Commit 9ac22517 authored by Max Filippov's avatar Max Filippov
Browse files

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: default avatarLaurent Vivier <laurent@vivier.eu>
Reviewed-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 9abfc88a

linux-user/syscall.c

+25 −2
Original line number Diff line number Diff line
@@ -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);