linux-user: fix preadv/pwritev offsets

preadv/pwritev accept low and high parts of file offset in two separate
parameters. When host bitness doesn't match guest bitness these parts
must be appropriately recombined.
Introduce target_to_host_low_high that does this recombination and use
it in preadv/pwritev syscalls.

This fixes glibc testsuite test misc/tst-preadvwritev64.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2018-04-04 17:30:41 -07:00
parent 9abfc88af3
commit 9ac225171c
1 changed files with 25 additions and 2 deletions
linux-user

View File

@ -3386,6 +3386,23 @@ static abi_long do_getsockopt(int sockfd, int level, int optname,
return ret;
}
/* Convert target low/high pair representing file offset into the host
* low/high pair. This function doesn't handle offsets bigger than 64 bits
* as the kernel doesn't handle them either.
*/
static void target_to_host_low_high(abi_ulong tlow,
abi_ulong thigh,
unsigned long *hlow,
unsigned long *hhigh)
{
uint64_t off = tlow |
((unsigned long long)thigh << TARGET_LONG_BITS / 2) <<
TARGET_LONG_BITS / 2;
*hlow = off;
*hhigh = (off >> HOST_LONG_BITS / 2) >> HOST_LONG_BITS / 2;
}
static struct iovec *lock_iovec(int type, abi_ulong target_addr,
abi_ulong count, int copy)
{
@ -10449,7 +10466,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
{
struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0);
if (vec != NULL) {
ret = get_errno(safe_preadv(arg1, vec, arg3, arg4, arg5));
unsigned long low, high;
target_to_host_low_high(arg4, arg5, &low, &high);
ret = get_errno(safe_preadv(arg1, vec, arg3, low, high));
unlock_iovec(vec, arg2, arg3, 1);
} else {
ret = -host_to_target_errno(errno);
@ -10462,7 +10482,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
{
struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);
if (vec != NULL) {
ret = get_errno(safe_pwritev(arg1, vec, arg3, arg4, arg5));
unsigned long low, high;
target_to_host_low_high(arg4, arg5, &low, &high);
ret = get_errno(safe_pwritev(arg1, vec, arg3, low, high));
unlock_iovec(vec, arg2, arg3, 0);
} else {
ret = -host_to_target_errno(errno);