1. 12 Feb, 2019 1 commit
  2. 16 Jan, 2019 1 commit
  3. 19 Dec, 2018 1 commit
  4. 28 Oct, 2018 1 commit
  5. 19 Oct, 2018 1 commit
  6. 04 Oct, 2018 1 commit
    • Nadav Amit's avatar
      kbuild/Makefile: Prepare for using macros in inline assembly code to work... · 77b0bf55
      Nadav Amit authored
      kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs
      Using macros in inline assembly allows us to work around bugs
      in GCC's inlining decisions.
      Compile macros.S and use it to assemble all C files.
      Currently only x86 will use it.
      The inlining pass of GCC doesn't include an assembler, so it's not aware
      of basic properties of the generated code, such as its size in bytes,
      or that there are such things as discontiuous blocks of code and data
      due to the newfangled linker feature called 'sections' ...
      Instead GCC uses a lazy and fragile heuristic: it does a linear count of
      certain syntactic and whitespace elements in inlined assembly block source
      code, such as a count of new-lines and semicolons (!), as a poor substitute
      for "code size and complexity".
      Unsurprisingly this heuristic falls over and breaks its neck whith certain
      common types of kernel code that use inline assembly, such as the frequent
      practice of putting useful information into alternative sections.
      As a result of this fresh, 20+ years old GCC bug, GCC's inlining decisions
      are effectively disabled for inlined functions that make use of such asm()
      blocks, because GCC thinks those sections of code are "large" - when in
      reality they are often result in just a very low number of machine
      This absolute lack of inlining provess when GCC comes across such asm()
      blocks both increases generated kernel code size and causes performance
      overhead, which is particularly noticeable on paravirt kernels, which make
      frequent use of these inlining facilities in attempt to stay out of the
      way when running on baremetal hardware.
      Instead of fixing the compiler we use a workaround: we set an assembly macro
      and call it from the inlined assembly block. As a result GCC considers the
      inline assembly block as a single instruction. (Which it often isn't but I digress.)
      This uglifies and bloats the source code - for example just the refcount
      related changes have this impact:
       Makefile                 |    9 +++++++--
       arch/x86/Makefile        |    7 +++++++
       arch/x86/kernel/macros.S |    7 +++++++
       scripts/Kbuild.include   |    4 +++-
       scripts/mod/Makefile     |    2 ++
       5 files changed, 26 insertions(+), 3 deletions(-)
      Yay readability and maintainability, it's not like assembly code is hard to read
      and maintain ...
      We also hope that GCC will eventually get fixed, but we are not holding
      our breath for that. Yet we are optimistic, it might still happen, any decade now.
      [ mingo: Wrote new changelog describing the background. ]
      Tested-by: 's avatarKees Cook <keescook@chromium.org>
      Signed-off-by: 's avatarNadav Amit <namit@vmware.com>
      Acked-by: 's avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      Acked-by: 's avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Michal Marek <michal.lkml@markovi.net>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kbuild@vger.kernel.org
      Link: http://lkml.kernel.org/r/20181003213100.189959-3-namit@vmware.comSigned-off-by: 's avatarIngo Molnar <mingo@kernel.org>
  7. 22 Aug, 2018 1 commit
  8. 17 Jul, 2018 1 commit
    • Laura Abbott's avatar
      kbuild: Add build salt to the kernel and modules · 9afb719e
      Laura Abbott authored
      In Fedora, the debug information is packaged separately (foo-debuginfo) and
      can be installed separately. There's been a long standing issue where only
      one version of a debuginfo info package can be installed at a time. There's
      been an effort for Fedora for parallel debuginfo to rectify this problem.
      Part of the requirement to allow parallel debuginfo to work is that build ids
      are unique between builds. The existing upstream rpm implementation ensures
      this by re-calculating the build-id using the version and release as a
      seed. This doesn't work 100% for the kernel because of the vDSO which is
      its own binary and doesn't get updated when embedded.
      Fix this by adding some data in an ELF note for both the kernel and modules.
      The data is controlled via a Kconfig option so distributions can set it
      to an appropriate value to ensure uniqueness between builds.
      Suggested-by: 's avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      Signed-off-by: 's avatarLaura Abbott <labbott@redhat.com>
      Signed-off-by: 's avatarMasahiro Yamada <yamada.masahiro@socionext.com>
  9. 02 Jul, 2018 1 commit
  10. 17 May, 2018 5 commits
  11. 14 May, 2018 1 commit
  12. 02 May, 2018 1 commit
  13. 09 Mar, 2018 1 commit
  14. 26 Jan, 2018 1 commit
    • Andi Kleen's avatar
      module/retpoline: Warn about missing retpoline in module · caf7501a
      Andi Kleen authored
      There's a risk that a kernel which has full retpoline mitigations becomes
      vulnerable when a module gets loaded that hasn't been compiled with the
      right compiler or the right option.
      To enable detection of that mismatch at module load time, add a module info
      string "retpoline" at build time when the module was compiled with
      retpoline support. This only covers compiled C source, but assembler source
      or prebuilt object files are not checked.
      If a retpoline enabled kernel detects a non retpoline protected module at
      load time, print a warning and report it in the sysfs vulnerability file.
      [ tglx: Massaged changelog ]
      Signed-off-by: 's avatarAndi Kleen <ak@linux.intel.com>
      Signed-off-by: 's avatarThomas Gleixner <tglx@linutronix.de>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: gregkh@linuxfoundation.org
      Cc: torvalds@linux-foundation.org
      Cc: jeyu@kernel.org
      Cc: arjan@linux.intel.com
      Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org
  15. 16 Jan, 2018 1 commit
  16. 19 Dec, 2017 1 commit
  17. 12 Nov, 2017 1 commit
    • Randy Dunlap's avatar
      modpost: detect modules without a MODULE_LICENSE · ba1029c9
      Randy Dunlap authored
      Partially revert commit 2fa36568 ("kbuild: soften MODULE_LICENSE
      check") so that modpost detects modules that do not have a
      Sam's commit also changed the fatal error to a warning, which I am
      leaving as is.
      This gives advance notice of when a module has no license and will taint
      the kernel if the module is loaded.
      This produces the following warnings on x86_64 allmodconfig:
          MODPOST 6520 modules
        WARNING: modpost: missing MODULE_LICENSE() in drivers/auxdisplay/img-ascii-lcd.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/gpio/gpio-ath79.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/gpio/gpio-iop.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/iio/accel/kxsd9-i2c.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/iio/adc/qcom-vadc-common.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/media/platform/mtk-vcodec/mtk-vcodec-common.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/media/platform/soc_camera/soc_scale_crop.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/mtd/nand/denali_pci.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/net/phy/cortina.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/pinctrl/pxa/pinctrl-pxa2xx.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/power/reset/zx-reboot.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/rpmsg/qcom_glink_native.o
        WARNING: modpost: missing MODULE_LICENSE() in drivers/staging/comedi/drivers/ni_atmio.o
        WARNING: modpost: missing MODULE_LICENSE() in net/9p/9pnet_xen.o
        WARNING: modpost: missing MODULE_LICENSE() in sound/soc/codecs/snd-soc-pcm512x-spi.o
      Signed-off-by: 's avatarRandy Dunlap <rdunlap@infradead.org>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
  18. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      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
      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: 's avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: 's avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: 's avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
  19. 22 Oct, 2017 1 commit
  20. 19 Oct, 2017 1 commit
  21. 02 Oct, 2017 1 commit
    • Mika Westerberg's avatar
      thunderbolt: Add support for XDomain discovery protocol · d1ff7024
      Mika Westerberg authored
      When two hosts are connected over a Thunderbolt cable, there is a
      protocol they can use to communicate capabilities supported by the host.
      The discovery protocol uses automatically configured control channel
      (ring 0) and is build on top of request/response transactions using
      special XDomain primitives provided by the Thunderbolt base protocol.
      The capabilities consists of a root directory block of basic properties
      used for identification of the host, and then there can be zero or more
      directories each describing a Thunderbolt service and its capabilities.
      Once both sides have discovered what is supported the two hosts can
      setup high-speed DMA paths and transfer data to the other side using
      whatever protocol was agreed based on the properties. The software
      protocol used to communicate which DMA paths to enable is service
      This patch adds support for the XDomain discovery protocol to the
      Thunderbolt bus. We model each remote host connection as a Linux XDomain
      device. For each Thunderbolt service found supported on the XDomain
      device, we create Linux Thunderbolt service device which Thunderbolt
      service drivers can then bind to based on the protocol identification
      information retrieved from the property directory describing the
      This code is based on the work done by Amir Levy and Michael Jamet.
      Signed-off-by: 's avatarMichael Jamet <michael.jamet@intel.com>
      Signed-off-by: 's avatarMika Westerberg <mika.westerberg@linux.intel.com>
      Reviewed-by: 's avatarYehezkel Bernat <yehezkel.bernat@intel.com>
      Reviewed-by: 's avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
      Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
  22. 07 Sep, 2017 1 commit
  23. 25 Jul, 2017 1 commit
    • Wanlong Gao's avatar
      modpost: abort if module name is too long · 4fd3e4ef
      Wanlong Gao authored
      Module name has a limited length, but currently the build system
      allows the build finishing even if the module name is too long.
        CC      /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.o
       warning: initializer-string for array of chars is too long [enabled by default]
        .name = KBUILD_MODNAME,
      but it's merely a warning.
      This patch adds the check of the module name length in modpost and stops
      the build properly.
      Signed-off-by: 's avatarWanlong Gao <wanlong.gao@gmail.com>
      Signed-off-by: 's avatarJessica Yu <jeyu@kernel.org>
  24. 23 May, 2017 1 commit
    • Kees Cook's avatar
      module: Add module name to modinfo · 3e2e857f
      Kees Cook authored
      Accessing the mod structure (e.g. for mod->name) prior to having completed
      check_modstruct_version() can result in writing garbage to the error logs
      if the layout of the mod structure loaded from disk doesn't match the
      running kernel's mod structure layout. This kind of mismatch will become
      much more likely if a kernel is built with different randomization seed
      for the struct layout randomization plugin.
      Instead, add and use a new modinfo string for logging the module name.
      Signed-off-by: 's avatarKees Cook <keescook@chromium.org>
      Signed-off-by: 's avatarJessica Yu <jeyu@redhat.com>
  25. 12 Apr, 2017 1 commit
  26. 01 Mar, 2017 1 commit
  27. 03 Feb, 2017 1 commit
    • Ard Biesheuvel's avatar
      kbuild: modversions: add infrastructure for emitting relative CRCs · 56067812
      Ard Biesheuvel authored
      This add the kbuild infrastructure that will allow architectures to emit
      vmlinux symbol CRCs as 32-bit offsets to another location in the kernel
      where the actual value is stored. This works around problems with CRCs
      being mistaken for relocatable symbols on kernels that self relocate at
      runtime (i.e., powerpc with CONFIG_RELOCATABLE=y)
      For the kbuild side of things, this comes down to the following:
       - introducing a Kconfig symbol MODULE_REL_CRCS
       - adding a -R switch to genksyms to instruct it to emit the CRC symbols
         as references into the .rodata section
       - making modpost distinguish such references from absolute CRC symbols
         by the section index (SHN_ABS)
       - making kallsyms disregard non-absolute symbols with a __crc_ prefix
      Signed-off-by: 's avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
  28. 29 Nov, 2016 1 commit
    • Nicholas Piggin's avatar
      kbuild: modpost warn if export version crc is missing · d8c1eb86
      Nicholas Piggin authored
      This catches the failing ceph CRC on with:
          LD      vmlinux.o
          MODPOST vmlinux.o
        WARNING: EXPORT symbol "ceph_monc_do_statfs" [vmlinux] version
        generation failed, symbol will not be versioned.
      When the modules referring to exported symbols are built, there is an
      existing warning for missing CRC, but it's not always the case such
      any such module will be built, and in any case it is useful to get a
      warning at the source.
      This gets a little verbose with CONFIG_DEBUG_SECTION_MISMATCH,
      producing a warning with each object linked, but I didn't think
      that warranted extra complexity to avoid.
      Signed-off-by: 's avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: 's avatarMichal Marek <mmarek@suse.com>
  29. 26 Nov, 2016 1 commit
  30. 08 Oct, 2016 1 commit
  31. 27 Jun, 2016 1 commit
  32. 08 Jun, 2016 1 commit
  33. 06 May, 2016 1 commit
    • Philipp Zabel's avatar
      modpost: fix module autoloading for OF devices with generic compatible property · acbef7b7
      Philipp Zabel authored
      Since the wildcard at the end of OF module aliases is gone, autoloading
      of modules that don't match a device's last (most generic) compatible
      value fails.
      For example the CODA960 VPU on i.MX6Q has the SoC specific compatible
      "fsl,imx6q-vpu" and the generic compatible "cnm,coda960".  Since the
      driver currently only works with knowledge about the SoC specific
      integration, it doesn't list "cnm,cod960" in the module device table.
      This results in the device compatible
      "of:NvpuT<NULL>Cfsl,imx6q-vpuCcnm,coda960" not matching the module alias
      "of:N*T*Cfsl,imx6q-vpu" anymore, whereas before commit 2f632369
      ("modpost: don't add a trailing wildcard for OF module aliases") it
      matched the module alias "of:N*T*Cfsl,imx6q-vpu*".
      This patch adds two module aliases for each compatible, one without the
      wildcard and one with "C*" appended.
        $ modinfo coda | grep imx6q
        alias:          of:N*T*Cfsl,imx6q-vpuC*
        alias:          of:N*T*Cfsl,imx6q-vpu
      Fixes: 2f632369 ("modpost: don't add a trailing wildcard for OF module aliases")
      Link: http://lkml.kernel.org/r/1462203339-15340-1-git-send-email-p.zabel@pengutronix.deSigned-off-by: 's avatarPhilipp Zabel <p.zabel@pengutronix.de>
      Cc: Javier Martinez Canillas <javier@osg.samsung.com>
      Cc: Brian Norris <computersforpeace@gmail.com>
      Cc: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: <stable@vger.kernel.org>	[4.5+]
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
  34. 29 Feb, 2016 1 commit
    • Josh Poimboeuf's avatar
      objtool: Mark non-standard object files and directories · c0dd6716
      Josh Poimboeuf authored
      Code which runs outside the kernel's normal mode of operation often does
      unusual things which can cause a static analysis tool like objtool to
      emit false positive warnings:
       - boot image
       - vdso image
       - relocation
       - realmode
       - efi
       - head
       - purgatory
       - modpost
      Set OBJECT_FILES_NON_STANDARD for their related files and directories,
      which will tell objtool to skip checking them.  It's ok to skip them
      because they don't affect runtime stack traces.
      Also skip the following code which does the right thing with respect to
      frame pointers, but is too "special" to be validated by a tool:
       - entry
       - mcount
      Also skip the test_nx module because it modifies its exception handling
      table at runtime, which objtool can't understand.  Fortunately it's
      just a test module so it doesn't matter much.
      Currently objtool is the only user of OBJECT_FILES_NON_STANDARD, but it
      might eventually be useful for other tools.
      Signed-off-by: 's avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Chris J Arges <chris.j.arges@canonical.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Michal Marek <mmarek@suse.cz>
      Cc: Namhyung Kim <namhyung@gmail.com>
      Cc: Pedro Alves <palves@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: live-patching@vger.kernel.org
      Link: http://lkml.kernel.org/r/366c080e3844e8a5b6a0327dc7e8c2b90ca3baeb.1456719558.git.jpoimboe@redhat.comSigned-off-by: 's avatarIngo Molnar <mingo@kernel.org>
  35. 21 Jan, 2016 1 commit
    • Alan Modra's avatar
      powerpc: Simplify module TOC handling · c153693d
      Alan Modra authored
      PowerPC64 uses the symbol .TOC. much as other targets use
      _GLOBAL_OFFSET_TABLE_. It identifies the value of the GOT pointer (or in
      powerpc parlance, the TOC pointer). Global offset tables are generally
      local to an executable or shared library, or in the kernel, module. Thus
      it does not make sense for a module to resolve a relocation against
      .TOC. to the kernel's .TOC. value. A module has its own .TOC., and
      indeed the powerpc64 module relocation processing ignores the kernel
      value of .TOC. and instead calculates a module-local value.
      This patch removes code involved in exporting the kernel .TOC., tweaks
      modpost to ignore an undefined .TOC., and the module loader to twiddle
      the section symbol so that .TOC. isn't seen as undefined.
      Note that if the kernel was compiled with -msingle-pic-base then ELFv2
      would not have function global entry code setting up r2. In that case
      the module call stubs would need to be modified to set up r2 using the
      kernel .TOC. value, requiring some of this code to be reinstated.
      mpe: Furthermore a change in binutils master (not yet released) causes
      the current way we handle the TOC to no longer work when building with
      MODVERSIONS=y and RELOCATABLE=n. The symptom is that modules can not be
      loaded due to there being no version found for TOC.
      Cc: stable@vger.kernel.org # 3.16+
      Signed-off-by: 's avatarAlan Modra <amodra@gmail.com>
      Signed-off-by: Michael Ellerman's avatarMichael Ellerman <mpe@ellerman.id.au>
  36. 15 Jan, 2016 1 commit