| // Copyright 2017 syzkaller project authors. All rights reserved. |
| // Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file. |
| |
| package main |
| |
| import ( |
| "fmt" |
| "path/filepath" |
| "runtime" |
| "strings" |
| "time" |
| |
| "github.com/google/syzkaller/pkg/build" |
| "github.com/google/syzkaller/pkg/compiler" |
| "github.com/google/syzkaller/pkg/osutil" |
| ) |
| |
| type linux struct{} |
| |
| func (*linux) prepare(sourcedir string, build bool, arches []*Arch) error { |
| if build { |
| // Run 'make mrproper', otherwise out-of-tree build fails. |
| // However, it takes unreasonable amount of time, |
| // so first check few files and if they are missing hope for best. |
| for _, a := range arches { |
| arch := a.target.KernelArch |
| if osutil.IsExist(filepath.Join(sourcedir, ".config")) || |
| osutil.IsExist(filepath.Join(sourcedir, "init/main.o")) || |
| osutil.IsExist(filepath.Join(sourcedir, "include/config")) || |
| osutil.IsExist(filepath.Join(sourcedir, "include/generated/compile.h")) || |
| osutil.IsExist(filepath.Join(sourcedir, "arch", arch, "include", "generated")) { |
| fmt.Printf("make mrproper ARCH=%v\n", arch) |
| out, err := osutil.RunCmd(time.Hour, sourcedir, "make", "mrproper", "ARCH="+arch, |
| "-j", fmt.Sprint(runtime.NumCPU())) |
| if err != nil { |
| return fmt.Errorf("make mrproper failed: %v\n%s", err, out) |
| } |
| } |
| } |
| } else { |
| if len(arches) > 1 { |
| return fmt.Errorf("more than 1 arch is invalid without -build") |
| } |
| } |
| return nil |
| } |
| |
| func (*linux) prepareArch(arch *Arch) error { |
| // Kernel misses these headers on some arches. |
| // So we create empty stubs in buildDir/syzkaller and add -IbuildDir/syzkaller |
| // as the last flag so it won't override real kernel headers. |
| for hdr, data := range map[string]string{ |
| // This is the only compiler header kernel uses, |
| // need to provide it since we use -nostdinc below. |
| "stdarg.h": ` |
| #pragma once |
| #define va_list __builtin_va_list |
| #define va_start __builtin_va_start |
| #define va_end __builtin_va_end |
| #define va_arg __builtin_va_arg |
| #define va_copy __builtin_va_copy |
| #define __va_copy __builtin_va_copy |
| `, |
| "asm/a.out.h": "", |
| "asm/prctl.h": "", |
| "asm/mce.h": "", |
| "asm/msr.h": "", |
| "uapi/asm/msr.h": "", |
| } { |
| fullPath := filepath.Join(arch.buildDir, "syzkaller", hdr) |
| if err := osutil.MkdirAll(filepath.Dir(fullPath)); err != nil { |
| return err |
| } |
| if err := osutil.WriteFile(fullPath, []byte(data)); err != nil { |
| return nil |
| } |
| } |
| if !arch.build { |
| return nil |
| } |
| kernelDir := arch.sourceDir |
| makeArgs := build.LinuxMakeArgs(arch.target, "", "", arch.buildDir) |
| out, err := osutil.RunCmd(time.Hour, kernelDir, "make", append(makeArgs, "defconfig")...) |
| if err != nil { |
| return fmt.Errorf("make defconfig failed: %v\n%s", err, out) |
| } |
| _, err = osutil.RunCmd(time.Minute, arch.buildDir, filepath.Join(kernelDir, "scripts", "config"), |
| // powerpc arch is configured to be big-endian by default, but we want little-endian powerpc. |
| // Since all of our archs are little-endian for now, we just blindly switch it. |
| "-d", "CPU_BIG_ENDIAN", "-e", "CPU_LITTLE_ENDIAN", |
| // s390 enables BTF in defconfig, but our packaged toolchains can't build it. |
| "-d", "DEBUG_INFO_BTF", |
| // Without CONFIG_NETFILTER kernel does not build. |
| "-e", "NETFILTER", |
| // include/net/mptcp.h is the only header in kernel that guards some |
| // of the consts with own config, so we need to enable CONFIG_MPTCP. |
| "-e", "MPTCP", |
| // security/smack/smack.h requires this to build. |
| "-e", "SECURITY", |
| "-e", "SECURITY_SMACK", |
| // include/net/nl802154.h does not define some consts without this. |
| "-e", "IEEE802154", "-e", "IEEE802154_NL802154_EXPERIMENTAL", |
| ) |
| if err != nil { |
| return err |
| } |
| out, err = osutil.RunCmd(time.Hour, kernelDir, "make", append(makeArgs, "olddefconfig")...) |
| if err != nil { |
| return fmt.Errorf("make olddefconfig failed: %v\n%s", err, out) |
| } |
| out, err = osutil.RunCmd(time.Hour, kernelDir, "make", append(makeArgs, "init/main.o")...) |
| if err != nil { |
| return fmt.Errorf("make failed: %v\n%s", err, out) |
| } |
| return nil |
| } |
| |
| func (*linux) processFile(arch *Arch, info *compiler.ConstInfo) (map[string]uint64, map[string]bool, error) { |
| headerArch := arch.target.KernelHeaderArch |
| sourceDir := arch.sourceDir |
| buildDir := arch.buildDir |
| args := []string{ |
| // This makes the build completely hermetic, only kernel headers are used. |
| "-nostdinc", |
| "-w", "-fmessage-length=0", |
| "-O3", // required to get expected values for some __builtin_constant_p |
| "-I.", |
| "-D__KERNEL__", |
| "-DKBUILD_MODNAME=\"-\"", |
| "-I" + sourceDir + "/arch/" + headerArch + "/include", |
| "-I" + buildDir + "/arch/" + headerArch + "/include/generated/uapi", |
| "-I" + buildDir + "/arch/" + headerArch + "/include/generated", |
| "-I" + sourceDir + "/arch/" + headerArch + "/include/asm/mach-malta", |
| "-I" + sourceDir + "/arch/" + headerArch + "/include/asm/mach-generic", |
| "-I" + buildDir + "/include", |
| "-I" + sourceDir + "/include", |
| "-I" + sourceDir + "/arch/" + headerArch + "/include/uapi", |
| "-I" + buildDir + "/arch/" + headerArch + "/include/generated/uapi", |
| "-I" + sourceDir + "/include/uapi", |
| "-I" + buildDir + "/include/generated/uapi", |
| "-I" + sourceDir, |
| "-I" + sourceDir + "/include/linux", |
| "-I" + buildDir + "/syzkaller", |
| "-include", sourceDir + "/include/linux/kconfig.h", |
| } |
| args = append(args, arch.target.CFlags...) |
| for _, incdir := range info.Incdirs { |
| args = append(args, "-I"+sourceDir+"/"+incdir) |
| } |
| if arch.includeDirs != "" { |
| for _, dir := range strings.Split(arch.includeDirs, ",") { |
| args = append(args, "-I"+dir) |
| } |
| } |
| params := &extractParams{ |
| AddSource: "#include <asm/unistd.h>", |
| ExtractFromELF: true, |
| TargetEndian: arch.target.HostEndian, |
| } |
| cc := arch.target.CCompiler |
| res, undeclared, err := extract(info, cc, args, params) |
| if err != nil { |
| return nil, nil, err |
| } |
| if arch.target.PtrSize == 4 { |
| // mmap syscall on i386/arm is translated to old_mmap and has different signature. |
| // As a workaround fix it up to mmap2, which has signature that we expect. |
| // pkg/csource has the same hack. |
| const mmap = "__NR_mmap" |
| const mmap2 = "__NR_mmap2" |
| if res[mmap] != 0 || undeclared[mmap] { |
| if res[mmap2] == 0 { |
| return nil, nil, fmt.Errorf("%v is missing", mmap2) |
| } |
| res[mmap] = res[mmap2] |
| delete(undeclared, mmap) |
| } |
| } |
| return res, undeclared, nil |
| } |