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Commit 7e7ec6a9 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Greg Ungerer
Browse files

elf_fdpic_transfer_args_to_stack(): make it generic 



This copying of arguments and environment is common to both NOMMU
binary formats we support. Let's make the elf_fdpic version available
to the flat format as well.

While at it, improve the code a bit not to copy below the actual
data area.

Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
Reviewed-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
Signed-off-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
parent c995ee28

fs/binfmt_elf_fdpic.c

+2 −36
Original line number Diff line number Diff line
@@ -67,8 +67,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *, 
				   struct elf_fdpic_params *);



#ifndef CONFIG_MMU

static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,

					    unsigned long *);

static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,

						   struct file *,

						   struct mm_struct *);
@@ -515,8 +513,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, 
	sp = mm->start_stack;



	/* stack the program arguments and environment */

	if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)

	if (transfer_args_to_stack(bprm, &sp) < 0)

		return -EFAULT;

	sp &= ~15;

#endif



	/*
@@ -709,39 +708,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, 
	return 0;

}



/*****************************************************************************/

/*

 * transfer the program arguments and environment from the holding pages onto

 * the stack

 */

#ifndef CONFIG_MMU

static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,

					    unsigned long *_sp)

{

	unsigned long index, stop, sp;

	char *src;

	int ret = 0;



	stop = bprm->p >> PAGE_SHIFT;

	sp = *_sp;



	for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {

		src = kmap(bprm->page[index]);

		sp -= PAGE_SIZE;

		if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)

			ret = -EFAULT;

		kunmap(bprm->page[index]);

		if (ret < 0)

			goto out;

	}



	*_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;



out:

	return ret;

}

#endif



/*****************************************************************************/

/*

 * load the appropriate binary image (executable or interpreter) into memory

fs/exec.c

+33 −0
Original line number Diff line number Diff line
@@ -762,6 +762,39 @@ int setup_arg_pages(struct linux_binprm *bprm, 
}

EXPORT_SYMBOL(setup_arg_pages);



#else



/*

 * Transfer the program arguments and environment from the holding pages

 * onto the stack. The provided stack pointer is adjusted accordingly.

 */

int transfer_args_to_stack(struct linux_binprm *bprm,

			   unsigned long *sp_location)

{

	unsigned long index, stop, sp;

	int ret = 0;



	stop = bprm->p >> PAGE_SHIFT;

	sp = *sp_location;



	for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {

		unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0;

		char *src = kmap(bprm->page[index]) + offset;

		sp -= PAGE_SIZE - offset;

		if (copy_to_user((void *) sp, src, PAGE_SIZE - offset) != 0)

			ret = -EFAULT;

		kunmap(bprm->page[index]);

		if (ret)

			goto out;

	}



	*sp_location = sp;



out:

	return ret;

}

EXPORT_SYMBOL(transfer_args_to_stack);



#endif /* CONFIG_MMU */



static struct file *do_open_execat(int fd, struct filename *name, int flags)

include/linux/binfmts.h

+2 −0
Original line number Diff line number Diff line
@@ -113,6 +113,8 @@ extern int suid_dumpable; 
extern int setup_arg_pages(struct linux_binprm * bprm,

			   unsigned long stack_top,

			   int executable_stack);

extern int transfer_args_to_stack(struct linux_binprm *bprm,

				  unsigned long *sp_location);

extern int bprm_change_interp(char *interp, struct linux_binprm *bprm);

extern int copy_strings_kernel(int argc, const char *const *argv,

			       struct linux_binprm *bprm);