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| author |   Alexander Popov <alex.popov@linux.com> | 2018-08-17 01:17:01 +0300 |
|---|---|---|
| committer |   Kees Cook <keescook@chromium.org> | 2018-09-04 10:35:48 -0700 |
| commit | c8d126275a5fa59394fe17109bdb9812fed296b8 (patch) | |
| tree | 81be08434798afffb46681c2625c0d16e4e188cc /fs/proc | |
| parent | lkdtm: Add a test for STACKLEAK (diff) | |
| download | linux-dev-c8d126275a5fa59394fe17109bdb9812fed296b8.tar.xz linux-dev-c8d126275a5fa59394fe17109bdb9812fed296b8.zip | |
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 'fs/proc')
| -rw-r--r-- | fs/proc/base.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index ccf86f16d9f0..2a238d68610e 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2891,6 +2891,21 @@ static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, } #endif /* CONFIG_LIVEPATCH */ +#ifdef CONFIG_STACKLEAK_METRICS +static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + unsigned long prev_depth = THREAD_SIZE - + (task->prev_lowest_stack & (THREAD_SIZE - 1)); + unsigned long depth = THREAD_SIZE - + (task->lowest_stack & (THREAD_SIZE - 1)); + + seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n", + prev_depth, depth); + return 0; +} +#endif /* CONFIG_STACKLEAK_METRICS */ + /* * Thread groups */ @@ -2992,6 +3007,9 @@ static const struct pid_entry tgid_base_stuff[] = { #ifdef CONFIG_LIVEPATCH ONE("patch_state", S_IRUSR, proc_pid_patch_state), #endif +#ifdef CONFIG_STACKLEAK_METRICS + ONE("stack_depth", S_IRUGO, proc_stack_depth), +#endif }; static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) |