From: Ingo Molnar <mingo@kernel.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-efi@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Jia-Ju Bai <baijiaju1990@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 06/12] x86: efi: Replace GFP_ATOMIC with GFP_KERNEL in efi_query_variable_store
Date: Fri, 9 Mar 2018 08:54:36 +0100 [thread overview]
Message-ID: <20180309075436.tedbueuh3wuocr3p@gmail.com> (raw)
In-Reply-To: <20180308080020.22828-7-ard.biesheuvel@linaro.org>
* Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> From: Jia-Ju Bai <baijiaju1990@gmail.com>
>
> The function kzalloc here is not called in atomic context.
> If nonblocking in efi_query_variable_store is true,
> namely it is in atomic context, efi_query_variable_store will return before
> this kzalloc is called.
> Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL.
>
> This is found by a static analysis tool named DCNS written by myself.
Please fix typos/spelling in changelogs when applying patches.
I improved the above to:
efi_query_variable_store() does an atomic kzalloc() unnecessarily,
because we can never get this far when called in an atomic context,
namely when nonblocking == 1.
Replace it with GFP_KERNEL.
This was found by the DCNS static analysis tool written by myself.
Thanks,
Ingo
next prev parent reply other threads:[~2018-03-09 7:54 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-08 8:00 [GIT PULL 00/12] first batch of EFI changes for v4.17 Ard Biesheuvel
2018-03-08 8:00 ` [PATCH 01/12] efi/arm*: Only register page tables when they exist Ard Biesheuvel
2018-03-09 9:11 ` [tip:efi/core] " tip-bot for Mark Rutland
2018-03-08 8:00 ` [PATCH 02/12] efi/apple-properties: Device core takes care of empty properties Ard Biesheuvel
2018-03-09 9:11 ` [tip:efi/core] efi/apple-properties: Remove redundant attribute initialization from unmarshal_key_value_pairs() tip-bot for Andy Shevchenko
2018-03-08 8:00 ` [PATCH 03/12] efi/arm*: Stop printing addresses of virtual mappings Ard Biesheuvel
2018-03-09 9:12 ` [tip:efi/core] " tip-bot for Ard Biesheuvel
2018-03-08 8:00 ` [PATCH 04/12] efi/x86: Fix trailing semicolons Ard Biesheuvel
2018-03-08 8:00 ` [PATCH 05/12] efi: arm64: Check whether x18 is preserved by runtime services calls Ard Biesheuvel
2018-03-09 9:12 ` [tip:efi/core] efi/arm64: " tip-bot for Ard Biesheuvel
2018-03-08 8:00 ` [PATCH 06/12] x86: efi: Replace GFP_ATOMIC with GFP_KERNEL in efi_query_variable_store Ard Biesheuvel
2018-03-09 7:54 ` Ingo Molnar [this message]
2018-03-09 9:13 ` [tip:efi/core] x86/efi: Replace GFP_ATOMIC with GFP_KERNEL in efi_query_variable_store() tip-bot for Jia-Ju Bai
2018-03-08 8:00 ` [PATCH 07/12] efi: Use efi_mm in x86 as well as ARM Ard Biesheuvel
2018-03-09 7:40 ` Ingo Molnar
2018-03-09 8:37 ` Prakhya, Sai Praneeth
2018-03-09 9:56 ` Ard Biesheuvel
2018-03-08 8:00 ` [PATCH 08/12] x86/efi: Replace efi_pgd with efi_mm.pgd Ard Biesheuvel
2018-03-08 8:00 ` [PATCH 09/12] x86/efi: Use efi_switch_mm() rather than manually twiddling with %cr3 Ard Biesheuvel
2018-03-08 8:00 ` [PATCH 10/12] efi: reorder pr_notice() with add_device_randomness() call Ard Biesheuvel
2018-03-09 9:13 ` [tip:efi/core] efi: Reorder " tip-bot for Ard Biesheuvel
2018-03-08 8:00 ` [PATCH 11/12] efi/apple-properties: Use memremap() instead of ioremap() Ard Biesheuvel
2018-03-09 9:14 ` [tip:efi/core] " tip-bot for Andy Shevchenko
2018-03-08 8:00 ` [PATCH 12/12] efi: make const array 'apple' static Ard Biesheuvel
2018-03-08 11:05 ` Joe Perches
2018-03-09 7:43 ` Ard Biesheuvel
2018-03-09 7:44 ` Ard Biesheuvel
2018-03-09 9:37 ` Joe Perches
2018-03-09 7:47 ` Ingo Molnar
2018-03-09 7:52 ` Ard Biesheuvel
2018-03-09 8:04 ` Ingo Molnar
2018-03-09 8:07 ` Ard Biesheuvel
2018-03-09 8:19 ` Ard Biesheuvel
2018-03-09 8:31 ` Ingo Molnar
2018-03-09 8:29 ` Lukas Wunner
2018-03-09 8:33 ` Ard Biesheuvel
2018-03-09 9:16 ` [tip:efi/core] efi: Make " tip-bot for Colin Ian King
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