Commit Graph

47 Commits

Author SHA1 Message Date
Mark Brown
264c03a245 stacktrace: Remove reliable argument from arch_stack_walk() callback
Currently the callback passed to arch_stack_walk() has an argument called
reliable passed to it to indicate if the stack entry is reliable, a comment
says that this is used by some printk() consumers. However in the current
kernel none of the arch_stack_walk() implementations ever set this flag to
true and the only callback implementation we have is in the generic
stacktrace code which ignores the flag. It therefore appears that this
flag is redundant so we can simplify and clarify things by removing it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/20200914153409.25097-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-09-18 14:24:16 +01:00
Josh Poimboeuf
039a7a30ec x86/stacktrace: Fix reliable check for empty user task stacks
If a user task's stack is empty, or if it only has user regs, ORC
reports it as a reliable empty stack.  But arch_stack_walk_reliable()
incorrectly treats it as unreliable.

That happens because the only success path for user tasks is inside the
loop, which only iterates on non-empty stacks.  Generally, a user task
must end in a user regs frame, but an empty stack is an exception to
that rule.

Thanks to commit 71c9582528 ("x86/unwind/orc: Fix error handling in
__unwind_start()"), unwind_start() now sets state->error appropriately.
So now for both ORC and FP unwinders, unwind_done() and !unwind_error()
always means the end of the stack was successfully reached.  So the
success path for kthreads is no longer needed -- it can also be used for
empty user tasks.

Reported-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Link: https://lkml.kernel.org/r/f136a4e5f019219cbc4f4da33b30c2f44fa65b84.1594994374.git.jpoimboe@redhat.com
2020-07-22 23:47:47 +02:00
Al Viro
c8e3dd8660 x86 user stack frame reads: switch to explicit __get_user()
rather than relying upon the magic in raw_copy_from_user()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-15 17:26:26 -05:00
Eiichi Tsukata
2af7c85714 x86/stacktrace: Prevent access_ok() warnings in arch_stack_walk_user()
When arch_stack_walk_user() is called from atomic contexts, access_ok() can
trigger the following warning if compiled with CONFIG_DEBUG_ATOMIC_SLEEP=y.

Reproducer:

  // CONFIG_DEBUG_ATOMIC_SLEEP=y
  # cd /sys/kernel/debug/tracing
  # echo 1 > options/userstacktrace
  # echo 1 > events/irq/irq_handler_entry/enable

  WARNING: CPU: 0 PID: 2649 at arch/x86/kernel/stacktrace.c:103 arch_stack_walk_user+0x6e/0xf6
  CPU: 0 PID: 2649 Comm: bash Not tainted 5.3.0-rc1+ #99
  RIP: 0010:arch_stack_walk_user+0x6e/0xf6
  Call Trace:
   <IRQ>
   stack_trace_save_user+0x10a/0x16d
   trace_buffer_unlock_commit_regs+0x185/0x240
   trace_event_buffer_commit+0xec/0x330
   trace_event_raw_event_irq_handler_entry+0x159/0x1e0
   __handle_irq_event_percpu+0x22d/0x440
   handle_irq_event_percpu+0x70/0x100
   handle_irq_event+0x5a/0x8b
   handle_edge_irq+0x12f/0x3f0
   handle_irq+0x34/0x40
   do_IRQ+0xa6/0x1f0
   common_interrupt+0xf/0xf
   </IRQ>

Fix it by calling __range_not_ok() directly instead of access_ok() as
copy_from_user_nmi() does. This is fine here because the actual copy is
inside a pagefault disabled region.

Reported-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190722083216.16192-2-devel@etsukata.com
2019-07-22 10:42:36 +02:00
Eiichi Tsukata
cbf5b73d16 x86/stacktrace: Prevent infinite loop in arch_stack_walk_user()
arch_stack_walk_user() checks `if (fp == frame.next_fp)` to prevent a
infinite loop by self reference but it's not enogh for circular reference.

Once a lack of return address is found, there is no point to continue the
loop, so break out.

Fixes: 02b67518e2 ("tracing: add support for userspace stacktraces in tracing/iter_ctrl")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20190711023501.963-1-devel@etsukata.com
2019-07-11 08:22:03 +02:00
Thomas Gleixner
3599fe12a1 x86/stacktrace: Use common infrastructure
Replace the stack_trace_save*() functions with the new arch_stack_walk()
interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: linux-arch@vger.kernel.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20190425094803.816485461@linutronix.de
2019-04-29 12:37:57 +02:00
Thomas Gleixner
c5c27a0a58 x86/stacktrace: Remove the pointless ULONG_MAX marker
Terminating the last trace entry with ULONG_MAX is a completely pointless
exercise and none of the consumers can rely on it because it's
inconsistently implemented across architectures. In fact quite some of the
callers remove the entry and adjust stack_trace.nr_entries afterwards.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Potapenko <glider@google.com>
Link: https://lkml.kernel.org/r/20190410103643.750954603@linutronix.de
2019-04-14 19:58:27 +02:00
Linus Torvalds
96d4f267e4 Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03 18:57:57 -08:00
Jiri Slaby
0c414367c0 x86/stacktrace: Do not fail for ORC with regs on stack
save_stack_trace_reliable now returns "non reliable" when there are
kernel pt_regs on stack. This means an interrupt or exception happened
somewhere down the route. It is a problem for the frame pointer
unwinder, because the frame might not have been set up yet when the irq
happened, so the unwinder might fail to unwind from the interrupted
function.

With ORC, this is not a problem, as ORC has out-of-band data. We can
find ORC data even for the IP in the interrupted function and always
unwind one level up reliably.

So lift the check to apply only when CONFIG_FRAME_POINTER=y is enabled.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/lkml/20180518064713.26440-4-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 16:34:56 +02:00
Jiri Slaby
441ccc3580 x86/stacktrace: Clarify the reliable success paths
Make clear which path is for user tasks and for kthreads and idle
tasks. This will allow easier plug-in of the ORC unwinder in the next
patches.

Note that we added a check for unwind error to the top of the loop, so
that an error is returned also for user tasks (the 'goto success' would
skip the check after the loop otherwise).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/lkml/20180518064713.26440-3-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 16:34:55 +02:00
Jiri Slaby
17426923b0 x86/stacktrace: Remove STACKTRACE_DUMP_ONCE
The stack unwinding can sometimes fail yet. Especially with the
generated debug info. So do not yell at users -- live patching (the only
user of this interface) will inform the user about the failure
gracefully.

And given this was the only user of the macro, remove the macro proper
too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/lkml/20180518064713.26440-2-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 16:34:55 +02:00
Jiri Slaby
0797a8d0d7 x86/stacktrace: Do not unwind after user regs
Josh pointed out, that there is no way a frame can be after user regs.
So remove the last unwind and the check.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/lkml/20180518064713.26440-1-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-21 16:34:55 +02:00
Linus Torvalds
00a5ae218d Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 page table isolation fixes from Thomas Gleixner:
 "A couple of urgent fixes for PTI:

   - Fix a PTE mismatch between user and kernel visible mapping of the
     cpu entry area (differs vs. the GLB bit) and causes a TLB mismatch
     MCE on older AMD K8 machines

   - Fix the misplaced CR3 switch in the SYSCALL compat entry code which
     causes access to unmapped kernel memory resulting in double faults.

   - Fix the section mismatch of the cpu_tss_rw percpu storage caused by
     using a different mechanism for declaration and definition.

   - Two fixes for dumpstack which help to decode entry stack issues
     better

   - Enable PTI by default in Kconfig. We should have done that earlier,
     but it slipped through the cracks.

   - Exclude AMD from the PTI enforcement. Not necessarily a fix, but if
     AMD is so confident that they are not affected, then we should not
     burden users with the overhead"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/process: Define cpu_tss_rw in same section as declaration
  x86/pti: Switch to kernel CR3 at early in entry_SYSCALL_compat()
  x86/dumpstack: Print registers for first stack frame
  x86/dumpstack: Fix partial register dumps
  x86/pti: Make sure the user/kernel PTEs match
  x86/cpu, x86/pti: Do not enable PTI on AMD processors
  x86/pti: Enable PTI by default
2018-01-03 16:41:07 -08:00
Josh Poimboeuf
a9cdbe72c4 x86/dumpstack: Fix partial register dumps
The show_regs_safe() logic is wrong.  When there's an iret stack frame,
it prints the entire pt_regs -- most of which is random stack data --
instead of just the five registers at the end.

show_regs_safe() is also poorly named: the on_stack() checks aren't for
safety.  Rename the function to show_regs_if_on_stack() and add a
comment to explain why the checks are needed.

These issues were introduced with the "partial register dump" feature of
the following commit:

  b02fcf9ba1 ("x86/unwinder: Handle stack overflows more gracefully")

That patch had gone through a few iterations of development, and the
above issues were artifacts from a previous iteration of the patch where
'regs' pointed directly to the iret frame rather than to the (partially
empty) pt_regs.

Tested-by: Alexander Tsoy <alexander@tsoy.me>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toralf Förster <toralf.foerster@gmx.de>
Cc: stable@vger.kernel.org
Fixes: b02fcf9ba1 ("x86/unwinder: Handle stack overflows more gracefully")
Link: http://lkml.kernel.org/r/5b05b8b344f59db2d3d50dbdeba92d60f2304c54.1514736742.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-03 16:14:46 +01:00
Josh Poimboeuf
6454b3bdd1 x86/stacktrace: Make zombie stack traces reliable
Commit:

  1959a60182 ("x86/dumpstack: Pin the target stack when dumping it")

changed the behavior of stack traces for zombies.  Before that commit,
/proc/<pid>/stack reported the last execution path of the zombie before
it died:

  [<ffffffff8105b877>] do_exit+0x6f7/0xa80
  [<ffffffff8105bc79>] do_group_exit+0x39/0xa0
  [<ffffffff8105bcf0>] __wake_up_parent+0x0/0x30
  [<ffffffff8152dd09>] system_call_fastpath+0x16/0x1b
  [<00007fd128f9c4f9>] 0x7fd128f9c4f9
  [<ffffffffffffffff>] 0xffffffffffffffff

After the commit, it just reports an empty stack trace.

The new behavior is actually probably more correct.  If the stack
refcount has gone down to zero, then the task has already gone through
do_exit() and isn't going to run anymore.  The stack could be freed at
any time and is basically gone, so reporting an empty stack makes sense.

However, save_stack_trace_tsk_reliable() treats such a missing stack
condition as an error.  That can cause livepatch transition stalls if
there are any unreaped zombies.  Instead, just treat it as a reliable,
empty stack.

Reported-and-tested-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Fixes: af085d9084 ("stacktrace/x86: add function for detecting reliable stack traces")
Link: http://lkml.kernel.org/r/e4b09e630e99d0c1080528f0821fc9d9dbaeea82.1513631620.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-19 09:01:05 +01:00
Vlastimil Babka
77072f09ea x86/stacktrace: Avoid recording save_stack_trace() wrappers
The save_stack_trace() and save_stack_trace_tsk() wrappers of
__save_stack_trace() add themselves to the call stack, and thus appear in the
recorded stacktraces. This is redundant and wasteful when we have limited space
to record the useful part of the backtrace with e.g. page_owner functionality.

Fix this by making sure __save_stack_trace() is noinline (which matches the
current gcc decision) and bumping the skip in the wrappers
(save_stack_trace_tsk() only when called for the current task). This is similar
to what was done for arm in 3683f44c42 ("ARM: stacktrace: avoid listing
stacktrace functions in stacktrace") and is pending for arm64.

Also make sure that __save_stack_trace_reliable() doesn't get this problem in
the future by marking it __always_inline (which matches current gcc decision),
per Josh Poimboeuf.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170929092335.2744-1-vbabka@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-29 19:44:03 +02:00
Josh Poimboeuf
af085d9084 stacktrace/x86: add function for detecting reliable stack traces
For live patching and possibly other use cases, a stack trace is only
useful if it can be assured that it's completely reliable.  Add a new
save_stack_trace_tsk_reliable() function to achieve that.

Note that if the target task isn't the current task, and the target task
is allowed to run, then it could be writing the stack while the unwinder
is reading it, resulting in possible corruption.  So the caller of
save_stack_trace_tsk_reliable() must ensure that the task is either
'current' or inactive.

save_stack_trace_tsk_reliable() relies on the x86 unwinder's detection
of pt_regs on the stack.  If the pt_regs are not user-mode registers
from a syscall, then they indicate an in-kernel interrupt or exception
(e.g. preemption or a page fault), in which case the stack is considered
unreliable due to the nature of frame pointers.

It also relies on the x86 unwinder's detection of other issues, such as:

- corrupted stack data
- stack grows the wrong way
- stack walk doesn't reach the bottom
- user didn't provide a large enough entries array

Such issues are reported by checking unwind_error() and !unwind_done().

Also add CONFIG_HAVE_RELIABLE_STACKTRACE so arch-independent code can
determine at build time whether the function is implemented.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Ingo Molnar <mingo@kernel.org>	# for the x86 changes
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-03-08 09:18:02 +01:00
Ingo Molnar
68db0cf106 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:36 +01:00
Ingo Molnar
b17b01533b sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>
We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/debug.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:34 +01:00
Josh Poimboeuf
49a612c6b0 x86/stacktrace: Convert save_stack_trace_*() to use the new unwinder
Convert save_stack_trace_*() to use the new unwinder.  dump_trace() has
been deprecated.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/815494c627d89887db0ce56ceffd58ad16ee6c21.1474045023.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-20 08:29:33 +02:00
Andy Lutomirski
1959a60182 x86/dumpstack: Pin the target stack when dumping it
Specifically, pin the stack in save_stack_trace_tsk() and
show_trace_log_lvl().

This will prevent a crash if the target task dies before or while
dumping its stack once we start freeing task stacks early.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/cf0082cde65d1941a996d026f2b2cdbfaca17bfa.1474003868.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-16 09:18:53 +02:00
Josh Poimboeuf
cb76c93982 x86/dumpstack: Add get_stack_info() interface
valid_stack_ptr() is buggy: it assumes that all stacks are of size
THREAD_SIZE, which is not true for exception stacks.  So the
walk_stack() callbacks will need to know the location of the beginning
of the stack as well as the end.

Another issue is that in general the various features of a stack (type,
size, next stack pointer, description string) are scattered around in
various places throughout the stack dump code.

Encapsulate all that information in a single place with a new stack_info
struct and a get_stack_info() interface.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/8164dd0db96b7e6a279fa17ae5e6dc375eecb4a9.1473905218.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-15 08:13:15 +02:00
Paul Gortmaker
186f43608a x86/kernel: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed.  Build testing
revealed some implicit header usage that was fixed up accordingly.

Note that some bool/obj-y instances remain since module.h is
the header for some exception table entry stuff, and for things
like __init_or_module (code that is tossed when MODULES=n).

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160714001901.31603-4-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 15:06:41 +02:00
Alexei Starovoitov
568b329a02 perf: generalize perf_callchain
. avoid walking the stack when there is no room left in the buffer
. generalize get_perf_callchain() to be called from bpf helper

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-20 00:21:44 -05:00
Masami Hiramatsu
395810627b x86: Swap save_stack_trace_regs parameters
Swap the 1st and 2nd parameters of save_stack_trace_regs()
as same as the parameters of save_stack_trace_tsk().

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@gmail.com>
Link: http://lkml.kernel.org/r/20110608070921.17777.31103.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-06-14 22:48:51 -04:00
Richard Weinberger
449a66fd1f x86: Remove warning and warning_symbol from struct stacktrace_ops
Both warning and warning_symbol are nowhere used.
Let's get rid of them.

Signed-off-by: Richard Weinberger <richard@nod.at>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Soeren Sandmann Pedersen <ssp@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: x86 <x86@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Link: http://lkml.kernel.org/r/1305205872-10321-2-git-send-email-richard@nod.at
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2011-05-12 15:31:28 +02:00
Namhyung Kim
e8e999cf3c x86, dumpstack: Correct stack dump info when frame pointer is available
Current stack dump code scans entire stack and check each entry
contains a pointer to kernel code. If CONFIG_FRAME_POINTER=y it
could mark whether the pointer is valid or not based on value of
the frame pointer. Invalid entries could be preceded by '?' sign.

However this was not going to happen because scan start point
was always higher than the frame pointer so that they could not
meet.

Commit 9c0729dc80 ("x86: Eliminate bp argument from the stack
tracing routines") delayed bp acquisition point, so the bp was
read in lower frame, thus all of the entries were marked
invalid.

This patch fixes this by reverting above commit while retaining
stack_frame() helper as suggested by Frederic Weisbecker.

End result looks like below:

before:

 [    3.508329] Call Trace:
 [    3.508551]  [<ffffffff814f35c9>] ? panic+0x91/0x199
 [    3.508662]  [<ffffffff814f3739>] ? printk+0x68/0x6a
 [    3.508770]  [<ffffffff81a981b2>] ? mount_block_root+0x257/0x26e
 [    3.508876]  [<ffffffff81a9821f>] ? mount_root+0x56/0x5a
 [    3.508975]  [<ffffffff81a98393>] ? prepare_namespace+0x170/0x1a9
 [    3.509216]  [<ffffffff81a9772b>] ? kernel_init+0x1d2/0x1e2
 [    3.509335]  [<ffffffff81003894>] ? kernel_thread_helper+0x4/0x10
 [    3.509442]  [<ffffffff814f6880>] ? restore_args+0x0/0x30
 [    3.509542]  [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2
 [    3.509641]  [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10

after:

 [    3.522991] Call Trace:
 [    3.523351]  [<ffffffff814f35b9>] panic+0x91/0x199
 [    3.523468]  [<ffffffff814f3729>] ? printk+0x68/0x6a
 [    3.523576]  [<ffffffff81a981b2>] mount_block_root+0x257/0x26e
 [    3.523681]  [<ffffffff81a9821f>] mount_root+0x56/0x5a
 [    3.523780]  [<ffffffff81a98393>] prepare_namespace+0x170/0x1a9
 [    3.523885]  [<ffffffff81a9772b>] kernel_init+0x1d2/0x1e2
 [    3.523987]  [<ffffffff81003894>] kernel_thread_helper+0x4/0x10
 [    3.524228]  [<ffffffff814f6880>] ? restore_args+0x0/0x30
 [    3.524345]  [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2
 [    3.524445]  [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10

 -v5:
   * fix build breakage with oprofile

 -v4:
   * use 0 instead of regs->bp
   * separate out printk changes

 -v3:
   * apply comment from Frederic
   * add a couple of printk fixes

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Soren Sandmann <ssp@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1300416006-3163-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 10:51:42 +01:00
Soeren Sandmann Pedersen
9c0729dc80 x86: Eliminate bp argument from the stack tracing routines
The various stack tracing routines take a 'bp' argument in which the
caller is supposed to provide the base pointer to use, or 0 if doesn't
have one. Since bp is garbage whenever CONFIG_FRAME_POINTER is not
defined, this means all callers in principle should either always pass
0, or be conditional on CONFIG_FRAME_POINTER.

However, there are only really three use cases for stack tracing:

(a) Trace the current task, including IRQ stack if any
(b) Trace the current task, but skip IRQ stack
(c) Trace some other task

In all cases, if CONFIG_FRAME_POINTER is not defined, bp should just
be 0.  If it _is_ defined, then

- in case (a) bp should be gotten directly from the CPU's register, so
  the caller should pass NULL for regs,

- in case (b) the caller should should pass the IRQ registers to
  dump_trace(),

- in case (c) bp should be gotten from the top of the task's stack, so
  the caller should pass NULL for regs.

Hence, the bp argument is not necessary because the combination of
task and regs is sufficient to determine an appropriate value for bp.

This patch introduces a new inline function stack_frame(task, regs)
that computes the desired bp. This function is then called from the
two versions of dump_stack().

Signed-off-by: Soren Sandmann <ssp@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@infradead.org>,
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>,
LKML-Reference: <m3oc9rop28.fsf@dhcp-100-3-82.bos.redhat.com>>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-11-18 14:37:34 +01:00
Oleg Nesterov
018378c55b x86: Unify save_stack_address() and save_stack_address_nosched()
Cleanup. Factor the common code in save_stack_address() and
save_stack_address_nosched().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20100603193243.GA31534@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-06-09 17:32:19 +02:00
Oleg Nesterov
147ec4d236 x86: Make save_stack_address() !CONFIG_FRAME_POINTER friendly
If CONFIG_FRAME_POINTER=n, print_context_stack() shouldn't neglect the
non-reliable addresses on stack, this is all we have if dump_trace(bp)
is called with the wrong or zero bp.

For example, /proc/pid/stack doesn't work if CONFIG_FRAME_POINTER=n.

This patch obviously has no effect if CONFIG_FRAME_POINTER=y, otherwise
it reverts 1650743c "x86: don't save unreliable stack trace entries".

Also, remove the unnecessary type-cast.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20100603193239.GA31530@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-06-09 17:32:15 +02:00
Frederic Weisbecker
c9cf4dbb4d x86: Unify dumpstack.h and stacktrace.h
arch/x86/include/asm/stacktrace.h and arch/x86/kernel/dumpstack.h
declare headers of objects that deal with the same topic.
Actually most of the files that include stacktrace.h also include
dumpstack.h

Although dumpstack.h seems more reserved for internals of stack
traces, those are quite often needed to define specialized stack
trace operations. And perf event arch headers are going to need
access to such low level operations anyway. So don't continue to
bother with dumpstack.h as it's not anymore about isolated deep
internals.

v2: fix struct stack_frame definition conflict in sysprof

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Soeren Sandmann <sandmann@daimi.au.dk>
2010-06-08 23:29:52 +02:00
Frederic Weisbecker
61c1917f47 perf events, x86/stacktrace: Make stack walking optional
The current print_context_stack helper that does the stack
walking job is good for usual stacktraces as it walks through
all the stack and reports even addresses that look unreliable,
which is nice when we don't have frame pointers for example.

But we have users like perf that only require reliable
stacktraces, and those may want a more adapted stack walker, so
lets make this function a callback in stacktrace_ops that users
can tune for their needs.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1261024834-5336-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 09:56:19 +01:00
Vegard Nossum
acc6be5405 x86: add save_stack_trace_bp() for tracing from a specific stack frame
This will help kmemcheck (and possibly other debugging tools) since we
can now simply pass regs->bp to the stack tracer instead of specifying
the number of stack frames to skip, which is unreliable if gcc decides
to inline functions, etc.

Note that this makes the API incomplete for other architectures, but I
expect that those can be updated lazily, e.g. when they need it.

Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2009-06-12 23:01:05 +02:00
Steven Rostedt
29a679754b x86/stacktrace: return 0 instead of -1 for stack ops
If we return -1 in the ops->stack for the stacktrace saving, we end up
breaking out of the loop if the stack we are tracing is in the exception
stack. This causes traces like:

          <idle>-0     [002] 34263.745825: raise_softirq_irqoff <-__blk_complete_request
          <idle>-0     [002] 34263.745826:
 <= 0
 <= 0
 <= 0
 <= 0
 <= 0
 <= 0
 <= 0

By returning "0" instead, the irq stack is saved as well, and we see:

          <idle>-0     [003]   883.280992: raise_softirq_irqoff <-__hrtimer_star
t_range_ns
          <idle>-0     [003]   883.280992:
 <= hrtimer_start_range_ns
 <= tick_nohz_restart_sched_tick
 <= cpu_idle
 <= start_secondary
 <=
 <= 0
 <= 0

[ Impact: record stacks from interrupts ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-05-14 23:19:09 -04:00
Ingo Molnar
8f47e16348 x86: update copyrights
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-31 04:21:18 +01:00
Török Edwin
8d7c6a9616 tracing/stack-tracer: fix style issues
Impact: cleanup

Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23 11:53:48 +01:00
Török Edwin
02b67518e2 tracing: add support for userspace stacktraces in tracing/iter_ctrl
Impact: add new (default-off) tracing visualization feature

Usage example:

 mount -t debugfs nodev /sys/kernel/debug
 cd /sys/kernel/debug/tracing
 echo userstacktrace >iter_ctrl
 echo sched_switch >current_tracer
 echo 1 >tracing_enabled
 .... run application ...
 echo 0 >tracing_enabled

Then read one of 'trace','latency_trace','trace_pipe'.

To get the best output you can compile your userspace programs with
frame pointers (at least glibc + the app you are tracing).

Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-23 09:25:15 +01:00
Ingo Molnar
8594698ebd stacktrace: fix modular build, export print_stack_trace and save_stack_trace
fix:

ERROR: "print_stack_trace" [kernel/backtracetest.ko] undefined!
ERROR: "save_stack_trace" [kernel/backtracetest.ko] undefined!

Signed-off-by: Ingo Molnar <mingo@elte.hu>

and fix:

  Building modules, stage 2.
  MODPOST 376 modules
ERROR: "print_stack_trace" [kernel/backtracetest.ko] undefined!
make[1]: *** [__modpost] Error 1

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-30 09:20:55 +02:00
Vegard Nossum
1650743cdc x86: don't save unreliable stack trace entries
Currently, there is no way for print_stack_trace() to determine whether
a given stack trace entry was deemed reliable or not, simply because
save_stack_trace() does not record this information. (Perhaps needless
to say, this makes the saved stack traces A LOT harder to read, and
probably with no other benefits, since debugging features that use
save_stack_trace() most likely also require frame pointers, etc.)

This patch reverts to the old behaviour of only recording the reliable trace
entries for saved stack traces.

Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-26 12:55:58 +01:00
Jan Engelhardt
ade1af7712 x86: remove unneded casts
x86: remove unneeded casts

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:23 +01:00
Arjan van de Ven
5bc27dc2f5 x86: pull bp calculation earlier into the backtrace path
Right now, we take the stack pointer early during the backtrace path, but
only calculate bp several functions deep later, making it hard to reconcile
the stack and bp backtraces (as well as showing several internal backtrace
functions on the stack with bp based backtracing).

This patch moves the bp taking to the same place we take the stack pointer;
sadly this ripples through several layers of the back tracing stack,
but it's not all that bad in the end I hope.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:07 +01:00
Arjan van de Ven
bc850d6b37 x86: add the capability to print fuzzy backtraces
For enhancing the 32 bit EBP based backtracer, I need the capability
for the backtracer to tell it's customer that an entry is either
reliable or unreliable, and the backtrace printing code then needs to
print the unreliable ones slightly different.

This patch adds the basic capability, the next patch will add a user
of this capability.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:07 +01:00
Thomas Gleixner
3abf024d2a x86: nuke a ton of unused exports
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30 13:30:28 +01:00
Arjan van de Ven
9745512ce7 sched: latencytop support
LatencyTOP kernel infrastructure; it measures latencies in the
scheduler and tracks it system wide and per process.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:34 +01:00
Jan Beulich
9689ba8ad0 x86: constify stacktrace_ops
.. as they're never written to.

[ tglx: arch/x86 adaptation ]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-17 20:16:11 +02:00
Dave Jones
835c34a168 Delete filenames in comments.
Since the x86 merge, lots of files that referenced their own filenames
are no longer correct.  Rather than keep them up to date, just delete
them, as they add no real value.

Additionally:
- fix up comment formatting in scx200_32.c
- Remove a credit from myself in setup_64.c from a time when we had no SCM
- remove longwinded history from tsc_32.c which can be figured out from
  git.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-13 10:01:23 -07:00
Thomas Gleixner
250c22777f x86_64: move kernel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 11:17:24 +02:00