diff options
Diffstat (limited to 'arch/x86/entry/vdso/vdso-layout.lds.S')
-rw-r--r-- | arch/x86/entry/vdso/vdso-layout.lds.S | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S new file mode 100644 index 000000000..acfd5ba7d --- /dev/null +++ b/arch/x86/entry/vdso/vdso-layout.lds.S @@ -0,0 +1,120 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <asm/vdso.h> + +/* + * Linker script for vDSO. This is an ELF shared object prelinked to + * its virtual address, and with only one read-only segment. + * This script controls its layout. + */ + +#if defined(BUILD_VDSO64) +# define SHDR_SIZE 64 +#elif defined(BUILD_VDSO32) || defined(BUILD_VDSOX32) +# define SHDR_SIZE 40 +#else +# error unknown VDSO target +#endif + +#define NUM_FAKE_SHDRS 13 + +SECTIONS +{ + /* + * User/kernel shared data is before the vDSO. This may be a little + * uglier than putting it after the vDSO, but it avoids issues with + * non-allocatable things that dangle past the end of the PT_LOAD + * segment. + */ + + vvar_start = . - 3 * PAGE_SIZE; + vvar_page = vvar_start; + + /* Place all vvars at the offsets in asm/vvar.h. */ +#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset; +#define __VVAR_KERNEL_LDS +#include <asm/vvar.h> +#undef __VVAR_KERNEL_LDS +#undef EMIT_VVAR + + pvclock_page = vvar_start + PAGE_SIZE; + hvclock_page = vvar_start + 2 * PAGE_SIZE; + + . = SIZEOF_HEADERS; + + .hash : { *(.hash) } :text + .gnu.hash : { *(.gnu.hash) } + .dynsym : { *(.dynsym) } + .dynstr : { *(.dynstr) } + .gnu.version : { *(.gnu.version) } + .gnu.version_d : { *(.gnu.version_d) } + .gnu.version_r : { *(.gnu.version_r) } + + .dynamic : { *(.dynamic) } :text :dynamic + + .rodata : { + *(.rodata*) + *(.data*) + *(.sdata*) + *(.got.plt) *(.got) + *(.gnu.linkonce.d.*) + *(.bss*) + *(.dynbss*) + *(.gnu.linkonce.b.*) + + /* + * Ideally this would live in a C file, but that won't + * work cleanly for x32 until we start building the x32 + * C code using an x32 toolchain. + */ + VDSO_FAKE_SECTION_TABLE_START = .; + . = . + NUM_FAKE_SHDRS * SHDR_SIZE; + VDSO_FAKE_SECTION_TABLE_END = .; + } :text + + .fake_shstrtab : { *(.fake_shstrtab) } :text + + + .note : { *(.note.*) } :text :note + + .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr + .eh_frame : { KEEP (*(.eh_frame)) } :text + + + /* + * Text is well-separated from actual data: there's plenty of + * stuff that isn't used at runtime in between. + */ + + .text : { *(.text*) } :text =0x90909090, + + /* + * At the end so that eu-elflint stays happy when vdso2c strips + * these. A better implementation would avoid allocating space + * for these. + */ + .altinstructions : { *(.altinstructions) } :text + .altinstr_replacement : { *(.altinstr_replacement) } :text + + /DISCARD/ : { + *(.discard) + *(.discard.*) + *(__bug_table) + } +} + +/* + * Very old versions of ld do not recognize this name token; use the constant. + */ +#define PT_GNU_EH_FRAME 0x6474e550 + +/* + * We must supply the ELF program headers explicitly to get just one + * PT_LOAD segment, and set the flags explicitly to make segments read-only. + */ +PHDRS +{ + text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */ + dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ + note PT_NOTE FLAGS(4); /* PF_R */ + eh_frame_hdr PT_GNU_EH_FRAME; +} |