Commit 34b4664a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Greg Ungerer
Browse files

binfmt_flat: use fixed size type for the on-disk format 



So far binfmt_flat has only been supported on 32-bit platforms, so the
variable size of the fields didn't matter.  But the upcoming RISC-V
nommu port supports 64-bit CPUs, and we now have a conflict between
the elf2flt creation tool that always uses 32-bit fields and the kernel
that uses (unsigned) long field.  Switch to the userspace view as the
rest of the binfmt_flat format is completely architecture neutral,
and binfmt_flat isn't the right binary format for huge executables to
start with.

While we're at it also ensure these fields are using __be types as
they big endian and are byte swapped when loaded.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
parent 3f8b76a6

include/linux/flat.h

+22 −22
Original line number Diff line number Diff line
@@ -25,25 +25,25 @@ 


struct flat_hdr {

	char	magic[4];

	unsigned long rev;          /* version (as above) */

	unsigned long entry;        /* Offset of first executable instruction

	__be32	rev;          /* version (as above) */

	__be32	entry;        /* Offset of first executable instruction

				 with text segment from beginning of file */

	unsigned long data_start;   /* Offset of data segment from beginning of

	__be32	data_start;   /* Offset of data segment from beginning of

				 file */

	unsigned long data_end;     /* Offset of end of data segment

	                               from beginning of file */

	unsigned long bss_end;      /* Offset of end of bss segment from beginning

	__be32	data_end;     /* Offset of end of data segment from beginning

				 of file */

	__be32	bss_end;      /* Offset of end of bss segment from beginning

				 of file */



	/* (It is assumed that data_end through bss_end forms the bss segment.) */



	unsigned long stack_size;   /* Size of stack, in bytes */

	unsigned long reloc_start;  /* Offset of relocation records from

	                               beginning of file */

	unsigned long reloc_count;  /* Number of relocation records */

	unsigned long flags;

	unsigned long build_date;   /* When the program/library was built */

	unsigned long filler[5];    /* Reservered, set to zero */

	__be32	stack_size;   /* Size of stack, in bytes */

	__be32	reloc_start;  /* Offset of relocation records from beginning of

				 file */

	__be32	reloc_count;  /* Number of relocation records */

	__be32	flags;

	__be32	build_date;   /* When the program/library was built */

	__u32	filler[5];    /* Reservered, set to zero */

};



#define FLAT_FLAG_RAM    0x0001 /* load program entirely into RAM */
@@ -67,15 +67,15 @@ struct flat_hdr { 
#define OLD_FLAT_RELOC_TYPE_BSS		2



typedef union {

	unsigned long	value;

	u32		value;

	struct {

#if defined(__LITTLE_ENDIAN_BITFIELD) || \

    (defined(mc68000) && !defined(CONFIG_COLDFIRE))

		signed long offset : 30;

		unsigned long type : 2;

		s32	offset : 30;

		u32	type : 2;

# elif defined(__BIG_ENDIAN_BITFIELD)

		unsigned long type : 2;

		signed long offset : 30;

		u32	type : 2;

		s32	offset : 30;

# else

#   	error "Unknown bitfield order for flat files."

# endif

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