Commit 713c4815 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Russell King
Browse files

[ARM] 3108/2: old ABI compat: statfs64 and fstatfs64 



Patch from Nicolas Pitre

struct statfs64 has extra padding with EABI growing its size from 84 to
88. This struct is now __attribute__((packed,aligned(4))) with a small
assembly wrapper to force the sz argument to 84 if it is 88 to avoid
copying the extra padding over user space memory unexpecting it.

Signed-off-by: default avatarNicolas Pitre <nico@cam.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 704bdda0

arch/arm/kernel/calls.S

+2 −2
Original line number Diff line number Diff line
@@ -280,8 +280,8 @@ __syscall_start: 
		.long	sys_clock_gettime

		.long	sys_clock_getres

/* 265 */	.long	sys_clock_nanosleep

		.long	sys_statfs64

		.long	sys_fstatfs64

		.long	sys_statfs64_wrapper

		.long	sys_fstatfs64_wrapper

		.long	sys_tgkill

		.long	sys_utimes

/* 270 */	.long	sys_arm_fadvise64_64

arch/arm/kernel/entry-common.S

+10 −0
Original line number Diff line number Diff line
@@ -262,6 +262,16 @@ sys_sigaltstack_wrapper: 
		ldr	r2, [sp, #S_OFF + S_SP]

		b	do_sigaltstack



sys_statfs64_wrapper:

		teq	r1, #88

		moveq	r1, #84

		b	sys_statfs64



sys_fstatfs64_wrapper:

		teq	r1, #88

		moveq	r1, #84

		b	sys_fstatfs64



/*

 * Note: off_4k (r5) is always units of 4K.  If we can't do the requested

 * offset, we return EINVAL.

include/asm-arm/statfs.h

+37 −1
Original line number Diff line number Diff line 
#ifndef _ASMARM_STATFS_H

#define _ASMARM_STATFS_H



#include <asm-generic/statfs.h>

#ifndef __KERNEL_STRICT_NAMES

# include <linux/types.h>

typedef __kernel_fsid_t	fsid_t;

#endif



struct statfs {

	__u32 f_type;

	__u32 f_bsize;

	__u32 f_blocks;

	__u32 f_bfree;

	__u32 f_bavail;

	__u32 f_files;

	__u32 f_ffree;

	__kernel_fsid_t f_fsid;

	__u32 f_namelen;

	__u32 f_frsize;

	__u32 f_spare[5];

};



/*

 * With EABI there is 4 bytes of padding added to this structure.

 * Let's pack it so the padding goes away to simplify dual ABI support.

 * Note that user space does NOT have to pack this structure.

 */

struct statfs64 {

	__u32 f_type;

	__u32 f_bsize;

	__u64 f_blocks;

	__u64 f_bfree;

	__u64 f_bavail;

	__u64 f_files;

	__u64 f_ffree;

	__kernel_fsid_t f_fsid;

	__u32 f_namelen;

	__u32 f_frsize;

	__u32 f_spare[5];

} __attribute__ ((packed,aligned(4)));



#endif

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