VisionFive2 Linux kernel

b24413180f560 (Greg Kroah-Hartman 2017-11-01 15:07:57 +0100  1) // SPDX-License-Identifier: GPL-2.0
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700  2) /*
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700  3)  *  arch/um/kernel/elf_aux.c
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700  4)  *
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700  5)  *  Scan the Elf auxiliary vector provided by the host to extract
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700  6)  *  information about vsyscall-page, etc.
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700  7)  *
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700  8)  *  Copyright (C) 2004 Fujitsu Siemens Computers GmbH
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700  9)  *  Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com)
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 10)  */
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 11) #include <elf.h>
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 12) #include <stddef.h>
37185b3324087 (Al Viro            2012-10-08 03:27:32 +0100 13) #include <init.h>
37185b3324087 (Al Viro            2012-10-08 03:27:32 +0100 14) #include <elf_user.h>
37185b3324087 (Al Viro            2012-10-08 03:27:32 +0100 15) #include <mem_user.h>
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 16) 
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 17) typedef Elf32_auxv_t elf_auxv_t;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 18) 
c538b391a7e8f (Jeff Dike          2007-02-10 01:44:26 -0800 19) /* These are initialized very early in boot and never changed */
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 20) char * elf_aux_platform;
b743ac54e54ca (Richard Weinberger 2011-07-25 17:12:52 -0700 21) extern long elf_aux_hwcap;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 22) unsigned long vsyscall_ehdr;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 23) unsigned long vsyscall_end;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 24) unsigned long __kernel_vsyscall;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 25) 
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 26) __init void scan_elf_aux( char **envp)
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 27) {
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 28) 	long page_size = 0;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 29) 	elf_auxv_t * auxv;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 30) 
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 31) 	while ( *envp++ != NULL) ;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 32) 
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 33) 	for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 34) 		switch ( auxv->a_type ) {
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 35) 			case AT_SYSINFO:
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 36) 				__kernel_vsyscall = auxv->a_un.a_val;
14251809b1921 (Jeff Dike          2007-02-28 20:13:31 -0800 37) 				/* See if the page is under TASK_SIZE */
14251809b1921 (Jeff Dike          2007-02-28 20:13:31 -0800 38) 				if (__kernel_vsyscall < (unsigned long) envp)
14251809b1921 (Jeff Dike          2007-02-28 20:13:31 -0800 39) 					__kernel_vsyscall = 0;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 40) 				break;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 41) 			case AT_SYSINFO_EHDR:
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 42) 				vsyscall_ehdr = auxv->a_un.a_val;
a502a3593c7aa (Jeff Dike          2005-07-29 14:03:33 -0700 43) 				/* See if the page is under TASK_SIZE */
a502a3593c7aa (Jeff Dike          2005-07-29 14:03:33 -0700 44) 				if (vsyscall_ehdr < (unsigned long) envp)
a502a3593c7aa (Jeff Dike          2005-07-29 14:03:33 -0700 45) 					vsyscall_ehdr = 0;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 46) 				break;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 47) 			case AT_HWCAP:
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 48) 				elf_aux_hwcap = auxv->a_un.a_val;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 49) 				break;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 50) 			case AT_PLATFORM:
da00d9a546655 (Jeff Dike          2005-06-08 15:48:01 -0700 51)                                 /* elf.h removed the pointer elements from
da00d9a546655 (Jeff Dike          2005-06-08 15:48:01 -0700 52)                                  * a_un, so we have to use a_val, which is
da00d9a546655 (Jeff Dike          2005-06-08 15:48:01 -0700 53)                                  * all that's left.
da00d9a546655 (Jeff Dike          2005-06-08 15:48:01 -0700 54)                                  */
64b7673f91c0c (Jeff Dike          2005-09-16 19:27:48 -0700 55) 				elf_aux_platform =
64b7673f91c0c (Jeff Dike          2005-09-16 19:27:48 -0700 56) 					(char *) (long) auxv->a_un.a_val;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 57) 				break;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 58) 			case AT_PAGESZ:
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 59) 				page_size = auxv->a_un.a_val;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 60) 				break;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 61) 		}
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 62) 	}
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 63) 	if ( ! __kernel_vsyscall || ! vsyscall_ehdr ||
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 64) 	     ! elf_aux_hwcap || ! elf_aux_platform ||
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 65) 	     ! page_size || (vsyscall_ehdr % page_size) ) {
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 66) 		__kernel_vsyscall = 0;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 67) 		vsyscall_ehdr = 0;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 68) 		elf_aux_hwcap = 0;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 69) 		elf_aux_platform = "i586";
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 70) 	}
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 71) 	else {
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 72) 		vsyscall_end = vsyscall_ehdr + page_size;
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 73) 	}
^1da177e4c3f4 (Linus Torvalds     2005-04-16 15:20:36 -0700 74) }