414 lines
11 KiB
C
414 lines
11 KiB
C
/* Copyright (C) 2005 David Decotigny
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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USA.
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*/
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#include <hwcore/paging.h>
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#include <sos/thread.h>
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#include <sos/assert.h>
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#include <sos/kmalloc.h>
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#include "uaccess.h"
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int __uaccess_zero_fool_gcc = 0;
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/**
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* Make sure gcc optimizations don't go too far and don't suppress the
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* code at the given label because 1/ a global return is "above" (wrt
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* source code lines), 2/ it is never "goto"
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*/
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#define KEEP_LABEL(lbl) \
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({ if (__uaccess_zero_fool_gcc) goto lbl; })
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/**
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* @param user_as The user address space we want to transfer from/to
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*
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* @return >=0 : number of bytes successfully transferred, <0 an error code
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*/
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static sos_ret_t nocheck_user_memcpy(struct sos_umem_vmm_as * user_as,
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sos_vaddr_t dest,
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sos_vaddr_t src,
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sos_size_t size,
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sos_bool_t transfer_from_user)
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{
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__label__ catch_pgflt;
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char *cptr_dst;
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const char *cptr_src;
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sos_size_t transfer_sz;
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sos_ret_t retval;
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KEEP_LABEL(catch_pgflt);
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if (size <= 0)
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return 0;
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retval = sos_thread_prepare_user_space_access(user_as,
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(sos_vaddr_t) && catch_pgflt);
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if (SOS_OK != retval)
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return retval;
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/* Version of memcpy that does not alter the stack pointer, in
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order to be able to abruptedly jump to catch_pgflt without stack
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inconsistency. That's the reason why we don't call the normal
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memcpy here: on page fault, it would return back in here, with
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the stack frame returning back here again */
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for (cptr_dst = (char*)dest,
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cptr_src = (const char*)src,
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transfer_sz = size ;
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transfer_sz > 0 ;
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cptr_dst++, cptr_src++, transfer_sz--)
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*cptr_dst = *cptr_src;
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retval = sos_thread_end_user_space_access();
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if (SOS_OK != retval)
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return retval;
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return size;
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/* An unresolved page fault occured while accessing user space */
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catch_pgflt:
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{
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struct sos_thread * cur_thr = sos_thread_get_current();
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sos_uaddr_t faulted_uaddr = cur_thr->fixup_uaccess.faulted_uaddr;
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if (transfer_from_user)
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{
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if ( (faulted_uaddr < src) || (faulted_uaddr - size > src) )
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sos_display_fatal_error("Unexpected read access in user space");
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retval = faulted_uaddr - src;
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}
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else
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{
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if ( (faulted_uaddr < dest) || (faulted_uaddr - size > dest) )
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sos_display_fatal_error("Unexpected write access in user space");
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retval = faulted_uaddr - dest;
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}
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sos_thread_end_user_space_access();
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return retval;
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}
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}
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sos_ret_t sos_memcpy_from_user(sos_vaddr_t kernel_to,
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sos_uaddr_t user_from,
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sos_size_t size)
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{
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/* Make sure user is trying to access user space */
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if (! SOS_PAGING_IS_USER_AREA(user_from, size) )
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return -SOS_EPERM;
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/* Make sure the copy totally resides inside kernel space */
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if (! SOS_PAGING_IS_KERNEL_AREA(kernel_to, size) )
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return -SOS_EPERM;
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return nocheck_user_memcpy(NULL, kernel_to, user_from, size, TRUE);
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}
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sos_ret_t sos_memdup_from_user(sos_vaddr_t * kernel_to, sos_uaddr_t from_user,
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sos_size_t length,
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sos_ui32_t kmalloc_flags)
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{
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sos_ret_t retval;
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if (length <= 0)
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return -SOS_EINVAL;
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*kernel_to = sos_kmalloc(length, kmalloc_flags);
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if (NULL == (void*) *kernel_to)
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return -SOS_ENOMEM;
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retval = sos_memcpy_from_user(*kernel_to, from_user, length);
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if ((sos_ret_t)length != retval)
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{
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sos_kfree((sos_vaddr_t)*kernel_to);
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*kernel_to = (sos_vaddr_t) NULL;
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retval = -SOS_EFAULT;
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}
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else
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retval = SOS_OK;
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return retval;
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}
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sos_ret_t sos_memcpy_to_user(sos_uaddr_t user_to,
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sos_vaddr_t kernel_from,
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sos_size_t size)
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{
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/* Make sure the source totally resides inside kernel space */
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if (! SOS_PAGING_IS_KERNEL_AREA(kernel_from, size) )
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return -SOS_EPERM;
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/* Make sure user is trying to access user space */
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if (! SOS_PAGING_IS_USER_AREA(user_to, size) )
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return -SOS_EPERM;
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return nocheck_user_memcpy(NULL, user_to, kernel_from, size, FALSE);
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}
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sos_ret_t sos_memcpy_from_specified_userspace(sos_vaddr_t kernel_to,
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struct sos_umem_vmm_as * src_as,
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sos_uaddr_t user_from,
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sos_size_t size)
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{
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if (NULL == src_as)
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return -SOS_EINVAL;
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/* Make sure user is trying to access user space */
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if (! SOS_PAGING_IS_USER_AREA(user_from, size) )
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return -SOS_EPERM;
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/* Make sure the copy totally resides inside kernel space */
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if (! SOS_PAGING_IS_KERNEL_AREA(kernel_to, size) )
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return -SOS_EPERM;
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return nocheck_user_memcpy(src_as, kernel_to, user_from, size, TRUE);
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}
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sos_ret_t sos_memcpy_to_specified_userspace(struct sos_umem_vmm_as * dst_as,
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sos_uaddr_t user_to,
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sos_vaddr_t kernel_from,
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sos_size_t size)
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{
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if (NULL == dst_as)
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return -SOS_EINVAL;
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/* Make sure the source totally resides inside kernel space */
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if (! SOS_PAGING_IS_KERNEL_AREA(kernel_from, size) )
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return -SOS_EPERM;
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/* Make sure user is trying to access user space */
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if (! SOS_PAGING_IS_USER_AREA(user_to, size) )
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return -SOS_EPERM;
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return nocheck_user_memcpy(dst_as, user_to, kernel_from, size, FALSE);
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}
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sos_ret_t sos_usercpy(struct sos_umem_vmm_as * dst_as,
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sos_uaddr_t dst_uaddr,
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struct sos_umem_vmm_as * src_as,
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sos_uaddr_t src_uaddr,
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sos_size_t size)
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{
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sos_vaddr_t kern_addr;
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sos_ret_t retval;
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if (size <= 0)
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return 0;
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/* Make sure user is trying to access user space */
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if (! SOS_PAGING_IS_USER_AREA(src_uaddr, size) )
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return -SOS_EPERM;
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if (! SOS_PAGING_IS_USER_AREA(dst_uaddr, size) )
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return -SOS_EPERM;
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kern_addr = sos_kmalloc(size, 0);
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if (! kern_addr)
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return -SOS_ENOMEM;
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retval = nocheck_user_memcpy(src_as, kern_addr, src_uaddr,
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size, TRUE);
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if (retval <= 0)
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{
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sos_kfree((sos_vaddr_t)kern_addr);
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return retval;
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}
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retval = nocheck_user_memcpy(dst_as, dst_uaddr, kern_addr,
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retval, FALSE);
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sos_kfree((sos_vaddr_t)kern_addr);
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return retval;
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}
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sos_ret_t sos_strnlen_from_user(sos_uaddr_t user_str, sos_size_t max_len)
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{
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__label__ catch_pgflt;
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const char *sc;
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sos_ret_t retval;
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KEEP_LABEL(catch_pgflt);
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if (max_len <= 0)
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return 0;
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/* Make sure user is trying to access user space */
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if (! SOS_PAGING_IS_USER_AREA(user_str, max_len) )
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return -SOS_EPERM;
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retval = sos_thread_prepare_user_space_access(NULL,
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(sos_vaddr_t) && catch_pgflt);
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if (SOS_OK != retval)
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return retval;
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/* Version of strnlen that does not alter the stack pointer, in
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order to be able to abruptedly jump to catch_pgflt without stack
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inconsistency. That's the reason why we don't call the normal
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strnlen here: on page fault, it would return back in here, with
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the stack frame returning back here again */
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for (sc = (const char *)user_str; max_len-- && *sc != '\0'; ++sc)
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continue;
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retval = sos_thread_end_user_space_access();
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if (SOS_OK != retval)
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return retval;
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return ((sos_uaddr_t)sc - user_str);
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/* An unresolved page fault occured while accessing user space */
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catch_pgflt:
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{
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sos_thread_end_user_space_access();
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return -SOS_EFAULT;
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}
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}
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static sos_ret_t nocheck_user_strzcpy(char *dst, const char *src,
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sos_size_t len)
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{
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__label__ catch_pgflt;
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unsigned int i;
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sos_ret_t retval;
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KEEP_LABEL(catch_pgflt);
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if (len <= 0)
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return 0;
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retval = sos_thread_prepare_user_space_access(NULL,
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(sos_vaddr_t) && catch_pgflt);
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if (SOS_OK != retval)
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return retval;
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/* Version of strzcpy that does not alter the stack pointer, in
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order to be able to abruptedly jump to catch_pgflt without stack
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inconsistency. That's the reason why we don't call the normal
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strzcpy here: on page fault, it would return back in here, with
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the stack frame returning back here again */
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for (i = 0; i < len; i++)
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{
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dst[i] = src[i];
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if(src[i] == '\0')
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break;
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}
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dst[len-1] = '\0';
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retval = sos_thread_end_user_space_access();
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if (SOS_OK != retval)
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return retval;
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return SOS_OK;
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/* An unresolved page fault occured while accessing user space */
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catch_pgflt:
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{
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sos_thread_end_user_space_access();
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return -SOS_EFAULT;
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}
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}
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sos_ret_t sos_strzcpy_from_user(char *kernel_to, sos_uaddr_t user_from,
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sos_size_t max_len)
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{
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if (max_len <= 0)
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return -SOS_EINVAL;
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/* Make sure user is trying to access user space */
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if (! SOS_PAGING_IS_USER_AREA(user_from, max_len) )
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return -SOS_EPERM;
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/* Make sure the copy totally resides inside kernel space */
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if (! SOS_PAGING_IS_KERNEL_AREA((sos_vaddr_t)kernel_to, max_len) )
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return -SOS_EPERM;
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return nocheck_user_strzcpy(kernel_to, (const char*)user_from, max_len);
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}
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sos_ret_t sos_strzcpy_to_user(sos_uaddr_t user_to, const char *kernel_from,
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sos_size_t max_len)
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{
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if (max_len <= 0)
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return -SOS_EINVAL;
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/* Make sure the source totally resides inside kernel space */
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if (! SOS_PAGING_IS_KERNEL_AREA((sos_vaddr_t)kernel_from, max_len) )
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return -SOS_EPERM;
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/* Make sure user is trying to access user space */
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if (! SOS_PAGING_IS_USER_AREA(user_to, max_len) )
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return -SOS_EPERM;
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return nocheck_user_strzcpy((char*)user_to, kernel_from, max_len);
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}
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sos_ret_t sos_strndup_from_user(char ** kernel_to, sos_uaddr_t from_user,
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sos_size_t max_len,
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sos_ui32_t kmalloc_flags)
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{
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sos_ret_t retval = sos_strnlen_from_user(from_user, max_len);
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if (retval < 0)
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return retval;
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*kernel_to = (char*)sos_kmalloc(retval + 1, kmalloc_flags);
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if (NULL == *kernel_to)
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return -SOS_ENOMEM;
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retval = sos_strzcpy_from_user(*kernel_to, from_user, retval + 1);
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if (SOS_OK != retval)
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{
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sos_kfree((sos_vaddr_t)*kernel_to);
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*kernel_to = NULL;
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}
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return retval;
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}
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sos_ret_t sos_memcpy_generic_to(sos_genaddr_t to_addr,
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sos_vaddr_t kernel_from,
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sos_size_t size)
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{
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if (to_addr.is_user)
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return sos_memcpy_to_user(to_addr.addr, kernel_from, size);
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memcpy((void*)to_addr.addr, (const void*)kernel_from, size);
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return size;
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}
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sos_ret_t sos_memcpy_generic_from(sos_vaddr_t kernel_from,
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sos_genaddr_t from_addr,
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sos_size_t size)
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{
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if (from_addr.is_user)
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return sos_memcpy_from_user(kernel_from, from_addr.addr, size);
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memcpy((void*)kernel_from, (const void*)from_addr.addr, size);
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return size;
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}
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