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 <>
parent cb1863a4
......@@ -1710,3 +1710,13 @@ compat_sys_timerfd_wrapper:
llgfr %r2,%r2 # unsigned int
jg sys_eventfd
.globl 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
......@@ -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);
......@@ -322,7 +322,7 @@ NI_SYSCALL /* 310 sys_move_pages */
NI_SYSCALL /* 314 sys_fallocate */
SYSCALL(sys_utimensat,sys_utimensat,compat_sys_utimensat_wrapper) /* 315 */
......@@ -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
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