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: David Woodhouse <dwmw2@infradead.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-arm/unistd.h b/include/asm-arm/unistd.h
index 250d7f1..bfdbebe 100644
--- a/include/asm-arm/unistd.h
+++ b/include/asm-arm/unistd.h
@@ -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)