linux-stable.git/arch/x86/kernel/dumpstack_64.c, branch linux-4.8.y

Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-08-01T18:23:42+00:00

Pull x86 header cleanups from Ingo Molnar:
 "This tree is a cleanup of the x86 tree reducing spurious uses of
  module.h - which should improve build performance a bit"

* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, crypto: Restore MODULE_LICENSE() to glue_helper.c so it loads
  x86/apic: Remove duplicated include from probe_64.c
  x86/ce4100: Remove duplicated include from ce4100.c
  x86/headers: Include spinlock_types.h in x8664_ksyms_64.c for missing spinlock_t
  x86/platform: Delete extraneous MODULE_* tags fromm ts5500
  x86: Audit and remove any remaining unnecessary uses of module.h
  x86/kvm: Audit and remove any unnecessary uses of module.h
  x86/xen: Audit and remove any unnecessary uses of module.h
  x86/platform: Audit and remove any unnecessary uses of module.h
  x86/lib: Audit and remove any unnecessary uses of module.h
  x86/kernel: Audit and remove any unnecessary uses of module.h
  x86/mm: Audit and remove any unnecessary uses of module.h
  x86: Don't use module.h just for AUTHOR / LICENSE tags

Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-07-26T01:18:04+00:00

Pull x86 stackdump update from Ingo Molnar:
 "A number of stackdump enhancements"

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/dumpstack: Add show_stack_regs() and use it
  printk: Make the printk*once() variants return a value
  x86/dumpstack: Honor supplied @regs arg

x86/dumpstack/64: Handle faults when printing the "Stack: " part of an OOPS

2016-07-15T08:26:27+00:00

If we overflow the stack into a guard page, we'll recursively fault
when trying to dump the contents of the guard page.  Use
probe_kernel_address() so we can recover if this happens.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Josh Poimboeuf 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/e626d47a55d7b04dcb1b4d33faa95e8505b217c8.1468527351.git.luto@kernel.org
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

x86/dumpstack: Honor supplied @regs arg

2016-07-08T09:33:18+00:00

The comment suggests that show_stack(NULL, NULL) should backtrace the
current context, but the code doesn't match the comment. If regs are
given, start the "Stack:" hexdump at regs->sp.

Signed-off-by: Andy Lutomirski 
Signed-off-by: Borislav Petkov 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: Frederic Weisbecker 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1467671487-10344-2-git-send-email-bp@alien8.de
Link: http://lkml.kernel.org/r/efcd79bf4106d61f1cd258c2caa87f3a0618eeac.1466036668.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86: avoid avoid passing around 'thread_info' in stack dumping code

2016-06-23T19:20:01+00:00

None of the code actually wants a thread_info, it all wants a
task_struct, and it's just converting to a thread_info pointer much too
early.

No semantic change.

Signed-off-by: Linus Torvalds

x86/kernel: Use kstack_end() in dumpstack_64.c

2015-02-23T17:37:13+00:00

i386 is already using kstack_end() in dumpstack_32.c. We should also
use it to make the code clearer and unify the stack printing logic some
more.

Suggested-by: Ingo Molnar 
Signed-off-by: Adrien Schildknecht 
Acked-by: Steven Rostedt 
Cc: c: Linus Torvalds 
Link: http://lkml.kernel.org/r/1424618638-6375-1-git-send-email-adrien+dev@schischi.me
Signed-off-by: Borislav Petkov

x86/kernel: Fix output of show_stack_log_lvl()

2015-02-23T17:34:42+00:00

show_stack_log_lvl() does not set the log level after a new line, the
following messages printed with pr_cont() are thus assigned to the
default log level.

This patch prepends the log level to the next message following a new
line.

print_trace_address() uses printk(log_lvl). Using printk() with just
a log level is ignored and thus has no effect on the next pr_cont().
We need to prepend the log level directly into the message.

Signed-off-by: Adrien Schildknecht 
Acked-by: Ingo Molnar 
Cc: Steven Rostedt 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/1424399661-20327-1-git-send-email-adrien+dev@schischi.me
Signed-off-by: Borislav Petkov

x86_64, traps: Stop using IST for #SS

2014-11-23T21:56:19+00:00

On a 32-bit kernel, this has no effect, since there are no IST stacks.

On a 64-bit kernel, #SS can only happen in user code, on a failed iret
to user space, a canonical violation on access via RSP or RBP, or a
genuine stack segment violation in 32-bit kernel code.  The first two
cases don't need IST, and the latter two cases are unlikely fatal bugs,
and promoting them to double faults would be fine.

This fixes a bug in which the espfix64 code mishandles a stack segment
violation.

This saves 4k of memory per CPU and a tiny bit of code.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds

x86: Fix dumpstack_64 irq stack handling

2014-04-02T18:46:50+00:00

Commit 2223f6f6eeaa "x86: Clean up dumpstack_64.c code" changed
the irq_stack processing a little from what it was before.
The irq_stack_end variable needed to be cleared after its first
use. By setting irq_stack to the per cpu irq_stack and passing
that to analyze_stack(), and then clearing it after it is processed,
we can get back the original behavior.

Signed-off-by: Steven Rostedt 
Signed-off-by: Linus Torvalds