linux-toradex.git/arch/mn10300/kernel, branch v3.11-rc5

mn10300: Use early_param() to parse "mem=" parameter

2013-06-28T15:53:03+00:00

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 026cee0 upstream (params: _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: David Howells

MN10300: Enable IRQs more in system call exit work path

2013-05-30T04:38:48+00:00

Enable IRQs when calling schedule() for TIF_NEED_RESCHED and
do_notify_resume().  If interrupts are enabled during do_notify_resume(), a
warning can be seen (see lower down).

Whilst we're at it, resume_userspace can be made local to entry.S as it is not
called outside of there and it can be merged with the part of work_resched that
occurs after schedule() is called.

  WARNING: at kernel/softirq.c:160 local_bh_enable+0x42/0xa0()
  Call Trace:
    local_bh_enable+0x42/0xa0
    unix_release_sock+0x86/0x23c
    unix_release+0x20/0x28
    sock_release+0x17/0x88
    sock_close+0x20/0x28
    __fput+0xc9/0x1fc
    ____fput+0xb/0x10
    task_work_run+0x64/0x78
    do_notify_resume+0x53d/0x544
    work_notifysig+0xa/0xc

Signed-off-by: David Howells 
Acked-by: Ken Cox 
Signed-off-by: Linus Torvalds

MN10300: Fix ret_from_kernel_thread

2013-05-30T04:38:48+00:00

ret_from_kernel_thread needs to set A2 to the thread_info pointer before
jumping to syscall_exit.

Without this, we never correctly start userspace.

This was caused by the rejuggling of the fork/exec paths in commit
ddf23e87a804 ("mn10300: switch to saner kernel_execve() semantics")

Reported-by: Ken Cox 
Signed-off-by: David Howells 
Acked-by: Ken Cox 
Acked-by: Al Viro 
Signed-off-by: Linus Torvalds

dump_stack: unify debug information printed by show_regs()

2013-05-01T00:04:02+00:00

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:[]  [] 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:
  [] do_one_initcall+0x122/0x170
  [] kernel_init_freeable+0x9b/0x1c8
  [] ? rest_init+0x140/0x140
  [] kernel_init+0xe/0xf0
  [] ret_from_fork+0x7c/0xb0
  [] ? 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: Tejun Heo 
Acked-by: David S. Miller 
Acked-by: Jesper Nilsson 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Bjorn Helgaas 
Cc: Fengguang Wu 
Cc: Mike Frysinger 
Cc: Vineet Gupta 
Cc: Sam Ravnborg 
Acked-by: Chris Metcalf 		[tile bits]
Acked-by: Richard Kuo 		[hexagon bits]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dump_stack: consolidate dump_stack() implementations and unify their behaviors

2013-05-01T00:04:02+00:00

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:
  [] dump_stack+0x19/0x1b
  [] warn_slowpath_common+0x7f/0xc0
  [] warn_slowpath_null+0x1a/0x20
  [] 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: Tejun Heo 
Acked-by: David S. Miller 
Acked-by: Vineet Gupta 
Acked-by: Jesper Nilsson 
Acked-by: Vineet Gupta 
Acked-by: Martin Schwidefsky 	[s390 bits]
Cc: Heiko Carstens 
Cc: Mike Frysinger 
Cc: Fengguang Wu 
Cc: Bjorn Helgaas 
Cc: Sam Ravnborg 
Acked-by: Richard Kuo 		[hexagon bits]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mn10300: Use generic idle loop

2013-04-08T15:39:27+00:00

default_idle() boils down to safe_halt() and the other option is idle
polling. Use the core functionality.

Signed-off-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Rusty Russell 
Cc: Paul McKenney 
Cc: Peter Zijlstra 
Reviewed-by: Cc: Srivatsa S. Bhat 
Cc: Magnus Damm 
Cc: David Howells 
Link: http://lkml.kernel.org/r/20130321215234.822656036@linutronix.de
Signed-off-by: Thomas Gleixner

arch: Cleanup enable/disable_hlt

2013-04-08T15:39:22+00:00

enable/disable_hlt() does not need to be exported and can be killed on
architectures which do not use it at all.

Signed-off-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Rusty Russell 
Cc: Paul McKenney 
Cc: Peter Zijlstra 
Reviewed-by: Cc: Srivatsa S. Bhat 
Cc: Magnus Damm 
Link: http://lkml.kernel.org/r/20130321215233.377959540@linutronix.de
Signed-off-by: Thomas Gleixner

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

2013-02-24T02:50:11+00:00

Pull signal handling cleanups from Al Viro:
 "This is the first pile; another one will come a bit later and will
  contain SYSCALL_DEFINE-related patches.

   - a bunch of signal-related syscalls (both native and compat)
     unified.

   - a bunch of compat syscalls switched to COMPAT_SYSCALL_DEFINE
     (fixing several potential problems with missing argument
     validation, while we are at it)

   - a lot of now-pointless wrappers killed

   - a couple of architectures (cris and hexagon) forgot to save
     altstack settings into sigframe, even though they used the
     (uninitialized) values in sigreturn; fixed.

   - microblaze fixes for delivery of multiple signals arriving at once

   - saner set of helpers for signal delivery introduced, several
     architectures switched to using those."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (143 commits)
  x86: convert to ksignal
  sparc: convert to ksignal
  arm: switch to struct ksignal * passing
  alpha: pass k_sigaction and siginfo_t using ksignal pointer
  burying unused conditionals
  make do_sigaltstack() static
  arm64: switch to generic old sigaction() (compat-only)
  arm64: switch to generic compat rt_sigaction()
  arm64: switch compat to generic old sigsuspend
  arm64: switch to generic compat rt_sigqueueinfo()
  arm64: switch to generic compat rt_sigpending()
  arm64: switch to generic compat rt_sigprocmask()
  arm64: switch to generic sigaltstack
  sparc: switch to generic old sigsuspend
  sparc: COMPAT_SYSCALL_DEFINE does all sign-extension as well as SYSCALL_DEFINE
  sparc: kill sign-extending wrappers for native syscalls
  kill sparc32_open()
  sparc: switch to use of generic old sigaction
  sparc: switch sys_compat_rt_sigaction() to COMPAT_SYSCALL_DEFINE
  mips: switch to generic sys_fork() and sys_clone()
  ...

Merge tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2013-02-21T21:41:04+00:00

Pull tty/serial patches from Greg Kroah-Hartman:
 "Here's the big tty/serial driver patches for 3.9-rc1.

  More tty port rework and fixes from Jiri here, as well as lots of
  individual serial driver updates and fixes.

  All of these have been in the linux-next tree for a while."

* tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits)
  tty: mxser: improve error handling in mxser_probe() and mxser_module_init()
  serial: imx: fix uninitialized variable warning
  serial: tegra: assume CONFIG_OF
  TTY: do not update atime/mtime on read/write
  lguest: select CONFIG_TTY to build properly.
  ARM defconfigs: add missing inclusions of linux/platform_device.h
  fb/exynos: include platform_device.h
  ARM: sa1100/assabet: include platform_device.h directly
  serial: imx: Fix recursive locking bug
  pps: Fix build breakage from decoupling pps from tty
  tty: Remove ancient hardpps()
  pps: Additional cleanups in uart_handle_dcd_change
  pps: Move timestamp read into PPS code proper
  pps: Don't crash the machine when exiting will do
  pps: Fix a use-after free bug when unregistering a source.
  pps: Use pps_lookup_dev to reduce ldisc coupling
  pps: Add pps_lookup_dev() function
  tty: serial: uartlite: Support uartlite on big and little endian systems
  tty: serial: uartlite: Fix sparse and checkpatch warnings
  serial/arc-uart: Miscll DT related updates (Grant's review comments)
  ...

Fix up trivial conflicts, mostly just due to the TTY config option
clashing with the EXPERIMENTAL removal.

mn10300 idle: delete pm_idle

2013-02-18T04:37:07+00:00

pm_idle on mn10300 served no purpose.

Signed-off-by: Len Brown 
Cc: linux-am33-list@redhat.com