linux-user: don't use MAP_FIXED in pgd_find_hole_fallback
authorAlex Bennée <alex.bennee@linaro.org>
Fri, 24 Jul 2020 06:45:01 +0000 (07:45 +0100)
committerAlex Bennée <alex.bennee@linaro.org>
Mon, 27 Jul 2020 08:41:18 +0000 (09:41 +0100)
commit2667e069e7b5807c69f32109d930967bc1b222cb
tree7b24dbe48c14f5e0c2c8809dcfa359ef679f1aa0
parent163b3d1af2552845a60967979aca8d78a6b1b088
linux-user: don't use MAP_FIXED in pgd_find_hole_fallback

Plain MAP_FIXED has the undesirable behaviour of splatting exiting
maps so we don't actually achieve what we want when looking for gaps.
We should be using MAP_FIXED_NOREPLACE. As this isn't always available
we need to potentially check the returned address to see if the kernel
gave us what we asked for.

Fixes: ad592e37dfc ("linux-user: provide fallback pgd_find_hole for bare chroots")
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200724064509.331-9-alex.bennee@linaro.org>
include/qemu/osdep.h
linux-user/elfload.c