Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux-2.6-microblaze.git] / scripts / gcc-plugins / Kconfig

diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
index cb0c889..0d5c799 100644 (file)
--- a/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@ -139,4 +139,55 @@ config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE
          in structures.  This reduces the performance hit of RANDSTRUCT
          at the cost of weakened randomization.
 
+config GCC_PLUGIN_STACKLEAK
+       bool "Erase the kernel stack before returning from syscalls"
+       depends on GCC_PLUGINS
+       depends on HAVE_ARCH_STACKLEAK
+       help
+         This option makes the kernel erase the kernel stack before
+         returning from system calls. That reduces the information which
+         kernel stack leak bugs can reveal and blocks some uninitialized
+         stack variable attacks.
+
+         The tradeoff is the performance impact: on a single CPU system kernel
+         compilation sees a 1% slowdown, other systems and workloads may vary
+         and you are advised to test this feature on your expected workload
+         before deploying it.
+
+         This plugin was ported from grsecurity/PaX. More information at:
+          * https://grsecurity.net/
+          * https://pax.grsecurity.net/
+
+config STACKLEAK_TRACK_MIN_SIZE
+       int "Minimum stack frame size of functions tracked by STACKLEAK"
+       default 100
+       range 0 4096
+       depends on GCC_PLUGIN_STACKLEAK
+       help
+         The STACKLEAK gcc plugin instruments the kernel code for tracking
+         the lowest border of the kernel stack (and for some other purposes).
+         It inserts the stackleak_track_stack() call for the functions with
+         a stack frame size greater than or equal to this parameter.
+         If unsure, leave the default value 100.
+
+config STACKLEAK_METRICS
+       bool "Show STACKLEAK metrics in the /proc file system"
+       depends on GCC_PLUGIN_STACKLEAK
+       depends on PROC_FS
+       help
+         If this is set, STACKLEAK metrics for every task are available in
+         the /proc file system. In particular, /proc/<pid>/stack_depth
+         shows the maximum kernel stack consumption for the current and
+         previous syscalls. Although this information is not precise, it
+         can be useful for estimating the STACKLEAK performance impact for
+         your workloads.
+
+config STACKLEAK_RUNTIME_DISABLE
+       bool "Allow runtime disabling of kernel stack erasing"
+       depends on GCC_PLUGIN_STACKLEAK
+       help
+         This option provides 'stack_erasing' sysctl, which can be used in
+         runtime to control kernel stack erasing for kernels built with
+         CONFIG_GCC_PLUGIN_STACKLEAK.
+
 endif