 3ddc5b46a8
			
		
	
	
	3ddc5b46a8
	
	
	
		
			
			I found the following pattern that leads in to interesting findings: grep -r "ret.*|=.*__put_user" * grep -r "ret.*|=.*__get_user" * grep -r "ret.*|=.*__copy" * The __put_user() calls in compat_ioctl.c, ptrace compat, signal compat, since those appear in compat code, we could probably expect the kernel addresses not to be reachable in the lower 32-bit range, so I think they might not be exploitable. For the "__get_user" cases, I don't think those are exploitable: the worse that can happen is that the kernel will copy kernel memory into in-kernel buffers, and will fail immediately afterward. The alpha csum_partial_copy_from_user() seems to be missing the access_ok() check entirely. The fix is inspired from x86. This could lead to information leak on alpha. I also noticed that many architectures map csum_partial_copy_from_user() to csum_partial_copy_generic(), but I wonder if the latter is performing the access checks on every architectures. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			254 lines
		
	
	
	
		
			7.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			254 lines
		
	
	
	
		
			7.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /* sys_sparc32.c: Conversion between 32bit and 64bit native syscalls.
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|  *
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|  * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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|  * Copyright (C) 1997, 2007 David S. Miller (davem@davemloft.net)
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|  *
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|  * These routines maintain argument size conversion between 32bit and 64bit
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|  * environment.
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/sched.h>
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| #include <linux/capability.h>
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| #include <linux/fs.h> 
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| #include <linux/mm.h> 
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| #include <linux/file.h> 
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| #include <linux/signal.h>
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| #include <linux/resource.h>
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| #include <linux/times.h>
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| #include <linux/smp.h>
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| #include <linux/sem.h>
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| #include <linux/msg.h>
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| #include <linux/shm.h>
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| #include <linux/uio.h>
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| #include <linux/nfs_fs.h>
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| #include <linux/quota.h>
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| #include <linux/poll.h>
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| #include <linux/personality.h>
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| #include <linux/stat.h>
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| #include <linux/filter.h>
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| #include <linux/highmem.h>
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| #include <linux/highuid.h>
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| #include <linux/mman.h>
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| #include <linux/ipv6.h>
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| #include <linux/in.h>
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| #include <linux/icmpv6.h>
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| #include <linux/syscalls.h>
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| #include <linux/sysctl.h>
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| #include <linux/binfmts.h>
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| #include <linux/dnotify.h>
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| #include <linux/security.h>
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| #include <linux/compat.h>
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| #include <linux/vfs.h>
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| #include <linux/ptrace.h>
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| #include <linux/slab.h>
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| 
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| #include <asm/types.h>
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| #include <asm/uaccess.h>
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| #include <asm/fpumacro.h>
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| #include <asm/mmu_context.h>
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| #include <asm/compat_signal.h>
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| 
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| asmlinkage long sys32_truncate64(const char __user * path, unsigned long high, unsigned long low)
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| {
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| 	if ((int)high < 0)
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| 		return -EINVAL;
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| 	else
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| 		return sys_truncate(path, (high << 32) | low);
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| }
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| 
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| asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned long low)
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| {
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| 	if ((int)high < 0)
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| 		return -EINVAL;
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| 	else
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| 		return sys_ftruncate(fd, (high << 32) | low);
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| }
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| 
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| static int cp_compat_stat64(struct kstat *stat,
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| 			    struct compat_stat64 __user *statbuf)
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| {
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| 	int err;
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| 
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| 	err  = put_user(huge_encode_dev(stat->dev), &statbuf->st_dev);
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| 	err |= put_user(stat->ino, &statbuf->st_ino);
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| 	err |= put_user(stat->mode, &statbuf->st_mode);
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| 	err |= put_user(stat->nlink, &statbuf->st_nlink);
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| 	err |= put_user(from_kuid_munged(current_user_ns(), stat->uid), &statbuf->st_uid);
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| 	err |= put_user(from_kgid_munged(current_user_ns(), stat->gid), &statbuf->st_gid);
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| 	err |= put_user(huge_encode_dev(stat->rdev), &statbuf->st_rdev);
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| 	err |= put_user(0, (unsigned long __user *) &statbuf->__pad3[0]);
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| 	err |= put_user(stat->size, &statbuf->st_size);
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| 	err |= put_user(stat->blksize, &statbuf->st_blksize);
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| 	err |= put_user(0, (unsigned int __user *) &statbuf->__pad4[0]);
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| 	err |= put_user(0, (unsigned int __user *) &statbuf->__pad4[4]);
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| 	err |= put_user(stat->blocks, &statbuf->st_blocks);
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| 	err |= put_user(stat->atime.tv_sec, &statbuf->st_atime);
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| 	err |= put_user(stat->atime.tv_nsec, &statbuf->st_atime_nsec);
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| 	err |= put_user(stat->mtime.tv_sec, &statbuf->st_mtime);
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| 	err |= put_user(stat->mtime.tv_nsec, &statbuf->st_mtime_nsec);
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| 	err |= put_user(stat->ctime.tv_sec, &statbuf->st_ctime);
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| 	err |= put_user(stat->ctime.tv_nsec, &statbuf->st_ctime_nsec);
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| 	err |= put_user(0, &statbuf->__unused4);
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| 	err |= put_user(0, &statbuf->__unused5);
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| 
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| 	return err;
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| }
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| 
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| asmlinkage long compat_sys_stat64(const char __user * filename,
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| 		struct compat_stat64 __user *statbuf)
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| {
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| 	struct kstat stat;
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| 	int error = vfs_stat(filename, &stat);
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| 
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| 	if (!error)
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| 		error = cp_compat_stat64(&stat, statbuf);
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| 	return error;
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| }
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| 
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| asmlinkage long compat_sys_lstat64(const char __user * filename,
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| 		struct compat_stat64 __user *statbuf)
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| {
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| 	struct kstat stat;
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| 	int error = vfs_lstat(filename, &stat);
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| 
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| 	if (!error)
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| 		error = cp_compat_stat64(&stat, statbuf);
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| 	return error;
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| }
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| 
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| asmlinkage long compat_sys_fstat64(unsigned int fd,
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| 		struct compat_stat64 __user * statbuf)
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| {
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| 	struct kstat stat;
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| 	int error = vfs_fstat(fd, &stat);
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| 
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| 	if (!error)
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| 		error = cp_compat_stat64(&stat, statbuf);
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| 	return error;
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| }
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| 
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| asmlinkage long compat_sys_fstatat64(unsigned int dfd,
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| 		const char __user *filename,
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| 		struct compat_stat64 __user * statbuf, int flag)
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| {
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| 	struct kstat stat;
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| 	int error;
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| 
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| 	error = vfs_fstatat(dfd, filename, &stat, flag);
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| 	if (error)
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| 		return error;
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| 	return cp_compat_stat64(&stat, statbuf);
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| }
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| 
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| COMPAT_SYSCALL_DEFINE3(sparc_sigaction, int, sig,
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| 			struct compat_old_sigaction __user *,act,
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| 			struct compat_old_sigaction __user *,oact)
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| {
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| 	WARN_ON_ONCE(sig >= 0);
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| 	return compat_sys_sigaction(-sig, act, oact);
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| }
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| 
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| COMPAT_SYSCALL_DEFINE5(rt_sigaction, int, sig,
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| 			struct compat_sigaction __user *,act,
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| 			struct compat_sigaction __user *,oact,
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| 			void __user *,restorer,
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| 			compat_size_t,sigsetsize)
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| {
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|         struct k_sigaction new_ka, old_ka;
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|         int ret;
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| 	compat_sigset_t set32;
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| 
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|         /* XXX: Don't preclude handling different sized sigset_t's.  */
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|         if (sigsetsize != sizeof(compat_sigset_t))
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|                 return -EINVAL;
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| 
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|         if (act) {
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| 		u32 u_handler, u_restorer;
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| 
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| 		new_ka.ka_restorer = restorer;
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| 		ret = get_user(u_handler, &act->sa_handler);
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| 		new_ka.sa.sa_handler =  compat_ptr(u_handler);
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| 		ret |= copy_from_user(&set32, &act->sa_mask, sizeof(compat_sigset_t));
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| 		sigset_from_compat(&new_ka.sa.sa_mask, &set32);
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| 		ret |= get_user(new_ka.sa.sa_flags, &act->sa_flags);
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| 		ret |= get_user(u_restorer, &act->sa_restorer);
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| 		new_ka.sa.sa_restorer = compat_ptr(u_restorer);
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|                 if (ret)
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|                 	return -EFAULT;
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| 	}
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| 
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| 	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
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| 
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| 	if (!ret && oact) {
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| 		sigset_to_compat(&set32, &old_ka.sa.sa_mask);
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| 		ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), &oact->sa_handler);
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| 		ret |= copy_to_user(&oact->sa_mask, &set32, sizeof(compat_sigset_t));
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| 		ret |= put_user(old_ka.sa.sa_flags, &oact->sa_flags);
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| 		ret |= put_user(ptr_to_compat(old_ka.sa.sa_restorer), &oact->sa_restorer);
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| 		if (ret)
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| 			ret = -EFAULT;
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|         }
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| 
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|         return ret;
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| }
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| 
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| asmlinkage compat_ssize_t sys32_pread64(unsigned int fd,
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| 					char __user *ubuf,
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| 					compat_size_t count,
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| 					unsigned long poshi,
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| 					unsigned long poslo)
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| {
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| 	return sys_pread64(fd, ubuf, count, (poshi << 32) | poslo);
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| }
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| 
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| asmlinkage compat_ssize_t sys32_pwrite64(unsigned int fd,
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| 					 char __user *ubuf,
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| 					 compat_size_t count,
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| 					 unsigned long poshi,
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| 					 unsigned long poslo)
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| {
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| 	return sys_pwrite64(fd, ubuf, count, (poshi << 32) | poslo);
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| }
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| 
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| asmlinkage long compat_sys_readahead(int fd,
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| 				     unsigned long offhi,
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| 				     unsigned long offlo,
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| 				     compat_size_t count)
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| {
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| 	return sys_readahead(fd, (offhi << 32) | offlo, count);
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| }
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| 
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| long compat_sys_fadvise64(int fd,
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| 			  unsigned long offhi,
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| 			  unsigned long offlo,
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| 			  compat_size_t len, int advice)
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| {
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| 	return sys_fadvise64_64(fd, (offhi << 32) | offlo, len, advice);
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| }
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| 
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| long compat_sys_fadvise64_64(int fd,
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| 			     unsigned long offhi, unsigned long offlo,
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| 			     unsigned long lenhi, unsigned long lenlo,
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| 			     int advice)
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| {
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| 	return sys_fadvise64_64(fd,
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| 				(offhi << 32) | offlo,
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| 				(lenhi << 32) | lenlo,
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| 				advice);
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| }
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| 
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| long sys32_sync_file_range(unsigned int fd, unsigned long off_high, unsigned long off_low, unsigned long nb_high, unsigned long nb_low, unsigned int flags)
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| {
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| 	return sys_sync_file_range(fd,
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| 				   (off_high << 32) | off_low,
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| 				   (nb_high << 32) | nb_low,
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| 				   flags);
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| }
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| 
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| asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
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| 				     u32 lenhi, u32 lenlo)
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| {
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| 	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
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| 			     ((loff_t)lenhi << 32) | lenlo);
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| }
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