07 Apr, 2014

1 commit

  • Pull module updates from Rusty Russell:
    "Nothing major: the stricter permissions checking for sysfs broke a
    staging driver; fix included. Greg KH said he'd take the patch but
    hadn't as the merge window opened, so it's included here to avoid
    breaking build"

    * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
    staging: fix up speakup kobject mode
    Use 'E' instead of 'X' for unsigned module taint flag.
    VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms.
    kallsyms: fix percpu vars on x86-64 with relocation.
    kallsyms: generalize address range checking
    module: LLVMLinux: Remove unused function warning from __param_check macro
    Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE
    module: remove MODULE_GENERIC_TABLE
    module: allow multiple calls to MODULE_DEVICE_TABLE() per module
    module: use pr_cont

    Linus Torvalds
     

31 Mar, 2014

1 commit

  • Takashi Iwai says:
    > The letter 'X' has been already used for SUSE kernels for very long
    > time, to indicate the external supported modules. Can the new flag be
    > changed to another letter for avoiding conflict...?
    > (BTW, we also use 'N' for "no support", too.)

    Note: this code should be cleaned up, so we don't have such maps in
    three places!

    Signed-off-by: Rusty Russell

    Rusty Russell
     

13 Mar, 2014

1 commit

  • Users have reported being unable to trace non-signed modules loaded
    within a kernel supporting module signature.

    This is caused by tracepoint.c:tracepoint_module_coming() refusing to
    take into account tracepoints sitting within force-loaded modules
    (TAINT_FORCED_MODULE). The reason for this check, in the first place, is
    that a force-loaded module may have a struct module incompatible with
    the layout expected by the kernel, and can thus cause a kernel crash
    upon forced load of that module on a kernel with CONFIG_TRACEPOINTS=y.

    Tracepoints, however, specifically accept TAINT_OOT_MODULE and
    TAINT_CRAP, since those modules do not lead to the "very likely system
    crash" issue cited above for force-loaded modules.

    With kernels having CONFIG_MODULE_SIG=y (signed modules), a non-signed
    module is tainted re-using the TAINT_FORCED_MODULE taint flag.
    Unfortunately, this means that Tracepoints treat that module as a
    force-loaded module, and thus silently refuse to consider any tracepoint
    within this module.

    Since an unsigned module does not fit within the "very likely system
    crash" category of tainting, add a new TAINT_UNSIGNED_MODULE taint flag
    to specifically address this taint behavior, and accept those modules
    within Tracepoints. We use the letter 'X' as a taint flag character for
    a module being loaded that doesn't know how to sign its name (proposed
    by Steven Rostedt).

    Also add the missing 'O' entry to trace event show_module_flags() list
    for the sake of completeness.

    Signed-off-by: Mathieu Desnoyers
    Acked-by: Steven Rostedt
    NAKed-by: Ingo Molnar
    CC: Thomas Gleixner
    CC: David Howells
    CC: Greg Kroah-Hartman
    Signed-off-by: Rusty Russell

    Mathieu Desnoyers
     

20 Feb, 2014

1 commit


13 Dec, 2013

1 commit

  • This patch adds the Documentation/module-signing.txt file that is
    currently missing from the Documentation directory. The init/Kconfig
    file references the Documentation/module-signing.txt file to explain
    how kernel module signing works. This patch supplies this documentation.

    Signed-off-by: James Solner
    Signed-off-by: David Howells

    James Solner