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2019-06-03sh: no need to check return value of debugfs_create functionsGreg Kroah-Hartman4-47/+13
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: <linux-sh@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 211Thomas Gleixner9-18/+9
Based on 1 normalized pattern(s): released under the terms of the gnu gpl v2 0 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 9 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171439.076212120@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-29signal: Remove the task parameter from force_sig_faultEric W. Biederman1-1/+1
As synchronous exceptions really only make sense against the current task (otherwise how are you synchronous) remove the task parameter from from force_sig_fault to make it explicit that is what is going on. The two known exceptions that deliver a synchronous exception to a stopped ptraced task have already been changed to force_sig_fault_to_task. The callers have been changed with the following emacs regular expression (with obvious variations on the architectures that take more arguments) to avoid typos: force_sig_fault[(]\([^,]+\)[,]\([^,]+\)[,]\([^,]+\)[,]\W+current[)] -> force_sig_fault(\1,\2,\3) Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-05-29signal/sh: Remove tsk parameter from force_sig_info_faultEric W. Biederman1-7/+4
The force_sig_info_fault function is always called with tsk == current. Make that explicit by removing the tsk parameter. This also makes it clear that the sh force_sig_info_fault passes current into force_sig_fault. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-15treewide: replace #include <asm/sizes.h> with #include <linux/sizes.h>Masahiro Yamada3-3/+3
Since commit dccd2304cc90 ("ARM: 7430/1: sizes.h: move from asm-generic to <linux/sizes.h>"), <asm/sizes.h> and <asm-generic/sizes.h> are just wrappers of <linux/sizes.h>. This commit replaces all <asm/sizes.h> and <asm-generic/sizes.h> to prepare for the removal. Link: http://lkml.kernel.org/r/1553267665-27228-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14mm/memory_hotplug: make __remove_pages() and arch_remove_memory() never failDavid Hildenbrand1-8/+3
All callers of arch_remove_memory() ignore errors. And we should really try to remove any errors from the memory removal path. No more errors are reported from __remove_pages(). BUG() in s390x code in case arch_remove_memory() is triggered. We may implement that properly later. WARN in case powerpc code failed to remove the section mapping, which is better than ignoring the error completely right now. Link: http://lkml.kernel.org/r/20190409100148.24703-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Stefan Agner <stefan@agner.ch> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Arun KS <arunks@codeaurora.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Rob Herring <robh@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Qian Cai <cai@lca.pw> Cc: Mathieu Malaterre <malat@debian.org> Cc: Andrew Banman <andrew.banman@hpe.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mike Travis <mike.travis@hpe.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14mm, memory_hotplug: provide a more generic restrictions for memory hotplugMichal Hocko1-3/+3
arch_add_memory, __add_pages take a want_memblock which controls whether the newly added memory should get the sysfs memblock user API (e.g. ZONE_DEVICE users do not want/need this interface). Some callers even want to control where do we allocate the memmap from by configuring altmap. Add a more generic hotplug context for arch_add_memory and __add_pages. struct mhp_restrictions contains flags which contains additional features to be enabled by the memory hotplug (MHP_MEMBLOCK_API currently) and altmap for alternative memmap allocator. This patch shouldn't introduce any functional change. [akpm@linux-foundation.org: build fix] Link: http://lkml.kernel.org/r/20190408082633.2864-3-osalvador@suse.de Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14init: provide a generic free_initmem implementationMike Rapoport1-5/+0
Patch series "provide a generic free_initmem implementation", v2. Many architectures implement free_initmem() in exactly the same or very similar way: they wrap the call to free_initmem_default() with sometimes different 'poison' parameter. These patches switch those architectures to use a generic implementation that does free_initmem_default(POISON_FREE_INITMEM). This was inspired by Christoph's patches for free_initrd_mem [1] and I shamelessly copied changelog entries from his patches :) [1] https://lore.kernel.org/lkml/20190213174621.29297-1-hch@lst.de/ This patch (of 2): For most architectures free_initmem just a wrapper for the same free_initmem_default(-1) call. Provide that as a generic implementation marked __weak. Link: http://lkml.kernel.org/r/1550515285-17446-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14initramfs: provide a generic free_initrd_mem implementationChristoph Hellwig1-7/+0
For most architectures free_initrd_mem just expands to the same free_reserved_area call. Provide that as a generic implementation marked __weak. Link: http://lkml.kernel.org/r/20190213174621.29297-8-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Steven Price <steven.price@arm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14mm/gup: change GUP fast to use flags rather than a write 'bool'Ira Weiny1-5/+6
To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12memblock: drop memblock_alloc_*_nopanic() variantsMike Rapoport1-1/+1
As all the memblock allocation functions return NULL in case of error rather than panic(), the duplicates with _nopanic suffix can be removed. Link: http://lkml.kernel.org/r/1548057848-15136-22-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Petr Mladek <pmladek@suse.com> [printk] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Christoph Hellwig <hch@lst.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dennis Zhou <dennis@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> [c-sky] Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Juergen Gross <jgross@suse.com> [Xen] Cc: Mark Salter <msalter@redhat.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12treewide: add checks for the return value of memblock_alloc*()Mike Rapoport2-0/+10
Add check for the return value of memblock_alloc*() functions and call panic() in case of error. The panic message repeats the one used by panicing memblock allocators with adjustment of parameters to include only relevant ones. The replacement was mostly automated with semantic patches like the one below with manual massaging of format strings. @@ expression ptr, size, align; @@ ptr = memblock_alloc(size, align); + if (!ptr) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, size, align); [anders.roxell@linaro.org: use '%pa' with 'phys_addr_t' type] Link: http://lkml.kernel.org/r/20190131161046.21886-1-anders.roxell@linaro.org [rppt@linux.ibm.com: fix format strings for panics after memblock_alloc] Link: http://lkml.kernel.org/r/1548950940-15145-1-git-send-email-rppt@linux.ibm.com [rppt@linux.ibm.com: don't panic if the allocation in sparse_buffer_init fails] Link: http://lkml.kernel.org/r/20190131074018.GD28876@rapoport-lnx [akpm@linux-foundation.org: fix xtensa printk warning] Link: http://lkml.kernel.org/r/1548057848-15136-20-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Reviewed-by: Guo Ren <ren_guo@c-sky.com> [c-sky] Acked-by: Paul Burton <paul.burton@mips.com> [MIPS] Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390] Reviewed-by: Juergen Gross <jgross@suse.com> [Xen] Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Christoph Hellwig <hch@lst.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dennis Zhou <dennis@kernel.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Mark Salter <msalter@redhat.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-08sh: prefer memblock APIs returning virtual addressMike Rapoport2-16/+7
Rather than use the memblock_alloc_base that returns a physical address and then convert this address to the virtual one, use appropriate memblock function that returns a virtual address. There is a small functional change in the allocation of then NODE_DATA(). Instead of panicing if the local allocation failed, the non-local allocation attempt will be made. Link: http://lkml.kernel.org/r/1546248566-14910-4-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <michal.simek@xilinx.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04Remove 'type' argument from access_ok() functionLinus Torvalds1-2/+1
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28mm, memory_hotplug: add nid parameter to arch_remove_memoryOscar Salvador1-1/+1
Patch series "Do not touch pages in hot-remove path", v2. This patchset aims for two things: 1) A better definition about offline and hot-remove stage 2) Solving bugs where we can access non-initialized pages during hot-remove operations [2] [3]. This is achieved by moving all page/zone handling to the offline stage, so we do not need to access pages when hot-removing memory. [1] https://patchwork.kernel.org/cover/10691415/ [2] https://patchwork.kernel.org/patch/10547445/ [3] https://www.spinics.net/lists/linux-mm/msg161316.html This patch (of 5): This is a preparation for the following-up patches. The idea of passing the nid is that it will allow us to get rid of the zone parameter afterwards. Link: http://lkml.kernel.org/r/20181127162005.15833-2-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31mm: remove include/linux/bootmem.hMike Rapoport2-3/+2
Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include <linux/memblock.h> @@ @@ - #include <linux/bootmem.h> + #include <linux/memblock.h> [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31memblock: rename free_all_bootmem to memblock_free_allMike Rapoport1-1/+1
The conversion is done using sed -i 's@free_all_bootmem@memblock_free_all@' \ $(git grep -l free_all_bootmem) Link: http://lkml.kernel.org/r/1536927045-23536-26-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31memblock: replace alloc_bootmem_pages with memblock_allocMike Rapoport1-2/+2
The alloc_bootmem_pages() function allocates PAGE_SIZE aligned memory. memblock_alloc() with alignment set to PAGE_SIZE does exactly the same thing. The conversion is done using the following semantic patch: @@ expression e; @@ - alloc_bootmem_pages(e) + memblock_alloc(e, PAGE_SIZE) Link: http://lkml.kernel.org/r/1536927045-23536-20-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-18mm: convert return type of handle_mm_fault() caller to vm_fault_tSouptick Joarder1-2/+2
Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t") In this patch all the caller of handle_mm_fault() are changed to return vm_fault_t type. Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Tony Luck <tony.luck@intel.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: James Hogan <jhogan@kernel.org> Cc: Ley Foon Tan <lftan@altera.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: David S. Miller <davem@davemloft.net> Cc: Richard Weinberger <richard@nod.at> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-15Merge tag 'kconfig-v4.19-2' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kconfig consolidation from Masahiro Yamada: "Consolidation of Kconfig files by Christoph Hellwig. Move the source statements of arch-independent Kconfig files instead of duplicating the includes in every arch/$(SRCARCH)/Kconfig" * tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: add a Memory Management options" menu kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt kconfig: use a menu in arch/Kconfig to reduce clutter kconfig: include kernel/Kconfig.preempt from init/Kconfig Kconfig: consolidate the "Kernel hacking" menu kconfig: include common Kconfig files from top-level Kconfig kconfig: remove duplicate SWAP symbol defintions um: create a proper drivers Kconfig um: cleanup Kconfig files um: stop abusing KBUILD_KCONFIG
2018-08-02sh: split arch/sh/mm/consistent.cChristoph Hellwig1-80/+0
Half of the file just contains platform device memory setup code which is required for all builds, and half contains helpers for dma coherent allocation, which is only needed if CONFIG_DMA_NONCOHERENT is enabled. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
2018-08-02sh: introduce a sh_cacheop_vaddr helperChristoph Hellwig1-5/+1
And use it in the maple bus code to avoid a dma API dependency. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
2018-08-02sh: simplify get_arch_dma_opsChristoph Hellwig2-13/+0
Remove the indirection through the dma_ops variable, and just return nommu_dma_ops directly from get_arch_dma_ops. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
2018-08-02kconfig: include common Kconfig files from top-level KconfigChristoph Hellwig1-2/+0
Instead of duplicating the source statements in every architecture just do it once in the toplevel Kconfig file. Note that with this the inclusion of arch/$(SRCARCH/Kconfig moves out of the top-level Kconfig into arch/Kconfig so that don't violate ordering constraits while keeping a sensible menu structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-06-05Merge branch 'siginfo-linus' of ↵Linus Torvalds1-8/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull siginfo updates from Eric Biederman: "This set of changes close the known issues with setting si_code to an invalid value, and with not fully initializing struct siginfo. There remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64 and x86 to get the code that generates siginfo into a simpler and more maintainable state. Most of that work involves refactoring the signal handling code and thus careful code review. Also not included is the work to shrink the in kernel version of struct siginfo. That depends on getting the number of places that directly manipulate struct siginfo under control, as it requires the introduction of struct kernel_siginfo for the in kernel things. Overall this set of changes looks like it is making good progress, and with a little luck I will be wrapping up the siginfo work next development cycle" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits) signal/sh: Stop gcc warning about an impossible case in do_divide_error signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions signal/um: More carefully relay signals in relay_signal. signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR} signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code signal/signalfd: Add support for SIGSYS signal/signalfd: Remove __put_user from signalfd_copyinfo signal/xtensa: Use force_sig_fault where appropriate signal/xtensa: Consistenly use SIGBUS in do_unaligned_user signal/um: Use force_sig_fault where appropriate signal/sparc: Use force_sig_fault where appropriate signal/sparc: Use send_sig_fault where appropriate signal/sh: Use force_sig_fault where appropriate signal/s390: Use force_sig_fault where appropriate signal/riscv: Replace do_trap_siginfo with force_sig_fault signal/riscv: Use force_sig_fault where appropriate signal/parisc: Use force_sig_fault where appropriate signal/parisc: Use force_sig_mceerr where appropriate signal/openrisc: Use force_sig_fault where appropriate signal/nios2: Use force_sig_fault where appropriate ...
2018-06-04Merge tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds1-9/+0
Pull dma-mapping updates from Christoph Hellwig: - replace the force_dma flag with a dma_configure bus method. (Nipun Gupta, although one patch is іncorrectly attributed to me due to a git rebase bug) - use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai) - remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the right thing for bounce buffering. - move dma-debug initialization to common code, and apply a few cleanups to the dma-debug code. - cleanup the Kconfig mess around swiotlb selection - swiotlb comment fixup (Yisheng Xie) - a trivial swiotlb fix. (Dan Carpenter) - support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt) - add a new generic dma-noncoherent dma_map_ops implementation and use it for arc, c6x and nds32. - improve scatterlist validity checking in dma-debug. (Robin Murphy) - add a struct device quirk to limit the dma-mask to 32-bit due to bridge/system issues, and switch x86 to use it instead of a local hack for VIA bridges. - handle devices without a dma_mask more gracefully in the dma-direct code. * tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping: (48 commits) dma-direct: don't crash on device without dma_mask nds32: use generic dma_noncoherent_ops nds32: implement the unmap_sg DMA operation nds32: consolidate DMA cache maintainance routines x86/pci-dma: switch the VIA 32-bit DMA quirk to use the struct device flag x86/pci-dma: remove the explicit nodac and allowdac option x86/pci-dma: remove the experimental forcesac boot option Documentation/x86: remove a stray reference to pci-nommu.c core, dma-direct: add a flag 32-bit dma limits dma-mapping: remove unused gfp_t parameter to arch_dma_alloc_attrs dma-debug: check scatterlist segments c6x: use generic dma_noncoherent_ops arc: use generic dma_noncoherent_ops arc: fix arc_dma_{map,unmap}_page arc: fix arc_dma_sync_sg_for_{cpu,device} arc: simplify arc_dma_sync_single_for_{cpu,device} dma-mapping: provide a generic dma-noncoherent implementation dma-mapping: simplify Kconfig dependencies riscv: add swiotlb support riscv: only enable ZONE_DMA32 for 64-bit ...
2018-05-11sh: switch to NO_BOOTMEMRob Herring2-81/+6
Commit 0fa1c579349f ("of/fdt: use memblock_virt_alloc for early alloc") inadvertently switched the DT unflattening allocations from memblock to bootmem which doesn't work because the unflattening happens before bootmem is initialized. Swapping the order of bootmem init and unflattening could also fix this, but removing bootmem is desired. So enable NO_BOOTMEM on SH like other architectures have done. Fixes: 0fa1c579349f ("of/fdt: use memblock_virt_alloc for early alloc") Reported-by: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Rich Felker <dalias@libc.org>
2018-05-08dma-debug: move initialization to common codeChristoph Hellwig1-9/+0
Most mainstream architectures are using 65536 entries, so lets stick to that. If someone is really desperate to override it that can still be done through <asm/dma-mapping.h>, but I'd rather see a really good rationale for that. dma_debug_init is now called as a core_initcall, which for many architectures means much earlier, and provides dma-debug functionality earlier in the boot process. This should be safe as it only relies on the memory allocator already being available. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2018-05-05sh: mm: Fix unprotected access to struct deviceJacopo Mondi1-3/+8
With commit ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset") the generic DMA allocation function on which the SH 'dma_alloc_coherent()' function relies on, accesses the 'dma_pfn_offset' field of struct device. Unfortunately the 'dma_generic_alloc_coherent()' function is called from several places with a NULL struct device argument, halting the CPU during the boot process. This patch fixes the issue by protecting access to dev->dma_pfn_offset, with a trivial check for validity. It also passes a valid 'struct device' in the 'platform_resource_setup_memory()' function which is the main user of 'dma_alloc_coherent()', and inserts a WARN_ON() check to remind to future (and existing) bogus users of this function to provide a valid 'struct device' whenever possible. Fixes: ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset") Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Signed-off-by: Rich Felker <dalias@libc.org>
2018-04-25signal/sh: Use force_sig_fault where appropriateEric W. Biederman1-9/+1
Filling in struct siginfo before calling force_sig_info a tedious and error prone process, where once in a great while the wrong fields are filled out, and siginfo has been inconsistently cleared. Simplify this process by using the helper force_sig_fault. Which takes as a parameters all of the information it needs, ensures all of the fiddly bits of filling in struct siginfo are done properly and then calls force_sig_info. In short about a 5 line reduction in code for every time force_sig_info is called, which makes the calling function clearer. Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: linux-sh@vger.kernel.org Acked-by: Rich Felker <dalias@libc.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25signal: Ensure every siginfo we send has all bits initializedEric W. Biederman1-0/+1
Call clear_siginfo to ensure every stack allocated siginfo is properly initialized before being passed to the signal sending functions. Note: It is not safe to depend on C initializers to initialize struct siginfo on the stack because C is allowed to skip holes when initializing a structure. The initialization of struct siginfo in tracehook_report_syscall_exit was moved from the helper user_single_step_siginfo into tracehook_report_syscall_exit itself, to make it clear that the local variable siginfo gets fully initialized. In a few cases the scope of struct siginfo has been reduced to make it clear that siginfo siginfo is not used on other paths in the function in which it is declared. Instances of using memset to initialize siginfo have been replaced with calls clear_siginfo for clarity. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-14Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+2
Merge yet more updates from Andrew Morton: - various hotfixes - kexec_file updates and feature work * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (27 commits) kernel/kexec_file.c: move purgatories sha256 to common code kernel/kexec_file.c: allow archs to set purgatory load address kernel/kexec_file.c: remove mis-use of sh_offset field during purgatory load kernel/kexec_file.c: remove unneeded variables in kexec_purgatory_setup_sechdrs kernel/kexec_file.c: remove unneeded for-loop in kexec_purgatory_setup_sechdrs kernel/kexec_file.c: split up __kexec_load_puragory kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations* kernel/kexec_file.c: search symbols in read-only kexec_purgatory kernel/kexec_file.c: make purgatory_info->ehdr const kernel/kexec_file.c: remove checks in kexec_purgatory_load include/linux/kexec.h: silence compile warnings kexec_file, x86: move re-factored code to generic side x86: kexec_file: clean up prepare_elf64_headers() x86: kexec_file: lift CRASH_MAX_RANGES limit on crash_mem buffer x86: kexec_file: remove X86_64 dependency from prepare_elf64_headers() x86: kexec_file: purge system-ram walking from prepare_elf64_headers() kexec_file,x86,powerpc: factor out kexec_file_ops functions kexec_file: make use of purgatory optional proc: revalidate misc dentries mm, slab: reschedule cache_reap() on the same CPU ...
2018-04-14mm/gup.c: document return valueMichael S. Tsirkin1-0/+2
__get_user_pages_fast handles errors differently from get_user_pages_fast: the former always returns the number of pages pinned, the later might return a negative error code. Link: http://lkml.kernel.org/r/1522962072-182137-6-git-send-email-mst@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-13Merge tag 'sh-for-4.17' of git://git.libc.org/linux-shLinus Torvalds1-2/+2
Pull arch/sh updates from Rich Felker: "Fixes for bugs in futex, device tree, and userspace breakpoint traps, and for PCI issues on SH7786" * tag 'sh-for-4.17' of git://git.libc.org/linux-sh: arch/sh: pcie-sh7786: handle non-zero DMA offset arch/sh: pcie-sh7786: adjust the memory mapping arch/sh: pcie-sh7786: adjust PCI MEM and IO regions arch/sh: pcie-sh7786: exclude unusable PCI MEM areas arch/sh: pcie-sh7786: mark unavailable PCI resource as disabled arch/sh: pci: don't use disabled resources arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset arch/sh: add sh7786_mm_sel() function sh: fix debug trap failure to process signals before return to user sh: fix memory corruption of unflattened device tree sh: fix futex FUTEX_OP_SET op on userspace addresses
2018-04-13arch/sh: make the DMA mapping operations observe dev->dma_pfn_offsetThomas Petazzoni1-2/+2
Some devices may have a non-zero DMA offset, i.e an offset between the DMA address and the physical address. Such an offset can be encoded into the dma_pfn_offset field of "struct device", but the SuperH implementation of the DMA mapping API does not observe this information. This commit fixes that by ensuring the DMA address is properly calculated depending on this DMA offset. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Rich Felker <dalias@libc.org>
2018-04-06mm: fix races between swapoff and flush dcacheHuang Ying2-2/+2
Thanks to commit 4b3ef9daa4fc ("mm/swap: split swap cache into 64MB trunks"), after swapoff the address_space associated with the swap device will be freed. So page_mapping() users which may touch the address_space need some kind of mechanism to prevent the address_space from being freed during accessing. The dcache flushing functions (flush_dcache_page(), etc) in architecture specific code may access the address_space of swap device for anonymous pages in swap cache via page_mapping() function. But in some cases there are no mechanisms to prevent the swap device from being swapoff, for example, CPU1 CPU2 __get_user_pages() swapoff() flush_dcache_page() mapping = page_mapping() ... exit_swap_address_space() ... kvfree(spaces) mapping_mapped(mapping) The address space may be accessed after being freed. But from cachetlb.txt and Russell King, flush_dcache_page() only care about file cache pages, for anonymous pages, flush_anon_page() should be used. The implementation of flush_dcache_page() in all architectures follows this too. They will check whether page_mapping() is NULL and whether mapping_mapped() is true to determine whether to flush the dcache immediately. And they will use interval tree (mapping->i_mmap) to find all user space mappings. While mapping_mapped() and mapping->i_mmap isn't used by anonymous pages in swap cache at all. So, to fix the race between swapoff and flush dcache, __page_mapping() is add to return the address_space for file cache pages and NULL otherwise. All page_mapping() invoking in flush dcache functions are replaced with page_mapping_file(). [akpm@linux-foundation.org: simplify page_mapping_file(), per Mike] Link: http://lkml.kernel.org/r/20180305083634.15174-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Zankel <chris@zankel.net> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Ley Foon Tan <lftan@altera.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-08mm: pass the vmem_altmap to arch_remove_memory and __remove_pagesChristoph Hellwig1-2/+2
We can just pass this on instead of having to do a radix tree lookup without proper locking 2 levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-01-08mm: pass the vmem_altmap to arch_add_memory and __add_pagesChristoph Hellwig1-2/+3
We can just pass this on instead of having to do a radix tree lookup without proper locking 2 levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-01-08mm: don't export arch_add_memoryChristoph Hellwig1-1/+0
Only x86_64 and sh export this symbol, and it is not used by any modular code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-11-15Merge tag 'dma-mapping-4.15' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds1-3/+3
Pull dma-mapping updates from Christoph Hellwig: - turn dma_cache_sync into a dma_map_ops instance and remove implementation that purely are dead because the architecture doesn't support noncoherent allocations - add a flag for busses that need DMA configuration (Robin Murphy) * tag 'dma-mapping-4.15' of git://git.infradead.org/users/hch/dma-mapping: dma-mapping: turn dma_cache_sync into a dma_map_ops method sh: make dma_cache_sync a no-op xtensa: make dma_cache_sync a no-op unicore32: make dma_cache_sync a no-op powerpc: make dma_cache_sync a no-op mn10300: make dma_cache_sync a no-op microblaze: make dma_cache_sync a no-op ia64: make dma_cache_sync a no-op frv: make dma_cache_sync a no-op x86: make dma_cache_sync a no-op floppy: consolidate the dummy fd_cacheflush definition drivers: flag buses which demand DMA configuration
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman9-0/+9
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-19sh: make dma_cache_sync a no-opChristoph Hellwig1-3/+3
sh does not implement DMA_ATTR_NON_CONSISTENT allocations, so it doesn't make any sense to do any work in dma_cache_sync given that it must be a no-op when dma_alloc_attrs returns coherent memory. On the other hand sh uses dma_cache_sync internally in the dma_ops implementation and for the maple bus that does not use the DMA API, so a the old functionality for dma_cache_sync is still provided under the name sh_sync_dma_for_device, and without the redundant dev argument. While at it two of the syncing dma_ops also go the proper _for_device postfix. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2017-07-13sh: move inline before return typeJoe Perches1-1/+1
Make the code like the rest of the kernel. Link: http://lkml.kernel.org/r/f81bb2a67a97b1fd8b6ea99bd350d8a0f6864fb1.1499284835.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-11lib/extable.c: use bsearch() library function in search_extable()Thomas Meyer1-16/+18
[thomas@m3y3r.de: v3: fix arch specific implementations] Link: http://lkml.kernel.org/r/1497890858.12931.7.camel@m3y3r.de Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07mm/hugetlb: add size parameter to huge_pte_offset()Punit Agrawal1-1/+2
A poisoned or migrated hugepage is stored as a swap entry in the page tables. On architectures that support hugepages consisting of contiguous page table entries (such as on arm64) this leads to ambiguity in determining the page table entry to return in huge_pte_offset() when a poisoned entry is encountered. Let's remove the ambiguity by adding a size parameter to convey additional information about the requested address. Also fixup the definition/usage of huge_pte_offset() throughout the tree. Link: http://lkml.kernel.org/r/20170522133604.11392-4-punit.agrawal@arm.com Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> (odd fixer:METAG ARCHITECTURE) Cc: Ralf Baechle <ralf@linux-mips.org> (supporter:MIPS) Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07mm, memory_hotplug: replace for_device by want_memblock in arch_add_memoryMichal Hocko1-2/+2
arch_add_memory gets for_device argument which then controls whether we want to create memblocks for created memory sections. Simplify the logic by telling whether we want memblocks directly rather than going through pointless negation. This also makes the api easier to understand because it is clear what we want rather than nothing telling for_device which can mean anything. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-13-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07mm, memory_hotplug: do not associate hotadded memory to zones until onlineMichal Hocko1-7/+1
The current memory hotplug implementation relies on having all the struct pages associate with a zone/node during the physical hotplug phase (arch_add_memory->__add_pages->__add_section->__add_zone). In the vast majority of cases this means that they are added to ZONE_NORMAL. This has been so since 9d99aaa31f59 ("[PATCH] x86_64: Support memory hotadd without sparsemem") and it wasn't a big deal back then because movable onlining didn't exist yet. Much later memory hotplug wanted to (ab)use ZONE_MOVABLE for movable onlining 511c2aba8f07 ("mm, memory-hotplug: dynamic configure movable memory and portion memory") and then things got more complicated. Rather than reconsidering the zone association which was no longer needed (because the memory hotplug already depended on SPARSEMEM) a convoluted semantic of zone shifting has been developed. Only the currently last memblock or the one adjacent to the zone_movable can be onlined movable. This essentially means that the online type changes as the new memblocks are added. Let's simulate memory hot online manually $ echo 0x100000000 > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory32/valid_zones Normal Movable $ echo $((0x100000000+(128<<20))) > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable $ echo $((0x100000000+2*(128<<20))) > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal /sys/devices/system/memory/memory34/valid_zones:Normal Movable $ echo online_movable > /sys/devices/system/memory/memory34/state $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable Normal This is an awkward semantic because an udev event is sent as soon as the block is onlined and an udev handler might want to online it based on some policy (e.g. association with a node) but it will inherently race with new blocks showing up. This patch changes the physical online phase to not associate pages with any zone at all. All the pages are just marked reserved and wait for the onlining phase to be associated with the zone as per the online request. There are only two requirements - existing ZONE_NORMAL and ZONE_MOVABLE cannot overlap - ZONE_NORMAL precedes ZONE_MOVABLE in physical addresses the latter one is not an inherent requirement and can be changed in the future. It preserves the current behavior and made the code slightly simpler. This is subject to change in future. This means that the same physical online steps as above will lead to the following state: Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable Implementation: The current move_pfn_range is reimplemented to check the above requirements (allow_online_pfn_range) and then updates the respective zone (move_pfn_range_to_zone), the pgdat and links all the pages in the pfn range with the zone/node. __add_pages is updated to not require the zone and only initializes sections in the range. This allowed to simplify the arch_add_memory code (s390 could get rid of quite some of code). devm_memremap_pages is the only user of arch_add_memory which relies on the zone association because it only hooks into the memory hotplug only half way. It uses it to associate the new memory with ZONE_DEVICE but doesn't allow it to be {on,off}lined via sysfs. This means that this particular code path has to call move_pfn_range_to_zone explicitly. The original zone shifting code is kept in place and will be removed in the follow up patch for an easier review. Please note that this patch also changes the original behavior when offlining a memory block adjacent to another zone (Normal vs. Movable) used to allow to change its movable type. This will be handled later. [richard.weiyang@gmail.com: simplify zone_intersects()] Link: http://lkml.kernel.org/r/20170616092335.5177-1-richard.weiyang@gmail.com [richard.weiyang@gmail.com: remove duplicate call for set_page_links] Link: http://lkml.kernel.org/r/20170616092335.5177-2-richard.weiyang@gmail.com [akpm@linux-foundation.org: remove unused local `i'] Link: http://lkml.kernel.org/r/20170515085827.16474-12-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # For s390 bits Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07mm, memory_hotplug: get rid of is_zone_device_sectionMichal Hocko1-1/+1
Device memory hotplug hooks into regular memory hotplug only half way. It needs memory sections to track struct pages but there is no need/desire to associate those sections with memory blocks and export them to the userspace via sysfs because they cannot be onlined anyway. This is currently expressed by for_device argument to arch_add_memory which then makes sure to associate the given memory range with ZONE_DEVICE. register_new_memory then relies on is_zone_device_section to distinguish special memory hotplug from the regular one. While this works now, later patches in this series want to move __add_zone outside of arch_add_memory path so we have to come up with something else. Add want_memblock down the __add_pages path and use it to control whether the section->memblock association should be done. arch_add_memory then just trivially want memblock for everything but for_device hotplug. remove_memory_section doesn't need is_zone_device_section either. We can simply skip all the memblock specific cleanup if there is no memblock for the given section. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-19mm: larger stack guard gap, between vmasHugh Dickins1-2/+2
Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>