| // Copyright 2014 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package elfexec |
| |
| import ( |
| "debug/elf" |
| "reflect" |
| "testing" |
| ) |
| |
| func TestGetBase(t *testing.T) { |
| |
| fhExec := &elf.FileHeader{ |
| Type: elf.ET_EXEC, |
| } |
| fhRel := &elf.FileHeader{ |
| Type: elf.ET_REL, |
| } |
| fhDyn := &elf.FileHeader{ |
| Type: elf.ET_DYN, |
| } |
| lsOffset := &elf.ProgHeader{ |
| Vaddr: 0x400000, |
| Off: 0x200000, |
| } |
| kernelHeader := &elf.ProgHeader{ |
| Vaddr: 0xffffffff81000000, |
| } |
| kernelAslrHeader := &elf.ProgHeader{ |
| Vaddr: 0xffffffff80200000, |
| Off: 0x1000, |
| } |
| ppc64KernelHeader := &elf.ProgHeader{ |
| Vaddr: 0xc000000000000000, |
| } |
| |
| testcases := []struct { |
| label string |
| fh *elf.FileHeader |
| loadSegment *elf.ProgHeader |
| stextOffset *uint64 |
| start, limit, offset uint64 |
| want uint64 |
| wanterr bool |
| }{ |
| {"exec", fhExec, nil, nil, 0x400000, 0, 0, 0, false}, |
| {"exec offset", fhExec, lsOffset, nil, 0x400000, 0x800000, 0, 0x200000, false}, |
| {"exec offset 2", fhExec, lsOffset, nil, 0x200000, 0x600000, 0, 0, false}, |
| {"exec nomap", fhExec, nil, nil, 0, 0, 0, 0, false}, |
| {"exec kernel", fhExec, kernelHeader, uint64p(0xffffffff81000198), 0xffffffff82000198, 0xffffffff83000198, 0, 0x1000000, false}, |
| {"exec kernel", fhExec, kernelHeader, uint64p(0xffffffff810002b8), 0xffffffff81000000, 0xffffffffa0000000, 0x0, 0x0, false}, |
| {"exec kernel ASLR", fhExec, kernelHeader, uint64p(0xffffffff810002b8), 0xffffffff81000000, 0xffffffffa0000000, 0xffffffff81000000, 0x0, false}, |
| // TODO(aalexand): Figure out where this test case exactly comes from and |
| // whether it's still relevant. |
| {"exec kernel ASLR 2", fhExec, kernelAslrHeader, nil, 0xffffffff83e00000, 0xfffffffffc3fffff, 0x3c00000, 0x3c00000, false}, |
| {"exec PPC64 kernel", fhExec, ppc64KernelHeader, uint64p(0xc000000000000000), 0xc000000000000000, 0xd00000001a730000, 0x0, 0x0, false}, |
| {"exec chromeos kernel", fhExec, kernelHeader, uint64p(0xffffffff81000198), 0, 0x10197, 0, 0x7efffe68, false}, |
| {"exec chromeos kernel 2", fhExec, kernelHeader, uint64p(0xffffffff81000198), 0, 0x10198, 0, 0x7efffe68, false}, |
| {"exec chromeos kernel 3", fhExec, kernelHeader, uint64p(0xffffffff81000198), 0x198, 0x100000, 0, 0x7f000000, false}, |
| {"exec chromeos kernel 4", fhExec, kernelHeader, uint64p(0xffffffff81200198), 0x198, 0x100000, 0, 0x7ee00000, false}, |
| {"exec chromeos kernel unremapped", fhExec, kernelHeader, uint64p(0xffffffff810001c8), 0xffffffff834001c8, 0xffffffffc0000000, 0xffffffff834001c8, 0x2400000, false}, |
| {"dyn", fhDyn, nil, nil, 0x200000, 0x300000, 0, 0x200000, false}, |
| {"dyn map", fhDyn, lsOffset, nil, 0x0, 0x300000, 0, 0xFFFFFFFFFFE00000, false}, |
| {"dyn nomap", fhDyn, nil, nil, 0x0, 0x0, 0, 0, false}, |
| {"dyn map+offset", fhDyn, lsOffset, nil, 0x900000, 0xa00000, 0x200000, 0x500000, false}, |
| {"rel", fhRel, nil, nil, 0x2000000, 0x3000000, 0, 0x2000000, false}, |
| {"rel nomap", fhRel, nil, nil, 0x0, ^uint64(0), 0, 0, false}, |
| {"rel offset", fhRel, nil, nil, 0x100000, 0x200000, 0x1, 0, true}, |
| } |
| |
| for _, tc := range testcases { |
| base, err := GetBase(tc.fh, tc.loadSegment, tc.stextOffset, tc.start, tc.limit, tc.offset) |
| if err != nil { |
| if !tc.wanterr { |
| t.Errorf("%s: want no error, got %v", tc.label, err) |
| } |
| continue |
| } |
| if tc.wanterr { |
| t.Errorf("%s: want error, got nil", tc.label) |
| continue |
| } |
| if base != tc.want { |
| t.Errorf("%s: want 0x%x, got 0x%x", tc.label, tc.want, base) |
| } |
| } |
| } |
| |
| func uint64p(n uint64) *uint64 { |
| return &n |
| } |
| |
| func TestFindProgHeaderForMapping(t *testing.T) { |
| smallELFFile := elf.File{ |
| Progs: []*elf.Prog{ |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_PHDR, Flags: elf.PF_R | elf.PF_X, Off: 0x40, Vaddr: 0x400040, Paddr: 0x400040, Filesz: 0x1f8, Memsz: 0x1f8, Align: 8}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_INTERP, Flags: elf.PF_R, Off: 0x238, Vaddr: 0x400238, Paddr: 0x400238, Filesz: 0x1c, Memsz: 0x1c, Align: 1}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x400000, Paddr: 0x400000, Filesz: 0x6fc, Memsz: 0x6fc, Align: 0x200000}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe10, Vaddr: 0x600e10, Paddr: 0x600e10, Filesz: 0x230, Memsz: 0x238, Align: 0x200000}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_DYNAMIC, Flags: elf.PF_R | elf.PF_W, Off: 0xe28, Vaddr: 0x600e28, Paddr: 0x600e28, Filesz: 0x1d0, Memsz: 0x1d0, Align: 8}}, |
| }, |
| } |
| largeELFFile := elf.File{ |
| Progs: []*elf.Prog{ |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_PHDR, Flags: elf.PF_R, Off: 0x40, Vaddr: 0x40, Paddr: 0x40, Filesz: 0x268, Memsz: 0x268, Align: 8}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_INTERP, Flags: elf.PF_R, Off: 0x2a8, Vaddr: 0x2a8, Paddr: 0x2a8, Filesz: 0x28, Memsz: 0x28, Align: 1}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0x2ec5d2c0, Memsz: 0x2ec5d2c0, Align: 0x200000}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x2ec5d2c0, Vaddr: 0x2ee5d2c0, Paddr: 0x2ee5d2c0, Filesz: 0x1361118, Memsz: 0x1361150, Align: 0x200000}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x2ffbe440, Vaddr: 0x303be440, Paddr: 0x303be440, Filesz: 0x4637c0, Memsz: 0xc91610, Align: 0x200000}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_TLS, Flags: elf.PF_R, Off: 0x2ec5d2c0, Vaddr: 0x2ee5d2c0, Paddr: 0x2ee5d2c0, Filesz: 0x120, Memsz: 0x103f8, Align: 0x40}}, |
| {ProgHeader: elf.ProgHeader{Type: elf.PT_DYNAMIC, Flags: elf.PF_R | elf.PF_W, Off: 0x2ffbc9e0, Vaddr: 0x301bc9e0, Paddr: 0x301bc9e0, Filesz: 0x1f0, Memsz: 0x1f0, Align: 8}}, |
| }, |
| } |
| for _, tc := range []struct { |
| desc string |
| file *elf.File |
| pgoff, memsz uint64 |
| wantError bool |
| want *elf.ProgHeader |
| }{ |
| { |
| desc: "no prog headers ELF file", |
| file: &elf.File{}, |
| pgoff: 0, |
| memsz: 0x1000, |
| want: nil, |
| }, |
| { |
| desc: "small ELF file / executable mapping", |
| file: &smallELFFile, |
| pgoff: 0, |
| memsz: 0x1000, |
| want: &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x400000, Paddr: 0x400000, Filesz: 0x6fc, Memsz: 0x6fc, Align: 0x200000}, |
| }, |
| { |
| desc: "small ELF file / page aligned data mapping disambiguation", |
| file: &smallELFFile, |
| pgoff: 0, |
| memsz: 0x2000, |
| want: &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe10, Vaddr: 0x600e10, Paddr: 0x600e10, Filesz: 0x230, Memsz: 0x238, Align: 0x200000}, |
| }, |
| { |
| desc: "small ELF file / no matching segment", |
| file: &smallELFFile, |
| pgoff: 0x1000, |
| memsz: 0x1000, |
| wantError: true, |
| }, |
| { |
| desc: "small ELF file / multiple matching segments, but incorrect size ", |
| file: &smallELFFile, |
| pgoff: 0, |
| memsz: 0x3000, |
| wantError: true, |
| }, |
| { |
| desc: "large ELF file / executable mapping", |
| file: &largeELFFile, |
| pgoff: 0, |
| memsz: 0x2ec5e000, |
| want: &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0x2ec5d2c0, Memsz: 0x2ec5d2c0, Align: 0x200000}, |
| }, |
| { |
| desc: "large ELF file / first data mapping", |
| file: &largeELFFile, |
| pgoff: 0x2ec5d000, |
| memsz: 0x1362000, |
| want: &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x2ec5d2c0, Vaddr: 0x2ee5d2c0, Paddr: 0x2ee5d2c0, Filesz: 0x1361118, Memsz: 0x1361150, Align: 0x200000}, |
| }, |
| { |
| desc: "large ELF file / split mapping doesn't match", |
| file: &largeELFFile, |
| pgoff: 0x2ffbe000, |
| memsz: 0xb11000, |
| wantError: true, |
| }, |
| { |
| desc: "large ELF file / combined mapping matches second data mapping", |
| file: &largeELFFile, |
| pgoff: 0x2ffbe000, |
| memsz: 0xb11000 + 0x181000, |
| want: &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x2ffbe440, Vaddr: 0x303be440, Paddr: 0x303be440, Filesz: 0x4637c0, Memsz: 0xc91610, Align: 0x200000}, |
| }, |
| } { |
| t.Run(tc.desc, func(t *testing.T) { |
| got, err := FindProgHeaderForMapping(tc.file, tc.pgoff, tc.memsz) |
| if (err != nil) != tc.wantError { |
| t.Errorf("got error %v, want any error=%v", err, tc.wantError) |
| } |
| if err != nil { |
| return |
| } |
| if !reflect.DeepEqual(got, tc.want) { |
| t.Errorf("got program header %#v; want %#v", got, tc.want) |
| } |
| }) |
| } |
| } |
