#ifdef CONFIG_X86_64 /* Set up %gs. * * The base of %gs always points to fixed_percpu_data. If the * stack protector canary is enabled, it is located at %gs:40. * Note that, on SMP, the boot cpu uses init data section until * the per cpu areas are set up. */ movl $MSR_GS_BASE,%ecx movq $INIT_PER_CPU_VAR(fixed_percpu_data),%rax cdq wrmsr #endif
/* * Helper macros to generate ELF Note structures, which are put into a * PT_NOTE segment of the final vmlinux image. These are useful for * including name-value pairs of metadata into the kernel binary (or * modules?) for use by external programs. * * Each note has three parts: a name, a type and a desc. The name is * intended to distinguish the note's originator, so it would be a * company, project, subsystem, etc; it must be in a suitable form for * use in a section name. The type is an integer which is used to tag * the data, and is considered to be within the "name" namespace (so * "FooCo"'s type 42 is distinct from "BarProj"'s type 42). The * "desc" field is the actual data. There are no constraints on the * desc field's contents, though typically they're fairly small. * * All notes from a given NAME are put into a section named * .note.NAME. When the kernel image is finally linked, all the notes * are packed into a single .notes section, which is mapped into the * PT_NOTE segment. Because notes for a given name are grouped into * the same section, they'll all be adjacent the output file. * * This file defines macros for both C and assembler use. Their * syntax is slightly different, but they're semantically similar. * * See the ELF specification for more detail about ELF notes. */
#ifdef __ASSEMBLER__ /* * Generate a structure with the same shape as Elf{32,64}_Nhdr (which * turn out to be the same size and shape), followed by the name and * desc data with appropriate padding. The 'desctype' argument is the * assembler pseudo op defining the type of the data e.g. .asciz while * 'descdata' is the data itself e.g. "hello, world". * * e.g. ELFNOTE(XYZCo, 42, .asciz, "forty-two") * ELFNOTE(XYZCo, 12, .long, 0xdeadbeef) */ #define ELFNOTE_START(name, type, flags) \ .pushsection .note.name, flags,@note ; \ .balign 4 ; \ .long 2f - 1f /* namesz */ ; \ .long 4484f - 3f /* descsz */ ; \ .long type ; \ 1:.asciz #name ; \ 2:.balign 4 ; \ 3:
/* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. */ externconstvoid __start_notes __weak; externconstvoid __stop_notes __weak; #define notes_size (&__stop_notes - &__start_notes)
/* * The compressed kernel image (ZO), has been moved so that its position * is against the end of the buffer used to hold the uncompressed kernel * image (VO) and the execution environment (.bss, .brk), which makes sure * there is room to do the in-place decompression. (See header.S for the * calculations.) * * |-----compressed kernel image------| * V V * 0 extract_offset +INIT_SIZE * |-----------|---------------|-------------------------|--------| * | | | | * VO__text startup_32 of ZO VO__end ZO__end * ^ ^ * |-------uncompressed kernel image---------| * */ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, unsignedchar *input_data, unsignedlong input_len, unsignedchar *output, unsignedlong output_len)
