102 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			102 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * (C) Copyright 2002 Linus Torvalds
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|  * Portions based on the vdso-randomization code from exec-shield:
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|  * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
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|  *
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|  * This file contains the needed initializations to support sysenter.
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|  */
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| 
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| #include <linux/init.h>
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| #include <linux/smp.h>
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| #include <linux/kernel.h>
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| #include <linux/mm_types.h>
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| 
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| #include <asm/processor.h>
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| #include <asm/vdso.h>
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| 
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| #ifdef CONFIG_COMPAT_VDSO
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| #define VDSO_DEFAULT	0
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| #else
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| #define VDSO_DEFAULT	1
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| #endif
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| 
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| /*
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|  * Should the kernel map a VDSO page into processes and pass its
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|  * address down to glibc upon exec()?
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|  */
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| unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT;
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| 
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| static int __init vdso32_setup(char *s)
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| {
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| 	vdso32_enabled = simple_strtoul(s, NULL, 0);
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| 
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| 	if (vdso32_enabled > 1) {
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| 		pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
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| 		vdso32_enabled = 0;
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| 	}
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| 
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| 	return 1;
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| }
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| 
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| /*
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|  * For consistency, the argument vdso32=[012] affects the 32-bit vDSO
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|  * behavior on both 64-bit and 32-bit kernels.
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|  * On 32-bit kernels, vdso=[012] means the same thing.
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|  */
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| __setup("vdso32=", vdso32_setup);
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| 
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| #ifdef CONFIG_X86_32
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| __setup_param("vdso=", vdso_setup, vdso32_setup, 0);
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| #endif
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| 
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| int __init sysenter_setup(void)
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| {
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| 	init_vdso_image(&vdso_image_32);
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| 
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| 	return 0;
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| }
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| 
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| #ifdef CONFIG_X86_64
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| 
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| subsys_initcall(sysenter_setup);
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| 
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| #ifdef CONFIG_SYSCTL
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| /* Register vsyscall32 into the ABI table */
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| #include <linux/sysctl.h>
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| 
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| static const int zero;
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| static const int one = 1;
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| 
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| static struct ctl_table abi_table2[] = {
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| 	{
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| 		.procname	= "vsyscall32",
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| 		.data		= &vdso32_enabled,
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| 		.maxlen		= sizeof(int),
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| 		.mode		= 0644,
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| 		.proc_handler	= proc_dointvec_minmax,
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| 		.extra1		= (int *)&zero,
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| 		.extra2		= (int *)&one,
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| 	},
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| 	{}
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| };
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| 
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| static struct ctl_table abi_root_table2[] = {
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| 	{
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| 		.procname = "abi",
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| 		.mode = 0555,
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| 		.child = abi_table2
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| 	},
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| 	{}
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| };
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| 
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| static __init int ia32_binfmt_init(void)
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| {
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| 	register_sysctl_table(abi_root_table2);
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| 	return 0;
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| }
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| __initcall(ia32_binfmt_init);
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| #endif /* CONFIG_SYSCTL */
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| 
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| #endif	/* CONFIG_X86_64 */
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