From: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, leif.lindholm-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, catalin.marinas-5wv7dgnIgG8@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org, dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, msalter-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Subject: [PATCH 7/8] arm64: use 'physmem' memblock to improve CONFIG_STRICT_DEVMEM handling Date: Mon, 22 Dec 2014 19:08:41 +0000 [thread overview] Message-ID: <1419275322-29811-8-git-send-email-ard.biesheuvel@linaro.org> (raw) In-Reply-To: <1419275322-29811-1-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> The 'physmem' memblock table allows us to classify memory as RAM even if it is not covered by the ordinary 'memory' memblock table. Under CONFIG_STRICT_DEVMEM, we can use this to: - allow read-only access to parts of RAM that are not considered memory by the kernel, this is mainly intended for exposing UEFI configuration tables such as SMBIOS to userland; - avoid using non-cached mappings for those parts of RAM, as it may result in mismatched attributes. Signed-off-by: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> --- arch/arm64/Kconfig | 1 + arch/arm64/mm/mmap.c | 2 +- arch/arm64/mm/mmu.c | 15 ++++++++++++++- 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b1f9a20a3677..86902f8d8e36 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -60,6 +60,7 @@ config ARM64 select HAVE_GENERIC_DMA_COHERENT select HAVE_HW_BREAKPOINT if PERF_EVENTS select HAVE_MEMBLOCK + select HAVE_MEMBLOCK_PHYS_MAP select HAVE_PATA_PLATFORM select HAVE_PERF_EVENTS select HAVE_PERF_REGS diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index 54922d1275b8..9f558ab41f39 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -126,7 +126,7 @@ int devmem_is_allowed(unsigned long pfn) { if (iomem_is_exclusive(pfn << PAGE_SHIFT)) return 0; - if (!page_is_ram(pfn)) + if (!pfn_valid(pfn)) return 1; return 0; } diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 328638548871..083be3de1a87 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -122,7 +122,7 @@ early_param("cachepolicy", early_cachepolicy); pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size, pgprot_t vma_prot) { - if (!pfn_valid(pfn)) + if (!memblock_is_physmem(PFN_PHYS(pfn))) return pgprot_noncached(vma_prot); else if (file->f_flags & O_SYNC) return pgprot_writecombine(vma_prot); @@ -130,6 +130,19 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, } EXPORT_SYMBOL(phys_mem_access_prot); +/* + * This definition of phys_mem_access_prot_allowed() overrides + * the __weak definition in drivers/char/mem.c + */ +int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t *prot) +{ + /* Disallow read-write access to system RAM */ + if (memblock_is_physmem(PFN_PHYS(pfn)) && pgprot_val(*prot) & PTE_WRITE) + return 0; + return 1; +} + static void __init *early_alloc(unsigned long sz) { void *ptr = __va(memblock_alloc(sz, sz)); -- 1.8.3.2
WARNING: multiple messages have this Message-ID (diff)
From: ard.biesheuvel@linaro.org (Ard Biesheuvel) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 7/8] arm64: use 'physmem' memblock to improve CONFIG_STRICT_DEVMEM handling Date: Mon, 22 Dec 2014 19:08:41 +0000 [thread overview] Message-ID: <1419275322-29811-8-git-send-email-ard.biesheuvel@linaro.org> (raw) In-Reply-To: <1419275322-29811-1-git-send-email-ard.biesheuvel@linaro.org> The 'physmem' memblock table allows us to classify memory as RAM even if it is not covered by the ordinary 'memory' memblock table. Under CONFIG_STRICT_DEVMEM, we can use this to: - allow read-only access to parts of RAM that are not considered memory by the kernel, this is mainly intended for exposing UEFI configuration tables such as SMBIOS to userland; - avoid using non-cached mappings for those parts of RAM, as it may result in mismatched attributes. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/Kconfig | 1 + arch/arm64/mm/mmap.c | 2 +- arch/arm64/mm/mmu.c | 15 ++++++++++++++- 3 files changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b1f9a20a3677..86902f8d8e36 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -60,6 +60,7 @@ config ARM64 select HAVE_GENERIC_DMA_COHERENT select HAVE_HW_BREAKPOINT if PERF_EVENTS select HAVE_MEMBLOCK + select HAVE_MEMBLOCK_PHYS_MAP select HAVE_PATA_PLATFORM select HAVE_PERF_EVENTS select HAVE_PERF_REGS diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index 54922d1275b8..9f558ab41f39 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -126,7 +126,7 @@ int devmem_is_allowed(unsigned long pfn) { if (iomem_is_exclusive(pfn << PAGE_SHIFT)) return 0; - if (!page_is_ram(pfn)) + if (!pfn_valid(pfn)) return 1; return 0; } diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 328638548871..083be3de1a87 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -122,7 +122,7 @@ early_param("cachepolicy", early_cachepolicy); pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size, pgprot_t vma_prot) { - if (!pfn_valid(pfn)) + if (!memblock_is_physmem(PFN_PHYS(pfn))) return pgprot_noncached(vma_prot); else if (file->f_flags & O_SYNC) return pgprot_writecombine(vma_prot); @@ -130,6 +130,19 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, } EXPORT_SYMBOL(phys_mem_access_prot); +/* + * This definition of phys_mem_access_prot_allowed() overrides + * the __weak definition in drivers/char/mem.c + */ +int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t *prot) +{ + /* Disallow read-write access to system RAM */ + if (memblock_is_physmem(PFN_PHYS(pfn)) && pgprot_val(*prot) & PTE_WRITE) + return 0; + return 1; +} + static void __init *early_alloc(unsigned long sz) { void *ptr = __va(memblock_alloc(sz, sz)); -- 1.8.3.2
next prev parent reply other threads:[~2014-12-22 19:08 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-12-22 19:08 [PATCH 0/8] arm64: improved memory map handling for /dev/mem, ACPI etc Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel [not found] ` <1419275322-29811-1-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2014-12-22 19:08 ` [PATCH 1/8] arm64/efi: use UEFI memory map unconditionally if available Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel [not found] ` <1419275322-29811-2-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2015-01-06 9:04 ` Matt Fleming 2015-01-06 9:04 ` Matt Fleming [not found] ` <20150106090407.GF3163-HNK1S37rvNbeXh+fF434Mdi2O/JbrIOy@public.gmane.org> 2015-01-07 11:48 ` Ard Biesheuvel 2015-01-07 11:48 ` Ard Biesheuvel [not found] ` <CAKv+Gu_q5wFhjb8M7VptVtHfm5vfp6_YiqN_XoTs9qV5=8OOdg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2015-01-12 10:46 ` Matt Fleming 2015-01-12 10:46 ` Matt Fleming 2015-01-09 15:41 ` Will Deacon 2015-01-09 15:41 ` Will Deacon 2014-12-22 19:08 ` [PATCH 2/8] arm64/efi: register UEFI reserved regions as iomem resources Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel [not found] ` <1419275322-29811-3-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2015-01-06 9:13 ` Matt Fleming 2015-01-06 9:13 ` Matt Fleming [not found] ` <20150106091322.GG3163-HNK1S37rvNbeXh+fF434Mdi2O/JbrIOy@public.gmane.org> 2015-01-07 11:53 ` Ard Biesheuvel 2015-01-07 11:53 ` Ard Biesheuvel 2014-12-22 19:08 ` [PATCH 3/8] memblock: add physmem to memblock_dump_all() output Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel 2015-01-06 9:15 ` Matt Fleming 2015-01-06 9:15 ` Matt Fleming 2015-01-06 9:15 ` Matt Fleming 2014-12-22 19:08 ` [PATCH 4/8] memblock: introduce memblock_add_phys() and memblock_is_physmem() Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel 2015-01-06 9:19 ` Matt Fleming 2015-01-06 9:19 ` Matt Fleming 2015-01-06 9:19 ` Matt Fleming 2014-12-22 19:08 ` [PATCH 5/8] of: fdt: register physmem in early_init_dt_scan_memory() Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel 2014-12-22 19:08 ` [PATCH 6/8] arm64/efi: register physmem in reserve_regions() Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel [this message] 2014-12-22 19:08 ` [PATCH 7/8] arm64: use 'physmem' memblock to improve CONFIG_STRICT_DEVMEM handling Ard Biesheuvel [not found] ` <1419275322-29811-8-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2015-01-09 15:38 ` Will Deacon 2015-01-09 15:38 ` Will Deacon 2014-12-22 19:08 ` [PATCH 8/8] arm64/efi: memblock_remove rather than _reserve UEFI reserved RAM Ard Biesheuvel 2014-12-22 19:08 ` Ard Biesheuvel 2014-12-26 9:35 ` [PATCH 0/8] arm64: improved memory map handling for /dev/mem, ACPI etc Dave Young 2014-12-26 9:35 ` Dave Young [not found] ` <20141226093528.GA26133-4/PLUo9XfK/1wF9wiOj0lkEOCMrvLtNR@public.gmane.org> 2014-12-29 9:22 ` Ard Biesheuvel 2014-12-29 9:22 ` Ard Biesheuvel [not found] ` <CAKv+Gu_1VCJK7y5U9H-mhjjN6AFW8+SGvbKUZfuzx6qGEpVg0A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2014-12-30 9:25 ` Dave Young 2014-12-30 9:25 ` Dave Young [not found] ` <20141230092514.GF2457-4/PLUo9XfK/1wF9wiOj0lkEOCMrvLtNR@public.gmane.org> 2014-12-30 13:21 ` Ard Biesheuvel 2014-12-30 13:21 ` Ard Biesheuvel [not found] ` <CAKv+Gu_Ou6Fv7-AUcpbUJAijwEJ8=PCB1mQU3mCfctLFAMhu_w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2015-01-04 8:19 ` Dave Young 2015-01-04 8:19 ` Dave Young [not found] ` <20150104081905.GA6231-4/PLUo9XfK/1wF9wiOj0lkEOCMrvLtNR@public.gmane.org> 2015-01-05 9:18 ` Ard Biesheuvel 2015-01-05 9:18 ` Ard Biesheuvel [not found] ` <CAKv+Gu-P7AeMNveZMe814FgrEr_z26vaYKWa=borKoPSc76Y6g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2015-01-06 8:16 ` Dave Young 2015-01-06 8:16 ` Dave Young [not found] ` <20150106081635.GE2113-4/PLUo9XfK/1wF9wiOj0lkEOCMrvLtNR@public.gmane.org> 2015-01-07 11:41 ` Ard Biesheuvel 2015-01-07 11:41 ` Ard Biesheuvel [not found] ` <CAKv+Gu9DQLZnvNyF0qdk5jSH6=NvdsKYTX+E46U=kGRzCEfwHg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2015-01-08 1:29 ` Dave Young 2015-01-08 1:29 ` Dave Young
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