include/linux/randomize_kstack.h

1 /* SPDX-License-Identifier: GPL-2.0-only */
8 #include <linux/percpu-defs.h>
16  * it provides an arch-agnostic way to grow the stack with correct
18  * 10 bits, stack-clash style attacks are unlikely. For more details see
35  * Use, at most, 6 bits of entropy (on 64-bit; 8 on 32-bit). This cap is
37  * the bottom 4 bits (on 64-bit systems, 2 for 32-bit), since stack
38  * alignment will always be at least word size. This makes the compiler
39  * code gen better when it is applying the actual per-arch alignment to
50  * add_random_kstack_offset - Increase stack utilization by previously
56  * tools/testing/selftests/lkdtm/stack-entropy.sh
69  * choose_random_kstack_offset - Choose the random offset for the next
75  * - Maximize the timing uncertainty visible from userspace: if the
80  * - Reduce the lifetime of the new offset sitting in memory during
81  *   kernel mode execution. Exposure of "thread-local" memory content