[PW_SID:968942] [v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts#476
[PW_SID:968942] [v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts#476linux-riscv-bot wants to merge 2 commits into
Conversation
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. 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 establish two separate functions - walk_page_range_debug() for this single usage, and walk_kernel_page_table_range() for general kernel page table walking. The walk_page_range_debug() function is currently used to traverse both userland and kernel mappings, so we maintain this and in the case of kernel mappings being traversed, we have walk_page_range_debug() invoke walk_kernel_page_table_range() internally. We additionally make walk_page_range_debug() internal to mm. Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Linux RISC-V bot <linux.riscv.bot@gmail.com>
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
|
Patch 1: "[v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts" |
7d18b70 to
0b44c19
Compare
PR for series 968942 applied to workflow__riscv__fixes
Name: [v3] mm/pagewalk: split walk_page_range_novma() into kernel/user parts
URL: https://patchwork.kernel.org/project/linux-riscv/list/?series=968942
Version: 3