1// Copyright 2014 Google Inc. All Rights Reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package elfexec
16
17import (
18	"debug/elf"
19	"fmt"
20	"reflect"
21	"strings"
22	"testing"
23)
24
25func TestGetBase(t *testing.T) {
26
27	fhExec := &elf.FileHeader{
28		Type: elf.ET_EXEC,
29	}
30	fhRel := &elf.FileHeader{
31		Type: elf.ET_REL,
32	}
33	fhDyn := &elf.FileHeader{
34		Type: elf.ET_DYN,
35	}
36	lsOffset := &elf.ProgHeader{
37		Vaddr: 0x400000,
38		Off:   0x200000,
39	}
40	kernelHeader := &elf.ProgHeader{
41		Vaddr: 0xffffffff81000000,
42	}
43	kernelAslrHeader := &elf.ProgHeader{
44		Vaddr: 0xffffffff80200000,
45		Off:   0x1000,
46	}
47	// Kernel PIE header with vaddr aligned to a 4k boundary
48	kernelPieAlignedHeader := &elf.ProgHeader{
49		Vaddr: 0xffff000010080000,
50		Off:   0x10000,
51	}
52	// Kernel PIE header with vaddr that doesn't fall on a 4k boundary
53	kernelPieUnalignedHeader := &elf.ProgHeader{
54		Vaddr: 0xffffffc010080800,
55		Off:   0x10800,
56	}
57	ppc64KernelHeader := &elf.ProgHeader{
58		Vaddr: 0xc000000000000000,
59	}
60
61	testcases := []struct {
62		label                string
63		fh                   *elf.FileHeader
64		loadSegment          *elf.ProgHeader
65		stextOffset          *uint64
66		start, limit, offset uint64
67		want                 uint64
68		wanterr              bool
69	}{
70		{"exec", fhExec, nil, nil, 0x400000, 0, 0, 0, false},
71		{"exec offset", fhExec, lsOffset, nil, 0x400000, 0x800000, 0, 0x200000, false},
72		{"exec offset 2", fhExec, lsOffset, nil, 0x200000, 0x600000, 0, 0, false},
73		{"exec nomap", fhExec, nil, nil, 0, 0, 0, 0, false},
74		{"exec kernel", fhExec, kernelHeader, uint64p(0xffffffff81000198), 0xffffffff82000198, 0xffffffff83000198, 0, 0x1000000, false},
75		{"exec kernel", fhExec, kernelHeader, uint64p(0xffffffff810002b8), 0xffffffff81000000, 0xffffffffa0000000, 0x0, 0x0, false},
76		{"exec kernel ASLR", fhExec, kernelHeader, uint64p(0xffffffff810002b8), 0xffffffff81000000, 0xffffffffa0000000, 0xffffffff81000000, 0x0, false},
77		// TODO(aalexand): Figure out where this test case exactly comes from and
78		// whether it's still relevant.
79		{"exec kernel ASLR 2", fhExec, kernelAslrHeader, nil, 0xffffffff83e00000, 0xfffffffffc3fffff, 0x3c00000, 0x3c00000, false},
80		{"exec PPC64 kernel", fhExec, ppc64KernelHeader, uint64p(0xc000000000000000), 0xc000000000000000, 0xd00000001a730000, 0x0, 0x0, false},
81		{"exec chromeos kernel", fhExec, kernelHeader, uint64p(0xffffffff81000198), 0, 0x10197, 0, 0x7efffe68, false},
82		{"exec chromeos kernel 2", fhExec, kernelHeader, uint64p(0xffffffff81000198), 0, 0x10198, 0, 0x7efffe68, false},
83		{"exec chromeos kernel 3", fhExec, kernelHeader, uint64p(0xffffffff81000198), 0x198, 0x100000, 0, 0x7f000000, false},
84		{"exec chromeos kernel 4", fhExec, kernelHeader, uint64p(0xffffffff81200198), 0x198, 0x100000, 0, 0x7ee00000, false},
85		{"exec chromeos kernel unremapped", fhExec, kernelHeader, uint64p(0xffffffff810001c8), 0xffffffff834001c8, 0xffffffffc0000000, 0xffffffff834001c8, 0x2400000, false},
86		{"dyn", fhDyn, nil, nil, 0x200000, 0x300000, 0, 0x200000, false},
87		{"dyn map", fhDyn, lsOffset, nil, 0x0, 0x300000, 0, 0xFFFFFFFFFFE00000, false},
88		{"dyn nomap", fhDyn, nil, nil, 0x0, 0x0, 0, 0, false},
89		{"dyn map+offset", fhDyn, lsOffset, nil, 0x900000, 0xa00000, 0x200000, 0x500000, false},
90		{"dyn kernel", fhDyn, kernelPieAlignedHeader, uint64p(0xffff000010080000), 0xffff000010080000, 0xffffffffffffffff, 0xffff000010080000, 0, false},
91		{"dyn chromeos aslr kernel", fhDyn, kernelPieUnalignedHeader, uint64p(0xffffffc010080800), 0x800, 0xb7f800, 0, 0x3feff80000, false},
92		{"dyn chromeos aslr kernel unremapped", fhDyn, kernelPieUnalignedHeader, uint64p(0xffffffc010080800), 0xffffffdb5d680800, 0xffffffdb5e200000, 0xffffffdb5d680800, 0x1b4d600000, false},
93		{"rel", fhRel, nil, nil, 0x2000000, 0x3000000, 0, 0x2000000, false},
94		{"rel nomap", fhRel, nil, nil, 0x0, ^uint64(0), 0, 0, false},
95		{"rel offset", fhRel, nil, nil, 0x100000, 0x200000, 0x1, 0, true},
96	}
97
98	for _, tc := range testcases {
99		base, err := GetBase(tc.fh, tc.loadSegment, tc.stextOffset, tc.start, tc.limit, tc.offset)
100		if err != nil {
101			if !tc.wanterr {
102				t.Errorf("%s: want no error, got %v", tc.label, err)
103			}
104			continue
105		}
106		if tc.wanterr {
107			t.Errorf("%s: want error, got nil", tc.label)
108			continue
109		}
110		if base != tc.want {
111			t.Errorf("%s: want 0x%x, got 0x%x", tc.label, tc.want, base)
112		}
113	}
114}
115
116func uint64p(n uint64) *uint64 {
117	return &n
118}
119
120func TestFindProgHeaderForMapping(t *testing.T) {
121	buildList := func(headers []*elf.ProgHeader) (result string) {
122		builder := strings.Builder{}
123		if err := builder.WriteByte('['); err != nil {
124			t.Error("Failed to append '[' to the builder")
125		}
126		defer func() {
127			if err := builder.WriteByte(']'); err != nil {
128				t.Error("Failed to append ']' to the builder")
129			}
130			result = builder.String()
131		}()
132		if len(headers) == 0 {
133			if _, err := builder.WriteString("nil"); err != nil {
134				t.Error("Failed to append 'nil' to the builder")
135			}
136			return
137		}
138		if _, err := builder.WriteString(fmt.Sprintf("%#v", *headers[0])); err != nil {
139			t.Error("Failed to append first header to the builder")
140		}
141		for i, h := range headers[1:] {
142			if _, err := builder.WriteString(fmt.Sprintf(", %#v", *h)); err != nil {
143				t.Errorf("Failed to append header %d to the builder", i+1)
144			}
145		}
146		return
147	}
148
149	// Variuos ELF program headers for unit tests.
150	tinyHeaders := []elf.ProgHeader{
151		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
152		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000},
153	}
154	tinyBadBSSHeaders := []elf.ProgHeader{
155		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
156		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x100, Memsz: 0x1f0, Align: 0x200000},
157		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xd80, Vaddr: 0x400d80, Paddr: 0x400d80, Filesz: 0x90, Memsz: 0x90, Align: 0x200000},
158	}
159	smallHeaders := []elf.ProgHeader{
160		{Type: elf.PT_PHDR, Flags: elf.PF_R | elf.PF_X, Off: 0x40, Vaddr: 0x400040, Paddr: 0x400040, Filesz: 0x1f8, Memsz: 0x1f8, Align: 8},
161		{Type: elf.PT_INTERP, Flags: elf.PF_R, Off: 0x238, Vaddr: 0x400238, Paddr: 0x400238, Filesz: 0x1c, Memsz: 0x1c, Align: 1},
162		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x400000, Paddr: 0x400000, Filesz: 0x6fc, Memsz: 0x6fc, Align: 0x200000},
163		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe10, Vaddr: 0x600e10, Paddr: 0x600e10, Filesz: 0x230, Memsz: 0x238, Align: 0x200000},
164		{Type: elf.PT_DYNAMIC, Flags: elf.PF_R | elf.PF_W, Off: 0xe28, Vaddr: 0x600e28, Paddr: 0x600e28, Filesz: 0x1d0, Memsz: 0x1d0, Align: 8},
165	}
166	smallBadBSSHeaders := []elf.ProgHeader{
167		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x200000, Paddr: 0x200000, Filesz: 0x6fc, Memsz: 0x6fc, Align: 0x200000},
168		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x700, Vaddr: 0x400700, Paddr: 0x400700, Filesz: 0x500, Memsz: 0x710, Align: 0x200000},
169		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe10, Vaddr: 0x600e10, Paddr: 0x600e10, Filesz: 0x230, Memsz: 0x238, Align: 0x200000},
170	}
171	mediumHeaders := []elf.ProgHeader{
172		{Type: elf.PT_PHDR, Flags: elf.PF_R, Off: 0x40, Vaddr: 0x40, Paddr: 0x40, Filesz: 0x268, Memsz: 0x268, Align: 8},
173		{Type: elf.PT_INTERP, Flags: elf.PF_R, Off: 0x2a8, Vaddr: 0x2a8, Paddr: 0x2a8, Filesz: 0x28, Memsz: 0x28, Align: 1},
174		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0x51800, Memsz: 0x51800, Align: 0x200000},
175		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x51800, Vaddr: 0x251800, Paddr: 0x251800, Filesz: 0x24a8, Memsz: 0x24e8, Align: 0x200000},
176		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x53d00, Vaddr: 0x453d00, Paddr: 0x453d00, Filesz: 0x13a58, Memsz: 0x91a198, Align: 0x200000},
177		{Type: elf.PT_TLS, Flags: elf.PF_R, Off: 0x51800, Vaddr: 0x51800, Paddr: 0x51800, Filesz: 0x0, Memsz: 0x38, Align: 0x8},
178		{Type: elf.PT_DYNAMIC, Flags: elf.PF_R | elf.PF_W, Off: 0x51d00, Vaddr: 0x251d00, Paddr: 0x251d00, Filesz: 0x1ef0, Memsz: 0x1ef0, Align: 8},
179	}
180	largeHeaders := []elf.ProgHeader{
181		{Type: elf.PT_PHDR, Flags: elf.PF_R, Off: 0x40, Vaddr: 0x40, Paddr: 0x40, Filesz: 0x268, Memsz: 0x268, Align: 8},
182		{Type: elf.PT_INTERP, Flags: elf.PF_R, Off: 0x2a8, Vaddr: 0x2a8, Paddr: 0x2a8, Filesz: 0x28, Memsz: 0x28, Align: 1},
183		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0x2ec5d2c0, Memsz: 0x2ec5d2c0, Align: 0x200000},
184		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x2ec5d2c0, Vaddr: 0x2ee5d2c0, Paddr: 0x2ee5d2c0, Filesz: 0x1361118, Memsz: 0x1361150, Align: 0x200000},
185		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x2ffbe440, Vaddr: 0x303be440, Paddr: 0x303be440, Filesz: 0x4637c0, Memsz: 0xc91610, Align: 0x200000},
186		{Type: elf.PT_TLS, Flags: elf.PF_R, Off: 0x2ec5d2c0, Vaddr: 0x2ee5d2c0, Paddr: 0x2ee5d2c0, Filesz: 0x120, Memsz: 0x103f8, Align: 0x40},
187		{Type: elf.PT_DYNAMIC, Flags: elf.PF_R | elf.PF_W, Off: 0x2ffbc9e0, Vaddr: 0x301bc9e0, Paddr: 0x301bc9e0, Filesz: 0x1f0, Memsz: 0x1f0, Align: 8},
188	}
189	ffmpegHeaders := []elf.ProgHeader{
190		{Type: elf.PT_PHDR, Flags: elf.PF_R, Off: 0x40, Vaddr: 0x200040, Paddr: 0x200040, Filesz: 0x1f8, Memsz: 0x1f8, Align: 8},
191		{Type: elf.PT_INTERP, Flags: elf.PF_R, Off: 0x238, Vaddr: 0x200238, Paddr: 0x200238, Filesz: 0x28, Memsz: 0x28, Align: 1},
192		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x200000, Paddr: 0x200000, Filesz: 0x48d8410, Memsz: 0x48d8410, Align: 0x200000},
193		{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x48d8440, Vaddr: 0x4cd8440, Paddr: 0x4cd8440, Filesz: 0x18cbe0, Memsz: 0xd2fb70, Align: 0x200000},
194		{Type: elf.PT_TLS, Flags: elf.PF_R, Off: 0x48d8440, Vaddr: 0x4cd8440, Paddr: 0x4cd8440, Filesz: 0xa8, Memsz: 0x468, Align: 0x40},
195		{Type: elf.PT_DYNAMIC, Flags: elf.PF_R | elf.PF_W, Off: 0x4a63ad0, Vaddr: 0x4e63ad0, Paddr: 0x4e63ad0, Filesz: 0x200, Memsz: 0x200, Align: 8},
196	}
197	sentryHeaders := []elf.ProgHeader{
198		{Type: elf.PT_LOAD, Flags: elf.PF_X + elf.PF_R, Off: 0x0, Vaddr: 0x7f0000000000, Paddr: 0x7f0000000000, Filesz: 0xbc64d5, Memsz: 0xbc64d5, Align: 0x1000},
199		{Type: elf.PT_LOAD, Flags: elf.PF_R, Off: 0xbc7000, Vaddr: 0x7f0000bc7000, Paddr: 0x7f0000bc7000, Filesz: 0xcd6b30, Memsz: 0xcd6b30, Align: 0x1000},
200		{Type: elf.PT_LOAD, Flags: elf.PF_W + elf.PF_R, Off: 0x189e000, Vaddr: 0x7f000189e000, Paddr: 0x7f000189e000, Filesz: 0x58180, Memsz: 0x92d10, Align: 0x1000},
201	}
202
203	for _, tc := range []struct {
204		desc        string
205		phdrs       []elf.ProgHeader
206		pgoff       uint64
207		memsz       uint64
208		wantHeaders []*elf.ProgHeader
209	}{
210		{
211			desc:        "no prog headers",
212			phdrs:       nil,
213			pgoff:       0,
214			memsz:       0x1000,
215			wantHeaders: nil,
216		},
217		{
218			desc:  "tiny file, 4KB at offset 0 matches both headers, b/178747588",
219			phdrs: tinyHeaders,
220			pgoff: 0,
221			memsz: 0x1000,
222			wantHeaders: []*elf.ProgHeader{
223				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
224				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000},
225			},
226		},
227		{
228			desc:        "tiny file, file offset 4KB matches no headers",
229			phdrs:       tinyHeaders,
230			pgoff:       0x1000,
231			memsz:       0x1000,
232			wantHeaders: nil,
233		},
234		{
235			desc:        "tiny file with unaligned memsz matches executable segment",
236			phdrs:       tinyHeaders,
237			pgoff:       0,
238			memsz:       0xc80,
239			wantHeaders: []*elf.ProgHeader{{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000}},
240		},
241		{
242			desc:        "tiny file with unaligned offset matches data segment",
243			phdrs:       tinyHeaders,
244			pgoff:       0xc80,
245			memsz:       0x1000,
246			wantHeaders: []*elf.ProgHeader{{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000}},
247		},
248		{
249			desc:  "tiny bad BSS file, 4KB at offset 0 matches all three headers",
250			phdrs: tinyBadBSSHeaders,
251			pgoff: 0,
252			memsz: 0x1000,
253			wantHeaders: []*elf.ProgHeader{
254				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
255				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x100, Memsz: 0x1f0, Align: 0x200000},
256				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xd80, Vaddr: 0x400d80, Paddr: 0x400d80, Filesz: 0x90, Memsz: 0x90, Align: 0x200000},
257			},
258		},
259		{
260			desc:  "small file, offset 0, memsz 4KB matches both segments",
261			phdrs: smallHeaders,
262			pgoff: 0,
263			memsz: 0x1000,
264			wantHeaders: []*elf.ProgHeader{
265				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x400000, Paddr: 0x400000, Filesz: 0x6fc, Memsz: 0x6fc, Align: 0x200000},
266				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe10, Vaddr: 0x600e10, Paddr: 0x600e10, Filesz: 0x230, Memsz: 0x238, Align: 0x200000},
267			},
268		},
269		{
270			desc:  "small file, offset 0, memsz 8KB matches both segments",
271			phdrs: smallHeaders,
272			pgoff: 0,
273			memsz: 0x2000,
274			wantHeaders: []*elf.ProgHeader{
275				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x400000, Paddr: 0x400000, Filesz: 0x6fc, Memsz: 0x6fc, Align: 0x200000},
276				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe10, Vaddr: 0x600e10, Paddr: 0x600e10, Filesz: 0x230, Memsz: 0x238, Align: 0x200000},
277			},
278		},
279		{
280			desc:        "small file, offset 4KB matches data segment",
281			phdrs:       smallHeaders,
282			pgoff:       0x1000,
283			memsz:       0x1000,
284			wantHeaders: []*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}},
285		},
286		{
287			desc:        "small file, offset 8KB matches no segment",
288			phdrs:       smallHeaders,
289			pgoff:       0x2000,
290			memsz:       0x1000,
291			wantHeaders: nil,
292		},
293		{
294			desc:  "small bad BSS file, offset 0, memsz 4KB matches all three segments",
295			phdrs: smallBadBSSHeaders,
296			pgoff: 0,
297			memsz: 0x1000,
298			wantHeaders: []*elf.ProgHeader{
299				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x200000, Paddr: 0x200000, Filesz: 0x6fc, Memsz: 0x6fc, Align: 0x200000},
300				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x700, Vaddr: 0x400700, Paddr: 0x400700, Filesz: 0x500, Memsz: 0x710, Align: 0x200000},
301				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe10, Vaddr: 0x600e10, Paddr: 0x600e10, Filesz: 0x230, Memsz: 0x238, Align: 0x200000},
302			},
303		},
304		{
305			desc:  "small bad BSS file, offset 0, memsz 8KB matches all three segments",
306			phdrs: smallBadBSSHeaders,
307			pgoff: 0,
308			memsz: 0x2000,
309			wantHeaders: []*elf.ProgHeader{
310				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x200000, Paddr: 0x200000, Filesz: 0x6fc, Memsz: 0x6fc, Align: 0x200000},
311				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0x700, Vaddr: 0x400700, Paddr: 0x400700, Filesz: 0x500, Memsz: 0x710, Align: 0x200000},
312				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe10, Vaddr: 0x600e10, Paddr: 0x600e10, Filesz: 0x230, Memsz: 0x238, Align: 0x200000},
313			},
314		},
315		{
316			desc:        "small bad BSS file, offset 4KB matches second data segment",
317			phdrs:       smallBadBSSHeaders,
318			pgoff:       0x1000,
319			memsz:       0x1000,
320			wantHeaders: []*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}},
321		},
322		{
323			desc:        "medium file large mapping that includes all address space matches executable segment, b/179920361",
324			phdrs:       mediumHeaders,
325			pgoff:       0,
326			memsz:       0xd6e000,
327			wantHeaders: []*elf.ProgHeader{{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0x51800, Memsz: 0x51800, Align: 0x200000}},
328		},
329		{
330			desc:        "large file executable mapping matches executable segment",
331			phdrs:       largeHeaders,
332			pgoff:       0,
333			memsz:       0x2ec5e000,
334			wantHeaders: []*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}},
335		},
336		{
337			desc:        "large file first data mapping matches first data segment",
338			phdrs:       largeHeaders,
339			pgoff:       0x2ec5d000,
340			memsz:       0x1362000,
341			wantHeaders: []*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}},
342		},
343		{
344			desc:        "large file, split second data mapping matches second data segment",
345			phdrs:       largeHeaders,
346			pgoff:       0x2ffbe000,
347			memsz:       0xb11000,
348			wantHeaders: []*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}},
349		},
350		{
351			desc:        "sentry headers, mapping for last page of executable segment matches executable segment",
352			phdrs:       sentryHeaders,
353			pgoff:       0xbc6000,
354			memsz:       0x1000,
355			wantHeaders: []*elf.ProgHeader{{Type: elf.PT_LOAD, Flags: elf.PF_X + elf.PF_R, Off: 0x0, Vaddr: 0x7f0000000000, Paddr: 0x7f0000000000, Filesz: 0xbc64d5, Memsz: 0xbc64d5, Align: 0x1000}},
356		},
357		{
358			desc:        "ffmpeg headers, split mapping for executable segment matches executable segment, b/193176694",
359			phdrs:       ffmpegHeaders,
360			pgoff:       0,
361			memsz:       0x48d8000,
362			wantHeaders: []*elf.ProgHeader{{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0x200000, Paddr: 0x200000, Filesz: 0x48d8410, Memsz: 0x48d8410, Align: 0x200000}},
363		},
364		{
365			desc: "segments with no file bits (b/195427553), mapping for executable segment matches executable segment",
366			phdrs: []elf.ProgHeader{
367				{Type: elf.PT_LOAD, Flags: elf.PF_R, Off: 0x0, Vaddr: 0x0, Paddr: 0x0, Filesz: 0x115000, Memsz: 0x115000, Align: 0x1000},
368				{Type: elf.PT_LOAD, Flags: elf.PF_X + elf.PF_R, Off: 0x115000, Vaddr: 0x115000, Paddr: 0x115000, Filesz: 0x361e15, Memsz: 0x361e15, Align: 0x1000},
369				{Type: elf.PT_LOAD, Flags: elf.PF_W + elf.PF_R, Off: 0x0, Vaddr: 0x477000, Paddr: 0x477000, Filesz: 0x0, Memsz: 0x33c, Align: 0x1000},
370				{Type: elf.PT_LOAD, Flags: elf.PF_R, Off: 0x0, Vaddr: 0x478000, Paddr: 0x478000, Filesz: 0x0, Memsz: 0x47dc28, Align: 0x1000},
371				{Type: elf.PT_LOAD, Flags: elf.PF_R, Off: 0x477000, Vaddr: 0x8f6000, Paddr: 0x8f6000, Filesz: 0x140, Memsz: 0x140, Align: 0x1000},
372				{Type: elf.PT_LOAD, Flags: elf.PF_W + elf.PF_R, Off: 0x478000, Vaddr: 0x8f7000, Paddr: 0x8f7000, Filesz: 0x38, Memsz: 0x38, Align: 0x1000},
373			},
374			pgoff:       0x115000,
375			memsz:       0x362000,
376			wantHeaders: []*elf.ProgHeader{{Type: elf.PT_LOAD, Flags: elf.PF_X + elf.PF_R, Off: 0x115000, Vaddr: 0x115000, Paddr: 0x115000, Filesz: 0x361e15, Memsz: 0x361e15, Align: 0x1000}},
377		},
378	} {
379		t.Run(tc.desc, func(t *testing.T) {
380			gotHeaders := ProgramHeadersForMapping(tc.phdrs, tc.pgoff, tc.memsz)
381			if !reflect.DeepEqual(gotHeaders, tc.wantHeaders) {
382				t.Errorf("got program headers %q; want %q", buildList(gotHeaders), buildList(tc.wantHeaders))
383			}
384		})
385	}
386}
387
388func TestHeaderForFileOffset(t *testing.T) {
389	for _, tc := range []struct {
390		desc       string
391		headers    []*elf.ProgHeader
392		fileOffset uint64
393		wantError  bool
394		want       *elf.ProgHeader
395	}{
396		{
397			desc:      "no headers, want error",
398			headers:   nil,
399			wantError: true,
400		},
401		{
402			desc: "three headers, BSS in last segment, file offset selects first header",
403			headers: []*elf.ProgHeader{
404				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
405				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000},
406				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe70, Vaddr: 0x400e70, Paddr: 0x400e70, Filesz: 0x90, Memsz: 0x100, Align: 0x200000},
407			},
408			fileOffset: 0xc79,
409			want:       &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
410		},
411		{
412			desc: "three headers, BSS in last segment, file offset selects second header",
413			headers: []*elf.ProgHeader{
414				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
415				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000},
416				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe70, Vaddr: 0x400e70, Paddr: 0x400e70, Filesz: 0x90, Memsz: 0x100, Align: 0x200000},
417			},
418			fileOffset: 0xc80,
419			want:       &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000},
420		},
421		{
422			desc: "three headers, BSS in last segment, file offset selects third header",
423			headers: []*elf.ProgHeader{
424				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
425				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000},
426				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe70, Vaddr: 0x400e70, Paddr: 0x400e70, Filesz: 0x90, Memsz: 0x100, Align: 0x200000},
427			},
428			fileOffset: 0xef0,
429			want:       &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe70, Vaddr: 0x400e70, Paddr: 0x400e70, Filesz: 0x90, Memsz: 0x100, Align: 0x200000},
430		},
431		{
432			desc: "three headers, BSS in last segment, file offset in uninitialized section selects third header",
433			headers: []*elf.ProgHeader{
434				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
435				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000},
436				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe70, Vaddr: 0x400e70, Paddr: 0x400e70, Filesz: 0x90, Memsz: 0x100, Align: 0x200000},
437			},
438			fileOffset: 0xf40,
439			want:       &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe70, Vaddr: 0x400e70, Paddr: 0x400e70, Filesz: 0x90, Memsz: 0x100, Align: 0x200000},
440		},
441		{
442			desc: "three headers, BSS in last segment, file offset past any segment gives error",
443			headers: []*elf.ProgHeader{
444				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
445				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x1f0, Memsz: 0x1f0, Align: 0x200000},
446				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xe70, Vaddr: 0x400e70, Paddr: 0x400e70, Filesz: 0x90, Memsz: 0x100, Align: 0x200000},
447			},
448			fileOffset: 0xf70,
449			wantError:  true,
450		},
451		{
452			desc: "three headers, BSS in second segment, file offset in mapped section selects second header",
453			headers: []*elf.ProgHeader{
454				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
455				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x100, Memsz: 0x1f0, Align: 0x200000},
456				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xd80, Vaddr: 0x400d80, Paddr: 0x400d80, Filesz: 0x100, Memsz: 0x100, Align: 0x200000},
457			},
458			fileOffset: 0xd79,
459			want:       &elf.ProgHeader{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x100, Memsz: 0x1f0, Align: 0x200000},
460		},
461		{
462			desc: "three headers, BSS in second segment, file offset in unmapped section gives error",
463			headers: []*elf.ProgHeader{
464				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_X, Off: 0, Vaddr: 0, Paddr: 0, Filesz: 0xc80, Memsz: 0xc80, Align: 0x200000},
465				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xc80, Vaddr: 0x200c80, Paddr: 0x200c80, Filesz: 0x100, Memsz: 0x1f0, Align: 0x200000},
466				{Type: elf.PT_LOAD, Flags: elf.PF_R | elf.PF_W, Off: 0xd80, Vaddr: 0x400d80, Paddr: 0x400d80, Filesz: 0x100, Memsz: 0x100, Align: 0x200000},
467			},
468			fileOffset: 0xd80,
469			wantError:  true,
470		},
471	} {
472		t.Run(tc.desc, func(t *testing.T) {
473			got, err := HeaderForFileOffset(tc.headers, tc.fileOffset)
474			if (err != nil) != tc.wantError {
475				t.Errorf("got error %v, want any error=%v", err, tc.wantError)
476			}
477			if err != nil {
478				return
479			}
480			if !reflect.DeepEqual(got, tc.want) {
481				t.Errorf("got program header %#v, want %#v", got, tc.want)
482			}
483		})
484	}
485}
486