Re: [PATCH RFC v2 0/4] mm: Introduce MAP_BELOW_HINT

Hi Liam, On 21/10/2024 20:48, Liam R. Howlett wrote: > * Steven Price [241021 09:23]: >> On 09/09/2024 10:46, Kirill A. Shutemov wrote: >>> On Thu, Sep 05, 2024 at 10:26:52AM -0700, Charlie Jenkins wrote: On Thu, Sep 05, 2024 at 09:47:47AM +0300, Kirill A. Shutemov wrote: > On Thu, Aug 2

[PATCH v7 0/8] x86/module: use large ROX pages for text allocations

From: "Mike Rapoport (Microsoft)" Hi, This is an updated version of execmem ROX caches. v6: https://lore.kernel.org/all/20241016122424.1655560-1-r...@kernel.org * Fixed handling of alternatives for fineibt (kbuild bot) * Restored usage of text_poke_early for ftrace boot time initialization (Ste

[PATCH v7 4/8] module: prepare to handle ROX allocations for text

From: "Mike Rapoport (Microsoft)" In order to support ROX allocations for module text, it is necessary to handle modifications to the code, such as relocations and alternatives patching, without write access to that memory. One option is to use text patching, but this would make module loading e

[PATCH v7 1/8] mm: vmalloc: group declarations depending on CONFIG_MMU together

From: "Mike Rapoport (Microsoft)" There are a couple of declarations that depend on CONFIG_MMU in include/linux/vmalloc.h spread all over the file. Group them all together to improve code readability. No functional changes. Signed-off-by: Mike Rapoport (Microsoft) Reviewed-by: Christoph Hellw

[PATCH v7 2/8] mm: vmalloc: don't account for number of nodes for HUGE_VMAP allocations

From: "Mike Rapoport (Microsoft)" vmalloc allocations with VM_ALLOW_HUGE_VMAP that do not explicitly specify node ID will use huge pages only if size_per_node is larger than a huge page. Still the actual allocated memory is not distributed between nodes and there is no advantage in such approach.

[PATCH v7 3/8] asm-generic: introduce text-patching.h

From: "Mike Rapoport (Microsoft)" Several architectures support text patching, but they name the header files that declare patching functions differently. Make all such headers consistently named text-patching.h and add an empty header in asm-generic for architectures that do not support text pa

[PATCH v7 6/8] x86/module: prepare module loading for ROX allocations of text

From: "Mike Rapoport (Microsoft)" When module text memory will be allocated with ROX permissions, the memory at the actual address where the module will live will contain invalid instructions and there will be a writable copy that contains the actual module code. Update relocations and alternati

[PATCH v7 7/8] execmem: add support for cache of large ROX pages

From: "Mike Rapoport (Microsoft)" Using large pages to map text areas reduces iTLB pressure and improves performance. Extend execmem_alloc() with an ability to use huge pages with ROX permissions as a cache for smaller allocations. To populate the cache, a writable large page is allocated from

[PATCH v7 5/8] arch: introduce set_direct_map_valid_noflush()

From: "Mike Rapoport (Microsoft)" Add an API that will allow updates of the direct/linear map for a set of physically contiguous pages. It will be used in the following patches. Signed-off-by: Mike Rapoport (Microsoft) Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain Tested-by: k

Re: [PATCH RFC v2 0/4] mm: Introduce MAP_BELOW_HINT

* Steven Price [241023 05:31]: > >> * Box64 seems to have a custom allocator based on reading > >> /proc/self/maps to allocate a block of VA space with a low enough > >> address [1] > >> > >> * PHP has code reading /proc/self/maps - I think this is to find a > >> segment which i

[PATCH v7 8/8] x86/module: enable ROX caches for module text on 64 bit

From: "Mike Rapoport (Microsoft)" Enable execmem's cache of PMD_SIZE'ed pages mapped as ROX for module text allocations on 64 bit. Signed-off-by: Mike Rapoport (Microsoft) Reviewed-by: Luis Chamberlain Tested-by: kdevops --- arch/x86/Kconfig | 1 + arch/x86/mm/init.c | 37