25 Jun, 2018

1 commit

  • When building a 64-bit 4.18-rc1 kernel with a 32-bit userland, I
    noticed that stack protection was silently disabled. Adding -m64 in
    gcc-x86_64-has-stack-protector.sh fixed that, similar to what has been
    noticed in commit 2a61f4747eea ("stack-protector: test compiler
    capability in Kconfig and drop AUTO mode") for
    gcc-x86_32-has-stack-protector.sh.

    Signed-off-by: Sven Joachim
    Signed-off-by: Masahiro Yamada

    Sven Joachim
     

08 Jun, 2018

1 commit

  • Move the test for -fstack-protector(-strong) option to Kconfig.

    If the compiler does not support the option, the corresponding menu
    is automatically hidden. If STRONG is not supported, it will fall
    back to REGULAR. If REGULAR is not supported, it will be disabled.
    This means, AUTO is implicitly handled by the dependency solver of
    Kconfig, hence removed.

    I also turned the 'choice' into only two boolean symbols. The use of
    'choice' is not a good idea here, because all of all{yes,mod,no}config
    would choose the first visible value, while we want allnoconfig to
    disable as many features as possible.

    X86 has additional shell scripts in case the compiler supports those
    options, but generates broken code. I added CC_HAS_SANE_STACKPROTECTOR
    to test this. I had to add -m32 to gcc-x86_32-has-stack-protector.sh
    to make it work correctly.

    Signed-off-by: Masahiro Yamada
    Acked-by: Kees Cook

    Masahiro Yamada
     

02 Nov, 2017

1 commit

  • 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
    Reviewed-by: Philippe Ombredanne
    Reviewed-by: Thomas Gleixner
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

10 Nov, 2016

1 commit

  • Adding -no-PIE to the fstack protector check. -no-PIE was introduced
    before -fstack-protector so there is no need for a runtime check.

    Without it the build stops:
    |Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: -fstack-protector-strong available but compiler is broken

    due to -mcmodel=kernel + -fPIE if -fPIE is enabled by default.

    Tagging it stable so it is possible to compile recent stable kernels as
    well.

    Cc: stable@vger.kernel.org
    Signed-off-by: Sebastian Andrzej Siewior
    Signed-off-by: Michal Marek

    Sebastian Andrzej Siewior
     

20 Aug, 2014

1 commit


03 Oct, 2012

1 commit

  • The correct syntax for gcc -x is "gcc -x assembler", not
    "gcc -xassembler". Even though the latter happens to work, the former
    is what is documented in the manual page and thus what gcc wrappers
    such as icecream do expect.

    This isn't a cosmetic change. The missing space prevents icecream from
    recognizing compilation tasks it can't handle, leading to silent kernel
    miscompilations.

    Besides me, credits go to Michael Matz and Dirk Mueller for
    investigating the miscompilation issue and tracking it down to this
    incorrect -x parameter syntax.

    Signed-off-by: Jean Delvare
    Acked-by: Ingo Molnar
    Cc: stable@vger.kernel.org
    Cc: Bernhard Walle
    Cc: Michal Marek
    Cc: Ralf Baechle
    Signed-off-by: Michal Marek

    Jean Delvare
     

11 Feb, 2009

1 commit


10 Feb, 2009

1 commit

  • Impact: no default -fno-stack-protector if stackp is enabled, cleanup

    Stackprotector make rules had the following problems.

    * cc support test and warning are scattered across makefile and
    kernel/panic.c.

    * -fno-stack-protector was always added regardless of configuration.

    Update such that cc support test and warning are contained in makefile
    and -fno-stack-protector is added iff stackp is turned off. While at
    it, prepare for 32bit support.

    Signed-off-by: Tejun Heo
    Signed-off-by: Ingo Molnar

    Tejun Heo
     

26 Sep, 2006

1 commit

  • Add a feature check that checks that the gcc compiler has stack-protector
    support and has the bugfix for PR28281 to make this work in kernel mode.
    The easiest solution I could find was to have a shell script in scripts/
    to do the detection; if needed we can make this fancier in the future
    without making the makefile too complex.

    Signed-off-by: Arjan van de Ven
    Signed-off-by: Andi Kleen
    CC: Andi Kleen
    CC: Sam Ravnborg

    Arjan van de Ven