bsd-user/mmap.c: Implement MAP_EXCL, required by jemalloc in head

jemalloc requires a working MAP_EXCL. Ensure that no page is double
mapped when specified. In addition, use guest_range_valid_untagged to
test for valid ranges of pages rather than an incomplete inlined version
of the test that might be wrong.

Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Kyle Evans 2018-11-08 14:39:47 -06:00 committed by Warner Losh
parent a6b2d06066
commit 0fc76b6859

View File

@ -574,12 +574,10 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
* It can fail only on 64-bit host with 32-bit target.
* On any other target/host host mmap() handles this error correctly.
*/
#if TARGET_ABI_BITS == 32 && HOST_LONG_BITS == 64
if ((unsigned long)start + len - 1 > (abi_ulong) -1) {
if (!guest_range_valid_untagged(start, len)) {
errno = EINVAL;
goto fail;
}
#endif
/*
* worst case: we cannot map the file because the offset is not
@ -614,6 +612,12 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
goto the_end;
}
/* Reject the mapping if any page within the range is mapped */
if ((flags & MAP_EXCL) && page_check_range(start, len, 0) < 0) {
errno = EINVAL;
goto fail;
}
/* handle the start of the mapping */
if (start > real_start) {
if (real_end == real_start + qemu_host_page_size) {