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Commit Graph

2955 Commits

Author SHA1 Message Date
Rusty Russell
6c730bfc89 modpost: handle -ffunction-sections
52dc0595d5 introduced OTHER_TEXT_SECTIONS for identifying what
sections could validly have __ex_table entries.  Unfortunately, it
wasn't tested with -ffunction-sections, which some architectures
use.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-22 17:31:31 +09:30
Thierry Reding
d7e0abcf4c modpost: Whitelist .text.fixup and .exception.text
32-bit and 64-bit ARM use these sections to store executable code, so
they must be whitelisted in modpost's table of valid text sections.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-22 17:31:20 +09:30
Quentin Casasnovas
e5d8f59a5c modpost: document the use of struct section_check.
struct section_check is used as a generic way of describing what
relocations are authorized/forbidden when running modpost.  This commit
tries to describe how each field is used.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (Fixed "mist"ake)
2015-04-13 21:03:04 +09:30
Quentin Casasnovas
52dc0595d5 modpost: handle relocations mismatch in __ex_table.
__ex_table is a simple table section where each entry is a pair of
addresses - the first address is an address which can fault in kernel
space, and the second address points to where the kernel should jump to
when handling that fault.  This is how copy_from_user() does not crash the
kernel if userspace gives a borked pointer for example.

If one of these addresses point to a non-executable section, something is
seriously wrong since it either means the kernel will never fault from
there or it will not be able to jump to there.  As both cases are serious
enough, we simply error out in these cases so the build fails and the
developper has to fix the issue.

In case the section is executable, but it isn't referenced in our list of
authorized sections to point to from __ex_table, we just dump a warning
giving more information about it.  We do this in case the new section is
executable but isn't supposed to be executed by the kernel.  This happened
with .altinstr_replacement, which is executable but is only used to copy
instructions from - we should never have our instruction pointer pointing
in .altinstr_replacement.  Admitedly, a proper fix in that case would be to
just set .altinstr_replacement NX, but we need to warn about future cases
like this.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (added long casts)
2015-04-13 21:03:03 +09:30
Quentin Casasnovas
c31e4b832f scripts: add check_extable.sh script.
This shell script can be used to sanity check the __ex_table section on an
object file, making sure the relocations in there are pointing to valid
executable sections.  If it finds some suspicious relocations, it'll use
addr2line to try and dump where this is coming from.

This works best with CONFIG_DEBUG_INFO.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-13 21:03:02 +09:30
Quentin Casasnovas
c7a65e0645 modpost: mismatch_handler: retrieve tosym information only when needed.
Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-13 21:03:01 +09:30
Quentin Casasnovas
356ad53812 modpost: factorize symbol pretty print in get_pretty_name().
Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-13 21:03:00 +09:30
Quentin Casasnovas
644e8f14cb modpost: add handler function pointer to sectioncheck.
This will be useful when we want to have special handlers which need to go
through more hops to print useful information to the user.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-13 21:02:59 +09:30
Quentin Casasnovas
157d1972d0 modpost: add .sched.text and .kprobes.text to the TEXT_SECTIONS list.
sched.text and .kprobes.text should behave exactly like .text with regards
to how we should warn about referencing sections which might get discarded
at runtime.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-13 21:02:58 +09:30
Quentin Casasnovas
050e57fd59 modpost: add strict white-listing when referencing sections.
Prints a warning when a section references a section outside a strict
white-list.  This will be useful to print a warning if __ex_table
references a non-executable section.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-13 21:02:57 +09:30
Jan Kiszka
586a1a125e scripts/gdb: add empty package initialization script
This got lost during the initial merge process: Python requires an
__init__.py script, even if empty, in order to accept a directory as
package.  Add it, this time as a non-empty file.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-28 09:57:51 -08:00
Linus Torvalds
b11a278397 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kconfig updates from Michal Marek:
 "Yann E Morin was supposed to take over kconfig maintainership, but
  this hasn't happened.  So I'm sending a few kconfig patches that I
  collected:

   - Fix for missing va_end in kconfig
   - merge_config.sh displays used if given too few arguments
   - s/boolean/bool/ in Kconfig files for consistency, with the plan to
     only support bool in the future"

* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kconfig: use va_end to match corresponding va_start
  merge_config.sh: Display usage if given too few arguments
  kconfig: use bool instead of boolean for type definition attributes
2015-02-19 10:36:45 -08:00
Linus Torvalds
7734334337 Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull misc kbuild changes from Michal Marek:
 "Just a few non-critical kbuild changes:

   - builddeb adds the actual distribution name in the changelog
   - documentation fixes"

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: trivial - fix the help doc of CONFIG_CC_OPTIMIZE_FOR_SIZE
  kbuild: Update documentation of clean-files and clean-dirs
  builddeb: Try to determine distribution
  builddeb: Update year and git repository URL in debian/copyright
2015-02-19 10:31:37 -08:00
Linus Torvalds
27a22ee4c7 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek:

 - several cleanups in kbuild

 - serialize multiple *config targets so that 'make defconfig kvmconfig'
   works

 - The cc-ifversion macro got support for an else-branch

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild,gcov: simplify kernel/gcov/Makefile more
  kbuild: allow cc-ifversion to have the argument for false condition
  kbuild,gcov: simplify kernel/gcov/Makefile
  kbuild,gcov: remove unnecessary workaround
  kbuild: do not add $(call ...) to invoke cc-version or cc-fullversion
  kbuild: fix cc-ifversion macro
  kbuild: drop $(version_h) from MRPROPER_FILES
  kbuild: use mixed-targets when two or more config targets are given
  kbuild: remove redundant line from bounds.h/asm-offsets.h
  kbuild: merge bounds.h and asm-offsets.h rules
  kbuild: Drop support for clean-rule
2015-02-19 10:07:08 -08:00
Jan Kiszka
a9c5bcfa43 scripts/gdb: disable pagination while printing from breakpoint handler
While reporting the (refreshed) list of modules on automatic updates we
may hit the page boundary of the output console and cause a stop if
pagination is enabled.  However, gdb does not accept user input while
running over the breakpoint handler.  So we get stuck, and the user is
forced to interrupt gdb.

Resolve this by disabling pagination during automatic symbol updates.  We
restore the user's configuration once done.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:55 -08:00
Jan Kiszka
a77e15e8b4 scripts/gdb: convert CpuList to generator function
Yet another code simplification.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:55 -08:00
Jan Kiszka
fffb944c4e scripts/gdb: convert ModuleList to generator function
Analogously to the task list, convert the module list to a generator
function.  It noticeably simplifies the code.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:55 -08:00
Daniel Wagner
54e2289a34 scripts/gdb: use a generator instead of iterator for task list
The iterator does not return any task_struct from the thread_group list
because the first condition in the 'if not t or ...' will only be the
first time None.

Instead of keeping track of the state ourself in the next() function, we
fall back using Python's generator.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Daniel Thompson
2478a8a15c scripts/gdb: ignore byte-compiled python files
Using the gdb scripts leaves byte-compiled python files in the scripts/
directory.  These should be ignored by git.

[jan.kiszka@siemens.com: drop redundant mrproper rule as suggested by Michal]
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Pantelis Koukousoulas
276d97d90a scripts/gdb: port to python3 / gdb7.7
I tried to use these scripts in an ubuntu 14.04 host (gdb 7.7 compiled
against python 3.3) but there were several errors.

I believe this patch fixes these issues so that the commands now work (I
tested lx-symbols, lx-dmesg, lx-lsmod).

Main issues that needed to be resolved:

  * In python 2 iterators have a "next()" method. In python 3 it is
    __next__() instead (so let's just add both).

  * In older python versions there was an implicit conversion
    in object.__format__() (used when an object is in string.format())
    where it was converting the object to str first and then
    calling str's __format__(). This has now been removed so
    we must explicitly convert to str the objects for which
    we need to keep this behavior.

  * In dmesg.py: in python 3 log_buf is now a "memoryview" object
    which needs to be converted to a string in order to use string
    methods like "splitlines()". Luckily memoryview exists in
    python 2.7.6 as well, so we can convert log_buf to memoryview
    and use the same code in both python 2 and python 3.

This version of the patch has now been tested with gdb 7.7 and both python
3.4 and python 2.7.6 (I think asking for at least python 2.7.6 is a
reasonable requirement instead of complicating the code with version
checks etc).

Signed-off-by: Pantelis Koukousoulas <pktoss@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
5403727f98 scripts/gdb: add lx-lsmod command
This adds a lsmod-like command to list all currently loaded modules of the
target.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
3d4cd9c941 scripts/gdb: add class to iterate over CPU masks
Will be used first to count module references.  It is optimized to read
the mask only once per stop.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
116b47b4da scripts/gdb: add lx_current convenience function
This is a shorthand for *$lx_per_cpu("current_task"), i.e.  a convenience
function to retrieve the currently running task of the active context.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
fe7f9ed98d scripts/gdb: add internal helper and convenience function for per-cpu lookup
This function allows to obtain a per-cpu variable, either of the current
or an explicitly specified CPU.

Note: sparc64 version is untested.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
a4d86792c7 scripts/gdb: add get_gdbserver_type helper
This helper probes the type of the gdb server.  Supported are QEMU and
KGDB so far.  Knowledge about the gdb server is required e.g.  to
retrieve the current CPU or current task.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
cf7492e933 scripts/gdb: add internal helper and convenience function to retrieve thread_info
Add the internal helper get_thread_info that calculates the thread_info
from a given task variable.  Also export this service as a convenience
function.

Note: ia64 version is untested.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
b24e2d21ac scripts/gdb: add is_target_arch helper
This helper caches to result of "show architecture" and matches the
provided arch (sub-)string against that output.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
4752871081 scripts/gdb: add helper and convenience function to look up tasks
Add the helper task_by_pid that can look up a task by its PID.  Also
export it as a convenience function.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
7704d58a85 scripts/gdb: add task iteration class
This class allows to iterate over all tasks of the target.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:54 -08:00
Jan Kiszka
ae7dbaad23 scripts/gdb: add lx-dmesg command
This pokes into the log buffer of the debugged kernel, dumping it to the
gdb console.  Helping in case the target should or can no longer execute
dmesg itself.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
78e8781723 scripts/gdb: add read_u16/32/64 helpers
Add helpers for reading integers from target memory buffers.  Required
when caching the memory access is more efficient than reading individual
values via gdb.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
7f99496374 scripts/gdb: add get_target_endianness helper
Parse the target endianness from the output of "show endian" and cache the
result to return it via the new helper get_target_endiannes.  We will need
it for reading integers from buffers that contain target memory.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
7b599ef535 scripts/gdb: add internal helper and convenience function to look up a module
Add the internal helper get_module_by_name to obtain the module structure
corresponding to the given name.  Also export this service as a
convenience function.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
82b41e3d61 scripts/gdb: add automatic symbol reloading on module insertion
This installs a silent breakpoint on the do_init_module function.  The
breakpoint handler will try to load symbols from the module files found
during lx-symbols execution.  This way, breakpoints can be set to module
initialization functions, and there is no need to explicitly call
lx-symbols after (re-)loading a module.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
66051720b8 scripts/gdb: add lx-symbols command
This is probably the most useful helper when debugging kernel modules:
lx-symbols first reloads vmlinux.  Then it searches recursively for *.ko
files in the specified paths and the current directory.  Finally it walks
the kernel's module list, issuing the necessary add-symbol-file command
for each loaded module so that gdb knows which module symbol corresponds
to which address.  It also looks up variable sections (bss, data, rodata)
and appends their address to the add-symbole-file command line.  This
allows to access global module variables just like any other variable.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
850202e17d scripts/gdb: add module iteration class
Will soon be used for loading symbols, printing global variables or
listing modules.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
b0fecd8c57 scripts/gdb: add container_of helper and convenience function
Provide an internal helper with container_of semantics.  As type lookups
are very slow in gdb-python and we need a type "long" for this, cache the
reference to this type object.  Then export the helper also as a
convenience function form use at the gdb command line.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
2b514827ef scripts/gdb: add cache for type objects
Type lookups are very slow in gdb-python which is often noticeable when
iterating over a number of objects.  Introduce the helper class CachedType
that keeps a reference to a gdb.Type object but also refreshes it after an
object file has been loaded.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Jan Kiszka
3ee7b3fa2c scripts/gdb: add infrastructure
This provides the basic infrastructure to load kernel-specific python
helper scripts when debugging the kernel in gdb.

The loading mechanism is based on gdb loading for <objfile>-gdb.py when
opening <objfile>.  Therefore, this places a corresponding link to the
main helper script into the output directory that contains vmlinux.

The main scripts will pull in submodules containing Linux specific gdb
commands and functions.  To avoid polluting the source directory with
compiled python modules, we link to them from the object directory.

Due to gdb.parse_and_eval and string redirection for gdb.execute, we
depend on gdb >= 7.2.

This feature is enabled via CONFIG_GDB_SCRIPTS.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Michal Marek <mmarek@suse.cz>		[kbuild stuff]
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-17 14:34:53 -08:00
Matthew Wilcox
6cd176a51e vfs,ext2: remove CONFIG_EXT2_FS_XIP and rename CONFIG_FS_XIP to CONFIG_FS_DAX
The fewer Kconfig options we have the better.  Use the generic
CONFIG_FS_DAX to enable XIP support in ext2 as well as in the core.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:04 -08:00
Andrey Ryabinin
bebf56a1b1 kasan: enable instrumentation of global variables
This feature let us to detect accesses out of bounds of global variables.
This will work as for globals in kernel image, so for globals in modules.
Currently this won't work for symbols in user-specified sections (e.g.
__init, __read_mostly, ...)

The idea of this is simple.  Compiler increases each global variable by
redzone size and add constructors invoking __asan_register_globals()
function.  Information about global variable (address, size, size with
redzone ...) passed to __asan_register_globals() so we could poison
variable's redzone.

This patch also forces module_alloc() to return 8*PAGE_SIZE aligned
address making shadow memory handling (
kasan_module_alloc()/kasan_module_free() ) more simple.  Such alignment
guarantees that each shadow page backing modules address space correspond
to only one module_alloc() allocation.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:42 -08:00
Andrey Ryabinin
9ddf82521c kernel: add support for .init_array.* constructors
KASan uses constructors for initializing redzones for global variables.
Globals instrumentation in GCC 4.9.2 produces constructors with priority
(.init_array.00099)

Currently kernel ignores such constructors.  Only constructors with
default priority supported (.init_array)

This patch adds support for constructors with priorities.  For kernel
image we put pointers to constructors between __ctors_start/__ctors_end
and do_ctors() will call them on start up.  For modules we merge
.init_array.* sections into resulting .init_array.  Module code properly
handles constructors in .init_array section.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:42 -08:00
Andrey Ryabinin
c420f167db kasan: enable stack instrumentation
Stack instrumentation allows to detect out of bounds memory accesses for
variables allocated on stack.  Compiler adds redzones around every
variable on stack and poisons redzones in function's prologue.

Such approach significantly increases stack usage, so all in-kernel stacks
size were doubled.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:41 -08:00
Andrey Ryabinin
0b24becc81 kasan: add kernel address sanitizer infrastructure
Kernel Address sanitizer (KASan) is a dynamic memory error detector.  It
provides fast and comprehensive solution for finding use-after-free and
out-of-bounds bugs.

KASAN uses compile-time instrumentation for checking every memory access,
therefore GCC > v4.9.2 required.  v4.9.2 almost works, but has issues with
putting symbol aliases into the wrong section, which breaks kasan
instrumentation of globals.

This patch only adds infrastructure for kernel address sanitizer.  It's
not available for use yet.  The idea and some code was borrowed from [1].

Basic idea:

The main idea of KASAN is to use shadow memory to record whether each byte
of memory is safe to access or not, and use compiler's instrumentation to
check the shadow memory on each memory access.

Address sanitizer uses 1/8 of the memory addressable in kernel for shadow
memory and uses direct mapping with a scale and offset to translate a
memory address to its corresponding shadow address.

Here is function to translate address to corresponding shadow address:

     unsigned long kasan_mem_to_shadow(unsigned long addr)
     {
                return (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET;
     }

where KASAN_SHADOW_SCALE_SHIFT = 3.

So for every 8 bytes there is one corresponding byte of shadow memory.
The following encoding used for each shadow byte: 0 means that all 8 bytes
of the corresponding memory region are valid for access; k (1 <= k <= 7)
means that the first k bytes are valid for access, and other (8 - k) bytes
are not; Any negative value indicates that the entire 8-bytes are
inaccessible.  Different negative values used to distinguish between
different kinds of inaccessible memory (redzones, freed memory) (see
mm/kasan/kasan.h).

To be able to detect accesses to bad memory we need a special compiler.
Such compiler inserts a specific function calls (__asan_load*(addr),
__asan_store*(addr)) before each memory access of size 1, 2, 4, 8 or 16.

These functions check whether memory region is valid to access or not by
checking corresponding shadow memory.  If access is not valid an error
printed.

Historical background of the address sanitizer from Dmitry Vyukov:

	"We've developed the set of tools, AddressSanitizer (Asan),
	ThreadSanitizer and MemorySanitizer, for user space. We actively use
	them for testing inside of Google (continuous testing, fuzzing,
	running prod services). To date the tools have found more than 10'000
	scary bugs in Chromium, Google internal codebase and various
	open-source projects (Firefox, OpenSSL, gcc, clang, ffmpeg, MySQL and
	lots of others): [2] [3] [4].
	The tools are part of both gcc and clang compilers.

	We have not yet done massive testing under the Kernel AddressSanitizer
	(it's kind of chicken and egg problem, you need it to be upstream to
	start applying it extensively). To date it has found about 50 bugs.
	Bugs that we've found in upstream kernel are listed in [5].
	We've also found ~20 bugs in out internal version of the kernel. Also
	people from Samsung and Oracle have found some.

	[...]

	As others noted, the main feature of AddressSanitizer is its
	performance due to inline compiler instrumentation and simple linear
	shadow memory. User-space Asan has ~2x slowdown on computational
	programs and ~2x memory consumption increase. Taking into account that
	kernel usually consumes only small fraction of CPU and memory when
	running real user-space programs, I would expect that kernel Asan will
	have ~10-30% slowdown and similar memory consumption increase (when we
	finish all tuning).

	I agree that Asan can well replace kmemcheck. We have plans to start
	working on Kernel MemorySanitizer that finds uses of unitialized
	memory. Asan+Msan will provide feature-parity with kmemcheck. As
	others noted, Asan will unlikely replace debug slab and pagealloc that
	can be enabled at runtime. Asan uses compiler instrumentation, so even
	if it is disabled, it still incurs visible overheads.

	Asan technology is easily portable to other architectures. Compiler
	instrumentation is fully portable. Runtime has some arch-dependent
	parts like shadow mapping and atomic operation interception. They are
	relatively easy to port."

Comparison with other debugging features:
========================================

KMEMCHECK:

  - KASan can do almost everything that kmemcheck can.  KASan uses
    compile-time instrumentation, which makes it significantly faster than
    kmemcheck.  The only advantage of kmemcheck over KASan is detection of
    uninitialized memory reads.

    Some brief performance testing showed that kasan could be
    x500-x600 times faster than kmemcheck:

$ netperf -l 30
		MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost (127.0.0.1) port 0 AF_INET
		Recv   Send    Send
		Socket Socket  Message  Elapsed
		Size   Size    Size     Time     Throughput
		bytes  bytes   bytes    secs.    10^6bits/sec

no debug:	87380  16384  16384    30.00    41624.72

kasan inline:	87380  16384  16384    30.00    12870.54

kasan outline:	87380  16384  16384    30.00    10586.39

kmemcheck: 	87380  16384  16384    30.03      20.23

  - Also kmemcheck couldn't work on several CPUs.  It always sets
    number of CPUs to 1.  KASan doesn't have such limitation.

DEBUG_PAGEALLOC:
	- KASan is slower than DEBUG_PAGEALLOC, but KASan works on sub-page
	  granularity level, so it able to find more bugs.

SLUB_DEBUG (poisoning, redzones):
	- SLUB_DEBUG has lower overhead than KASan.

	- SLUB_DEBUG in most cases are not able to detect bad reads,
	  KASan able to detect both reads and writes.

	- In some cases (e.g. redzone overwritten) SLUB_DEBUG detect
	  bugs only on allocation/freeing of object. KASan catch
	  bugs right before it will happen, so we always know exact
	  place of first bad read/write.

[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel
[2] https://code.google.com/p/address-sanitizer/wiki/FoundBugs
[3] https://code.google.com/p/thread-sanitizer/wiki/FoundBugs
[4] https://code.google.com/p/memory-sanitizer/wiki/FoundBugs
[5] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel#Trophies

Based on work by Andrey Konovalov.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:40 -08:00
Joe Perches
0f3c5aab5e checkpatch: add of_device_id to structs that should be const
Uses of struct of_device_id are most commonly const.

Suggest using it as such.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:40 -08:00
Joe Perches
a2fe16b9d8 checkpatch: try to avoid poor patch subject lines
Naming the tool that found an issue in the subject line isn't very useful.
 Emit a warning when a common tool (currently checkpatch, sparse or
smatch) is in the subject line.

Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:40 -08:00
Joe Perches
19c146a64c checkpatch: make sure a commit reference description uses parentheses
The preferred style for a commit reference in a commit log is:

    commit <foo> ("<title line>")

A recent commit removed this check for parentheses.  Add it back.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:40 -08:00
Joe Perches
d2e025f364 checkpatch: add --strict test for spaces around arithmetic
Some prefer code to have spaces around arithmetic so instead of:
        a = b*c+d;
suggest
        a = b * c + d;

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:40 -08:00
Joe Perches
101ee6802a checkpatch: neaten printk_ratelimited message position
Just neatening...

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:40 -08:00
Joe Perches
43f7fe52a8 checkpatch: improve "no space necessary after cast" test
Code like:
	if (a < sizeof(<type>) &&
and
	{ .len = sizeof(<type>) },

incorrectly emits that warning, so add more exceptions to avoid
the warning.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:40 -08:00