blueswir1 | 8477850 | 2008-10-26 20:33:16 +0000 | [diff] [blame] | 1 | /* User memory access */ |
Peter Maydell | 2231197 | 2016-01-29 17:49:53 +0000 | [diff] [blame] | 2 | #include "qemu/osdep.h" |
Ed Maste | abd4556 | 2016-04-05 10:01:21 -0400 | [diff] [blame] | 3 | #include "qemu/cutils.h" |
blueswir1 | 8477850 | 2008-10-26 20:33:16 +0000 | [diff] [blame] | 4 | |
| 5 | #include "qemu.h" |
| 6 | |
| 7 | /* copy_from_user() and copy_to_user() are usually used to copy data |
| 8 | * buffers between the target and host. These internally perform |
| 9 | * locking/unlocking of the memory. |
| 10 | */ |
| 11 | abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len) |
| 12 | { |
| 13 | abi_long ret = 0; |
| 14 | void *ghptr; |
| 15 | |
| 16 | if ((ghptr = lock_user(VERIFY_READ, gaddr, len, 1))) { |
| 17 | memcpy(hptr, ghptr, len); |
| 18 | unlock_user(ghptr, gaddr, 0); |
| 19 | } else |
| 20 | ret = -TARGET_EFAULT; |
| 21 | |
| 22 | return ret; |
| 23 | } |
| 24 | |
| 25 | |
| 26 | abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len) |
| 27 | { |
| 28 | abi_long ret = 0; |
| 29 | void *ghptr; |
| 30 | |
| 31 | if ((ghptr = lock_user(VERIFY_WRITE, gaddr, len, 0))) { |
| 32 | memcpy(ghptr, hptr, len); |
| 33 | unlock_user(ghptr, gaddr, len); |
| 34 | } else |
| 35 | ret = -TARGET_EFAULT; |
| 36 | |
| 37 | return ret; |
| 38 | } |
| 39 | |
blueswir1 | 8477850 | 2008-10-26 20:33:16 +0000 | [diff] [blame] | 40 | /* Return the length of a string in target memory or -TARGET_EFAULT if |
| 41 | access error */ |
| 42 | abi_long target_strlen(abi_ulong guest_addr1) |
| 43 | { |
| 44 | uint8_t *ptr; |
| 45 | abi_ulong guest_addr; |
| 46 | int max_len, len; |
| 47 | |
| 48 | guest_addr = guest_addr1; |
| 49 | for(;;) { |
| 50 | max_len = TARGET_PAGE_SIZE - (guest_addr & ~TARGET_PAGE_MASK); |
| 51 | ptr = lock_user(VERIFY_READ, guest_addr, max_len, 1); |
| 52 | if (!ptr) |
| 53 | return -TARGET_EFAULT; |
Ed Maste | 43b0ea1 | 2016-04-05 10:46:33 -0400 | [diff] [blame] | 54 | len = qemu_strnlen((const char *)ptr, max_len); |
blueswir1 | 8477850 | 2008-10-26 20:33:16 +0000 | [diff] [blame] | 55 | unlock_user(ptr, guest_addr, 0); |
| 56 | guest_addr += len; |
| 57 | /* we don't allow wrapping or integer overflow */ |
| 58 | if (guest_addr == 0 || |
| 59 | (guest_addr - guest_addr1) > 0x7fffffff) |
| 60 | return -TARGET_EFAULT; |
| 61 | if (len != max_len) |
| 62 | break; |
| 63 | } |
| 64 | return guest_addr - guest_addr1; |
| 65 | } |