acrn-kernel/arch/um/kernel/uaccess_user.c

65 lines
1.6 KiB
C

/*
* Copyright (C) 2001 Chris Emerson (cemerson@chiark.greenend.org.uk)
* Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <setjmp.h>
#include <string.h>
/* These are here rather than tt/uaccess.c because skas mode needs them in
* order to do SIGBUS recovery when a tmpfs mount runs out of room.
*/
unsigned long __do_user_copy(void *to, const void *from, int n,
void **fault_addr, void **fault_catcher,
void (*op)(void *to, const void *from,
int n), int *faulted_out)
{
unsigned long *faddrp = (unsigned long *) fault_addr, ret;
sigjmp_buf jbuf;
*fault_catcher = &jbuf;
if(sigsetjmp(jbuf, 1) == 0){
(*op)(to, from, n);
ret = 0;
*faulted_out = 0;
}
else {
ret = *faddrp;
*faulted_out = 1;
}
*fault_addr = NULL;
*fault_catcher = NULL;
return ret;
}
void __do_copy(void *to, const void *from, int n)
{
memcpy(to, from, n);
}
int __do_copy_to_user(void *to, const void *from, int n,
void **fault_addr, void **fault_catcher)
{
unsigned long fault;
int faulted;
fault = __do_user_copy(to, from, n, fault_addr, fault_catcher,
__do_copy, &faulted);
if(!faulted) return(0);
else return(n - (fault - (unsigned long) to));
}
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/