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authorAlexander Popov <alex.popov@linux.com>2018-08-17 01:17:01 +0300
committerKees Cook <keescook@chromium.org>2018-09-04 10:35:48 -0700
commitc8d126275a5fa59394fe17109bdb9812fed296b8 (patch)
tree81be08434798afffb46681c2625c0d16e4e188cc /kernel/stackleak.c
parentf90d1e0c7804b52e12fea501aa46a12c1ff6a567 (diff)
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>
Diffstat (limited to 'kernel/stackleak.c')
-rw-r--r--kernel/stackleak.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/stackleak.c b/kernel/stackleak.c
index 628485db37ba..f66239572c89 100644
--- a/kernel/stackleak.c
+++ b/kernel/stackleak.c
@@ -41,6 +41,10 @@ asmlinkage void stackleak_erase(void)
if (kstack_ptr == boundary)
kstack_ptr += sizeof(unsigned long);
+#ifdef CONFIG_STACKLEAK_METRICS
+ current->prev_lowest_stack = kstack_ptr;
+#endif
+
/*
* Now write the poison value to the kernel stack. Start from
* 'kstack_ptr' and move up till the new 'boundary'. We assume that