2023-11-20 17:48:18

by andrey.konovalov

Subject: [PATCH v4 01/22] lib/stackdepot: print disabled message only if truly disabled

From: Andrey Konovalov <[email protected]>

Currently, if stack_depot_disable=off is passed to the kernel
command-line after stack_depot_disable=on, stack depot prints a message
that it is disabled, while it is actually enabled.

Fix this by moving printing the disabled message to
stack_depot_early_init. Place it before the
__stack_depot_early_init_requested check, so that the message is printed
even if early stack depot init has not been requested.

Also drop the stack_table = NULL assignment from disable_stack_depot,
as stack_table is NULL by default.

Fixes: e1fdc403349c ("lib: stackdepot: add support to disable stack depot")
Reviewed-by: Marco Elver <[email protected]>
Signed-off-by: Andrey Konovalov <[email protected]>
---
lib/stackdepot.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 2f5aa851834e..0eeaef4f2523 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -101,14 +101,7 @@ static int next_pool_required = 1;

static int __init disable_stack_depot(char *str)
{
- int ret;
-
- ret = kstrtobool(str, &stack_depot_disabled);
- if (!ret && stack_depot_disabled) {
- pr_info("disabled\n");
- stack_table = NULL;
- }
- return 0;
+ return kstrtobool(str, &stack_depot_disabled);
}
early_param("stack_depot_disable", disable_stack_depot);

@@ -130,6 +123,15 @@ int __init stack_depot_early_init(void)
return 0;
__stack_depot_early_init_passed = true;

+ /*
+ * Print disabled message even if early init has not been requested:
+ * stack_depot_init() will not print one.
+ */
+ if (stack_depot_disabled) {
+ pr_info("disabled\n");
+ return 0;
+ }
+
/*
* If KASAN is enabled, use the maximum order: KASAN is frequently used
* in fuzzing scenarios, which leads to a large number of different
@@ -138,7 +140,11 @@ int __init stack_depot_early_init(void)
if (kasan_enabled() && !stack_bucket_number_order)
stack_bucket_number_order = STACK_BUCKET_NUMBER_ORDER_MAX;

- if (!__stack_depot_early_init_requested || stack_depot_disabled)
+ /*
+ * Check if early init has been requested after setting
+ * stack_bucket_number_order: stack_depot_init() uses its value.
+ */
+ if (!__stack_depot_early_init_requested)
return 0;

/*
--
2.25.1

2024-01-03 08:14:14

by Oscar Salvador

Subject: Re: [PATCH v4 01/22] lib/stackdepot: print disabled message only if truly disabled

On Mon, Nov 20, 2023 at 06:46:59PM +0100, [email protected] wrote:
> From: Andrey Konovalov <[email protected]>
>
> Currently, if stack_depot_disable=off is passed to the kernel
> command-line after stack_depot_disable=on, stack depot prints a message
> that it is disabled, while it is actually enabled.
>
> Fix this by moving printing the disabled message to
> stack_depot_early_init. Place it before the
> __stack_depot_early_init_requested check, so that the message is printed
> even if early stack depot init has not been requested.
>
> Also drop the stack_table = NULL assignment from disable_stack_depot,
> as stack_table is NULL by default.
>
> Fixes: e1fdc403349c ("lib: stackdepot: add support to disable stack depot")
> Reviewed-by: Marco Elver <[email protected]>
> Signed-off-by: Andrey Konovalov <[email protected]>

Reviewed-by: Oscar Salvador <[email protected]>

--
Oscar Salvador
SUSE Labs