Skip to content

GitLab

Switch branch/tag
  1. 10 Feb, 2010 2 commits
  3. 09 Feb, 2010 2 commits
  5. 03 Feb, 2010 2 commits
  7. 30 Jan, 2010 2 commits
    • Jason Wessel's avatar
      perf, hw_breakpoint, kgdb: Do not take mutex for kernel debugger · 5352ae63
      Jason Wessel authored 
      This patch fixes the regression in functionality where the
kernel debugger and the perf API do not nicely share hw
breakpoint reservations.

The kernel debugger cannot use any mutex_lock() calls because it
can start the kernel running from an invalid context.

A mutex free version of the reservation API needed to get
created for the kernel debugger to safely update hw breakpoint
reservations.

The possibility for a breakpoint reservation to be concurrently
processed at the time that kgdb interrupts the system is
improbable. Should this corner case occur the end user is
warned, and the kernel debugger will prohibit updating the
hardware breakpoint reservations.

Any time the kernel debugger reserves a hardware breakpoint it
will be a system wide reservation.
Signed-off-by: default avatarJason Wessel <jason.wessel@windriver.com>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: torvalds@linux-foundation.org
LKML-Reference: <1264719883-7285-3-git-send-email-jason.wessel@windriver.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      5352ae63
    • Jason Wessel's avatar
      x86, hw_breakpoints, kgdb: Fix kgdb to use hw_breakpoint API · cc096749
      Jason Wessel authored 
      In the 2.6.33 kernel, the hw_breakpoint API is now used for the
performance event counters.  The hw_breakpoint_handler() now
consumes the hw breakpoints that were previously set by kgdb
arch specific code.  In order for kgdb to work in conjunction
with this core API change, kgdb must use some of the low level
functions of the hw_breakpoint API to install, uninstall, and
deal with hw breakpoint reservations.

The kgdb core required a change to call kgdb_disable_hw_debug
anytime a slave cpu enters kgdb_wait() in order to keep all the
hw breakpoints in sync as well as to prevent hitting a hw
breakpoint while kgdb is active.

During the architecture specific initialization of kgdb, it will
pre-allocate 4 disabled (struct perf event **) structures.  Kgdb
will use these to manage the capabilities for the 4 hw
breakpoint registers, per cpu.  Right now the hw_breakpoint API
does not have a way to ask how many breakpoints are available,
on each CPU so it is possible that the install of a breakpoint
might fail when kgdb restores the system to the run state.  The
intent of this patch is to first get the basic functionality of
hw breakpoints working and leave it to the person debugging the
kernel to understand what hw breakpoints are in use and what
restrictions have been imposed as a result.  Breakpoint
constraints will be dealt with in a future patch.

While atomic, the x86 specific kgdb code will call
arch_uninstall_hw_breakpoint() and arch_install_hw_breakpoint()
to manage the cpu specific hw breakpoints.

The net result of these changes allow kgdb to use the same pool
of hw_breakpoints that are used by the perf event API, but
neither knows about future reservations for the available hw
breakpoint slots.
Signed-off-by: default avatarJason Wessel <jason.wessel@windriver.com>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: torvalds@linux-foundation.org
LKML-Reference: <1264719883-7285-2-git-send-email-jason.wessel@windriver.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      cc096749
  9. 29 Jan, 2010 3 commits
    • David Härdeman's avatar
      x86: Add quirk for Intel DG45FC board to avoid low memory corruption · 7c099ce1
      David Härdeman authored 
      Commit 6aa542a6 added a quirk for the
Intel DG45ID board due to low memory corruption. The Intel DG45FC
shares the same BIOS (and the same bug) as noted in:

  http://bugzilla.kernel.org/show_bug.cgi?id=13736Signed-off-by: default avatarDavid Härdeman <david@hardeman.nu>
LKML-Reference: <20100128200254.GA9134@hardeman.nu>
Cc: <stable@kernel.org>
Cc: Alexey Fisher <bug-track@fisher-privat.net>
Cc: ykzhao <yakui.zhao@intel.com>
Cc: Tony Bones <aabonesml@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      7c099ce1
    • H. Peter Anvin's avatar
      x86: get rid of the insane TIF_ABI_PENDING bit · 05d43ed8
      H. Peter Anvin authored 
      Now that the previous commit made it possible to do the personality
setting at the point of no return, we do just that for ELF binaries.
And suddenly all the reasons for that insane TIF_ABI_PENDING bit go
away, and we can just make SET_PERSONALITY() just do the obvious thing
for a 32-bit compat process.

Everything becomes much more straightforward this way.
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      05d43ed8
    • Linus Torvalds's avatar
      Split 'flush_old_exec' into two functions · 221af7f8
      Linus Torvalds authored 
      'flush_old_exec()' is the point of no return when doing an execve(), and
it is pretty badly misnamed.  It doesn't just flush the old executable
environment, it also starts up the new one.

Which is very inconvenient for things like setting up the new
personality, because we want the new personality to affect the starting
of the new environment, but at the same time we do _not_ want the new
personality to take effect if flushing the old one fails.

As a result, the x86-64 '32-bit' personality is actually done using this
insane "I'm going to change the ABI, but I haven't done it yet" bit
(TIF_ABI_PENDING), with SET_PERSONALITY() not actually setting the
personality, but just the "pending" bit, so that "flush_thread()" can do
the actual personality magic.

This patch in no way changes any of that insanity, but it does split the
'flush_old_exec()' function up into a preparatory part that can fail
(still called flush_old_exec()), and a new part that will actually set
up the new exec environment (setup_new_exec()).  All callers are changed
to trivially comply with the new world order.
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      221af7f8
  11. 28 Jan, 2010 2 commits
  13. 27 Jan, 2010 2 commits
  15. 25 Jan, 2010 7 commits
  17. 24 Jan, 2010 1 commit
    • H. Peter Anvin's avatar
      x86: Remove "x86 CPU features in debugfs" (CONFIG_X86_CPU_DEBUG) · b1600918
      H. Peter Anvin authored 
      CONFIG_X86_CPU_DEBUG, which provides some parsed versions of the x86
CPU configuration via debugfs, has caused boot failures on real
hardware.  The value of this feature has been marginal at best, as all
this information is already available to userspace via generic
interfaces.

Causes crashes that have not been fixed + minimal utility -> remove.

See the referenced LKML thread for more information.
Reported-by: default avatarOzan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
LKML-Reference: <alpine.LFD.2.00.1001221755320.13231@localhost.localdomain>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: <stable@kernel.org>
      b1600918
  19. 23 Jan, 2010 3 commits
  21. 22 Jan, 2010 4 commits
  23. 21 Jan, 2010 1 commit
  25. 18 Jan, 2010 2 commits
  27. 17 Jan, 2010 1 commit
  29. 15 Jan, 2010 2 commits
  31. 13 Jan, 2010 4 commits