projects / mirror_ubuntu-artful-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * arch/um/kernel/elf_aux.c | |
| 3 | * | |
| 4 | * Scan the Elf auxiliary vector provided by the host to extract | |
| 5 | * information about vsyscall-page, etc. | |
| 6 | * | |
| 7 | * Copyright (C) 2004 Fujitsu Siemens Computers GmbH | |
| 8 | * Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com) | |
| 9 | */ | |
| 10 | #include <elf.h> | |
| 11 | #include <stddef.h> | |
| 12 | #include "init.h" | |
| 13 | #include "elf_user.h" | |
| a502a359 | 14 | #include "mem_user.h" |
| ecba97d4 | 15 | #include <kern_constants.h> |
| 1da177e4 | 16 | |
| 41c79dc3 PBG |
17 | /* Use the one from the kernel - the host may miss it, if having old headers. */ |
| 18 | #if UM_ELF_CLASS == UM_ELFCLASS32 | |
| 1da177e4 LT |
19 | typedef Elf32_auxv_t elf_auxv_t; |
| 20 | #else | |
| 21 | typedef Elf64_auxv_t elf_auxv_t; | |
| 22 | #endif | |
| 23 | ||
| c538b391 | 24 | /* These are initialized very early in boot and never changed */ |
| 1da177e4 LT |
25 | char * elf_aux_platform; |
| 26 | long elf_aux_hwcap; | |
| 1da177e4 LT |
27 | unsigned long vsyscall_ehdr; |
| 28 | unsigned long vsyscall_end; | |
| 1da177e4 LT |
29 | unsigned long __kernel_vsyscall; |
| 30 | ||
| 31 | __init void scan_elf_aux( char **envp) | |
| 32 | { | |
| 33 | long page_size = 0; | |
| 34 | elf_auxv_t * auxv; | |
| 35 | ||
| 36 | while ( *envp++ != NULL) ; | |
| 37 | ||
| 38 | for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) { | |
| 39 | switch ( auxv->a_type ) { | |
| 40 | case AT_SYSINFO: | |
| 41 | __kernel_vsyscall = auxv->a_un.a_val; | |
| 42 | break; | |
| 43 | case AT_SYSINFO_EHDR: | |
| 44 | vsyscall_ehdr = auxv->a_un.a_val; | |
| a502a359 JD |
45 | /* See if the page is under TASK_SIZE */ |
| 46 | if (vsyscall_ehdr < (unsigned long) envp) | |
| 47 | vsyscall_ehdr = 0; | |
| 1da177e4 LT |
48 | break; |
| 49 | case AT_HWCAP: | |
| 50 | elf_aux_hwcap = auxv->a_un.a_val; | |
| 51 | break; | |
| 52 | case AT_PLATFORM: | |
| da00d9a5 JD |
53 | /* elf.h removed the pointer elements from |
| 54 | * a_un, so we have to use a_val, which is | |
| 55 | * all that's left. | |
| 56 | */ | |
| 64b7673f JD |
57 | elf_aux_platform = |
| 58 | (char *) (long) auxv->a_un.a_val; | |
| 1da177e4 LT |
59 | break; |
| 60 | case AT_PAGESZ: | |
| 61 | page_size = auxv->a_un.a_val; | |
| 62 | break; | |
| 63 | } | |
| 64 | } | |
| 65 | if ( ! __kernel_vsyscall || ! vsyscall_ehdr || | |
| 66 | ! elf_aux_hwcap || ! elf_aux_platform || | |
| 67 | ! page_size || (vsyscall_ehdr % page_size) ) { | |
| 68 | __kernel_vsyscall = 0; | |
| 69 | vsyscall_ehdr = 0; | |
| 70 | elf_aux_hwcap = 0; | |
| 71 | elf_aux_platform = "i586"; | |
| 72 | } | |
| 73 | else { | |
| 74 | vsyscall_end = vsyscall_ehdr + page_size; | |
| 75 | } | |
| 76 | } |