From: Ard Biesheuvel <ardb@kernel.org>
To: linke li <lilinke99@qq.com>
Cc: xujianhao01@gmail.com, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/efi: mark racy access on efi_rts_work.efi_rts_id
Date: Mon, 29 Apr 2024 17:40:30 +0200 [thread overview]
Message-ID: <CAMj1kXEfdJ9SzPO7NpYwXW3uPGYNOzVFndRswLZb=6TPAgN5TA@mail.gmail.com> (raw)
In-Reply-To: <tencent_E910110547D287B13FEDB6E161D8874E6E06@qq.com>
On Sat, 27 Apr 2024 at 07:28, linke li <lilinke99@qq.com> wrote:
>
> In efi_crash_gracefully_on_page_fault(), efi_rts_work.efi_rts_id can by
> changed by other thread from the comment. Mark possible data race on
> efi_rts_work.efi_rts_id as benign using READ_ONCE.
>
> This patch is aimed at reducing the number of benign races reported by
> KCSAN in order to focus future debugging effort on harmful races.
>
> Signed-off-by: linke li <lilinke99@qq.com>
> ---
> arch/x86/platform/efi/quirks.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
> index f0cc00032751..4acb81700caf 100644
> --- a/arch/x86/platform/efi/quirks.c
> +++ b/arch/x86/platform/efi/quirks.c
> @@ -751,7 +751,7 @@ void efi_crash_gracefully_on_page_fault(unsigned long phys_addr)
> * because this case occurs *very* rarely and hence could be improved
> * on a need by basis.
> */
> - if (efi_rts_work.efi_rts_id == EFI_RESET_SYSTEM) {
> + if (READ_ONCE(efi_rts_work.efi_rts_id) == EFI_RESET_SYSTEM) {
> pr_info("efi_reset_system() buggy! Reboot through BIOS\n");
> machine_real_restart(MRR_BIOS);
> return;
Why is this the only reference that needs an annotation?
next prev parent reply other threads:[~2024-04-29 15:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-27 5:25 [PATCH] x86/efi: mark racy access on efi_rts_work.efi_rts_id linke li
2024-04-29 15:40 ` Ard Biesheuvel [this message]
2024-05-01 2:59 ` linke li
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