提交 edd5cd4a 编写于 作者: D David Woodhouse 提交者: Linus Torvalds

Introduce fixed sys_sync_file_range2() syscall, implement on PowerPC and ARM

Not all the world is an i386.  Many architectures need 64-bit arguments to be
aligned in suitable pairs of registers, and the original
sys_sync_file_range(int, loff_t, loff_t, int) was therefore wasting an
argument register for padding after the first integer.  Since we don't
normally have more than 6 arguments for system calls, that left no room for
the final argument on some architectures.

Fix this by introducing sys_sync_file_range2(int, int, loff_t, loff_t) which
all fits nicely.  In fact, ARM already had that, but called it
sys_arm_sync_file_range.  Move it to fs/sync.c and rename it, then implement
the needed compatibility routine.  And stop the missing syscall check from
bitching about the absence of sys_sync_file_range() if we've implemented
sys_sync_file_range2() instead.

Tested on PPC32 and with 32-bit and 64-bit userspace on PPC64.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 2f4d4da8
......@@ -350,7 +350,7 @@
CALL(sys_set_robust_list)
CALL(sys_get_robust_list)
/* 340 */ CALL(sys_splice)
CALL(sys_arm_sync_file_range)
CALL(sys_sync_file_range2)
CALL(sys_tee)
CALL(sys_vmsplice)
CALL(sys_move_pages)
......
......@@ -328,16 +328,3 @@ asmlinkage long sys_arm_fadvise64_64(int fd, int advice,
{
return sys_fadvise64_64(fd, offset, len, advice);
}
/*
* Yet more syscall fsckage - we can't fit sys_sync_file_range's
* arguments into the available registers with EABI. So, let's
* create an ARM specific syscall for this which has _sane_
* arguments. (This incidentally also has an ABI-independent
* argument layout.)
*/
asmlinkage long sys_arm_sync_file_range(int fd, unsigned int flags,
loff_t offset, loff_t nbytes)
{
return sys_sync_file_range(fd, offset, nbytes, flags);
}
......@@ -810,3 +810,12 @@ asmlinkage long compat_sys_request_key(const char __user *_type,
return sys_request_key(_type, _description, _callout_info, destringid);
}
asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
unsigned offset_hi, unsigned offset_lo,
unsigned nbytes_hi, unsigned nbytes_lo)
{
loff_t offset = ((loff_t)offset_hi << 32) | offset_lo;
loff_t nbytes = ((loff_t)nbytes_hi << 32) | nbytes_lo;
return sys_sync_file_range(fd, offset, nbytes, flags);
}
......@@ -236,6 +236,14 @@ asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
return ret;
}
/* It would be nice if people remember that not all the world's an i386
when they introduce new system calls */
asmlinkage long sys_sync_file_range2(int fd, unsigned int flags,
loff_t offset, loff_t nbytes)
{
return sys_sync_file_range(fd, offset, nbytes, flags);
}
/*
* `endbyte' is inclusive
*/
......
......@@ -367,6 +367,7 @@
#define __NR_get_robust_list (__NR_SYSCALL_BASE+339)
#define __NR_splice (__NR_SYSCALL_BASE+340)
#define __NR_arm_sync_file_range (__NR_SYSCALL_BASE+341)
#define __NR_sync_file_range2 __NR_arm_sync_file_range
#define __NR_tee (__NR_SYSCALL_BASE+342)
#define __NR_vmsplice (__NR_SYSCALL_BASE+343)
#define __NR_move_pages (__NR_SYSCALL_BASE+344)
......
......@@ -311,3 +311,4 @@ COMPAT_SYS_SPU(utimensat)
COMPAT_SYS_SPU(signalfd)
COMPAT_SYS_SPU(timerfd)
SYSCALL_SPU(eventfd)
COMPAT_SYS_SPU(sync_file_range2)
......@@ -330,10 +330,11 @@
#define __NR_signalfd 305
#define __NR_timerfd 306
#define __NR_eventfd 307
#define __NR_sync_file_range2 308
#ifdef __KERNEL__
#define __NR_syscalls 308
#define __NR_syscalls 309
#define __NR__exit __NR_exit
#define NR_syscalls __NR_syscalls
......
......@@ -598,6 +598,8 @@ asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags);
asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
unsigned int flags);
asmlinkage long sys_sync_file_range2(int fd, unsigned int flags,
loff_t offset, loff_t nbytes);
asmlinkage long sys_get_robust_list(int pid,
struct robust_list_head __user * __user *head_ptr,
size_t __user *len_ptr);
......
......@@ -99,6 +99,11 @@ cat << EOF
#define __IGNORE_setfsuid32
#define __IGNORE_setfsgid32
/* sync_file_range had a stupid ABI. Allow sync_file_range2 instead */
#ifdef __NR_sync_file_range2
#define __IGNORE_sync_file_range
#endif
/* Unmerged syscalls for AFS, STREAMS, etc. */
#define __IGNORE_afs_syscall
#define __IGNORE_getpmsg
......
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