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Commit a97f52e6 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
Browse files

x86: compat_binfmt_elf 



This switches x86-64's 32-bit ELF support to use the shared
fs/compat_binfmt_elf.c code instead of our own ia32_binfmt.c.

Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 60b3b9af

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -1532,6 +1532,7 @@ source "fs/Kconfig.binfmt" 
config IA32_EMULATION

	bool "IA32 Emulation"

	depends on X86_64

	select COMPAT_BINFMT_ELF

	help

	  Include code to run 32-bit programs under a 64-bit kernel. You should

	  likely turn this on, unless you're 100% sure that you don't have any

arch/x86/ia32/Makefile

+1 −2
Original line number Diff line number Diff line
@@ -2,8 +2,7 @@ 
# Makefile for the ia32 kernel emulation subsystem.

#



obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o \

	ia32_binfmt.o

obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o



sysv-$(CONFIG_SYSVIPC) := ipc32.o

obj-$(CONFIG_IA32_EMULATION) += $(sysv-y)

arch/x86/vdso/vdso32-setup.c

+33 −0
Original line number Diff line number Diff line
@@ -377,6 +377,39 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack) 


__initcall(sysenter_setup);



#ifdef CONFIG_SYSCTL

/* Register vsyscall32 into the ABI table */

#include <linux/sysctl.h>



static ctl_table abi_table2[] = {

	{

		.procname	= "vsyscall32",

		.data		= &sysctl_vsyscall32,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec

	},

	{}

};



static ctl_table abi_root_table2[] = {

	{

		.ctl_name = CTL_ABI,

		.procname = "abi",

		.mode = 0555,

		.child = abi_table2

	},

	{}

};



static __init int ia32_binfmt_init(void)

{

	register_sysctl_table(abi_root_table2);

	return 0;

}

__initcall(ia32_binfmt_init);

#endif



#else  /* CONFIG_X86_32 */



const char *arch_vma_name(struct vm_area_struct *vma)

include/asm-x86/elf.h

+64 −24
Original line number Diff line number Diff line
@@ -73,6 +73,9 @@ typedef struct user_fxsr_struct elf_fpxregset_t; 
#endif



#ifdef __KERNEL__

#include <asm/vdso.h>



extern unsigned int vdso_enabled;



/*

 * This is used to ensure we don't load something for the wrong architecture.
@@ -84,7 +87,6 @@ typedef struct user_fxsr_struct elf_fpxregset_t; 
#include <asm/processor.h>

#include <asm/system.h>		/* for savesegment */

#include <asm/desc.h>

#include <asm/vdso.h>



#define elf_check_arch(x)	elf_check_arch_ia32(x)
@@ -106,7 +108,6 @@ typedef struct user_fxsr_struct elf_fpxregset_t; 


#define ELF_PLATFORM	(utsname()->machine)

#define set_personality_64bit()	do { } while (0)

extern unsigned int vdso_enabled;



#else /* CONFIG_X86_32 */
@@ -118,29 +119,57 @@ extern unsigned int vdso_enabled; 
#define elf_check_arch(x) \

	((x)->e_machine == EM_X86_64)



#define compat_elf_check_arch(x)	elf_check_arch_ia32(x)



static inline void start_ia32_thread(struct pt_regs *regs, u32 ip, u32 sp)

{

	asm volatile("movl %0,%%fs" :: "r" (0));

	asm volatile("movl %0,%%es; movl %0,%%ds" : : "r" (__USER32_DS));

	load_gs_index(0);

	regs->ip = ip;

	regs->sp = sp;

	regs->flags = X86_EFLAGS_IF;

	regs->cs = __USER32_CS;

	regs->ss = __USER32_DS;

}



static inline void elf_common_init(struct thread_struct *t,

				   struct pt_regs *regs, const u16 ds)

{

	regs->ax = regs->bx = regs->cx = regs->dx = 0;

	regs->si = regs->di = regs->bp = 0;

	regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;

	regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;

	t->fs = t->gs = 0;

	t->fsindex = t->gsindex = 0;

	t->ds = t->es = ds;

}



#define ELF_PLAT_INIT(_r, load_addr)	do {		  \

	struct task_struct *cur = current;		  \

	(_r)->bx = 0; (_r)->cx = 0; (_r)->dx = 0;	  \

	(_r)->si = 0; (_r)->di = 0; (_r)->bp = 0;	  \

	(_r)->ax = 0;					  \

	(_r)->r8 = 0;					  \

	(_r)->r9 = 0;					  \

	(_r)->r10 = 0;					  \

	(_r)->r11 = 0;					  \

	(_r)->r12 = 0;					  \

	(_r)->r13 = 0;					  \

	(_r)->r14 = 0;					  \

	(_r)->r15 = 0;					  \

	cur->thread.fs = 0; cur->thread.gs = 0;		  \

	cur->thread.fsindex = 0; cur->thread.gsindex = 0; \

	cur->thread.ds = 0; cur->thread.es = 0;		  \

	elf_common_init(&current->thread, _r, 0);	  \

	clear_thread_flag(TIF_IA32);			  \

} while (0)



#define	COMPAT_ELF_PLAT_INIT(regs, load_addr)	\

	elf_common_init(&current->thread, regs, __USER_DS)

#define	compat_start_thread(regs, ip, sp)	do {		\

		start_ia32_thread(regs, ip, sp);		\

		set_fs(USER_DS);				\

	} while (0)

#define COMPAT_SET_PERSONALITY(ex, ibcs2)	do {		\

		if (test_thread_flag(TIF_IA32))			\

			clear_thread_flag(TIF_ABI_PENDING);	\

		else						\

			set_thread_flag(TIF_ABI_PENDING);	\

		current->personality |= force_personality32;	\

	} while (0)

#define COMPAT_ELF_PLATFORM			("i686")



/* I'm not sure if we can use '-' here */

#define ELF_PLATFORM       ("x86_64")

extern void set_personality_64bit(void);

extern int vdso_enabled;

extern unsigned int sysctl_vsyscall32;

extern int force_personality32;



#endif /* !CONFIG_X86_32 */
@@ -179,17 +208,19 @@ extern int vdso_enabled; 


struct task_struct;



#define	ARCH_DLINFO_IA32(vdso_enabled) \

do if (vdso_enabled) {							\

		NEW_AUX_ENT(AT_SYSINFO,	VDSO_ENTRY);			\

		NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE);	\

} while (0)



#ifdef CONFIG_X86_32



#define VDSO_HIGH_BASE		(__fix_to_virt(FIX_VDSO))



/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */

#define ARCH_DLINFO		ARCH_DLINFO_IA32(vdso_enabled)



#define ARCH_DLINFO \

do if (vdso_enabled) {							\

		NEW_AUX_ENT(AT_SYSINFO,	VDSO_ENTRY);			\

		NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE);	\

} while (0)

/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */



#else /* CONFIG_X86_32 */
@@ -203,6 +234,12 @@ do if (vdso_enabled) { \ 
	NEW_AUX_ENT(AT_SYSINFO_EHDR,(unsigned long)current->mm->context.vdso);\

} while (0)



#define AT_SYSINFO		32



#define COMPAT_ARCH_DLINFO	ARCH_DLINFO_IA32(sysctl_vsyscall32)



#define COMPAT_ELF_ET_DYN_BASE	(TASK_UNMAPPED_BASE + 0x1000000)



#endif /* !CONFIG_X86_32 */



#define VDSO_CURRENT_BASE	((unsigned long)current->mm->context.vdso)
@@ -216,6 +253,9 @@ struct linux_binprm; 
extern int arch_setup_additional_pages(struct linux_binprm *bprm,

				       int executable_stack);



extern int syscall32_setup_pages(struct linux_binprm *, int exstack);

#define compat_arch_setup_additional_pages	syscall32_setup_pages



extern unsigned long arch_randomize_brk(struct mm_struct *mm);

#define arch_randomize_brk arch_randomize_brk