1 /* 1 /*
2 * Linker script for vDSO. This is an ELF sha 2 * Linker script for vDSO. This is an ELF shared object prelinked to
3 * its virtual address, and with only one read 3 * its virtual address, and with only one read-only segment.
4 * This script controls its layout. 4 * This script controls its layout.
5 */ 5 */
6 6
7 #if defined(BUILD_VDSO64) 7 #if defined(BUILD_VDSO64)
8 # define SHDR_SIZE 64 8 # define SHDR_SIZE 64
9 #elif defined(BUILD_VDSO32) 9 #elif defined(BUILD_VDSO32)
10 # define SHDR_SIZE 40 10 # define SHDR_SIZE 40
11 #else 11 #else
12 # error unknown VDSO target 12 # error unknown VDSO target
13 #endif 13 #endif
14 14
15 #define NUM_FAKE_SHDRS 7 15 #define NUM_FAKE_SHDRS 7
16 16
17 SECTIONS 17 SECTIONS
18 { 18 {
19 /* 19 /*
20 * User/kernel shared data is before t 20 * User/kernel shared data is before the vDSO. This may be a little
21 * uglier than putting it after the vD 21 * uglier than putting it after the vDSO, but it avoids issues with
22 * non-allocatable things that dangle 22 * non-allocatable things that dangle past the end of the PT_LOAD
23 * segment. Page size is 8192 for both 23 * segment. Page size is 8192 for both 64-bit and 32-bit vdso binaries
24 */ 24 */
25 25
26 vvar_start = . -8192; 26 vvar_start = . -8192;
27 vvar_data = vvar_start; 27 vvar_data = vvar_start;
28 28
29 . = SIZEOF_HEADERS; 29 . = SIZEOF_HEADERS;
30 30
31 .hash : { *(.hash) } 31 .hash : { *(.hash) } :text
32 .gnu.hash : { *(.gnu.hash) } 32 .gnu.hash : { *(.gnu.hash) }
33 .dynsym : { *(.dynsym) } 33 .dynsym : { *(.dynsym) }
34 .dynstr : { *(.dynstr) } 34 .dynstr : { *(.dynstr) }
35 .gnu.version : { *(.gnu.version) } 35 .gnu.version : { *(.gnu.version) }
36 .gnu.version_d : { *(.gnu.version_d) 36 .gnu.version_d : { *(.gnu.version_d) }
37 .gnu.version_r : { *(.gnu.version_r) 37 .gnu.version_r : { *(.gnu.version_r) }
38 38
39 .dynamic : { *(.dynamic) } 39 .dynamic : { *(.dynamic) } :text :dynamic
40 40
41 .rodata : { 41 .rodata : {
42 *(.rodata*) 42 *(.rodata*)
43 *(.data*) 43 *(.data*)
44 *(.sdata*) 44 *(.sdata*)
45 *(.got.plt) *(.got) 45 *(.got.plt) *(.got)
46 *(.gnu.linkonce.d.*) 46 *(.gnu.linkonce.d.*)
47 *(.bss*) 47 *(.bss*)
48 *(.dynbss*) 48 *(.dynbss*)
49 *(.gnu.linkonce.b.*) 49 *(.gnu.linkonce.b.*)
50 50
51 /* 51 /*
52 * Ideally this would live in 52 * Ideally this would live in a C file: kept in here for
53 * compatibility with x86-64. 53 * compatibility with x86-64.
54 */ 54 */
55 VDSO_FAKE_SECTION_TABLE_START 55 VDSO_FAKE_SECTION_TABLE_START = .;
56 . = . + NUM_FAKE_SHDRS * SHDR_ 56 . = . + NUM_FAKE_SHDRS * SHDR_SIZE;
57 VDSO_FAKE_SECTION_TABLE_END = 57 VDSO_FAKE_SECTION_TABLE_END = .;
58 } 58 } :text
59 59
60 .fake_shstrtab : { *(.fake_shstrtab) 60 .fake_shstrtab : { *(.fake_shstrtab) } :text
61 61
62 62
63 .note : { *(.note.*) } 63 .note : { *(.note.*) } :text :note
64 64
65 .eh_frame_hdr : { *(.eh_frame_hdr) } 65 .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
66 .eh_frame : { KEEP (*(.eh_frame) 66 .eh_frame : { KEEP (*(.eh_frame)) } :text
67 67
68 68
69 /* 69 /*
70 * Text is well-separated from actual 70 * Text is well-separated from actual data: there's plenty of
71 * stuff that isn't used at runtime in 71 * stuff that isn't used at runtime in between.
72 */ 72 */
73 73
74 .text : { *(.text*) } 74 .text : { *(.text*) } :text =0x90909090,
75 75
76 /DISCARD/ : { 76 /DISCARD/ : {
77 *(.discard) 77 *(.discard)
78 *(.discard.*) 78 *(.discard.*)
79 *(__bug_table) 79 *(__bug_table)
80 } 80 }
81 } 81 }
82 82
83 /* 83 /*
84 * Very old versions of ld do not recognize th 84 * Very old versions of ld do not recognize this name token; use the constant.
85 */ 85 */
86 #define PT_GNU_EH_FRAME 0x6474e550 86 #define PT_GNU_EH_FRAME 0x6474e550
87 87
88 /* 88 /*
89 * We must supply the ELF program headers expl 89 * We must supply the ELF program headers explicitly to get just one
90 * PT_LOAD segment, and set the flags explicit 90 * PT_LOAD segment, and set the flags explicitly to make segments read-only.
91 */ 91 */
92 PHDRS 92 PHDRS
93 { 93 {
94 text PT_LOAD FLAGS( 94 text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */
95 dynamic PT_DYNAMIC FLAGS( 95 dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
96 note PT_NOTE FLAGS( 96 note PT_NOTE FLAGS(4); /* PF_R */
97 eh_frame_hdr PT_GNU_EH_FRAME; 97 eh_frame_hdr PT_GNU_EH_FRAME;
98 } 98 }
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TOMOYO® is a registered trademark of NTT DATA CORPORATION.