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/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index 19326d7..a98d0c9 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -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)
diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c
index 1ca2d51..4d25e49 100644
--- a/arch/arm/kernel/sys_arm.c
+++ b/arch/arm/kernel/sys_arm.c
@@ -328,16 +328,3 @@
{
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);
-}
diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
index 047246a..b42cbf1 100644
--- a/arch/powerpc/kernel/sys_ppc32.c
+++ b/arch/powerpc/kernel/sys_ppc32.c
@@ -810,3 +810,12 @@
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);
+}
diff --git a/fs/sync.c b/fs/sync.c
index 2f97576..7cd005ea 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -236,6 +236,14 @@
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
*/
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)
diff --git a/include/asm-powerpc/systbl.h b/include/asm-powerpc/systbl.h
index 700ca59..1cc3f9c 100644
--- a/include/asm-powerpc/systbl.h
+++ b/include/asm-powerpc/systbl.h
@@ -311,3 +311,4 @@
COMPAT_SYS_SPU(signalfd)
COMPAT_SYS_SPU(timerfd)
SYSCALL_SPU(eventfd)
+COMPAT_SYS_SPU(sync_file_range2)
diff --git a/include/asm-powerpc/unistd.h b/include/asm-powerpc/unistd.h
index e3c28dc..f71c606 100644
--- a/include/asm-powerpc/unistd.h
+++ b/include/asm-powerpc/unistd.h
@@ -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
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index b02070e..83d0ec1 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -598,6 +598,8 @@
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);
diff --git a/scripts/checksyscalls.sh b/scripts/checksyscalls.sh
index f98171f..0dcc01c 100755
--- a/scripts/checksyscalls.sh
+++ b/scripts/checksyscalls.sh
@@ -99,6 +99,11 @@
#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