Since commit 1179f170b6f0 ("s390: fix fpu restore in entry.S"), the sie_block pointer is located at empty1[1], but in sie_block() it was taken from empty1[0]. This leads to a random pointer being dereferenced, possibly causing system crash. This problem can be observed when running a simple guest with an endless loop and recording the cpu-clock event: sudo perf kvm --guestvmlinux=<guestkernel> --guest top -e cpu-clock With this fix, the correct guest address is shown. Fixes: 1179f170b6f0 ("s390: fix fpu restore in entry.S") Cc: stable@vger.kernel.org Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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