diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/x86/vdso/vma.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/x86/vdso/vma.c | 206 |
1 files changed, 0 insertions, 206 deletions
diff --git a/ANDROID_3.4.5/arch/x86/vdso/vma.c b/ANDROID_3.4.5/arch/x86/vdso/vma.c deleted file mode 100644 index 00aaf047..00000000 --- a/ANDROID_3.4.5/arch/x86/vdso/vma.c +++ /dev/null @@ -1,206 +0,0 @@ -/* - * Set up the VMAs to tell the VM about the vDSO. - * Copyright 2007 Andi Kleen, SUSE Labs. - * Subject to the GPL, v.2 - */ -#include <linux/mm.h> -#include <linux/err.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/init.h> -#include <linux/random.h> -#include <linux/elf.h> -#include <asm/vsyscall.h> -#include <asm/vgtod.h> -#include <asm/proto.h> -#include <asm/vdso.h> -#include <asm/page.h> - -unsigned int __read_mostly vdso_enabled = 1; - -extern char vdso_start[], vdso_end[]; -extern unsigned short vdso_sync_cpuid; - -extern struct page *vdso_pages[]; -static unsigned vdso_size; - -#ifdef CONFIG_X86_X32_ABI -extern char vdsox32_start[], vdsox32_end[]; -extern struct page *vdsox32_pages[]; -static unsigned vdsox32_size; - -static void __init patch_vdsox32(void *vdso, size_t len) -{ - Elf32_Ehdr *hdr = vdso; - Elf32_Shdr *sechdrs, *alt_sec = 0; - char *secstrings; - void *alt_data; - int i; - - BUG_ON(len < sizeof(Elf32_Ehdr)); - BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0); - - sechdrs = (void *)hdr + hdr->e_shoff; - secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - - for (i = 1; i < hdr->e_shnum; i++) { - Elf32_Shdr *shdr = &sechdrs[i]; - if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) { - alt_sec = shdr; - goto found; - } - } - - /* If we get here, it's probably a bug. */ - pr_warning("patch_vdsox32: .altinstructions not found\n"); - return; /* nothing to patch */ - -found: - alt_data = (void *)hdr + alt_sec->sh_offset; - apply_alternatives(alt_data, alt_data + alt_sec->sh_size); -} -#endif - -static void __init patch_vdso64(void *vdso, size_t len) -{ - Elf64_Ehdr *hdr = vdso; - Elf64_Shdr *sechdrs, *alt_sec = 0; - char *secstrings; - void *alt_data; - int i; - - BUG_ON(len < sizeof(Elf64_Ehdr)); - BUG_ON(memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0); - - sechdrs = (void *)hdr + hdr->e_shoff; - secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - - for (i = 1; i < hdr->e_shnum; i++) { - Elf64_Shdr *shdr = &sechdrs[i]; - if (!strcmp(secstrings + shdr->sh_name, ".altinstructions")) { - alt_sec = shdr; - goto found; - } - } - - /* If we get here, it's probably a bug. */ - pr_warning("patch_vdso64: .altinstructions not found\n"); - return; /* nothing to patch */ - -found: - alt_data = (void *)hdr + alt_sec->sh_offset; - apply_alternatives(alt_data, alt_data + alt_sec->sh_size); -} - -static int __init init_vdso(void) -{ - int npages = (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE; - int i; - - patch_vdso64(vdso_start, vdso_end - vdso_start); - - vdso_size = npages << PAGE_SHIFT; - for (i = 0; i < npages; i++) - vdso_pages[i] = virt_to_page(vdso_start + i*PAGE_SIZE); - -#ifdef CONFIG_X86_X32_ABI - patch_vdsox32(vdsox32_start, vdsox32_end - vdsox32_start); - npages = (vdsox32_end - vdsox32_start + PAGE_SIZE - 1) / PAGE_SIZE; - vdsox32_size = npages << PAGE_SHIFT; - for (i = 0; i < npages; i++) - vdsox32_pages[i] = virt_to_page(vdsox32_start + i*PAGE_SIZE); -#endif - - return 0; -} -subsys_initcall(init_vdso); - -struct linux_binprm; - -/* Put the vdso above the (randomized) stack with another randomized offset. - This way there is no hole in the middle of address space. - To save memory make sure it is still in the same PTE as the stack top. - This doesn't give that many random bits */ -static unsigned long vdso_addr(unsigned long start, unsigned len) -{ - unsigned long addr, end; - unsigned offset; - end = (start + PMD_SIZE - 1) & PMD_MASK; - if (end >= TASK_SIZE_MAX) - end = TASK_SIZE_MAX; - end -= len; - /* This loses some more bits than a modulo, but is cheaper */ - offset = get_random_int() & (PTRS_PER_PTE - 1); - addr = start + (offset << PAGE_SHIFT); - if (addr >= end) - addr = end; - - /* - * page-align it here so that get_unmapped_area doesn't - * align it wrongfully again to the next page. addr can come in 4K - * unaligned here as a result of stack start randomization. - */ - addr = PAGE_ALIGN(addr); - addr = align_addr(addr, NULL, ALIGN_VDSO); - - return addr; -} - -/* Setup a VMA at program startup for the vsyscall page. - Not called for compat tasks */ -static int setup_additional_pages(struct linux_binprm *bprm, - int uses_interp, - struct page **pages, - unsigned size) -{ - struct mm_struct *mm = current->mm; - unsigned long addr; - int ret; - - if (!vdso_enabled) - return 0; - - down_write(&mm->mmap_sem); - addr = vdso_addr(mm->start_stack, size); - addr = get_unmapped_area(NULL, addr, size, 0, 0); - if (IS_ERR_VALUE(addr)) { - ret = addr; - goto up_fail; - } - - current->mm->context.vdso = (void *)addr; - - ret = install_special_mapping(mm, addr, size, - VM_READ|VM_EXEC| - VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, - pages); - if (ret) { - current->mm->context.vdso = NULL; - goto up_fail; - } - -up_fail: - up_write(&mm->mmap_sem); - return ret; -} - -int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) -{ - return setup_additional_pages(bprm, uses_interp, vdso_pages, - vdso_size); -} - -#ifdef CONFIG_X86_X32_ABI -int x32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) -{ - return setup_additional_pages(bprm, uses_interp, vdsox32_pages, - vdsox32_size); -} -#endif - -static __init int vdso_setup(char *s) -{ - vdso_enabled = simple_strtoul(s, NULL, 0); - return 0; -} -__setup("vdso=", vdso_setup); |