Re: [PATCH] mm, debug, kasan: save and dump freeing stack trace for kasan

[Andrey Ryabinin]

On 9/23/19 11:20 AM, Vlastimil Babka wrote:
> On 9/16/19 5:57 PM, Andrey Ryabinin wrote:
>> I'd rather keep all logic in one place, i.e. "if (!page_owner_disabled && (IS_ENABLED(CONFIG_KASAN) || debug_pagealloc_enabled())"
>> With this no changes in early_debug_pagealloc() required and CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT=y should also work correctly.
> 
> OK.
> 
> ----8<----
> 
> From 7437c43f02682fdde5680fa83e87029f7529e222 Mon Sep 17 00:00:00 2001
> From: Vlastimil Babka <vbabka@xxxxxxx>
> Date: Mon, 16 Sep 2019 11:28:19 +0200
> Subject: [PATCH] mm, debug, kasan: save and dump freeing stack trace for kasan
> 
> The commit "mm, page_owner, debug_pagealloc: save and dump freeing stack trace"
> enhanced page_owner to also store freeing stack trace, when debug_pagealloc is
> also enabled. KASAN would also like to do this [1] to improve error reports to
> debug e.g. UAF issues. This patch therefore introduces a helper config option
> PAGE_OWNER_FREE_STACK, which is enabled when PAGE_OWNER and either of
> DEBUG_PAGEALLOC or KASAN is enabled. Boot-time, the free stack saving is
> enabled when booting a KASAN kernel with page_owner=on, or non-KASAN kernel
> with debug_pagealloc=on and page_owner=on.
> 
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=203967
> 
> Suggested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Suggested-by: Walter Wu <walter-zh.wu@xxxxxxxxxxxx>
> Suggested-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
> ---

Reviewed-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>