kernel/arch/unicore32, branch linux-5.7.y

unicore32: do not evaluate compiler's library path when cleaning

2020-06-24T15:48:44Z

[ Upstream commit 081b4b54ff6c58be2ffcf09d42e5df8f031eacd0 ] Since commit a83e4ca26af8 ("kbuild: remove cc-option switch from -Wframe-larger-than="), 'make ARCH=unicore32 clean' emits error messages as follows: $ make ARCH=unicore32 clean gcc: error: missing argument to '-Wframe-larger-than=' gcc: error: missing argument to '-Wframe-larger-than=' We do not care compiler flags when cleaning. Use the '=' operator for lazy expansion because we do not use GNU_LIBC_A or GNU_LIBGCC_A when cleaning. Fixes: a83e4ca26af8 ("kbuild: remove cc-option switch from -Wframe-larger-than=") Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers Signed-off-by: Sasha Levin

mm/special: create generic fallbacks for pte_special() and pte_mkspecial()

2020-04-10T22:36:21Z

Currently there are many platforms that dont enable ARCH_HAS_PTE_SPECIAL but required to define quite similar fallback stubs for special page table entry helpers such as pte_special() and pte_mkspecial(), as they get build in generic MM without a config check. This creates two generic fallback stub definitions for these helpers, eliminating much code duplication. mips platform has a special case where pte_special() and pte_mkspecial() visibility is wider than what ARCH_HAS_PTE_SPECIAL enablement requires. This restricts those symbol visibility in order to avoid redefinitions which is now exposed through this new generic stubs and subsequent build failure. arm platform set_pte_at() definition needs to be moved into a C file just to prevent a build failure. [anshuman.khandual@arm.com: use defined(CONFIG_ARCH_HAS_PTE_SPECIAL) in mips per Thomas] Link: http://lkml.kernel.org/r/1583851924-21603-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Acked-by: Guo Ren [csky] Acked-by: Geert Uytterhoeven [m68k] Acked-by: Stafford Horne [openrisc] Acked-by: Helge Deller [parisc] Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Russell King Cc: Brian Cain Cc: Tony Luck Cc: Fenghua Yu Cc: Sam Creasey Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Greentime Hu Cc: Vincent Chen Cc: Ley Foon Tan Cc: Jonas Bonn Cc: Stefan Kristiansson Cc: "James E.J. Bottomley" Cc: "David S. Miller" Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: Guan Xuetao Cc: Chris Zankel Cc: Max Filippov Cc: Thomas Bogendoerfer Link: http://lkml.kernel.org/r/1583802551-15406-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds

mm/vma: introduce VM_ACCESS_FLAGS

2020-04-10T22:36:21Z

There are many places where all basic VMA access flags (read, write, exec) are initialized or checked against as a group. One such example is during page fault. Existing vma_is_accessible() wrapper already creates the notion of VMA accessibility as a group access permissions. Hence lets just create VM_ACCESS_FLAGS (VM_READ|VM_WRITE|VM_EXEC) which will not only reduce code duplication but also extend the VMA accessibility concept in general. Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Cc: Russell King Cc: Catalin Marinas Cc: Mark Salter Cc: Nick Hu Cc: Ley Foon Tan Cc: Michael Ellerman Cc: Heiko Carstens Cc: Yoshinori Sato Cc: Guan Xuetao Cc: Dave Hansen Cc: Thomas Gleixner Cc: Rob Springer Cc: Greg Kroah-Hartman Cc: Geert Uytterhoeven Link: http://lkml.kernel.org/r/1583391014-8170-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds

mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS

2020-04-10T22:36:21Z

There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros with standard VMA access flag combinations that are used frequently across many platforms. Apart from simplification, this reduces code duplication as well. Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Acked-by: Geert Uytterhoeven Cc: Richard Henderson Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Mark Salter Cc: Guo Ren Cc: Yoshinori Sato Cc: Brian Cain Cc: Tony Luck Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Ley Foon Tan Cc: Jonas Bonn Cc: "James E.J. Bottomley" Cc: Michael Ellerman Cc: Paul Walmsley Cc: Heiko Carstens Cc: Rich Felker Cc: "David S. Miller" Cc: Guan Xuetao Cc: Thomas Gleixner Cc: Jeff Dike Cc: Chris Zankel Link: http://lkml.kernel.org/r/1583391014-8170-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds

Merge tag 'backlight-next-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

2020-04-08T02:44:52Z

Pull backlight updates from Lee Jones: "Switch pwm_bl and corgi_lcd drivers to use GPIO descriptors" * tag 'backlight-next-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: backlight: corgi: Convert to use GPIO descriptors backlight: pwm_bl: Switch to full GPIO descriptor

Merge tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

2020-04-03T20:12:26Z

Pull SPDX updates from Greg KH: "Here are three SPDX patches for 5.7-rc1. One fixes up the SPDX tag for a single driver, while the other two go through the tree and add SPDX tags for all of the .gitignore files as needed. Nothing too complex, but you will get a merge conflict with your current tree, that should be trivial to handle (one file modified by two things, one file deleted.) All three of these have been in linux-next for a while, with no reported issues other than the merge conflict" * tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: ASoC: MT6660: make spdxcheck.py happy .gitignore: add SPDX License Identifier .gitignore: remove too obvious comments

mm: allow VM_FAULT_RETRY for multiple times

2020-04-02T16:35:30Z

The idea comes from a discussion between Linus and Andrea [1]. Before this patch we only allow a page fault to retry once. We achieved this by clearing the FAULT_FLAG_ALLOW_RETRY flag when doing handle_mm_fault() the second time. This was majorly used to avoid unexpected starvation of the system by looping over forever to handle the page fault on a single page. However that should hardly happen, and after all for each code path to return a VM_FAULT_RETRY we'll first wait for a condition (during which time we should possibly yield the cpu) to happen before VM_FAULT_RETRY is really returned. This patch removes the restriction by keeping the FAULT_FLAG_ALLOW_RETRY flag when we receive VM_FAULT_RETRY. It means that the page fault handler now can retry the page fault for multiple times if necessary without the need to generate another page fault event. Meanwhile we still keep the FAULT_FLAG_TRIED flag so page fault handler can still identify whether a page fault is the first attempt or not. Then we'll have these combinations of fault flags (only considering ALLOW_RETRY flag and TRIED flag): - ALLOW_RETRY and !TRIED: this means the page fault allows to retry, and this is the first try - ALLOW_RETRY and TRIED: this means the page fault allows to retry, and this is not the first try - !ALLOW_RETRY and !TRIED: this means the page fault does not allow to retry at all - !ALLOW_RETRY and TRIED: this is forbidden and should never be used In existing code we have multiple places that has taken special care of the first condition above by checking against (fault_flags & FAULT_FLAG_ALLOW_RETRY). This patch introduces a simple helper to detect the first retry of a page fault by checking against both (fault_flags & FAULT_FLAG_ALLOW_RETRY) and !(fault_flag & FAULT_FLAG_TRIED) because now even the 2nd try will have the ALLOW_RETRY set, then use that helper in all existing special paths. One example is in __lock_page_or_retry(), now we'll drop the mmap_sem only in the first attempt of page fault and we'll keep it in follow up retries, so old locking behavior will be retained. This will be a nice enhancement for current code [2] at the same time a supporting material for the future userfaultfd-writeprotect work, since in that work there will always be an explicit userfault writeprotect retry for protected pages, and if that cannot resolve the page fault (e.g., when userfaultfd-writeprotect is used in conjunction with swapped pages) then we'll possibly need a 3rd retry of the page fault. It might also benefit other potential users who will have similar requirement like userfault write-protection. GUP code is not touched yet and will be covered in follow up patch. Please read the thread below for more information. [1] https://lore.kernel.org/lkml/20171102193644.GB22686@redhat.com/ [2] https://lore.kernel.org/lkml/20181230154648.GB9832@redhat.com/ Suggested-by: Linus Torvalds Suggested-by: Andrea Arcangeli Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Tested-by: Brian Geffon Cc: Bobby Powers Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Link: http://lkml.kernel.org/r/20200220160246.9790-1-peterx@redhat.com Signed-off-by: Linus Torvalds

mm: introduce FAULT_FLAG_DEFAULT

2020-04-02T16:35:29Z

Although there're tons of arch-specific page fault handlers, most of them are still sharing the same initial value of the page fault flags. Say, merely all of the page fault handlers would allow the fault to be retried, and they also allow the fault to respond to SIGKILL. Let's define a default value for the fault flags to replace those initial page fault flags that were copied over. With this, it'll be far easier to introduce new fault flag that can be used by all the architectures instead of touching all the archs. Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Tested-by: Brian Geffon Reviewed-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Bobby Powers Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Link: http://lkml.kernel.org/r/20200220160238.9694-1-peterx@redhat.com Signed-off-by: Linus Torvalds

mm: introduce fault_signal_pending()

2020-04-02T16:35:29Z

For most architectures, we've got a quick path to detect fatal signal after a handle_mm_fault(). Introduce a helper for that quick path. It cleans the current codes a bit so we don't need to duplicate the same check across archs. More importantly, this will be an unified place that we handle the signal immediately right after an interrupted page fault, so it'll be much easier for us if we want to change the behavior of handling signals later on for all the archs. Note that currently only part of the archs are using this new helper, because some archs have their own way to handle signals. In the follow up patches, we'll try to apply this helper to all the rest of archs. Another note is that the "regs" parameter in the new helper is not used yet. It'll be used very soon. Now we kept it in this patch only to avoid touching all the archs again in the follow up patches. [peterx@redhat.com: fix sparse warnings] Link: http://lkml.kernel.org/r/20200311145921.GD479302@xz-x1 Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Tested-by: Brian Geffon Cc: Andrea Arcangeli Cc: Bobby Powers Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Link: http://lkml.kernel.org/r/20200220155353.8676-4-peterx@redhat.com Signed-off-by: Linus Torvalds

asm-generic: make more kernel-space headers mandatory

2020-04-02T16:35:25Z

Change a header to mandatory-y if both of the following are met: [1] At least one architecture (except um) specifies it as generic-y in arch/*/include/asm/Kbuild [2] Every architecture (except um) either has its own implementation (arch/*/include/asm/*.h) or specifies it as generic-y in arch/*/include/asm/Kbuild This commit was generated by the following shell script. ----------------------------------->8----------------------------------- arches=$(cd arch; ls -1 | sed -e '/Kconfig/d' -e '/um/d') tmpfile=$(mktemp) grep "^mandatory-y +=" include/asm-generic/Kbuild > $tmpfile find arch -path 'arch/*/include/asm/Kbuild' | xargs sed -n 's/^generic-y += $.*$/\1/p' | sort -u | while read header do mandatory=yes for arch in $arches do if ! grep -q "generic-y += $header" arch/$arch/include/asm/Kbuild && ! [ -f arch/$arch/include/asm/$header ]; then mandatory=no break fi done if [ "$mandatory" = yes ]; then echo "mandatory-y += $header" >> $tmpfile for arch in $arches do sed -i "/generic-y += $header/d" arch/$arch/include/asm/Kbuild done fi done sed -i '/^mandatory-y +=/d' include/asm-generic/Kbuild LANG=C sort $tmpfile >> include/asm-generic/Kbuild ----------------------------------->8----------------------------------- One obvious benefit is the diff stat: 25 files changed, 52 insertions(+), 557 deletions(-) It is tedious to list generic-y for each arch that needs it. So, mandatory-y works like a fallback default (by just wrapping asm-generic one) when arch does not have a specific header implementation. See the following commits: def3f7cefe4e81c296090e1722a76551142c227c a1b39bae16a62ce4aae02d958224f19316d98b24 It is tedious to convert headers one by one, so I processed by a shell script. Signed-off-by: Masahiro Yamada Signed-off-by: Andrew Morton Cc: Michal Simek Cc: Christoph Hellwig Cc: Arnd Bergmann Link: http://lkml.kernel.org/r/20200210175452.5030-1-masahiroy@kernel.org Signed-off-by: Linus Torvalds