diff options
Diffstat (limited to 'arch/s390/kernel/sys_s390.c')
| -rw-r--r-- | arch/s390/kernel/sys_s390.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/s390/kernel/sys_s390.c b/arch/s390/kernel/sys_s390.c index 1c90c7e99978..1eaff84a1eb6 100644 --- a/arch/s390/kernel/sys_s390.c +++ b/arch/s390/kernel/sys_s390.c @@ -16,6 +16,7 @@ #include <linux/errno.h> #include <linux/sched.h> #include <linux/mm.h> +#include <linux/fs.h> #include <linux/smp.h> #include <linux/sem.h> #include <linux/msg.h> @@ -265,3 +266,23 @@ 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 |