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Date: Thu, 13 Jun 2024 18:19:07 +0100
From: Catalin Marinas <catalin.marinas@arm.com>
To: Waiman Long <longman@redhat.com>
Cc: Ard Biesheuvel <ardb@kernel.org>, Will Deacon <will@kernel.org>,
	linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64/efi: Fix kmemleak false positive in
 arm64_efi_rt_init()
Message-ID: <ZmsqC_q1jyMGzvUF@arm.com>
References: <20240613162031.142224-1-longman@redhat.com>
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On Thu, Jun 13, 2024 at 12:20:31PM -0400, Waiman Long wrote:
> diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
> index 4a92096db34e..712718aed5dd 100644
> --- a/arch/arm64/kernel/efi.c
> +++ b/arch/arm64/kernel/efi.c
> @@ -9,6 +9,7 @@
>  
>  #include <linux/efi.h>
>  #include <linux/init.h>
> +#include <linux/kmemleak.h>
>  #include <linux/screen_info.h>
>  #include <linux/vmalloc.h>
>  
> @@ -213,6 +214,7 @@ l:	if (!p) {
>  		return -ENOMEM;
>  	}
>  
> +	kmemleak_not_leak(p);
>  	efi_rt_stack_top = p + THREAD_SIZE;

It looks like a false positive and the reason is that we only store
p + THREAD_SIZE in efi_rt_stack_top, not the actual allocated pointer.

-- 
Catalin