mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

linux-user: writev Partial Writes

Browse Source 
Although not technically not required by POSIX, the writev system call will
typically write out its buffers individually.  That is, if the first buffer
is written successfully, but the second buffer pointer is invalid, then
the first chuck will be written and its size is returned.

Signed-off-by: Tom Musta <tommusta@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This commit is contained in:
Tom Musta 2014-08-12 13:53:43 -05:00 committed by Riku Voipio
parent 6f6a40328b
commit 29560a6cb7
1 changed files with 14 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
linux-user/syscall.c
View File

@ -1803,6 +1803,7 @@ static struct iovec *lock_iovec(int type, abi_ulong target_addr,
abi_ulong total_len, max_len;
int i;
int err = 0;
bool bad_address = false;
if (count == 0) {
errno = 0;
@ -1843,9 +1844,20 @@ static struct iovec *lock_iovec(int type, abi_ulong target_addr,
vec[i].iov_base = 0;
} else {
vec[i].iov_base = lock_user(type, base, len, copy);
/* If the first buffer pointer is bad, this is a fault. But
* subsequent bad buffers will result in a partial write; this
* is realized by filling the vector with null pointers and
* zero lengths. */
if (!vec[i].iov_base) {
err = EFAULT;
goto fail;
if (i == 0) {
err = EFAULT;
goto fail;
} else {
bad_address = true;
}
}
if (bad_address) {
len = 0;
}
if (len > max_len - total_len) {
len = max_len - total_len;