qemu/linux-user/uaccess.c
bellard 579a97f7ff Linux user memory access API change (initial patch by Thayne Harbaugh)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3583 c046a42c-6fe2-441c-8c8c-71466251a162
2007-11-11 14:26:47 +00:00

52 lines
1.3 KiB
C

/* User memory access */
#include <stdio.h>
#include <string.h>
#include "qemu.h"
/* copy_from_user() and copy_to_user() are usually used to copy data
* buffers between the target and host. These internally perform
* locking/unlocking of the memory.
*/
abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len)
{
abi_long ret = 0;
void *ghptr;
if ((ghptr = lock_user(VERIFY_READ, gaddr, len, 1))) {
memcpy(hptr, ghptr, len);
unlock_user(ghptr, gaddr, 0);
} else
ret = -TARGET_EFAULT;
return ret;
}
abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len)
{
abi_long ret = 0;
void *ghptr;
if ((ghptr = lock_user(VERIFY_WRITE, gaddr, len, 0))) {
memcpy(ghptr, hptr, len);
unlock_user(ghptr, gaddr, len);
} else
ret = -TARGET_EFAULT;
return ret;
}
/* Return the length of a string in target memory. */
/* FIXME - this doesn't check access_ok() - it's rather complicated to
* do it correctly because we need to check the bytes in a page and then
* skip to the next page and check the bytes there until we find the
* terminator. There should be a general function to do this that
* can look for any byte terminator in a buffer - not strlen().
*/
abi_long target_strlen(abi_ulong gaddr)
{
return strlen(g2h(gaddr));
}