From: Vladimir Murzin <vladimir.murzin@arm.com>
To: Christoph Hellwig <hch@lst.de>, Palmer Dabbelt <palmer@sifive.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>,
linux-riscv@lists.infradead.org, uclinux-dev@uclinux.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 03/17] mm/nommu: fix the MAP_UNINITIALIZED flag
Date: Tue, 11 Jun 2019 11:19:23 +0100 [thread overview]
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);
>
>
next prev parent reply other threads:[~2019-06-11 10:19 UTC|newest]
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
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