tree f88b68b7f8d1c4bddac4547cd2b2f2b078265343
parent de3f1b98410e0d5b406a0df3a48547b559d18602
author Peter Maydell <peter.maydell@linaro.org> 1455033431 +0000
committer Riku Voipio <riku.voipio@linaro.org> 1456255509 +0200

linux-user: Don't assert if guest tries shmdt(0)

Our implementation of shmat() and shmdt() for linux-user was
using "zero guest address" as its marker for "entry in the
shm_regions[] array is not in use". This meant that if the
guest did a shmdt(0) we would match on an unused array entry
and call page_set_flags() with both start and end addresses zero,
which causes an assertion failure.

Use an explicit in_use flag to manage the shm_regions[] array,
so that we avoid this problem.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Pavel Shamis <pasharesearch@gmail.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>