linux-toradex.git/drivers/misc, branch v3.3.5 Linux kernel for Apalis and Colibri modules x86,kgdb: Fix DEBUG_RODATA limitation using text_poke() 2012-04-13T16:13:54+00:00 Jason Wessel jason.wessel@windriver.com 2012-03-23T14:35:05+00:00 c9f568f1a99794aa7b749828c41fb7cdf55fe435 commit 3751d3e85cf693e10e2c47c03c8caa65e171099b upstream. There has long been a limitation using software breakpoints with a kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For this particular patch, it will apply cleanly and has been tested all the way back to 2.6.36. The kprobes code uses the text_poke() function which accommodates writing a breakpoint into a read-only page. The x86 kgdb code can solve the problem similarly by overriding the default breakpoint set/remove routines and using text_poke() directly. The x86 kgdb code will first attempt to use the traditional probe_kernel_write(), and next try using a the text_poke() function. The break point install method is tracked such that the correct break point removal routine will get called later on. Cc: x86@kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Inspried-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3751d3e85cf693e10e2c47c03c8caa65e171099b upstream.

There has long been a limitation using software breakpoints with a
kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For
this particular patch, it will apply cleanly and has been tested all
the way back to 2.6.36.

The kprobes code uses the text_poke() function which accommodates
writing a breakpoint into a read-only page.  The x86 kgdb code can
solve the problem similarly by overriding the default breakpoint
set/remove routines and using text_poke() directly.

The x86 kgdb code will first attempt to use the traditional
probe_kernel_write(), and next try using a the text_poke() function.
The break point install method is tracked such that the correct break
point removal routine will get called later on.

Cc: x86@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Inspried-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kgdbts: (2 of 2) fix single step awareness to work correctly with SMP 2012-04-13T16:13:54+00:00 Jason Wessel jason.wessel@windriver.com 2012-03-29T22:41:24+00:00 3c608af0c2643a9f17fef2f1cfa2a43a97bdf8a4 commit 23bbd8e346f1ef3fc1219c79cea53d8d52b207d8 upstream. The do_fork and sys_open tests have never worked properly on anything other than a UP configuration with the kgdb test suite. This is because the test suite did not fully implement the behavior of a real debugger. A real debugger tracks the state of what thread it asked to single step and can correctly continue other threads of execution or conditionally stop while waiting for the original thread single step request to return. Below is a simple method to cause a fatal kernel oops with the kgdb test suite on a 2 processor ARM system: while [ 1 ] ; do ls > /dev/null 2> /dev/null; done& while [ 1 ] ; do ls > /dev/null 2> /dev/null; done& echo V1I1F100 > /sys/module/kgdbts/parameters/kgdbts Very soon after starting the test the kernel will start warning with messages like: kgdbts: BP mismatch c002487c expected c0024878 ------------[ cut here ]------------ WARNING: at drivers/misc/kgdbts.c:317 check_and_rewind_pc+0x9c/0xc4() [<c01f6520>] (check_and_rewind_pc+0x9c/0xc4) [<c01f595c>] (validate_simple_test+0x3c/0xc4) [<c01f60d4>] (run_simple_test+0x1e8/0x274) The kernel will eventually recovers, but the test suite has completely failed to test anything useful. This patch implements behavior similar to a real debugger that does not rely on hardware single stepping by using only software planted breakpoints. In order to mimic a real debugger, the kgdb test suite now tracks the most recent thread that was continued (cont_thread_id), with the intent to single step just this thread. When the response to the single step request stops in a different thread that hit the original break point that thread will now get continued, while the debugger waits for the thread with the single step pending. Here is a high level description of the sequence of events. cont_instead_of_sstep = 0; 1) set breakpoint at do_fork 2) continue 3) Save the thread id where we stop to cont_thread_id 4) Remove breakpoint at do_fork 5) Reset the PC if needed depending on kernel exception type 6) soft single step 7) Check where we stopped if current thread != cont_thread_id { if (here for more than 2 times for the same thead) { ### must be a really busy system, start test again ### goto step 1 } goto step 5 } else { cont_instead_of_sstep = 0; } 8) clean up and run test again if needed 9) Clear out any threads that were waiting on a break point at the point in time the test is ended with get_cont_catch(). This happens sometimes because breakpoints are used in place of single stepping and some threads could have been in the debugger exception handling queue because breakpoints were hit concurrently on different CPUs. This also means we wait at least one second before unplumbing the debugger connection at the very end, so as respond to any debug threads waiting to be serviced. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 23bbd8e346f1ef3fc1219c79cea53d8d52b207d8 upstream.

The do_fork and sys_open tests have never worked properly on anything
other than a UP configuration with the kgdb test suite.  This is
because the test suite did not fully implement the behavior of a real
debugger.  A real debugger tracks the state of what thread it asked to
single step and can correctly continue other threads of execution or
conditionally stop while waiting for the original thread single step
request to return.

Below is a simple method to cause a fatal kernel oops with the kgdb
test suite on a 2 processor ARM system:

while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
echo V1I1F100 > /sys/module/kgdbts/parameters/kgdbts

Very soon after starting the test the kernel will start warning with
messages like:

kgdbts: BP mismatch c002487c expected c0024878
------------[ cut here ]------------
WARNING: at drivers/misc/kgdbts.c:317 check_and_rewind_pc+0x9c/0xc4()
[<c01f6520>] (check_and_rewind_pc+0x9c/0xc4)
[<c01f595c>] (validate_simple_test+0x3c/0xc4)
[<c01f60d4>] (run_simple_test+0x1e8/0x274)

The kernel will eventually recovers, but the test suite has completely
failed to test anything useful.

This patch implements behavior similar to a real debugger that does
not rely on hardware single stepping by using only software planted
breakpoints.

In order to mimic a real debugger, the kgdb test suite now tracks the
most recent thread that was continued (cont_thread_id), with the
intent to single step just this thread.  When the response to the
single step request stops in a different thread that hit the original
break point that thread will now get continued, while the debugger
waits for the thread with the single step pending.  Here is a high
level description of the sequence of events.

   cont_instead_of_sstep = 0;

1) set breakpoint at do_fork
2) continue
3)   Save the thread id where we stop to cont_thread_id
4) Remove breakpoint at do_fork
5) Reset the PC if needed depending on kernel exception type
6) soft single step
7)   Check where we stopped
       if current thread != cont_thread_id {
           if (here for more than 2 times for the same thead) {
              ### must be a really busy system, start test again ###
	      goto step 1
           }
           goto step 5
       } else {
           cont_instead_of_sstep = 0;
       }
8) clean up and run test again if needed
9) Clear out any threads that were waiting on a break point at the
   point in time the test is ended with get_cont_catch().  This
   happens sometimes because breakpoints are used in place of single
   stepping and some threads could have been in the debugger exception
   handling queue because breakpoints were hit concurrently on
   different CPUs.  This also means we wait at least one second before
   unplumbing the debugger connection at the very end, so as respond
   to any debug threads waiting to be serviced.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kgdbts: (1 of 2) fix single step awareness to work correctly with SMP 2012-04-13T16:13:54+00:00 Jason Wessel jason.wessel@windriver.com 2012-03-29T22:41:24+00:00 1d6091eb1a9b7a6ce75a333c907cde4b15222bde commit 486c5987a00a89d56c2c04c506417ef8f823ca2e upstream. The do_fork and sys_open tests have never worked properly on anything other than a UP configuration with the kgdb test suite. This is because the test suite did not fully implement the behavior of a real debugger. A real debugger tracks the state of what thread it asked to single step and can correctly continue other threads of execution or conditionally stop while waiting for the original thread single step request to return. Below is a simple method to cause a fatal kernel oops with the kgdb test suite on a 4 processor x86 system: while [ 1 ] ; do ls > /dev/null 2> /dev/null; done& while [ 1 ] ; do ls > /dev/null 2> /dev/null; done& while [ 1 ] ; do ls > /dev/null 2> /dev/null; done& while [ 1 ] ; do ls > /dev/null 2> /dev/null; done& echo V1I1F1000 > /sys/module/kgdbts/parameters/kgdbts Very soon after starting the test the kernel will oops with a message like: kgdbts: BP mismatch 3b7da66480 expected ffffffff8106a590 WARNING: at drivers/misc/kgdbts.c:303 check_and_rewind_pc+0xe0/0x100() Call Trace: [<ffffffff812994a0>] check_and_rewind_pc+0xe0/0x100 [<ffffffff81298945>] validate_simple_test+0x25/0xc0 [<ffffffff81298f77>] run_simple_test+0x107/0x2c0 [<ffffffff81298a18>] kgdbts_put_char+0x18/0x20 The warn will turn to a hard kernel crash shortly after that because the pc will not get properly rewound to the right value after hitting a breakpoint leading to a hard lockup. This change is broken up into 2 pieces because archs that have hw single stepping (2.6.26 and up) need different changes than archs that do not have hw single stepping (3.0 and up). This change implements the correct behavior for an arch that supports hw single stepping. A minor defect was fixed where sys_open should be do_sys_open for the sys_open break point test. This solves the problem of running a 64 bit with a 32 bit user space. The sys_open() never gets called when using the 32 bit file system for the kgdb testsuite because the 32 bit binaries invoke the compat_sys_open() call leading to the test never completing. In order to mimic a real debugger, the kgdb test suite now tracks the most recent thread that was continued (cont_thread_id), with the intent to single step just this thread. When the response to the single step request stops in a different thread that hit the original break point that thread will now get continued, while the debugger waits for the thread with the single step pending. Here is a high level description of the sequence of events. cont_instead_of_sstep = 0; 1) set breakpoint at do_fork 2) continue 3) Save the thread id where we stop to cont_thread_id 4) Remove breakpoint at do_fork 5) Reset the PC if needed depending on kernel exception type 6) if (cont_instead_of_sstep) { continue } else { single step } 7) Check where we stopped if current thread != cont_thread_id { cont_instead_of_sstep = 1; goto step 5 } else { cont_instead_of_sstep = 0; } 8) clean up and run test again if needed Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 486c5987a00a89d56c2c04c506417ef8f823ca2e upstream.

The do_fork and sys_open tests have never worked properly on anything
other than a UP configuration with the kgdb test suite.  This is
because the test suite did not fully implement the behavior of a real
debugger.  A real debugger tracks the state of what thread it asked to
single step and can correctly continue other threads of execution or
conditionally stop while waiting for the original thread single step
request to return.

Below is a simple method to cause a fatal kernel oops with the kgdb
test suite on a 4 processor x86 system:

while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
while [ 1 ] ; do ls > /dev/null 2> /dev/null; done&
echo V1I1F1000 > /sys/module/kgdbts/parameters/kgdbts

Very soon after starting the test the kernel will oops with a message like:

kgdbts: BP mismatch 3b7da66480 expected ffffffff8106a590
WARNING: at drivers/misc/kgdbts.c:303 check_and_rewind_pc+0xe0/0x100()
Call Trace:
 [<ffffffff812994a0>] check_and_rewind_pc+0xe0/0x100
 [<ffffffff81298945>] validate_simple_test+0x25/0xc0
 [<ffffffff81298f77>] run_simple_test+0x107/0x2c0
 [<ffffffff81298a18>] kgdbts_put_char+0x18/0x20

The warn will turn to a hard kernel crash shortly after that because
the pc will not get properly rewound to the right value after hitting
a breakpoint leading to a hard lockup.

This change is broken up into 2 pieces because archs that have hw
single stepping (2.6.26 and up) need different changes than archs that
do not have hw single stepping (3.0 and up).  This change implements
the correct behavior for an arch that supports hw single stepping.

A minor defect was fixed where sys_open should be do_sys_open
for the sys_open break point test.  This solves the problem of running
a 64 bit with a 32 bit user space.  The sys_open() never gets called
when using the 32 bit file system for the kgdb testsuite because the
32 bit binaries invoke the compat_sys_open() call leading to the test
never completing.

In order to mimic a real debugger, the kgdb test suite now tracks the
most recent thread that was continued (cont_thread_id), with the
intent to single step just this thread.  When the response to the
single step request stops in a different thread that hit the original
break point that thread will now get continued, while the debugger
waits for the thread with the single step pending.  Here is a high
level description of the sequence of events.

   cont_instead_of_sstep = 0;

1) set breakpoint at do_fork
2) continue
3)   Save the thread id where we stop to cont_thread_id
4) Remove breakpoint at do_fork
5) Reset the PC if needed depending on kernel exception type
6) if (cont_instead_of_sstep) { continue } else { single step }
7)   Check where we stopped
       if current thread != cont_thread_id {
           cont_instead_of_sstep = 1;
           goto step 5
       } else {
           cont_instead_of_sstep = 0;
       }
8) clean up and run test again if needed

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kgdbts: Fix kernel oops with CONFIG_DEBUG_RODATA 2012-04-13T16:13:54+00:00 Jason Wessel jason.wessel@windriver.com 2012-03-29T11:55:44+00:00 6053b1e9ee29eb6daff652086ae06d2c577308a8 commit 456ca7ff24841bf2d2a2dfd690fe7d42ef70d932 upstream. On x86 the kgdb test suite will oops when the kernel is compiled with CONFIG_DEBUG_RODATA and you run the tests after boot time. This is regression has existed since 2.6.26 by commit: b33cb815 (kgdbts: Use HW breakpoints with CONFIG_DEBUG_RODATA). The test suite can use hw breakpoints for all the tests, but it has to execute the hardware breakpoint specific tests first in order to determine that the hw breakpoints actually work. Specifically the very first test causes an oops: # echo V1I1 > /sys/module/kgdbts/parameters/kgdbts kgdb: Registered I/O driver kgdbts. kgdbts:RUN plant and detach test Entering kdb (current=0xffff880017aa9320, pid 1078) on processor 0 due to Keyboard Entry [0]kdb> kgdbts: ERROR PUT: end of test buffer on 'plant_and_detach_test' line 1 expected OK got $E14#aa WARNING: at drivers/misc/kgdbts.c:730 run_simple_test+0x151/0x2c0() [...oops clipped...] This commit re-orders the running of the tests and puts the RODATA check into its own function so as to correctly avoid the kernel oops by detecting and using the hw breakpoints. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 456ca7ff24841bf2d2a2dfd690fe7d42ef70d932 upstream.

On x86 the kgdb test suite will oops when the kernel is compiled with
CONFIG_DEBUG_RODATA and you run the tests after boot time. This is
regression has existed since 2.6.26 by commit: b33cb815 (kgdbts: Use
HW breakpoints with CONFIG_DEBUG_RODATA).

The test suite can use hw breakpoints for all the tests, but it has to
execute the hardware breakpoint specific tests first in order to
determine that the hw breakpoints actually work.  Specifically the
very first test causes an oops:

# echo V1I1 > /sys/module/kgdbts/parameters/kgdbts
kgdb: Registered I/O driver kgdbts.
kgdbts:RUN plant and detach test

Entering kdb (current=0xffff880017aa9320, pid 1078) on processor 0 due to Keyboard Entry
[0]kdb> kgdbts: ERROR PUT: end of test buffer on 'plant_and_detach_test' line 1 expected OK got $E14#aa
WARNING: at drivers/misc/kgdbts.c:730 run_simple_test+0x151/0x2c0()
[...oops clipped...]

This commit re-orders the running of the tests and puts the RODATA
check into its own function so as to correctly avoid the kernel oops
by detecting and using the hw breakpoints.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
c2port: class_create() returns an ERR_PTR 2012-03-05T23:49:43+00:00 Dan Carpenter dan.carpenter@oracle.com 2012-03-05T22:59:15+00:00 22ea71d7f49c3115e3a9ced5eac109fef26d3559 class_create() doesn't return a NULL, it only returns ERR_PTRs. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
class_create() doesn't return a NULL, it only returns ERR_PTRs.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'char-misc-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc 2012-02-09T21:51:13+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-02-09T21:51:13+00:00 ae5cdd405bfc5799c07080ec35f48283a9b0142a Minor char-misc fixes for 3.3-rc3 Nothing big here, some Kconfig fixes for the MISC_DEVICES config option that was being used incorrectly, and some other minor bug fixes. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> * tag 'char-misc-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: mmc: cb710 core: Add missing spin_lock_init for irq_lock of struct cb710_chip cs5535-mfgpt: don't call __init function from __devinit vmw_balloon: fix for a -Wuninitialized warning drivers: misc: Remove MISC_DEVICES config option c2port: fix build error for duramar2150 due to missing header. 
Minor char-misc fixes for 3.3-rc3

Nothing big here, some Kconfig fixes for the MISC_DEVICES config option
that was being used incorrectly, and some other minor bug fixes.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* tag 'char-misc-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  mmc: cb710 core: Add missing spin_lock_init for irq_lock of struct cb710_chip
  cs5535-mfgpt: don't call __init function from __devinit
  vmw_balloon: fix for a -Wuninitialized warning
  drivers: misc: Remove MISC_DEVICES config option
  c2port: fix build error for duramar2150 due to missing header.
lkdtm: avoid calling lkdtm_do_action() with spinlock held 2012-02-04T00:16:41+00:00 Cong Wang xiyou.wangcong@gmail.com 2012-02-03T23:37:15+00:00 92618184cb92c5b39d4d8573572d576f9ccb3c28 lkdtm_do_action() may call sleeping functions like kmalloc(), so do not call it with spin lock held. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <greg@kroah.com> Reviewed-by: Dave Young <dyoung@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
lkdtm_do_action() may call sleeping functions like kmalloc(), so do not
call it with spin lock held.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Reviewed-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mmc: cb710 core: Add missing spin_lock_init for irq_lock of struct cb710_chip 2012-02-03T00:28:14+00:00 Axel Lin axel.lin@gmail.com 2012-02-01T04:31:47+00:00 b5266ea675c5a041e2852c7ccec4cf2d4f5e0cf4 Signed-off-by: Axel Lin <axel.lin@gmail.com> Acked-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cs5535-mfgpt: don't call __init function from __devinit 2012-02-03T00:28:13+00:00 Danny Kukawka danny.kukawka@bisect.de 2012-02-02T13:20:29+00:00 474de3bbadd9cb75ffc32cc759c40d868343d46c Fix scan_timers() to be __devinit and not __init since the function get called from cs5535_mfgpt_probe which is __devinit. Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Fix scan_timers() to be __devinit and not __init since
the function get called from cs5535_mfgpt_probe which is
__devinit.

Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vmw_balloon: fix for a -Wuninitialized warning 2012-02-03T00:28:13+00:00 Danny Kukawka danny.kukawka@bisect.de 2012-01-30T22:00:08+00:00 3e5ba466d515eb3fb1e0e975a3d8e499126ae2b5 Fix for a -Wuninitialized compiler warning. Changed return value of vmballoon_send_lock_page() from bool to int to be able to distinguish between the error cases to avoid uninitialized use of hv_status in vmballoon_reserve_page() Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Fix for a -Wuninitialized compiler warning. Changed return value of
vmballoon_send_lock_page() from bool to int to be able to distinguish
between the error cases to avoid uninitialized use of hv_status in
vmballoon_reserve_page()

Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>