Commit 7a8e0c8d authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[S390] Wire up sys_fallocate. 



This patch implements support of fallocate system call on s390(x)
platform.  A wrapper is added to address the issue which s390 ABI has with
the arguments of this system call.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent cb1863a4

arch/s390/kernel/compat_wrapper.S

+10 −0
Original line number Diff line number Diff line
@@ -1710,3 +1710,13 @@ compat_sys_timerfd_wrapper: 
sys_eventfd_wrapper:

	llgfr	%r2,%r2			# unsigned int

	jg	sys_eventfd



	.globl	sys_fallocate_wrapper

sys_fallocate_wrapper:

	lgfr	%r2,%r2			# int

	lgfr	%r3,%r3			# int

	sllg	%r4,%r4,32		# get high word of 64bit loff_t

	lr	%r4,%r5			# get low word of 64bit loff_t

	sllg	%r5,%r6,32		# get high word of 64bit loff_t

	l	%r5,164(%r15)		# get low word of 64bit loff_t

	jg	sys_fallocate

arch/s390/kernel/sys_s390.c

+20 −0
Original line number Diff line number Diff line
@@ -265,3 +265,23 @@ s390_fadvise64_64(struct fadvise64_64_args __user *args) 
		return -EFAULT;

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

}



#ifndef CONFIG_64BIT

/*

 * This is a wrapper to call sys_fallocate(). For 31 bit s390 the last

 * 64 bit argument "len" is split into the upper and lower 32 bits. The

 * system call wrapper in the user space loads the value to %r6/%r7.

 * The code in entry.S keeps the values in %r2 - %r6 where they are and

 * stores %r7 to 96(%r15). But the standard C linkage requires that

 * the whole 64 bit value for len is stored on the stack and doesn't

 * use %r6 at all. So s390_fallocate has to convert the arguments from

 *   %r2: fd, %r3: mode, %r4/%r5: offset, %r6/96(%r15)-99(%r15): len

 * to

 *   %r2: fd, %r3: mode, %r4/%r5: offset, 96(%r15)-103(%r15): len

 */

asmlinkage long s390_fallocate(int fd, int mode, loff_t offset,

			       u32 len_high, u32 len_low)

{

	return sys_fallocate(fd, mode, offset, ((u64)len_high << 32) | len_low);

}

#endif

arch/s390/kernel/syscalls.S

+1 −1
Original line number Diff line number Diff line
@@ -322,7 +322,7 @@ NI_SYSCALL /* 310 sys_move_pages */ 
SYSCALL(sys_getcpu,sys_getcpu,sys_getcpu_wrapper)

SYSCALL(sys_epoll_pwait,sys_epoll_pwait,compat_sys_epoll_pwait_wrapper)

SYSCALL(sys_utimes,sys_utimes,compat_sys_utimes_wrapper)

NI_SYSCALL							/* 314 sys_fallocate */

SYSCALL(s390_fallocate,sys_fallocate,sys_fallocate_wrapper)

SYSCALL(sys_utimensat,sys_utimensat,compat_sys_utimensat_wrapper)	/* 315 */

SYSCALL(sys_signalfd,sys_signalfd,compat_sys_signalfd_wrapper)

SYSCALL(sys_timerfd,sys_timerfd,compat_sys_timerfd_wrapper)

include/asm-s390/unistd.h

+1 −1
Original line number Diff line number Diff line
@@ -251,7 +251,7 @@ 
#define __NR_getcpu		311

#define __NR_epoll_pwait	312

#define __NR_utimes		313

/* Number 314 is reserved for new sys_fallocate */

#define __NR_fallocate		314

#define __NR_utimensat		315

#define __NR_signalfd		316

#define __NR_timerfd		317