arch/x86_64/ia32/ia32_binfmt.c - kernel/msm-4.9 - Gitiles

 /*
  * Written 2000,2002 by Andi Kleen.
  *
  * Loosely based on the sparc64 and IA64 32bit emulation loaders.
  * This tricks binfmt_elf.c into loading 32bit binaries using lots
  * of ugly preprocessor tricks. Talk about very very poor man's inheritance.
  */
 #include <linux/types.h>
 #include <linux/stddef.h>
 #include <linux/rwsem.h>
 #include <linux/sched.h>
 #include <linux/compat.h>
 #include <linux/string.h>
 #include <linux/binfmts.h>
 #include <linux/mm.h>
 #include <linux/security.h>

 #include <asm/segment.h>
 #include <asm/ptrace.h>
 #include <asm/processor.h>
 #include <asm/user32.h>
 #include <asm/sigcontext32.h>
 #include <asm/fpu32.h>
 #include <asm/i387.h>
 #include <asm/uaccess.h>
 #include <asm/ia32.h>
 #include <asm/vsyscall32.h>

 #define ELF_NAME "elf/i386"

 #define AT_SYSINFO 32
 #define AT_SYSINFO_EHDR		33

 int sysctl_vsyscall32 = 1;

 #define ARCH_DLINFO do {  \
 	if (sysctl_vsyscall32) { \
 	NEW_AUX_ENT(AT_SYSINFO, (u32)(u64)VSYSCALL32_VSYSCALL); \
 	NEW_AUX_ENT(AT_SYSINFO_EHDR, VSYSCALL32_BASE);    \
 	}	\
 } while(0)

 struct file;
 struct elf_phdr;

 #define IA32_EMULATOR 1

 #define ELF_ET_DYN_BASE		(TASK_UNMAPPED_BASE + 0x1000000)

 #undef ELF_ARCH
 #define ELF_ARCH EM_386

 #undef ELF_CLASS
 #define ELF_CLASS ELFCLASS32

 #define ELF_DATA	ELFDATA2LSB

 #define USE_ELF_CORE_DUMP 1

 /* Override elfcore.h */
 #define _LINUX_ELFCORE_H 1
 typedef unsigned int elf_greg_t;

 #define ELF_NGREG (sizeof (struct user_regs_struct32) / sizeof(elf_greg_t))
 typedef elf_greg_t elf_gregset_t[ELF_NGREG];

 struct elf_siginfo
 {
 	int	si_signo;			/* signal number */
 	int	si_code;			/* extra code */
 	int	si_errno;			/* errno */
 };

 #define jiffies_to_timeval(a,b) do { (b)->tv_usec = 0; (b)->tv_sec = (a)/HZ; }while(0)

 struct elf_prstatus
 {
 	struct elf_siginfo pr_info;	/* Info associated with signal */
 	short	pr_cursig;		/* Current signal */
 	unsigned int pr_sigpend;	/* Set of pending signals */
 	unsigned int pr_sighold;	/* Set of held signals */
 	pid_t	pr_pid;
 	pid_t	pr_ppid;
 	pid_t	pr_pgrp;
 	pid_t	pr_sid;
 	struct compat_timeval pr_utime;	/* User time */
 	struct compat_timeval pr_stime;	/* System time */
 	struct compat_timeval pr_cutime;	/* Cumulative user time */
 	struct compat_timeval pr_cstime;	/* Cumulative system time */
 	elf_gregset_t pr_reg;	/* GP registers */
 	int pr_fpvalid;		/* True if math co-processor being used.  */
 };

 #define ELF_PRARGSZ	(80)	/* Number of chars for args */

 struct elf_prpsinfo
 {
 	char	pr_state;	/* numeric process state */
 	char	pr_sname;	/* char for pr_state */
 	char	pr_zomb;	/* zombie */
 	char	pr_nice;	/* nice val */
 	unsigned int pr_flag;	/* flags */
 	__u16	pr_uid;
 	__u16	pr_gid;
 	pid_t	pr_pid, pr_ppid, pr_pgrp, pr_sid;
 	/* Lots missing */
 	char	pr_fname[16];	/* filename of executable */
 	char	pr_psargs[ELF_PRARGSZ];	/* initial part of arg list */
 };

 #define __STR(x) #x
 #define STR(x) __STR(x)

 #define _GET_SEG(x) \
 	({ __u32 seg; asm("movl %%" STR(x) ",%0" : "=r"(seg)); seg; })

 /* Assumes current==process to be dumped */
 #define ELF_CORE_COPY_REGS(pr_reg, regs)       		\
 	pr_reg[0] = regs->rbx;				\
 	pr_reg[1] = regs->rcx;				\
 	pr_reg[2] = regs->rdx;				\
 	pr_reg[3] = regs->rsi;				\
 	pr_reg[4] = regs->rdi;				\
 	pr_reg[5] = regs->rbp;				\
 	pr_reg[6] = regs->rax;				\
 	pr_reg[7] = _GET_SEG(ds);   			\
 	pr_reg[8] = _GET_SEG(es);			\
 	pr_reg[9] = _GET_SEG(fs);			\
 	pr_reg[10] = _GET_SEG(gs);			\
 	pr_reg[11] = regs->orig_rax;			\
 	pr_reg[12] = regs->rip;				\
 	pr_reg[13] = regs->cs;				\
 	pr_reg[14] = regs->eflags;			\
 	pr_reg[15] = regs->rsp;				\
 	pr_reg[16] = regs->ss;

 #define user user32

 #define __ASM_X86_64_ELF_H 1
 #define elf_read_implies_exec(ex, executable_stack)     (executable_stack != EXSTACK_DISABLE_X)
 //#include <asm/ia32.h>
 #include <linux/elf.h>

 typedef struct user_i387_ia32_struct elf_fpregset_t;
 typedef struct user32_fxsr_struct elf_fpxregset_t;


 static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *regs)
 {
 	ELF_CORE_COPY_REGS((*elfregs), regs)
 }

 static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t* elfregs)
 {
 	struct pt_regs *pp = task_pt_regs(t);
 	ELF_CORE_COPY_REGS((*elfregs), pp);
 	/* fix wrong segments */
 	(*elfregs)[7] = t->thread.ds;
 	(*elfregs)[9] = t->thread.fsindex;
 	(*elfregs)[10] = t->thread.gsindex;
 	(*elfregs)[8] = t->thread.es;
 	return 1;
 }

 static inline int
 elf_core_copy_task_fpregs(struct task_struct *tsk, struct pt_regs *regs, elf_fpregset_t *fpu)
 {
 	struct _fpstate_ia32 *fpstate = (void*)fpu;
 	mm_segment_t oldfs = get_fs();

 	if (!tsk_used_math(tsk))
 		return 0;
 	if (!regs)
 		regs = task_pt_regs(tsk);
 	if (tsk == current)
 		unlazy_fpu(tsk);
 	set_fs(KERNEL_DS);
 	save_i387_ia32(tsk, fpstate, regs, 1);
 	/* Correct for i386 bug. It puts the fop into the upper 16bits of
 	   the tag word (like FXSAVE), not into the fcs*/
 	fpstate->cssel |= fpstate->tag & 0xffff0000;
 	set_fs(oldfs);
 	return 1;
 }

 #define ELF_CORE_COPY_XFPREGS 1
 static inline int
 elf_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
 {
 	struct pt_regs *regs = task_pt_regs(t);
 	if (!tsk_used_math(t))
 		return 0;
 	if (t == current)
 		unlazy_fpu(t);
 	memcpy(xfpu, &t->thread.i387.fxsave, sizeof(elf_fpxregset_t));
 	xfpu->fcs = regs->cs;
 	xfpu->fos = t->thread.ds; /* right? */
 	return 1;
 }

 #undef elf_check_arch
 #define elf_check_arch(x) \
 	((x)->e_machine == EM_386)

 extern int force_personality32;

 #define ELF_EXEC_PAGESIZE PAGE_SIZE
 #define ELF_HWCAP (boot_cpu_data.x86_capability[0])
 #define ELF_PLATFORM  ("i686")
 #define SET_PERSONALITY(ex, ibcs2)			\
 do {							\
 	unsigned long new_flags = 0;				\
 	if ((ex).e_ident[EI_CLASS] == ELFCLASS32)		\
 		new_flags = _TIF_IA32;				\
 	if ((current_thread_info()->flags & _TIF_IA32)		\
 	    != new_flags)					\
 		set_thread_flag(TIF_ABI_PENDING);		\
 	else							\
 		clear_thread_flag(TIF_ABI_PENDING);		\
 	/* XXX This overwrites the user set personality */	\
 	current->personality |= force_personality32;		\
 } while (0)

 /* Override some function names */
 #define elf_format			elf32_format

 #define init_elf_binfmt			init_elf32_binfmt
 #define exit_elf_binfmt			exit_elf32_binfmt

 #define load_elf_binary load_elf32_binary

 #define ELF_PLAT_INIT(r, load_addr)	elf32_init(r)
 #define setup_arg_pages(bprm, stack_top, exec_stack) \
 	ia32_setup_arg_pages(bprm, stack_top, exec_stack)
 int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top, int executable_stack);

 #undef start_thread
 #define start_thread(regs,new_rip,new_rsp) do { \
 	asm volatile("movl %0,%%fs" :: "r" (0)); \
 	asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS)); \
 	load_gs_index(0); \
 	(regs)->rip = (new_rip); \
 	(regs)->rsp = (new_rsp); \
 	(regs)->eflags = 0x200; \
 	(regs)->cs = __USER32_CS; \
 	(regs)->ss = __USER32_DS; \
 	set_fs(USER_DS); \
 } while(0)


 #include <linux/module.h>

 MODULE_DESCRIPTION("Binary format loader for compatibility with IA32 ELF binaries.");
 MODULE_AUTHOR("Eric Youngdale, Andi Kleen");

 #undef MODULE_DESCRIPTION
 #undef MODULE_AUTHOR

 static void elf32_init(struct pt_regs *);

 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 #define arch_setup_additional_pages syscall32_setup_pages
 extern int syscall32_setup_pages(struct linux_binprm *, int exstack);

 #include "../../../fs/binfmt_elf.c"

 static void elf32_init(struct pt_regs *regs)
 {
 	struct task_struct *me = current;
 	regs->rdi = 0;
 	regs->rsi = 0;
 	regs->rdx = 0;
 	regs->rcx = 0;
 	regs->rax = 0;
 	regs->rbx = 0;
 	regs->rbp = 0;
 	regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
 		regs->r13 = regs->r14 = regs->r15 = 0;
     me->thread.fs = 0;
 	me->thread.gs = 0;
 	me->thread.fsindex = 0;
 	me->thread.gsindex = 0;
     me->thread.ds = __USER_DS;
 	me->thread.es = __USER_DS;
 }

 int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top,
 			 int executable_stack)
 {
 	unsigned long stack_base;
 	struct vm_area_struct *mpnt;
 	struct mm_struct *mm = current->mm;
 	int i, ret;

 	stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE;
 	mm->arg_start = bprm->p + stack_base;

 	bprm->p += stack_base;
 	if (bprm->loader)
 		bprm->loader += stack_base;
 	bprm->exec += stack_base;

 	mpnt = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
 	if (!mpnt)
 		return -ENOMEM;

 	memset(mpnt, 0, sizeof(*mpnt));

 	down_write(&mm->mmap_sem);
 	{
 		mpnt->vm_mm = mm;
 		mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
 		mpnt->vm_end = stack_top;
 		if (executable_stack == EXSTACK_ENABLE_X)
 			mpnt->vm_flags = VM_STACK_FLAGS |  VM_EXEC;
 		else if (executable_stack == EXSTACK_DISABLE_X)
 			mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
 		else
 			mpnt->vm_flags = VM_STACK_FLAGS;
  		mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC) ?
  			PAGE_COPY_EXEC : PAGE_COPY;
 		if ((ret = insert_vm_struct(mm, mpnt))) {
 			up_write(&mm->mmap_sem);
 			kmem_cache_free(vm_area_cachep, mpnt);
 			return ret;
 		}
 		mm->stack_vm = mm->total_vm = vma_pages(mpnt);
 	}

 	for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 		struct page *page = bprm->page[i];
 		if (page) {
 			bprm->page[i] = NULL;
 			install_arg_page(mpnt, page, stack_base);
 		}
 		stack_base += PAGE_SIZE;
 	}
 	up_write(&mm->mmap_sem);

 	return 0;
 }
 EXPORT_SYMBOL(ia32_setup_arg_pages);

 #ifdef CONFIG_SYSCTL
 /* Register vsyscall32 into the ABI table */
 #include <linux/sysctl.h>

 static ctl_table abi_table2[] = {
 	{ 99, "vsyscall32", &sysctl_vsyscall32, sizeof(int), 0644, NULL,
 	  proc_dointvec },
 	{ 0, }
 };

 static ctl_table abi_root_table2[] = {
 	{ .ctl_name = CTL_ABI, .procname = "abi", .mode = 0555,
 	  .child = abi_table2 },
 	{ 0 },
 };

 static __init int ia32_binfmt_init(void)
 {
 	register_sysctl_table(abi_root_table2, 1);
 	return 0;
 }
 __initcall(ia32_binfmt_init);
 #endif
	/*
	* Written 2000,2002 by Andi Kleen.
	*
	* Loosely based on the sparc64 and IA64 32bit emulation loaders.
	* This tricks binfmt_elf.c into loading 32bit binaries using lots
	* of ugly preprocessor tricks. Talk about very very poor man's inheritance.
	*/
	#include <linux/types.h>
	#include <linux/stddef.h>
	#include <linux/rwsem.h>
	#include <linux/sched.h>
	#include <linux/compat.h>
	#include <linux/string.h>
	#include <linux/binfmts.h>
	#include <linux/mm.h>
	#include <linux/security.h>

	#include <asm/segment.h>
	#include <asm/ptrace.h>
	#include <asm/processor.h>
	#include <asm/user32.h>
	#include <asm/sigcontext32.h>
	#include <asm/fpu32.h>
	#include <asm/i387.h>
	#include <asm/uaccess.h>
	#include <asm/ia32.h>
	#include <asm/vsyscall32.h>

	#define ELF_NAME "elf/i386"

	#define AT_SYSINFO 32
	#define AT_SYSINFO_EHDR 33

	int sysctl_vsyscall32 = 1;

	#define ARCH_DLINFO do { \
	if (sysctl_vsyscall32) { \
	NEW_AUX_ENT(AT_SYSINFO, (u32)(u64)VSYSCALL32_VSYSCALL); \
	NEW_AUX_ENT(AT_SYSINFO_EHDR, VSYSCALL32_BASE); \
	} \
	} while(0)

	struct file;
	struct elf_phdr;

	#define IA32_EMULATOR 1

	#define ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)

	#undef ELF_ARCH
	#define ELF_ARCH EM_386

	#undef ELF_CLASS
	#define ELF_CLASS ELFCLASS32

	#define ELF_DATA ELFDATA2LSB

	#define USE_ELF_CORE_DUMP 1

	/* Override elfcore.h */
	#define _LINUX_ELFCORE_H 1
	typedef unsigned int elf_greg_t;

	#define ELF_NGREG (sizeof (struct user_regs_struct32) / sizeof(elf_greg_t))
	typedef elf_greg_t elf_gregset_t[ELF_NGREG];

	struct elf_siginfo
	{
	int si_signo; /* signal number */
	int si_code; /* extra code */
	int si_errno; /* errno */
	};

	#define jiffies_to_timeval(a,b) do { (b)->tv_usec = 0; (b)->tv_sec = (a)/HZ; }while(0)

	struct elf_prstatus
	{
	struct elf_siginfo pr_info; /* Info associated with signal */
	short pr_cursig; /* Current signal */
	unsigned int pr_sigpend; /* Set of pending signals */
	unsigned int pr_sighold; /* Set of held signals */
	pid_t pr_pid;
	pid_t pr_ppid;
	pid_t pr_pgrp;
	pid_t pr_sid;
	struct compat_timeval pr_utime; /* User time */
	struct compat_timeval pr_stime; /* System time */
	struct compat_timeval pr_cutime; /* Cumulative user time */
	struct compat_timeval pr_cstime; /* Cumulative system time */
	elf_gregset_t pr_reg; /* GP registers */
	int pr_fpvalid; /* True if math co-processor being used. */
	};

	#define ELF_PRARGSZ (80) /* Number of chars for args */

	struct elf_prpsinfo
	{
	char pr_state; /* numeric process state */
	char pr_sname; /* char for pr_state */
	char pr_zomb; /* zombie */
	char pr_nice; /* nice val */
	unsigned int pr_flag; /* flags */
	__u16 pr_uid;
	__u16 pr_gid;
	pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid;
	/* Lots missing */
	char pr_fname[16]; /* filename of executable */
	char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
	};

	#define __STR(x) #x
	#define STR(x) __STR(x)

	#define _GET_SEG(x) \
	({ __u32 seg; asm("movl %%" STR(x) ",%0" : "=r"(seg)); seg; })

	/* Assumes current==process to be dumped */
	#define ELF_CORE_COPY_REGS(pr_reg, regs) \
	pr_reg[0] = regs->rbx; \
	pr_reg[1] = regs->rcx; \
	pr_reg[2] = regs->rdx; \
	pr_reg[3] = regs->rsi; \
	pr_reg[4] = regs->rdi; \
	pr_reg[5] = regs->rbp; \
	pr_reg[6] = regs->rax; \
	pr_reg[7] = _GET_SEG(ds); \
	pr_reg[8] = _GET_SEG(es); \
	pr_reg[9] = _GET_SEG(fs); \
	pr_reg[10] = _GET_SEG(gs); \
	pr_reg[11] = regs->orig_rax; \
	pr_reg[12] = regs->rip; \
	pr_reg[13] = regs->cs; \
	pr_reg[14] = regs->eflags; \
	pr_reg[15] = regs->rsp; \
	pr_reg[16] = regs->ss;

	#define user user32

	#define __ASM_X86_64_ELF_H 1
	#define elf_read_implies_exec(ex, executable_stack) (executable_stack != EXSTACK_DISABLE_X)
	//#include <asm/ia32.h>
	#include <linux/elf.h>

	typedef struct user_i387_ia32_struct elf_fpregset_t;
	typedef struct user32_fxsr_struct elf_fpxregset_t;


	static inline void elf_core_copy_regs(elf_gregset_t elfregs, struct pt_regs regs)
	{
	ELF_CORE_COPY_REGS((*elfregs), regs)
	}

	static inline int elf_core_copy_task_regs(struct task_struct t, elf_gregset_t elfregs)
	{
	struct pt_regs *pp = task_pt_regs(t);
	ELF_CORE_COPY_REGS((*elfregs), pp);
	/* fix wrong segments */
	(*elfregs)[7] = t->thread.ds;
	(*elfregs)[9] = t->thread.fsindex;
	(*elfregs)[10] = t->thread.gsindex;
	(*elfregs)[8] = t->thread.es;
	return 1;
	}

	static inline int
	elf_core_copy_task_fpregs(struct task_struct tsk, struct pt_regs regs, elf_fpregset_t *fpu)
	{
	struct _fpstate_ia32 fpstate = (void)fpu;
	mm_segment_t oldfs = get_fs();

	if (!tsk_used_math(tsk))
	return 0;
	if (!regs)
	regs = task_pt_regs(tsk);
	if (tsk == current)
	unlazy_fpu(tsk);
	set_fs(KERNEL_DS);
	save_i387_ia32(tsk, fpstate, regs, 1);
	/* Correct for i386 bug. It puts the fop into the upper 16bits of
	the tag word (like FXSAVE), not into the fcs*/
	fpstate->cssel \|= fpstate->tag & 0xffff0000;
	set_fs(oldfs);
	return 1;
	}

	#define ELF_CORE_COPY_XFPREGS 1
	static inline int
	elf_core_copy_task_xfpregs(struct task_struct t, elf_fpxregset_t xfpu)
	{
	struct pt_regs *regs = task_pt_regs(t);
	if (!tsk_used_math(t))
	return 0;
	if (t == current)
	unlazy_fpu(t);
	memcpy(xfpu, &t->thread.i387.fxsave, sizeof(elf_fpxregset_t));
	xfpu->fcs = regs->cs;
	xfpu->fos = t->thread.ds; /* right? */
	return 1;
	}

	#undef elf_check_arch
	#define elf_check_arch(x) \
	((x)->e_machine == EM_386)

	extern int force_personality32;

	#define ELF_EXEC_PAGESIZE PAGE_SIZE
	#define ELF_HWCAP (boot_cpu_data.x86_capability[0])
	#define ELF_PLATFORM ("i686")
	#define SET_PERSONALITY(ex, ibcs2) \
	do { \
	unsigned long new_flags = 0; \
	if ((ex).e_ident[EI_CLASS] == ELFCLASS32) \
	new_flags = _TIF_IA32; \
	if ((current_thread_info()->flags & _TIF_IA32) \
	!= new_flags) \
	set_thread_flag(TIF_ABI_PENDING); \
	else \
	clear_thread_flag(TIF_ABI_PENDING); \
	/* XXX This overwrites the user set personality */ \
	current->personality \|= force_personality32; \
	} while (0)

	/* Override some function names */
	#define elf_format elf32_format

	#define init_elf_binfmt init_elf32_binfmt
	#define exit_elf_binfmt exit_elf32_binfmt

	#define load_elf_binary load_elf32_binary

	#define ELF_PLAT_INIT(r, load_addr) elf32_init(r)
	#define setup_arg_pages(bprm, stack_top, exec_stack) \
	ia32_setup_arg_pages(bprm, stack_top, exec_stack)
	int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top, int executable_stack);

	#undef start_thread
	#define start_thread(regs,new_rip,new_rsp) do { \
	asm volatile("movl %0,%%fs" :: "r" (0)); \
	asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS)); \
	load_gs_index(0); \
	(regs)->rip = (new_rip); \
	(regs)->rsp = (new_rsp); \
	(regs)->eflags = 0x200; \
	(regs)->cs = __USER32_CS; \
	(regs)->ss = __USER32_DS; \
	set_fs(USER_DS); \
	} while(0)


	#include <linux/module.h>

	MODULE_DESCRIPTION("Binary format loader for compatibility with IA32 ELF binaries.");
	MODULE_AUTHOR("Eric Youngdale, Andi Kleen");

	#undef MODULE_DESCRIPTION
	#undef MODULE_AUTHOR

	static void elf32_init(struct pt_regs *);

	#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
	#define arch_setup_additional_pages syscall32_setup_pages
	extern int syscall32_setup_pages(struct linux_binprm *, int exstack);

	#include "../../../fs/binfmt_elf.c"

	static void elf32_init(struct pt_regs *regs)
	{
	struct task_struct *me = current;
	regs->rdi = 0;
	regs->rsi = 0;
	regs->rdx = 0;
	regs->rcx = 0;
	regs->rax = 0;
	regs->rbx = 0;
	regs->rbp = 0;
	regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
	regs->r13 = regs->r14 = regs->r15 = 0;
	me->thread.fs = 0;
	me->thread.gs = 0;
	me->thread.fsindex = 0;
	me->thread.gsindex = 0;
	me->thread.ds = __USER_DS;
	me->thread.es = __USER_DS;
	}

	int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top,
	int executable_stack)
	{
	unsigned long stack_base;
	struct vm_area_struct *mpnt;
	struct mm_struct *mm = current->mm;
	int i, ret;

	stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE;
	mm->arg_start = bprm->p + stack_base;

	bprm->p += stack_base;
	if (bprm->loader)
	bprm->loader += stack_base;
	bprm->exec += stack_base;

	mpnt = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
	if (!mpnt)
	return -ENOMEM;

	memset(mpnt, 0, sizeof(*mpnt));

	down_write(&mm->mmap_sem);
	{
	mpnt->vm_mm = mm;
	mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
	mpnt->vm_end = stack_top;
	if (executable_stack == EXSTACK_ENABLE_X)
	mpnt->vm_flags = VM_STACK_FLAGS \| VM_EXEC;
	else if (executable_stack == EXSTACK_DISABLE_X)
	mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
	else
	mpnt->vm_flags = VM_STACK_FLAGS;
	mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC) ?
	PAGE_COPY_EXEC : PAGE_COPY;
	if ((ret = insert_vm_struct(mm, mpnt))) {
	up_write(&mm->mmap_sem);
	kmem_cache_free(vm_area_cachep, mpnt);
	return ret;
	}
	mm->stack_vm = mm->total_vm = vma_pages(mpnt);
	}

	for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
	struct page *page = bprm->page[i];
	if (page) {
	bprm->page[i] = NULL;
	install_arg_page(mpnt, page, stack_base);
	}
	stack_base += PAGE_SIZE;
	}
	up_write(&mm->mmap_sem);

	return 0;
	}
	EXPORT_SYMBOL(ia32_setup_arg_pages);

	#ifdef CONFIG_SYSCTL
	/* Register vsyscall32 into the ABI table */
	#include <linux/sysctl.h>

	static ctl_table abi_table2[] = {
	{ 99, "vsyscall32", &sysctl_vsyscall32, sizeof(int), 0644, NULL,
	proc_dointvec },
	{ 0, }
	};

	static ctl_table abi_root_table2[] = {
	{ .ctl_name = CTL_ABI, .procname = "abi", .mode = 0555,
	.child = abi_table2 },
	{ 0 },
	};

	static __init int ia32_binfmt_init(void)
	{
	register_sysctl_table(abi_root_table2, 1);
	return 0;
	}
	__initcall(ia32_binfmt_init);
	#endif