1. 16 Sep, 2015 1 commit
    • Thomas Gleixner's avatar
      genirq: Remove irq argument from irq flow handlers · bd0b9ac4
      Thomas Gleixner authored
      Most interrupt flow handlers do not use the irq argument. Those few
      which use it can retrieve the irq number from the irq descriptor.
      
      Remove the argument.
      
      Search and replace was done with coccinelle and some extra helper
      scripts around it. Thanks to Julia for her help!
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Julia Lawall <Julia.Lawall@lip6.fr>
      Cc: Jiang Liu <jiang.liu@linux.intel.com>
      bd0b9ac4
  2. 10 Sep, 2015 7 commits
    • Christoph Hellwig's avatar
      dma-mapping: consolidate dma_set_mask · 452e06af
      Christoph Hellwig authored
      Almost everyone implements dma_set_mask the same way, although some time
      that's hidden in ->set_dma_mask methods.
      
      This patch consolidates those into a common implementation that either
      calls ->set_dma_mask if present or otherwise uses the default
      implementation.  Some architectures used to only call ->set_dma_mask
      after the initial checks, and those instance have been fixed to do the
      full work.  h8300 implemented dma_set_mask bogusly as a no-ops and has
      been fixed.
      
      Unfortunately some architectures overload unrelated semantics like changing
      the dma_ops into it so we still need to allow for an architecture override
      for now.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      452e06af
    • Christoph Hellwig's avatar
      dma-mapping: consolidate dma_supported · ee196371
      Christoph Hellwig authored
      Most architectures just call into ->dma_supported, but some also return 1
      if the method is not present, or 0 if no dma ops are present (although
      that should never happeb). Consolidate this more broad version into
      common code.
      
      Also fix h8300 which inorrectly always returned 0, which would have been
      a problem if it's dma_set_mask implementation wasn't a similarly buggy
      noop.
      
      As a few architectures have much more elaborate implementations, we
      still allow for arch overrides.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ee196371
    • Christoph Hellwig's avatar
      dma-mapping: cosolidate dma_mapping_error · efa21e43
      Christoph Hellwig authored
      Currently there are three valid implementations of dma_mapping_error:
      
       (1) call ->mapping_error
       (2) check for a hardcoded error code
       (3) always return 0
      
      This patch provides a common implementation that calls ->mapping_error
      if present, then checks for DMA_ERROR_CODE if defined or otherwise
      returns 0.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      efa21e43
    • Christoph Hellwig's avatar
      dma-mapping: consolidate dma_{alloc,free}_noncoherent · 1e893752
      Christoph Hellwig authored
      Most architectures do not support non-coherent allocations and either
      define dma_{alloc,free}_noncoherent to their coherent versions or stub
      them out.
      
      Openrisc uses dma_{alloc,free}_attrs to implement them, and only Mips
      implements them directly.
      
      This patch moves the Openrisc version to common code, and handles the
      DMA_ATTR_NON_CONSISTENT case in the mips dma_map_ops instance.
      
      Note that actual non-coherent allocations require a dma_cache_sync
      implementation, so if non-coherent allocations didn't work on
      an architecture before this patch they still won't work after it.
      
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1e893752
    • Christoph Hellwig's avatar
      dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent} · 6894258e
      Christoph Hellwig authored
      Since 2009 we have a nice asm-generic header implementing lots of DMA API
      functions for architectures using struct dma_map_ops, but unfortunately
      it's still missing a lot of APIs that all architectures still have to
      duplicate.
      
      This series consolidates the remaining functions, although we still need
      arch opt outs for two of them as a few architectures have very
      non-standard implementations.
      
      This patch (of 5):
      
      The coherent DMA allocator works the same over all architectures supporting
      dma_map operations.
      
      This patch consolidates them and converges the minor differences:
      
       - the debug_dma helpers are now called from all architectures, including
         those that were previously missing them
       - dma_alloc_from_coherent and dma_release_from_coherent are now always
         called from the generic alloc/free routines instead of the ops
         dma-mapping-common.h always includes dma-coherent.h to get the defintions
         for them, or the stubs if the architecture doesn't support this feature
       - checks for ->alloc / ->free presence are removed.  There is only one
         magic instead of dma_map_ops without them (mic_dma_ops) and that one
         is x86 only anyway.
      
      Besides that only x86 needs special treatment to replace a default devices
      if none is passed and tweak the gfp_flags.  An optional arch hook is provided
      for that.
      
      [linux@roeck-us.net: fix build]
      [jcmvbkbc@gmail.com: fix xtensa]
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6894258e
    • Yinghai Lu's avatar
      lib/decompressors: use real out buf size for gunzip with kernel · 2d3862d2
      Yinghai Lu authored
      When loading x86 64bit kernel above 4GiB with patched grub2, got kernel
      gunzip error.
      
      | early console in decompress_kernel
      | decompress_kernel:
      |       input: [0x807f2143b4-0x807ff61aee]
      |      output: [0x807cc00000-0x807f3ea29b] 0x027ea29c: output_len
      | boot via startup_64
      | KASLR using RDTSC...
      |  new output: [0x46fe000000-0x470138cfff] 0x0338d000: output_run_size
      |  decompress: [0x46fe000000-0x47007ea29b] <=== [0x807f2143b4-0x807ff61aee]
      |
      | Decompressing Linux... gz...
      |
      | uncompression error
      |
      | -- System halted
      
      the new buffer is at 0x46fe000000ULL, decompressor_gzip is using
      0xffffffb901ffffff as out_len.  gunzip in lib/zlib_inflate/inflate.c cap
      that len to 0x01ffffff and decompress fails later.
      
      We could hit this problem with crashkernel booting that uses kexec loading
      kernel above 4GiB.
      
      We have decompress_* support:
          1. inbuf[]/outbuf[] for kernel preboot.
          2. inbuf[]/flush() for initramfs
          3. fill()/flush() for initrd.
      This bug only affect kernel preboot path that use outbuf[].
      
      Add __decompress and take real out_buf_len for gunzip instead of guessing
      wrong buf size.
      
      Fixes: 1431574a (lib/decompressors: fix "no limit" output buffer length)
      Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
      Cc: Alexandre Courbot <acourbot@nvidia.com>
      Cc: Jon Medhurst <tixy@linaro.org>
      Cc: Stephen Warren <swarren@wwwdotorg.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2d3862d2
    • Dave Young's avatar
      kexec: split kexec_load syscall from kexec core code · 2965faa5
      Dave Young authored
      There are two kexec load syscalls, kexec_load another and kexec_file_load.
       kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
      split kexec_load syscall code to kernel/kexec.c.
      
      And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
      use kexec_file_load only, or vice verse.
      
      The original requirement is from Ted Ts'o, he want kexec kernel signature
      being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
      kexec_load syscall can bypass the checking.
      
      Vivek Goyal proposed to create a common kconfig option so user can compile
      in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
      KEXEC_CORE so that old config files still work.
      
      Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
      architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
      KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
      kexec_load syscall.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarDave Young <dyoung@redhat.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Petr Tesarik <ptesarik@suse.cz>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Josh Boyer <jwboyer@fedoraproject.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2965faa5
  3. 09 Sep, 2015 11 commits
  4. 08 Sep, 2015 4 commits
    • Julien Grall's avatar
      xen/privcmd: Further s/MFN/GFN/ clean-up · a13d7201
      Julien Grall authored
      The privcmd code is mixing the usage of GFN and MFN within the same
      functions which make the code difficult to understand when you only work
      with auto-translated guests.
      
      The privcmd driver is only dealing with GFN so replace all the mention
      of MFN into GFN.
      
      The ioctl structure used to map foreign change has been left unchanged
      given that the userspace is using it. Nonetheless, add a comment to
      explain the expected value within the "mfn" field.
      Signed-off-by: default avatarJulien Grall <julien.grall@citrix.com>
      Reviewed-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      a13d7201
    • Julien Grall's avatar
      xen: Use correctly the Xen memory terminologies · 0df4f266
      Julien Grall authored
      Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN
      is meant, I suspect this is because the first support for Xen was for
      PV. This resulted in some misimplementation of helpers on ARM and
      confused developers about the expected behavior.
      
      For instance, with pfn_to_mfn, we expect to get an MFN based on the name.
      Although, if we look at the implementation on x86, it's returning a GFN.
      
      For clarity and avoid new confusion, replace any reference to mfn with
      gfn in any helpers used by PV drivers. The x86 code will still keep some
      reference of pfn_to_mfn which may be used by all kind of guests
      No changes as been made in the hypercall field, even
      though they may be invalid, in order to keep the same as the defintion
      in xen repo.
      
      Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a
      name to close to the KVM function gfn_to_page.
      
      Take also the opportunity to simplify simple construction such
      as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up
      will come in follow-up patches.
      
      [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cbSigned-off-by: default avatarJulien Grall <julien.grall@citrix.com>
      Reviewed-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
      Acked-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Acked-by: default avatarWei Liu <wei.liu2@citrix.com>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      0df4f266
    • Julien Grall's avatar
      arm/xen: implement correctly pfn_to_mfn · 5192b35d
      Julien Grall authored
      After the commit introducing convertion between DMA and guest addresses,
      all the callers of pfn_to_mfn are expecting to get a GFN (Guest Frame
      Number). On ARM, all the guests are auto-translated so the GFN is equal
      to the Linux PFN (Pseudo-physical Frame Number).
      
      The current implementation may return an MFN if the caller is passing a
      PFN associated to a mapped foreign grant. In pratice, I haven't seen
      the problem on running guest but we should fix it for the sake of
      correctness.
      
      Correct the implementation by always returning the pfn passed in parameter.
      
      A follow-up patch will take care to rename pfn_to_mfn to a suitable
      name.
      Signed-off-by: default avatarJulien Grall <julien.grall@citrix.com>
      Reviewed-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      5192b35d
    • Julien Grall's avatar
      xen: Make clear that swiotlb and biomerge are dealing with DMA address · 32e09870
      Julien Grall authored
      The swiotlb is required when programming a DMA address on ARM when a
      device is not protected by an IOMMU.
      
      In this case, the DMA address should always be equal to the machine address.
      For DOM0 memory, Xen ensure it by have an identity mapping between the
      guest address and host address. However, when mapping a foreign grant
      reference, the 1:1 model doesn't work.
      
      For ARM guest, most of the callers of pfn_to_mfn expects to get a GFN
      (Guest Frame Number), i.e a PFN (Page Frame Number) from the Linux point
      of view given that all ARM guest are auto-translated.
      
      Even though the name pfn_to_mfn is misleading, we need to ensure that
      those caller get a GFN and not by mistake a MFN. In pratical, I haven't
      seen error related to this but we should fix it for the sake of
      correctness.
      
      In order to fix the implementation of pfn_to_mfn on ARM in a follow-up
      patch, we have to introduce new helpers to return the DMA from a PFN and
      the invert.
      
      On x86, the new helpers will be an alias of pfn_to_mfn and mfn_to_pfn.
      
      The helpers will be used in swiotlb and xen_biovec_phys_mergeable.
      
      This is necessary in the latter because we have to ensure that the
      biovec code will not try to merge a biovec using foreign page and
      another using Linux memory.
      
      Lastly, the helper mfn_to_local_pfn has been renamed to bfn_to_local_pfn
      given that the only usage was in swiotlb.
      Signed-off-by: default avatarJulien Grall <julien.grall@citrix.com>
      Reviewed-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      32e09870
  5. 05 Sep, 2015 6 commits
  6. 04 Sep, 2015 1 commit
    • Vladimir Zapolskiy's avatar
      genalloc: add name arg to gen_pool_get() and devm_gen_pool_create() · 73858173
      Vladimir Zapolskiy authored
      This change modifies gen_pool_get() and devm_gen_pool_create() client
      interfaces adding one more argument "name" of a gen_pool object.
      
      Due to implementation gen_pool_get() is capable to retrieve only one
      gen_pool associated with a device even if multiple gen_pools are created,
      fortunately right at the moment it is sufficient for the clients, hence
      provide NULL as a valid argument on both producer devm_gen_pool_create()
      and consumer gen_pool_get() sides.
      
      Because only one created gen_pool per device is addressable, explicitly
      add a restriction to devm_gen_pool_create() to create only one gen_pool
      per device, this implies two possible error codes returned by the
      function, account it on client side (only misc/sram).  This completes
      client side changes related to genalloc updates.
      
      [akpm@linux-foundation.org: gen_pool_get() cleanup]
      Signed-off-by: default avatarVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
      Cc: Philipp Zabel <p.zabel@pengutronix.de>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
      Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
      Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
      Cc: Shawn Guo <shawnguo@kernel.org>
      Cc: Sascha Hauer <kernel@pengutronix.de>
      Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      73858173
  7. 28 Aug, 2015 1 commit
  8. 27 Aug, 2015 1 commit
  9. 26 Aug, 2015 3 commits
    • Russell King's avatar
      ARM: software-based priviledged-no-access support · a5e090ac
      Russell King authored
      Provide a software-based implementation of the priviledged no access
      support found in ARMv8.1.
      
      Userspace pages are mapped using a different domain number from the
      kernel and IO mappings.  If we switch the user domain to "no access"
      when we enter the kernel, we can prevent the kernel from touching
      userspace.
      
      However, the kernel needs to be able to access userspace via the
      various user accessor functions.  With the wrapping in the previous
      patch, we can temporarily enable access when the kernel needs user
      access, and re-disable it afterwards.
      
      This allows us to trap non-intended accesses to userspace, eg, caused
      by an inadvertent dereference of the LIST_POISON* values, which, with
      appropriate user mappings setup, can be made to succeed.  This in turn
      can allow use-after-free bugs to be further exploited than would
      otherwise be possible.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      a5e090ac
    • Russell King's avatar
      ARM: entry: provide uaccess assembly macro hooks · 2190fed6
      Russell King authored
      Provide hooks into the kernel entry and exit paths to permit control
      of userspace visibility to the kernel.  The intended use is:
      
      - on entry to kernel from user, uaccess_disable will be called to
        disable userspace visibility
      - on exit from kernel to user, uaccess_enable will be called to
        enable userspace visibility
      - on entry from a kernel exception, uaccess_save_and_disable will be
        called to save the current userspace visibility setting, and disable
        access
      - on exit from a kernel exception, uaccess_restore will be called to
        restore the userspace visibility as it was before the exception
        occurred.
      
      These hooks allows us to keep userspace visibility disabled for the
      vast majority of the kernel, except for localised regions where we
      want to explicitly access userspace.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      2190fed6
    • Russell King's avatar
      ARM: entry: get rid of multiple macro definitions · aa06e5c1
      Russell King authored
      The following structure is just asking for trouble:
      
       #ifdef CONFIG_symbol
      	.macro foo
      	...
      	.endm
      	.macro bar
      	...
      	.endm
      	.macro baz
      	...
      	.endm
       #else
      	.macro foo
      	...
      	.endm
      	.macro bar
      	...
      	.endm
       #ifdef CONFIG_symbol2
      	.macro baz
      	...
      	.endm
       #else
      	.macro baz
      	...
      	.endm
       #endif
       #endif
      
      such as one defintion being updated, but the other definitions miss out.
      Where the contents of a macro needs to be conditional, the hint is in
      the first clause of this very sentence.  "contents" "conditional".  Not
      multiple separate definitions, especially not when much of the macro
      is the same between different configs.
      
      This patch fixes this bad style, which had caused the Thumb2 code to
      miss-out on the uaccess updates.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      aa06e5c1
  10. 25 Aug, 2015 5 commits