tcg: Workaround macOS 11.2 mprotect bug

There's a change in mprotect() behaviour [1] in the latest macOS
on M1 and it's not yet clear if it's going to be fixed by Apple.

As a short-term fix, ignore failures setting up the guard pages.

[1] https://gist.github.com/hikalium/75ae822466ee4da13cbbe486498a191f

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1914849
Message-Id: <20210320165720.1813545-3-richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-03-20 10:57:20 -06:00
parent 15c4e8fe44
commit c118881ee6

View File

@ -864,11 +864,15 @@ void tcg_region_init(void)
*/
for (i = 0; i < region.n; i++) {
void *start, *end;
int rc;
tcg_region_bounds(i, &start, &end);
rc = qemu_mprotect_none(end, page_size);
g_assert(!rc);
/*
* macOS 11.2 has a bug (Apple Feedback FB8994773) in which mprotect
* rejects a permission change from RWX -> NONE. Guard pages are
* nice for bug detection but are not essential; ignore any failure.
*/
(void)qemu_mprotect_none(end, page_size);
}
tcg_region_trees_init();