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.

David Woodhouse committed 19 years ago

Commit edd5cd41 parent 2f4d4da9 files · +29 −15Browse files

Unified · Split

9 files

arch/arm/kernel/calls.S +1 −1
arch/arm/kernel/sys_arm.c +0 −13
arch/powerpc/kernel/sys_ppc32.c +9 −0
fs/sync.c +8 −0
include/asm-arm/unistd.h +1 −0
include/asm-powerpc/systbl.h +1 −0
include/asm-powerpc/unistd.h +2 −1
include/linux/syscalls.h +2 −0
scripts/checksyscalls.sh +5 −0

arch/arm/kernel/calls.S+1−1

@@ -350,7 +350,7 @@ · 349 unmodified lines
350	350	CALL(sys_set_robust_list)
351	351	CALL(sys_get_robust_list)
352	352	/* 340 */ CALL(sys_splice)
353		− CALL(sys_arm_sync_file_range)
	353	+ CALL(sys_sync_file_range2)
354	354	CALL(sys_tee)
355	355	CALL(sys_vmsplice)
356	356	CALL(sys_move_pages)

arch/arm/kernel/sys_arm.c+0−13

@@ -328,16 +328,3 @@ asmlinkage long sys_arm_fadvise64_64(int fd, int advice, · 327 unmodified lines
328	328	{
329	329	return sys_fadvise64_64(fd, offset, len, advice);
330	330	}
331		−
332		−/*
333		− * Yet more syscall fsckage - we can't fit sys_sync_file_range's
334		− * arguments into the available registers with EABI. So, let's
335		− * create an ARM specific syscall for this which has _sane_
336		− * arguments. (This incidentally also has an ABI-independent
337		− * argument layout.)
338		− */
339		−asmlinkage long sys_arm_sync_file_range(int fd, unsigned int flags,
340		− loff_t offset, loff_t nbytes)
341		−{
342		− return sys_sync_file_range(fd, offset, nbytes, flags);
343		−}

arch/powerpc/kernel/sys_ppc32.c+9−0

@@ -810,3 +810,12 @@ asmlinkage long compat_sys_request_key(const char __user *_type, · 809 unmodified lines
810	810	return sys_request_key(_type, _description, _callout_info, destringid);
811	811	}
812	812
	813	+asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
	814	+ unsigned offset_hi, unsigned offset_lo,
	815	+ unsigned nbytes_hi, unsigned nbytes_lo)
	816	+{
	817	+ loff_t offset = ((loff_t)offset_hi << 32) \| offset_lo;
	818	+ loff_t nbytes = ((loff_t)nbytes_hi << 32) \| nbytes_lo;
	819	+
	820	+ return sys_sync_file_range(fd, offset, nbytes, flags);
	821	+}

fs/sync.c+8−0

@@ -236,6 +236,14 @@ out: · 235 unmodified lines
236	236	return ret;
237	237	}
238	238
	239	+/* It would be nice if people remember that not all the world's an i386
	240	+ when they introduce new system calls */
	241	+asmlinkage long sys_sync_file_range2(int fd, unsigned int flags,
	242	+ loff_t offset, loff_t nbytes)
	243	+{
	244	+ return sys_sync_file_range(fd, offset, nbytes, flags);
	245	+}
	246	+
239	247	/*
240	248	* `endbyte' is inclusive
241	249	*/

include/asm-arm/unistd.h+1−0

@@ -367,6 +367,7 @@ · 366 unmodified lines
367	367	#define __NR_get_robust_list (__NR_SYSCALL_BASE+339)
368	368	#define __NR_splice (__NR_SYSCALL_BASE+340)
369	369	#define __NR_arm_sync_file_range (__NR_SYSCALL_BASE+341)
	370	+#define __NR_sync_file_range2 __NR_arm_sync_file_range
370	371	#define __NR_tee (__NR_SYSCALL_BASE+342)
371	372	#define __NR_vmsplice (__NR_SYSCALL_BASE+343)
372	373	#define __NR_move_pages (__NR_SYSCALL_BASE+344)

include/asm-powerpc/systbl.h+1−0

@@ -311,3 +311,4 @@ COMPAT_SYS_SPU(utimensat) · 310 unmodified lines
311	311	COMPAT_SYS_SPU(signalfd)
312	312	COMPAT_SYS_SPU(timerfd)
313	313	SYSCALL_SPU(eventfd)
	314	+COMPAT_SYS_SPU(sync_file_range2)

include/asm-powerpc/unistd.h+2−1

@@ -330,10 +330,11 @@ · 329 unmodified lines
330	330	#define __NR_signalfd 305
331	331	#define __NR_timerfd 306
332	332	#define __NR_eventfd 307
	333	+#define __NR_sync_file_range2 308
333	334
334	335	#ifdef __KERNEL__
335	336
336		−#define __NR_syscalls 308
	337	+#define __NR_syscalls 309
337	338
338	339	#define __NR__exit __NR_exit
339	340	#define NR_syscalls __NR_syscalls

include/linux/syscalls.h+2−0

@@ -598,6 +598,8 @@ asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags); · 597 unmodified lines
598	598
599	599	asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
600	600	unsigned int flags);
	601	+asmlinkage long sys_sync_file_range2(int fd, unsigned int flags,
	602	+ loff_t offset, loff_t nbytes);
601	603	asmlinkage long sys_get_robust_list(int pid,
602	604	struct robust_list_head __user * __user *head_ptr,
603	605	size_t __user *len_ptr);

scripts/checksyscalls.sh+5−0

@@ -99,6 +99,11 @@ cat << EOF · 98 unmodified lines
99	99	#define __IGNORE_setfsuid32
100	100	#define __IGNORE_setfsgid32
101	101
	102	+/* sync_file_range had a stupid ABI. Allow sync_file_range2 instead */
	103	+#ifdef __NR_sync_file_range2
	104	+#define __IGNORE_sync_file_range
	105	+#endif
	106	+
102	107	/* Unmerged syscalls for AFS, STREAMS, etc. */
103	108	#define __IGNORE_afs_syscall
104	109	#define __IGNORE_getpmsg