projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 1da177e4 LT |
2 | /* |
| 3 | * arch/um/kernel/elf_aux.c | |
| 4 | * | |
| 70e79866 | 5 | * Scan the ELF auxiliary vector provided by the host to extract |
| 1da177e4 LT |
6 | * information about vsyscall-page, etc. |
| 7 | * | |
| 8 | * Copyright (C) 2004 Fujitsu Siemens Computers GmbH | |
| 9 | * Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com) | |
| 10 | */ | |
| 11 | #include <elf.h> | |
| 12 | #include <stddef.h> | |
| 37185b33 AV |
13 | #include <init.h> |
| 14 | #include <elf_user.h> | |
| 15 | #include <mem_user.h> | |
| 1da177e4 | 16 | |
| 1da177e4 | 17 | typedef Elf32_auxv_t elf_auxv_t; |
| 1da177e4 | 18 | |
| c538b391 | 19 | /* These are initialized very early in boot and never changed */ |
| 1da177e4 | 20 | char * elf_aux_platform; |
| b743ac54 | 21 | extern long elf_aux_hwcap; |
| 1da177e4 LT |
22 | unsigned long vsyscall_ehdr; |
| 23 | unsigned long vsyscall_end; | |
| 1da177e4 LT |
24 | unsigned long __kernel_vsyscall; |
| 25 | ||
| 26 | __init void scan_elf_aux( char **envp) | |
| 27 | { | |
| 28 | long page_size = 0; | |
| 29 | elf_auxv_t * auxv; | |
| 30 | ||
| 31 | while ( *envp++ != NULL) ; | |
| 32 | ||
| 33 | for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) { | |
| 34 | switch ( auxv->a_type ) { | |
| 35 | case AT_SYSINFO: | |
| 36 | __kernel_vsyscall = auxv->a_un.a_val; | |
| 14251809 JD |
37 | /* See if the page is under TASK_SIZE */ |
| 38 | if (__kernel_vsyscall < (unsigned long) envp) | |
| 39 | __kernel_vsyscall = 0; | |
| 1da177e4 LT |
40 | break; |
| 41 | case AT_SYSINFO_EHDR: | |
| 42 | vsyscall_ehdr = auxv->a_un.a_val; | |
| a502a359 JD |
43 | /* See if the page is under TASK_SIZE */ |
| 44 | if (vsyscall_ehdr < (unsigned long) envp) | |
| 45 | vsyscall_ehdr = 0; | |
| 1da177e4 LT |
46 | break; |
| 47 | case AT_HWCAP: | |
| 48 | elf_aux_hwcap = auxv->a_un.a_val; | |
| 49 | break; | |
| 50 | case AT_PLATFORM: | |
| da00d9a5 JD |
51 | /* elf.h removed the pointer elements from |
| 52 | * a_un, so we have to use a_val, which is | |
| 53 | * all that's left. | |
| 54 | */ | |
| 64b7673f JD |
55 | elf_aux_platform = |
| 56 | (char *) (long) auxv->a_un.a_val; | |
| 1da177e4 LT |
57 | break; |
| 58 | case AT_PAGESZ: | |
| 59 | page_size = auxv->a_un.a_val; | |
| 60 | break; | |
| 61 | } | |
| 62 | } | |
| 63 | if ( ! __kernel_vsyscall || ! vsyscall_ehdr || | |
| 64 | ! elf_aux_hwcap || ! elf_aux_platform || | |
| 65 | ! page_size || (vsyscall_ehdr % page_size) ) { | |
| 66 | __kernel_vsyscall = 0; | |
| 67 | vsyscall_ehdr = 0; | |
| 68 | elf_aux_hwcap = 0; | |
| 69 | elf_aux_platform = "i586"; | |
| 70 | } | |
| 71 | else { | |
| 72 | vsyscall_end = vsyscall_ehdr + page_size; | |
| 73 | } | |
| 74 | } |