1. 23 9月, 2017 1 次提交
  2. 13 7月, 2017 1 次提交
  3. 29 6月, 2017 1 次提交
  4. 16 5月, 2017 1 次提交
  5. 15 4月, 2017 1 次提交
    • N
      mn10300/cevt-mn10300: Set ->min_delta_ticks and ->max_delta_ticks · 5f664e2b
      Nicolai Stange 提交于
      In preparation for making the clockevents core NTP correction aware,
      all clockevent device drivers must set ->min_delta_ticks and
      ->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
      clockevent device's rate is going to change dynamically and thus, the
      ratio of ns to ticks ceases to stay invariant.
      
      Make the mn10300 arch's clockevent driver initialize these fields properly.
      
      This patch alone doesn't introduce any change in functionality as the
      clockevents core still looks exclusively at the (untouched) ->min_delta_ns
      and ->max_delta_ns. As soon as this has changed, a followup patch will
      purge the initialization of ->min_delta_ns and ->max_delta_ns from this
      driver.
      
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: linux-am33-list@redhat.com
      Signed-off-by: NNicolai Stange <nicstange@gmail.com>
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      5f664e2b
  6. 29 3月, 2017 1 次提交
  7. 02 3月, 2017 6 次提交
  8. 28 2月, 2017 1 次提交
  9. 25 12月, 2016 2 次提交
  10. 08 10月, 2016 1 次提交
  11. 28 9月, 2016 1 次提交
  12. 26 6月, 2016 1 次提交
  13. 25 6月, 2016 1 次提交
    • L
      Clarify naming of thread info/stack allocators · b235beea
      Linus Torvalds 提交于
      We've had the thread info allocated together with the thread stack for
      most architectures for a long time (since the thread_info was split off
      from the task struct), but that is about to change.
      
      But the patches that move the thread info to be off-stack (and a part of
      the task struct instead) made it clear how confused the allocator and
      freeing functions are.
      
      Because the common case was that we share an allocation with the thread
      stack and the thread_info, the two pointers were identical.  That
      identity then meant that we would have things like
      
      	ti = alloc_thread_info_node(tsk, node);
      	...
      	tsk->stack = ti;
      
      which certainly _worked_ (since stack and thread_info have the same
      value), but is rather confusing: why are we assigning a thread_info to
      the stack? And if we move the thread_info away, the "confusing" code
      just gets to be entirely bogus.
      
      So remove all this confusion, and make it clear that we are doing the
      stack allocation by renaming and clarifying the function names to be
      about the stack.  The fact that the thread_info then shares the
      allocation is an implementation detail, and not really about the
      allocation itself.
      
      This is a pure renaming and type fix: we pass in the same pointer, it's
      just that we clarify what the pointer means.
      
      The ia64 code that actually only has one single allocation (for all of
      task_struct, thread_info and kernel thread stack) now looks a bit odd,
      but since "tsk->stack" is actually not even used there, that oddity
      doesn't matter.  It would be a separate thing to clean that up, I
      intentionally left the ia64 changes as a pure brute-force renaming and
      type change.
      Acked-by: NAndy Lutomirski <luto@amacapital.net>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b235beea
  14. 04 6月, 2016 1 次提交
  15. 21 5月, 2016 2 次提交
    • J
      exit_thread: accept a task parameter to be exited · e6464694
      Jiri Slaby 提交于
      We need to call exit_thread from copy_process in a fail path.  So make it
      accept task_struct as a parameter.
      
      [v2]
      * s390: exit_thread_runtime_instr doesn't make sense to be called for
        non-current tasks.
      * arm: fix the comment in vfp_thread_copy
      * change 'me' to 'tsk' for task_struct
      * now we can change only archs that actually have exit_thread
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NJiri Slaby <jslaby@suse.cz>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e6464694
    • J
      mn10300: let exit_fpu accept a task · 2ec656eb
      Jiri Slaby 提交于
      We need to call exit_thread from copy_process in a fail path.  Since
      exit_thread on mn10300 calls exit_thread_runtime_instr, make it accept
      task_struct as a parameter now.
      Signed-off-by: NJiri Slaby <jslaby@suse.cz>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2ec656eb
  16. 18 3月, 2016 1 次提交
  17. 02 3月, 2016 1 次提交
    • T
      arch/hotplug: Call into idle with a proper state · fc6d73d6
      Thomas Gleixner 提交于
      Let the non boot cpus call into idle with the corresponding hotplug state, so
      the hotplug core can handle the further bringup. That's a first step to
      convert the boot side of the hotplugged cpus to do all the synchronization
      with the other side through the state machine. For now it'll only start the
      hotplug thread and kick the full bringup of the cpu.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: linux-arch@vger.kernel.org
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
      Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Sebastian Siewior <bigeasy@linutronix.de>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Paul Turner <pjt@google.com>
      Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      fc6d73d6
  18. 10 8月, 2015 1 次提交
  19. 01 8月, 2015 1 次提交
  20. 25 6月, 2015 1 次提交
  21. 13 4月, 2015 1 次提交
  22. 13 2月, 2015 1 次提交
    • A
      all arches, signal: move restart_block to struct task_struct · f56141e3
      Andy Lutomirski 提交于
      If an attacker can cause a controlled kernel stack overflow, overwriting
      the restart block is a very juicy exploit target.  This is because the
      restart_block is held in the same memory allocation as the kernel stack.
      
      Moving the restart block to struct task_struct prevents this exploit by
      making the restart_block harder to locate.
      
      Note that there are other fields in thread_info that are also easy
      targets, at least on some architectures.
      
      It's also a decent simplification, since the restart code is more or less
      identical on all architectures.
      
      [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
      Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: David Miller <davem@davemloft.net>
      Acked-by: NRichard Weinberger <richard@nod.at>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f56141e3
  23. 06 8月, 2014 2 次提交
  24. 05 3月, 2014 2 次提交
  25. 08 10月, 2013 1 次提交
  26. 11 9月, 2013 1 次提交
  27. 28 6月, 2013 1 次提交
    • A
      mn10300: Use early_param() to parse "mem=" parameter · e3f12a53
      Akira Takeuchi 提交于
      This fixes the problem that "init=" options may not be passed to kernel
      correctly.
      
      parse_mem_cmdline() of mn10300 arch gets rid of "mem=" string from
      redboot_command_line. Then init_setup() parses the "init=" options from
      static_command_line, which is a copy of redboot_command_line, and keeps
      the pointer to the init options in execute_command variable.
      
      Since the commit 026cee00 upstream (params: <level>_initcall-like kernel
      parameters), static_command_line becomes overwritten by saved_command_line at
      do_initcall_level(). Notice that saved_command_line is a command line
      which includes "mem=" string.
      
      As a result, execute_command may point to weird string by the length of
      "mem=" parameter.
      I noticed this problem when using the command line like this:
      
          mem=128M console=ttyS0,115200 init=/bin/sh
      
      Here is the processing flow of command line parameters.
          start_kernel()
            setup_arch(&command_line)
               parse_mem_cmdline(cmdline_p)
                 * strcpy(boot_command_line, redboot_command_line);
                 * Remove "mem=xxx" from redboot_command_line.
                 * *cmdline_p = redboot_command_line;
            setup_command_line(command_line) <-- command_line is redboot_command_line
              * strcpy(saved_command_line, boot_command_line)
              * strcpy(static_command_line, command_line)
            parse_early_param()
              strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
              parse_early_options(tmp_cmdline);
                parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
            parse_args("Booting ..", static_command_line, ...);
              init_setup() <-- save the pointer in execute_command
            rest_init()
              kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
      
      At this point, execute_command points to "/bin/sh" string.
      
          kernel_init()
            kernel_init_freeable()
              do_basic_setup()
                do_initcalls()
                  do_initcall_level()
                    (*) strcpy(static_command_line, saved_command_line);
      
      Here, execute_command gets to point to "200" string !!
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      e3f12a53
  28. 30 5月, 2013 2 次提交
  29. 01 5月, 2013 2 次提交
    • T
      dump_stack: unify debug information printed by show_regs() · a43cb95d
      Tejun Heo 提交于
      show_regs() is inherently arch-dependent but it does make sense to print
      generic debug information and some archs already do albeit in slightly
      different forms.  This patch introduces a generic function to print debug
      information from show_regs() so that different archs print out the same
      information and it's much easier to modify what's printed.
      
      show_regs_print_info() prints out the same debug info as dump_stack()
      does plus task and thread_info pointers.
      
      * Archs which didn't print debug info now do.
      
        alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
        metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
        um, xtensa
      
      * Already prints debug info.  Replaced with show_regs_print_info().
        The printed information is superset of what used to be there.
      
        arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86
      
      * s390 is special in that it used to print arch-specific information
        along with generic debug info.  Heiko and Martin think that the
        arch-specific extra isn't worth keeping s390 specfic implementation.
        Converted to use the generic version.
      
      Note that now all archs print the debug info before actual register
      dumps.
      
      An example BUG() dump follows.
      
       kernel BUG at /work/os/work/kernel/workqueue.c:4841!
       invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
       Modules linked in:
       CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
       Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
       task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
       RIP: 0010:[<ffffffff8234a07e>]  [<ffffffff8234a07e>] init_workqueues+0x4/0x6
       RSP: 0000:ffff88007c861ec8  EFLAGS: 00010246
       RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
       RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
       RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
       R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
       R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
       FS:  0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
       CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
       CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
       DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
       DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
       Stack:
        ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
        0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
        ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
       Call Trace:
        [<ffffffff81000312>] do_one_initcall+0x122/0x170
        [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
        [<ffffffff81c47760>] ? rest_init+0x140/0x140
        [<ffffffff81c4776e>] kernel_init+0xe/0xf0
        [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
        [<ffffffff81c47760>] ? rest_init+0x140/0x140
        ...
      
      v2: Typo fix in x86-32.
      
      v3: CPU number dropped from show_regs_print_info() as
          dump_stack_print_info() has been updated to print it.  s390
          specific implementation dropped as requested by s390 maintainers.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NDavid S. Miller <davem@davemloft.net>
      Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Fengguang Wu <fengguang.wu@intel.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Acked-by: Chris Metcalf <cmetcalf@tilera.com>		[tile bits]
      Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a43cb95d
    • T
      dump_stack: consolidate dump_stack() implementations and unify their behaviors · 196779b9
      Tejun Heo 提交于
      Both dump_stack() and show_stack() are currently implemented by each
      architecture.  show_stack(NULL, NULL) dumps the backtrace for the
      current task as does dump_stack().  On some archs, dump_stack() prints
      extra information - pid, utsname and so on - in addition to the
      backtrace while the two are identical on other archs.
      
      The usages in arch-independent code of the two functions indicate
      show_stack(NULL, NULL) should print out bare backtrace while
      dump_stack() is used for debugging purposes when something went wrong,
      so it does make sense to print additional information on the task which
      triggered dump_stack().
      
      There's no reason to require archs to implement two separate but mostly
      identical functions.  It leads to unnecessary subtle information.
      
      This patch expands the dummy fallback dump_stack() implementation in
      lib/dump_stack.c such that it prints out debug information (taken from
      x86) and invokes show_stack(NULL, NULL) and drops arch-specific
      dump_stack() implementations in all archs except blackfin.  Blackfin's
      dump_stack() does something wonky that I don't understand.
      
      Debug information can be printed separately by calling
      dump_stack_print_info() so that arch-specific dump_stack()
      implementation can still emit the same debug information.  This is used
      in blackfin.
      
      This patch brings the following behavior changes.
      
      * On some archs, an extra level in backtrace for show_stack() could be
        printed.  This is because the top frame was determined in
        dump_stack() on those archs while generic dump_stack() can't do that
        reliably.  It can be compensated by inlining dump_stack() but not
        sure whether that'd be necessary.
      
      * Most archs didn't use to print debug info on dump_stack().  They do
        now.
      
      An example WARN dump follows.
      
       WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
       Hardware name: empty
       Modules linked in:
       CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
        0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
        ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
        0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
       Call Trace:
        [<ffffffff81c614dc>] dump_stack+0x19/0x1b
        [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
        [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
        [<ffffffff8234a071>] init_workqueues+0x35/0x505
        ...
      
      v2: CPU number added to the generic debug info as requested by s390
          folks and dropped the s390 specific dump_stack().  This loses %ksp
          from the debug message which the maintainers think isn't important
          enough to keep the s390-specific dump_stack() implementation.
      
          dump_stack_print_info() is moved to kernel/printk.c from
          lib/dump_stack.c.  Because linkage is per objecct file,
          dump_stack_print_info() living in the same lib file as generic
          dump_stack() means that archs which implement custom dump_stack()
          - at this point, only blackfin - can't use dump_stack_print_info()
          as that will bring in the generic version of dump_stack() too.  v1
          The v1 patch broke build on blackfin due to this issue.  The build
          breakage was reported by Fengguang Wu.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NDavid S. Miller <davem@davemloft.net>
      Acked-by: NVineet Gupta <vgupta@synopsys.com>
      Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
      Acked-by: NVineet Gupta <vgupta@synopsys.com>
      Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>	[s390 bits]
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Fengguang Wu <fengguang.wu@intel.com>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      196779b9