fs/proc: Show STACKLEAK metrics in the /proc file system

Introduce CONFIG_STACKLEAK_METRICS providing STACKLEAK information about
tasks via 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.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
index c65fdd823591..b0a015ef5268 100644
--- a/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@ -170,4 +170,16 @@ config STACKLEAK_TRACK_MIN_SIZE
           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.
+
 endif