linux.git/arch/x86/kernel/stacktrace.c, branch v4.11

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:36+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  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 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:34+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  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 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

x86/stacktrace: Convert save_stack_trace_*() to use the new unwinder

2016-09-20T06:29:33+00:00

Convert save_stack_trace_*() to use the new unwinder.  dump_trace() has
been deprecated.

Signed-off-by: Josh Poimboeuf 
Cc: Andy Lutomirski 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Byungchul Park 
Cc: Denys Vlasenko 
Cc: Frederic Weisbecker 
Cc: H. Peter Anvin 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Nilay Vaish 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/815494c627d89887db0ce56ceffd58ad16ee6c21.1474045023.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar

x86/dumpstack: Pin the target stack when dumping it

2016-09-16T07:18:53+00:00

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 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Jann Horn 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/cf0082cde65d1941a996d026f2b2cdbfaca17bfa.1474003868.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/dumpstack: Add get_stack_info() interface

2016-09-15T06:13:15+00:00

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 
Cc: Andy Lutomirski 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Byungchul Park 
Cc: Denys Vlasenko 
Cc: Frederic Weisbecker 
Cc: H. Peter Anvin 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Nilay Vaish 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/8164dd0db96b7e6a279fa17ae5e6dc375eecb4a9.1473905218.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar

x86/kernel: Audit and remove any unnecessary uses of module.h

2016-07-14T13:06:41+00:00

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 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20160714001901.31603-4-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar

perf: generalize perf_callchain

2016-02-20T05:21:44+00:00

. 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 
Signed-off-by: David S. Miller

x86: Swap save_stack_trace_regs parameters

2011-06-15T02:48:51+00:00

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 
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Frederic Weisbecker 
Cc: Peter Zijlstra 
Cc: Namhyung Kim 
Link: http://lkml.kernel.org/r/20110608070921.17777.31103.stgit@fedora15
Signed-off-by: Steven Rostedt

x86: Remove warning and warning_symbol from struct stacktrace_ops

2011-05-12T13:31:28+00:00

Both warning and warning_symbol are nowhere used.
Let's get rid of them.

Signed-off-by: Richard Weinberger 
Cc: Oleg Nesterov 
Cc: Andrew Morton 
Cc: Huang Ying 
Cc: Soeren Sandmann Pedersen 
Cc: Namhyung Kim 
Cc: x86 
Cc: H. Peter Anvin 
Cc: Thomas Gleixner 
Cc: Robert Richter 
Cc: Paul Mundt 
Link: http://lkml.kernel.org/r/1305205872-10321-2-git-send-email-richard@nod.at
Signed-off-by: Frederic Weisbecker

x86, dumpstack: Correct stack dump info when frame pointer is available

2011-03-18T09:51:42+00:00

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 9c0729dc8062 ("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]  [] ? panic+0x91/0x199
 [    3.508662]  [] ? printk+0x68/0x6a
 [    3.508770]  [] ? mount_block_root+0x257/0x26e
 [    3.508876]  [] ? mount_root+0x56/0x5a
 [    3.508975]  [] ? prepare_namespace+0x170/0x1a9
 [    3.509216]  [] ? kernel_init+0x1d2/0x1e2
 [    3.509335]  [] ? kernel_thread_helper+0x4/0x10
 [    3.509442]  [] ? restore_args+0x0/0x30
 [    3.509542]  [] ? kernel_init+0x0/0x1e2
 [    3.509641]  [] ? kernel_thread_helper+0x0/0x10

after:

 [    3.522991] Call Trace:
 [    3.523351]  [] panic+0x91/0x199
 [    3.523468]  [] ? printk+0x68/0x6a
 [    3.523576]  [] mount_block_root+0x257/0x26e
 [    3.523681]  [] mount_root+0x56/0x5a
 [    3.523780]  [] prepare_namespace+0x170/0x1a9
 [    3.523885]  [] kernel_init+0x1d2/0x1e2
 [    3.523987]  [] kernel_thread_helper+0x4/0x10
 [    3.524228]  [] ? restore_args+0x0/0x30
 [    3.524345]  [] ? kernel_init+0x0/0x1e2
 [    3.524445]  [] ? 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 
Acked-by: Peter Zijlstra 
Acked-by: Frederic Weisbecker 
Cc: Soren Sandmann 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
Cc: Robert Richter 
LKML-Reference: <1300416006-3163-1-git-send-email-namhyung@gmail.com>
Signed-off-by: Ingo Molnar