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author | Robert Mustacchi <rm@joyent.com> | 2011-06-24 13:49:54 -0700 |
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committer | Robert Mustacchi <rm@joyent.com> | 2011-06-24 13:49:54 -0700 |
commit | 68396ea9c0fe4f75ce30b1eba2c44c43c13344bb (patch) | |
tree | 802587d411d9db461e6500c5b635043315f81c27 /linux-user/uaccess.c | |
download | illumos-kvm-cmd-68396ea9c0fe4f75ce30b1eba2c44c43c13344bb.tar.gz |
Initial commit of d32e8d0b8d9e0ef7cf7ab2e74548982972789dfc from qemu-kvm
Diffstat (limited to 'linux-user/uaccess.c')
-rw-r--r-- | linux-user/uaccess.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/linux-user/uaccess.c b/linux-user/uaccess.c new file mode 100644 index 0000000..a4d108c --- /dev/null +++ b/linux-user/uaccess.c @@ -0,0 +1,65 @@ +/* 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 or -TARGET_EFAULT if + access error */ +abi_long target_strlen(abi_ulong guest_addr1) +{ + uint8_t *ptr; + abi_ulong guest_addr; + int max_len, len; + + guest_addr = guest_addr1; + for(;;) { + max_len = TARGET_PAGE_SIZE - (guest_addr & ~TARGET_PAGE_MASK); + ptr = lock_user(VERIFY_READ, guest_addr, max_len, 1); + if (!ptr) + return -TARGET_EFAULT; + len = qemu_strnlen((const char *)ptr, max_len); + unlock_user(ptr, guest_addr, 0); + guest_addr += len; + /* we don't allow wrapping or integer overflow */ + if (guest_addr == 0 || + (guest_addr - guest_addr1) > 0x7fffffff) + return -TARGET_EFAULT; + if (len != max_len) + break; + } + return guest_addr - guest_addr1; +} |