[PW_SID:968391] [RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts#469
[PW_SID:968391] [RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts#469linux-riscv-bot wants to merge 1 commit into
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The walk_page_range_novma() function is rather confusing - it supports two modes, one used often, the other used only for debugging. The first mode is the common case of traversal of kernel page tables, which is what nearly all callers use this for. Secondly it provides an unusual debugging interface that allows for the traversal of page tables in a userland range of memory even for that memory which is not described by a VMA. This is highly unusual and it is far from certain that such page tables should even exist, but perhaps this is precisely why it is useful as a debugging mechanism. As a result, this is utilised by ptdump only. Historically, things were reversed - ptdump was the only user, and other parts of the kernel evolved to use the kernel page table walking here. Since we have some complicated and confusing locking rules for the novma case, it makes sense to separate the two usages into their own functions. Doing this also provide self-documentation as to the intent of the caller - are they doing something rather unusual or are they simply doing a standard kernel page table walk? We therefore maintain walk_page_range_novma() for this single usage, and document the function as such. Note that ptdump uses the precise same function for kernel walking as a convenience, so we permit this but make it very explicit by having walk_page_range_novma() invoke walk_page_range_kernel() in this case. We introduce walk_page_range_kernel() for the far more common case of kernel page table traversal. While it would result in less churn to keep the function signature the same for the kernel version, it doesn't make sense to pass an mm_struct in the kernel case (it's always &init_mm), so we must modify the signature accordingly. Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Linux RISC-V bot <linux.riscv.bot@gmail.com>
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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Patch 1: "[RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
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PR for series 968391 applied to workflow__riscv__fixes
Name: [RESEND] mm/pagewalk: split walk_page_range_novma() into kernel/user parts
URL: https://patchwork.kernel.org/project/linux-riscv/list/?series=968391
Version: 1