Commit 068e1b94 authored by Martin Schwidefsky's avatar Martin Schwidefsky Committed by Linus Torvalds
Browse files

[PATCH] s390: fadvise hint values. 



Add special case for the POSIX_FADV_DONTNEED and POSIX_FADV_NOREUSE hint
values for s390-64.  The user space values in the s390-64 glibc headers for
these two defines have always been 6 and 7 instead of 4 and 5.  All 64 bit
applications therefore use the "wrong" values.  To get these applications
working without recompiling the kernel needs to accept the "wrong" values.
Since the values for s390-31 are 4 and 5 the compat wrapper for fadvise64
and fadvise64_64 need to rewrite the values for 31 bit system calls.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ddca3b80

arch/s390/kernel/compat_linux.c

+38 −0
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ 
#include <linux/compat.h>

#include <linux/vfs.h>

#include <linux/ptrace.h>

#include <linux/fadvise.h>



#include <asm/types.h>

#include <asm/ipc.h>
@@ -1043,3 +1044,40 @@ sys32_timer_create(clockid_t which_clock, struct compat_sigevent *se32, 


	return ret;

}



/*

 * 31 bit emulation wrapper functions for sys_fadvise64/fadvise64_64.

 * These need to rewrite the advise values for POSIX_FADV_{DONTNEED,NOREUSE}

 * because the 31 bit values differ from the 64 bit values.

 */



asmlinkage long

sys32_fadvise64(int fd, loff_t offset, size_t len, int advise)

{

	if (advise == 4)

		advise = POSIX_FADV_DONTNEED;

	else if (advise == 5)

		advise = POSIX_FADV_NOREUSE;

	return sys_fadvise64(fd, offset, len, advise);

}



struct fadvise64_64_args {

	int fd;

	long long offset;

	long long len;

	int advice;

};



asmlinkage long

sys32_fadvise64_64(struct fadvise64_64_args __user *args)

{

	struct fadvise64_64_args a;



	if ( copy_from_user(&a, args, sizeof(a)) )

		return -EFAULT;

	if (a.advice == 4)

		a.advice = POSIX_FADV_DONTNEED;

	else if (a.advice == 5)

		a.advice = POSIX_FADV_NOREUSE;

	return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);

}

arch/s390/kernel/compat_wrapper.S

+2 −2
Original line number Diff line number Diff line
@@ -1251,12 +1251,12 @@ sys32_fadvise64_wrapper: 
	or	%r3,%r4			# get low word of 64bit loff_t

	llgfr	%r4,%r5			# size_t (unsigned long)

	lgfr	%r5,%r6			# int

	jg	sys_fadvise64

	jg	sys32_fadvise64



	.globl	sys32_fadvise64_64_wrapper

sys32_fadvise64_64_wrapper:

	llgtr	%r2,%r2			# struct fadvise64_64_args *

	jg	s390_fadvise64_64

	jg	sys32_fadvise64_64



	.globl	sys32_clock_settime_wrapper

sys32_clock_settime_wrapper:

include/linux/fadvise.h

+10 −0
Original line number Diff line number Diff line
@@ -5,7 +5,17 @@ 
#define POSIX_FADV_RANDOM	1 /* Expect random page references.  */

#define POSIX_FADV_SEQUENTIAL	2 /* Expect sequential page references.  */

#define POSIX_FADV_WILLNEED	3 /* Will need these pages.  */



/*

 * The advise values for POSIX_FADV_DONTNEED and POSIX_ADV_NOREUSE

 * for s390-64 differ from the values for the rest of the world.

 */

#if defined(__s390x__)

#define POSIX_FADV_DONTNEED	6 /* Don't need these pages.  */

#define POSIX_FADV_NOREUSE	7 /* Data will be accessed once.  */

#else

#define POSIX_FADV_DONTNEED	4 /* Don't need these pages.  */

#define POSIX_FADV_NOREUSE	5 /* Data will be accessed once.  */

#endif



#endif	/* FADVISE_H_INCLUDED */

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