Re: [PATCH] Wire up sys_sync_file_range() on powerpc
From: David Woodhouse <dwmw2@infradead.org>
Date: 2007-06-18 09:24:58
Also in:
linuxppc-dev
Subsystem:
arm port, filesystems (vfs and infrastructure), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Russell King, Alexander Viro, Christian Brauner, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
On Mon, 2007-06-18 at 15:37 +1000, Paul Mackerras wrote:
David Woodhouse writes:quoted
Pants.Ah. Is that a naughty word in the UK? If so I'll have to remember that when I go to kernel summit. :)
I think the most important thing you have to remember about 'pants' while in the UK is that you don't wear them on the outside.
quoted
It doesn't work because the 'flags' argument ends up in r9, and we can only use r3-r8 for syscall arguments. We'll need to do it the same way as ARM does, with the flags as the second argument.Yes. We'll need a wrapper for both 32-bit and for 32-on-64.quoted
Or is it? Can we ditch sys_sync_file_range now and implement a new sys_sync_file_range2 with the two 32-bit arguments first?Would be nice...
It might look something like this... I can't test it sensibly till I get
home next week; anyone else want to poke at it?
(Note that glibc's syscall() doesn't get 64-bit arguments like this
right; you'll want to implement do_sync_file_range() in assembly if
you're using Andrew's original test program.)
.section ".text"
.globl do_sync_file_range
.type do_sync_file_range, @function
do_sync_file_range:
stwu 1,-16(1)
mflr 0
stw 31,12(1)
stw 0,20(1)
li 0,308
sc
mfcr 0
andis. 9,0,4096
mr 31,3
beq 0,.L6
bl __errno_location
li 0,-1
stw 31,0(3)
.L6:
mr 3,0
lwz 0,20(1)
lwz 31,12(1)
addi 1,1,16
mtlr 0
blr
.size do_sync_file_range,.-do_sync_file_range
---
[PATCH] Add sys_sync_file_range2() system call
... with more sensible ABI, for those architectures which hated
sys_sync_file_range() for wasting argument slots by misaligning 64-bit
values. Convert ARM to use it, wire it up on PowerPC, and prevent the
missing syscall checker from bitching about sync_file_range if you have
sync_file_range2 instead.
Signed-off-by: David Woodhouse <dwmw2@infradead.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 @@ 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); -}
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 @@ 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); +}
diff --git a/fs/sync.c b/fs/sync.c
index 2f97576..7cd005e 100644
--- a/fs/sync.c
+++ b/fs/sync.c@@ -236,6 +236,14 @@ out: 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(utimensat) 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/scripts/checksyscalls.sh b/scripts/checksyscalls.sh
index f98171f..0dcc01c 100755
--- a/scripts/checksyscalls.sh
+++ b/scripts/checksyscalls.sh@@ -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
--
dwmw2