kernel/arch/powerpc/mm/mmap.c, branch linux-6.2.y

powerpc/mm: Convert to default topdown mmap layout

2022-05-05T12:11:58Z

Select CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT and remove arch/powerpc/mm/mmap.c This change reuses the generic framework added by commit 67f3977f805b ("arm64, mm: move generic mmap layout functions to mm") without any functional change. Comparison between powerpc implementation and the generic one: - mmap_is_legacy() is identical. - arch_mmap_rnd() does exactly the same allthough it's written slightly differently. - MIN_GAP and MAX_GAP are identical. - mmap_base() does the same but uses STACK_RND_MASK which provides the same values as stack_maxrandom_size(). - arch_pick_mmap_layout() is identical. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/518f9def87d3c889d5958103e7463cf45a2f673d.1649523076.git.christophe.leroy@csgroup.eu

powerpc/mm: Enable full randomisation of memory mappings

2022-05-05T12:11:58Z

Do like most other architectures and provide randomisation also to "legacy" memory mappings, by adding the random factor to mm->mmap_base in arch_pick_mmap_layout(). See commit 8b8addf891de ("x86/mm/32: Enable full randomization on i386 and X86_32") for all explanations and benefits of that mmap randomisation. At the moment, slice_find_area_bottomup() doesn't use mm->mmap_base but uses the fixed TASK_UNMAPPED_BASE instead. slice_find_area_bottomup() being used as a fallback to slice_find_area_topdown(), it can't use mm->mmap_base directly. Instead of always using TASK_UNMAPPED_BASE as base address, leave it to the caller. When called from slice_find_area_topdown() TASK_UNMAPPED_BASE is used. Otherwise mm->mmap_base is used. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/417fb10dde828534c73a03138b49621d74f4e5be.1649523076.git.christophe.leroy@csgroup.eu

powerpc/mm: Move get_unmapped_area functions to slice.c

2022-05-05T12:11:58Z

hugetlb_get_unmapped_area() is now identical to the generic version if only RADIX is enabled, so move it to slice.c and let it fallback on the generic one when HASH MMU is not compiled in. Do the same with arch_get_unmapped_area() and arch_get_unmapped_area_topdown(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b5d9c124e82889e0cb115c150915a0c0d84eb960.1649523076.git.christophe.leroy@csgroup.eu

powerpc/mm: Use generic_get_unmapped_area() and call it from arch_get_unmapped_area()

2022-05-05T12:11:57Z

Use the generic version of arch_get_unmapped_area() which is now available at all time instead of its copy radix__arch_get_unmapped_area() To allow that for PPC64, add arch_get_mmap_base() and arch_get_mmap_end() macros. Instead of setting mm->get_unmapped_area() to either arch_get_unmapped_area() or generic_get_unmapped_area(), always set it to arch_get_unmapped_area() and call generic_get_unmapped_area() from there when radix is enabled. Do the same with radix__arch_get_unmapped_area_topdown() Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/393be1fa386446443682fdb74544d733f68ef3bb.1649523076.git.christophe.leroy@csgroup.eu

powerpc/mm: Remove CONFIG_PPC_MM_SLICES

2022-05-05T12:11:57Z

CONFIG_PPC_MM_SLICES is always selected by hash book3s/64. CONFIG_PPC_MM_SLICES is never selected by other platforms. Remove it. Signed-off-by: Christophe Leroy Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/dc2cdc204de8978574bf7c02329b6cfc4db0bce7.1649523076.git.christophe.leroy@csgroup.eu

powerpc/64s: Always define arch unmapped area calls

2021-12-09T11:40:24Z

To avoid any functional changes to radix paths when building with hash MMU support disabled (and CONFIG_PPC_MM_SLICES=n), always define the arch get_unmapped_area calls on 64s platforms. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20211201144153.2456614-16-npiggin@gmail.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

exec: pass stack rlimit into mm layout functions

2018-04-11T17:28:37Z

Patch series "exec: Pin stack limit during exec". Attempts to solve problems with the stack limit changing during exec continue to be frustrated[1][2]. In addition to the specific issues around the Stack Clash family of flaws, Andy Lutomirski pointed out[3] other places during exec where the stack limit is used and is assumed to be unchanging. Given the many places it gets used and the fact that it can be manipulated/raced via setrlimit() and prlimit(), I think the only way to handle this is to move away from the "current" view of the stack limit and instead attach it to the bprm, and plumb this down into the functions that need to know the stack limits. This series implements the approach. [1] 04e35f4495dd ("exec: avoid RLIMIT_STACK races with prlimit()") [2] 779f4e1c6c7c ("Revert "exec: avoid RLIMIT_STACK races with prlimit()"") [3] to security@kernel.org, "Subject: existing rlimit races?" This patch (of 3): Since it is possible that the stack rlimit can change externally during exec (either via another thread calling setrlimit() or another process calling prlimit()), provide a way to pass the rlimit down into the per-architecture mm layout functions so that the rlimit can stay in the bprm structure instead of sitting in the signal structure until exec is finalized. Link: http://lkml.kernel.org/r/1518638796-20819-2-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook Cc: Michal Hocko Cc: Ben Hutchings Cc: Willy Tarreau Cc: Hugh Dickins Cc: Oleg Nesterov Cc: "Jason A. Donenfeld" Cc: Rik van Riel Cc: Laura Abbott Cc: Greg KH Cc: Andy Lutomirski Cc: Ben Hutchings Cc: Brad Spengler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc/64s: mm_context.addr_limit is only used on hash

2017-11-13T12:35:43Z

Radix keeps no meaningful state in addr_limit, so remove it from radix code and rename to slb_addr_limit to make it clear it applies to hash only. Signed-off-by: Nicholas Piggin Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman

powerpc/64s/radix: Fix 128TB-512TB virtual address boundary case allocation

2017-11-13T12:35:29Z

Radix VA space allocations test addresses against mm->task_size which is 512TB, even in cases where the intention is to limit allocation to below 128TB. This results in mmap with a hint address below 128TB but address + length above 128TB succeeding when it should fail (as hash does after the previous patch). Set the high address limit to be considered up front, and base subsequent allocation checks on that consistently. Fixes: f4ea6dcb08ea ("powerpc/mm: Enable mappings above 128TB") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Nicholas Piggin Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman