Eric Lee / smarc-fsl-linux-kernel

14 Dec, 2014

1 commit

  • 51f39a1f0   syscalls: implement execveat() system call ... Browse Code »

    This patchset adds execveat(2) for x86, and is derived from Meredydd
    Luff's patch from Sept 2012 (https://lkml.org/lkml/2012/9/11/528).

    The primary aim of adding an execveat syscall is to allow an
    implementation of fexecve(3) that does not rely on the /proc filesystem,
    at least for executables (rather than scripts). The current glibc version
    of fexecve(3) is implemented via /proc, which causes problems in sandboxed
    or otherwise restricted environments.

    Given the desire for a /proc-free fexecve() implementation, HPA suggested
    (https://lkml.org/lkml/2006/7/11/556) that an execveat(2) syscall would be
    an appropriate generalization.

    Also, having a new syscall means that it can take a flags argument without
    back-compatibility concerns. The current implementation just defines the
    AT_EMPTY_PATH and AT_SYMLINK_NOFOLLOW flags, but other flags could be
    added in future -- for example, flags for new namespaces (as suggested at
    https://lkml.org/lkml/2006/7/11/474).

    Related history:
    - https://lkml.org/lkml/2006/12/27/123 is an example of someone
    realizing that fexecve() is likely to fail in a chroot environment.
    - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514043 covered
    documenting the /proc requirement of fexecve(3) in its manpage, to
    "prevent other people from wasting their time".
    - https://bugzilla.redhat.com/show_bug.cgi?id=241609 described a
    problem where a process that did setuid() could not fexecve()
    because it no longer had access to /proc/self/fd; this has since
    been fixed.

    This patch (of 4):

    Add a new execveat(2) system call. execveat() is to execve() as openat()
    is to open(): it takes a file descriptor that refers to a directory, and
    resolves the filename relative to that.

    In addition, if the filename is empty and AT_EMPTY_PATH is specified,
    execveat() executes the file to which the file descriptor refers. This
    replicates the functionality of fexecve(), which is a system call in other
    UNIXen, but in Linux glibc it depends on opening "/proc/self/fd/" (and
    so relies on /proc being mounted).

    The filename fed to the executed program as argv[0] (or the name of the
    script fed to a script interpreter) will be of the form "/dev/fd/"
    (for an empty filename) or "/dev/fd//", effectively
    reflecting how the executable was found. This does however mean that
    execution of a script in a /proc-less environment won't work; also, script
    execution via an O_CLOEXEC file descriptor fails (as the file will not be
    accessible after exec).

    Based on patches by Meredydd Luff.

    Signed-off-by: David Drysdale
    Cc: Meredydd Luff
    Cc: Shuah Khan
    Cc: "Eric W. Biederman"
    Cc: Andy Lutomirski
    Cc: Alexander Viro
    Cc: Thomas Gleixner
    Cc: Ingo Molnar
    Cc: "H. Peter Anvin"
    Cc: Kees Cook
    Cc: Arnd Bergmann
    Cc: Rich Felker
    Cc: Christoph Hellwig
    Cc: Michael Kerrisk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Drysdale
     

20 Mar, 2014

1 commit

  • 4b5884114   audit: Add generic compat syscall support ... Browse Code »

    lib/audit.c provides a generic function for auditing system calls.
    This patch extends it for compat syscall support on bi-architectures
    (32/64-bit) by adding lib/compat_audit.c.
    What is required to support this feature are:
    * add asm/unistd32.h for compat system call names
    * select CONFIG_AUDIT_ARCH_COMPAT_GENERIC

    Signed-off-by: AKASHI Takahiro
    Acked-by: Richard Guy Briggs
    Signed-off-by: Eric Paris

    AKASHI Takahiro
     

05 May, 2011

1 commit

11 May, 2007

2 commits

  • e54dc2431   [PATCH] audit signal recipients ... Browse Code »

    When auditing syscalls that send signals, log the pid and security
    context for each target process. Optimize the data collection by
    adding a counter for signal-related rules, and avoiding allocating an
    aux struct unless we have more than one target process. For process
    groups, collect pid/context data in blocks of 16. Move the
    audit_signal_info() hook up in check_kill_permission() so we audit
    attempts where permission is denied.

    Signed-off-by: Amy Griffis
    Signed-off-by: Al Viro

    Amy Griffis
     
  • 7f13da40e   [PATCH] add SIGNAL syscall class (v3) ... Browse Code »

    Add a syscall class for sending signals.

    Signed-off-by: Amy Griffis
    Signed-off-by: Al Viro

    Amy Griffis
     

23 Sep, 2006

1 commit

12 Sep, 2006

1 commit