Linux-RISC-V Archive on lore.kernel.org
 help / color / Atom feed
From: Vladimir Murzin <vladimir.murzin@arm.com>
To: Christoph Hellwig <hch@lst.de>, Palmer Dabbelt <palmer@sifive.com>
Cc: linux-mm@kvack.org, Damien Le Moal <damien.lemoal@wdc.com>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	uclinux-dev@uclinux.org
Subject: Re: [PATCH 03/17] mm/nommu: fix the MAP_UNINITIALIZED flag
Date: Tue, 11 Jun 2019 11:19:23 +0100
Message-ID: <c902f38f-071d-cc83-801d-04d600f5ec12@arm.com> (raw)
In-Reply-To: <20190610221621.10938-4-hch@lst.de>

On 6/10/19 11:16 PM, Christoph Hellwig wrote:
> We can't expose UAPI symbols differently based on CONFIG_ symbols, as
> userspace won't have them available.  Instead always define the flag,
> but only repsect it based on the config option.
           ^^^^^^^
           respect
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/xtensa/include/uapi/asm/mman.h    | 6 +-----
>  include/uapi/asm-generic/mman-common.h | 8 +++-----
>  mm/nommu.c                             | 4 +++-
>  3 files changed, 7 insertions(+), 11 deletions(-)

FWIW:

Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>

> 
> diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
> index be726062412b..ebbb48842190 100644
> --- a/arch/xtensa/include/uapi/asm/mman.h
> +++ b/arch/xtensa/include/uapi/asm/mman.h
> @@ -56,12 +56,8 @@
>  #define MAP_STACK	0x40000		/* give out an address that is best suited for process/thread stacks */
>  #define MAP_HUGETLB	0x80000		/* create a huge page mapping */
>  #define MAP_FIXED_NOREPLACE 0x100000	/* MAP_FIXED which doesn't unmap underlying mapping */
> -#ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED
> -# define MAP_UNINITIALIZED 0x4000000	/* For anonymous mmap, memory could be
> +#define MAP_UNINITIALIZED 0x4000000	/* For anonymous mmap, memory could be
>  					 * uninitialized */
> -#else
> -# define MAP_UNINITIALIZED 0x0		/* Don't support this flag */
> -#endif
>  
>  /*
>   * Flags for msync
> diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
> index abd238d0f7a4..cb556b430e71 100644
> --- a/include/uapi/asm-generic/mman-common.h
> +++ b/include/uapi/asm-generic/mman-common.h
> @@ -19,15 +19,13 @@
>  #define MAP_TYPE	0x0f		/* Mask for type of mapping */
>  #define MAP_FIXED	0x10		/* Interpret addr exactly */
>  #define MAP_ANONYMOUS	0x20		/* don't use a file */
> -#ifdef CONFIG_MMAP_ALLOW_UNINITIALIZED
> -# define MAP_UNINITIALIZED 0x4000000	/* For anonymous mmap, memory could be uninitialized */
> -#else
> -# define MAP_UNINITIALIZED 0x0		/* Don't support this flag */
> -#endif
>  
>  /* 0x0100 - 0x80000 flags are defined in asm-generic/mman.h */
>  #define MAP_FIXED_NOREPLACE	0x100000	/* MAP_FIXED which doesn't unmap underlying mapping */
>  
> +#define MAP_UNINITIALIZED 0x4000000	/* For anonymous mmap, memory could be
> +					 * uninitialized */
> +
>  /*
>   * Flags for mlock
>   */
> diff --git a/mm/nommu.c b/mm/nommu.c
> index d8c02fbe03b5..ec75a0dffd4f 100644
> --- a/mm/nommu.c
> +++ b/mm/nommu.c
> @@ -1349,7 +1349,9 @@ unsigned long do_mmap(struct file *file,
>  	add_nommu_region(region);
>  
>  	/* clear anonymous mappings that don't ask for uninitialized data */
> -	if (!vma->vm_file && !(flags & MAP_UNINITIALIZED))
> +	if (!vma->vm_file &&
> +	    (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) ||
> +	     !(flags & MAP_UNINITIALIZED)))
>  		memset((void *)region->vm_start, 0,
>  		       region->vm_end - region->vm_start);
>  
> 


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  reply index

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-10 22:16 RISC-V nommu support Christoph Hellwig
2019-06-10 22:16 ` [PATCH 01/17] mm: provide a print_vma_addr stub for !CONFIG_MMU Christoph Hellwig
2019-06-11 10:11   ` Vladimir Murzin
2019-06-10 22:16 ` [PATCH 02/17] mm: stub out all of swapops.h " Christoph Hellwig
2019-06-11 10:15   ` Vladimir Murzin
2019-06-11 14:18     ` Christoph Hellwig
2019-06-11 14:36       ` Vladimir Murzin
2019-06-14  9:48         ` Christoph Hellwig
2019-06-10 22:16 ` [PATCH 03/17] mm/nommu: fix the MAP_UNINITIALIZED flag Christoph Hellwig
2019-06-11 10:19   ` Vladimir Murzin [this message]
2019-06-10 22:16 ` [PATCH 04/17] irqchip/sifive-plic: set max threshold for ignored handlers Christoph Hellwig
2019-06-10 22:16 ` [PATCH 05/17] riscv: use CSR_SATP instead of the legacy sptbr name in switch_mm Christoph Hellwig
2019-06-10 22:16 ` [PATCH 06/17] riscv: clear the instruction cache and all registers when booting Christoph Hellwig
2019-06-10 22:16 ` [PATCH 07/17] riscv: refactor the IPI code Christoph Hellwig
2019-06-10 22:16 ` [PATCH 08/17] riscv: abstract out CSR names for supervisor vs machine mode Christoph Hellwig
2019-06-10 22:16 ` [PATCH 09/17] riscv: improve the default power off implementation Christoph Hellwig
2019-06-10 22:16 ` [PATCH 10/17] riscv: provide a flat entry loader Christoph Hellwig
2019-06-10 22:16 ` [PATCH 11/17] riscv: read hart ID from mhartid on boot Christoph Hellwig
2019-06-10 22:16 ` [PATCH 12/17] riscv: provide native clint access for M-mode Christoph Hellwig
2019-06-10 22:16 ` [PATCH 13/17] riscv: implement remote sfence.i natively " Christoph Hellwig
2019-06-10 22:16 ` [PATCH 14/17] riscv: poison SBI calls " Christoph Hellwig
2019-06-10 22:16 ` [PATCH 15/17] riscv: don't allow selecting SBI-based drivers " Christoph Hellwig
2019-06-10 22:16 ` [PATCH 16/17] riscv: use the correct interrupt levels " Christoph Hellwig
2019-06-10 22:16 ` [PATCH 17/17] riscv: add nommu support Christoph Hellwig
2019-06-11 10:32   ` Vladimir Murzin
2019-06-11 12:44   ` David Hildenbrand
2019-06-24  5:42 RISC-V nommu support v2 Christoph Hellwig
2019-06-24  5:42 ` [PATCH 03/17] mm/nommu: fix the MAP_UNINITIALIZED flag Christoph Hellwig

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=c902f38f-071d-cc83-801d-04d600f5ec12@arm.com \
    --to=vladimir.murzin@arm.com \
    --cc=damien.lemoal@wdc.com \
    --cc=hch@lst.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=palmer@sifive.com \
    --cc=uclinux-dev@uclinux.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-RISC-V Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-riscv/0 linux-riscv/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-riscv linux-riscv/ https://lore.kernel.org/linux-riscv \
		linux-riscv@lists.infradead.org infradead-linux-riscv@archiver.kernel.org
	public-inbox-index linux-riscv


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-riscv


AGPL code for this site: git clone https://public-inbox.org/ public-inbox