From: Kees Cook <keescook@chromium.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Michael Ellerman <mpe@ellerman.id.au>,
x86@kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 08/11] x86: make TASK_SIZE_MAX usable from assembly code
Date: Tue, 18 Aug 2020 12:44:49 -0700 [thread overview]
Message-ID: <202008181244.BBDA7DAB@keescook> (raw)
In-Reply-To: <20200817073212.830069-9-hch@lst.de>
On Mon, Aug 17, 2020 at 09:32:09AM +0200, Christoph Hellwig wrote:
> For 64-bit the only hing missing was a strategic _AC, and for 32-bit we
typo: thing
> need to use __PAGE_OFFSET instead of PAGE_OFFSET in the TASK_SIZE
> definition to escape the explicit unsigned long cast. This just works
> because __PAGE_OFFSET is defined using _AC itself and thus never needs
> the cast anyway.
Shouldn't this be folded into the prior patch so there's no bisection
problem?
-Kees
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> arch/x86/include/asm/page_32_types.h | 4 ++--
> arch/x86/include/asm/page_64_types.h | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
> index 26236925fb2c36..f462895a33e452 100644
> --- a/arch/x86/include/asm/page_32_types.h
> +++ b/arch/x86/include/asm/page_32_types.h
> @@ -44,8 +44,8 @@
> /*
> * User space process size: 3GB (default).
> */
> -#define IA32_PAGE_OFFSET PAGE_OFFSET
> -#define TASK_SIZE PAGE_OFFSET
> +#define IA32_PAGE_OFFSET __PAGE_OFFSET
> +#define TASK_SIZE __PAGE_OFFSET
> #define TASK_SIZE_LOW TASK_SIZE
> #define TASK_SIZE_MAX TASK_SIZE
> #define DEFAULT_MAP_WINDOW TASK_SIZE
> diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
> index 996595c9897e0a..838515daf87b36 100644
> --- a/arch/x86/include/asm/page_64_types.h
> +++ b/arch/x86/include/asm/page_64_types.h
> @@ -76,7 +76,7 @@
> *
> * With page table isolation enabled, we map the LDT in ... [stay tuned]
> */
> -#define TASK_SIZE_MAX ((1UL << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)
> +#define TASK_SIZE_MAX ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)
>
> #define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE)
>
> --
> 2.28.0
>
--
Kees Cook
next prev parent reply other threads:[~2020-08-18 19:46 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-17 7:32 remove the last set_fs() in common code, and remove it for x86 and powerpc Christoph Hellwig
2020-08-17 7:32 ` [PATCH 01/11] mem: remove duplicate ops for /dev/zero and /dev/null Christoph Hellwig
2020-08-18 19:33 ` Kees Cook
2020-08-17 7:32 ` [PATCH 02/11] fs: don't allow kernel reads and writes without iter ops Christoph Hellwig
2020-08-18 19:34 ` Kees Cook
2020-08-17 7:32 ` [PATCH 03/11] fs: don't allow splice read/write without explicit ops Christoph Hellwig
2020-08-18 19:39 ` Kees Cook
2020-08-18 19:54 ` Christoph Hellwig
2020-08-18 19:58 ` Kees Cook
2020-08-18 20:07 ` Christoph Hellwig
2020-08-17 7:32 ` [PATCH 04/11] uaccess: add infrastructure for kernel builds with set_fs() Christoph Hellwig
2020-08-18 19:40 ` Kees Cook
2020-08-17 7:32 ` [PATCH 05/11] test_bitmap: skip user bitmap tests for !CONFIG_SET_FS Christoph Hellwig
2020-08-17 7:50 ` Christophe Leroy
2020-08-17 7:52 ` Christoph Hellwig
2020-08-18 19:43 ` Kees Cook
2020-08-17 7:32 ` [PATCH 06/11] lkdtm: disable set_fs-based " Christoph Hellwig
2020-08-18 19:32 ` Kees Cook
2020-08-17 7:32 ` [PATCH 07/11] x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h Christoph Hellwig
2020-08-18 19:27 ` Kees Cook
2020-08-17 7:32 ` [PATCH 08/11] x86: make TASK_SIZE_MAX usable from assembly code Christoph Hellwig
2020-08-18 19:44 ` Kees Cook [this message]
2020-08-18 19:55 ` Christoph Hellwig
2020-08-18 19:59 ` Kees Cook
2020-08-18 20:00 ` Christoph Hellwig
2020-08-18 20:08 ` Kees Cook
2020-08-17 7:32 ` [PATCH 09/11] x86: remove address space overrides using set_fs() Christoph Hellwig
2020-08-17 8:23 ` David Laight
2020-08-27 9:37 ` 'Christoph Hellwig'
2020-08-18 19:46 ` Kees Cook
2020-08-17 7:32 ` [PATCH 10/11] powerpc: use non-set_fs based maccess routines Christoph Hellwig
2020-08-17 15:47 ` Christophe Leroy
2020-08-17 7:32 ` [PATCH 11/11] powerpc: remove address space overrides using set_fs() Christoph Hellwig
2020-08-17 7:39 ` remove the last set_fs() in common code, and remove it for x86 and powerpc Christoph Hellwig
2020-08-18 17:46 ` Christophe Leroy
2020-08-18 18:05 ` Christoph Hellwig
2020-08-18 18:23 ` Christophe Leroy
2020-08-19 7:16 ` Christophe Leroy
2020-08-19 7:22 ` iter and normal ops on /dev/zero & co, was " Christoph Hellwig
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