, defines map[string]string, syscalls include = append(include, ch) } p.Parse('>') + logf(2, " Add #include file %v", string(include)) includes = append(includes, string(include)) } else if name == "define" { key := p.Ident() @@ -661,6 +676,7 @@ func parse(in io.Reader) (includes []string, defines map[string]string, syscalls if defines[key] != "" { failf("%v define is defined multiple times", key) } + logf(2, " Add #define %v %v", key, val) defines[key] = fmt.Sprintf("(%s)", val) } else { switch ch := p.Char(); ch { @@ -685,6 +701,7 @@ func parse(in io.Reader) (includes []string, defines map[string]string, syscalls if idx := strings.IndexByte(callName, '$'); idx != -1 { callName = callName[:idx] } + logf(2, " Add system call %v", name) syscalls = append(syscalls, Syscall{name, callName, args, ret}) case '=': // flag @@ -694,6 +711,7 @@ func parse(in io.Reader) (includes []string, defines map[string]string, syscalls p.Parse(',') vals = append(vals, p.Ident()) } + logf(2, " Add flag %v", name) flags[name] = vals case '{', '[': p.Parse(ch) @@ -779,3 +797,10 @@ func failf(msg string, args ...interface{}) { fmt.Fprintf(os.Stderr, msg+"\n", args...) os.Exit(1) } + +func logf(v int, msg string, args ...interface{}) { + if *flagV >= v { + log.Printf(msg, args...) + } +} + |