Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
切换分支/标签
  1. 30 3月, 2012 3 次提交
    • J
      kgdbts: (1 of 2) fix single step awareness to work correctly with SMP · 486c5987
      由 Jason Wessel 提交于 
      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

Cc: stable@vger.kernel.org # >= 2.6.26
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
      486c5987
    • J
      kgdbts: Fix kernel oops with CONFIG_DEBUG_RODATA · 456ca7ff
      由 Jason Wessel 提交于 
      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.

Cc: <stable@vger.kernel.org> # >= 2.6.26
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
      456ca7ff
    • J
      kdb: Fix smatch warning on dbg_io_ops->is_console · 78724b8e
      由 Jason Wessel 提交于 
      The Smatch tool warned that the change from commit b8adde8d
(kdb: Avoid using dbg_io_ops until it is initialized) should
add another null check later in the kdb_printf().

It is worth noting that the second use of dbg_io_ops->is_console
is protected by the KDB_PAGER state variable which would only
get set when kdb is fully active and initialized.  If we
ever encounter changes or defects in the KDB_PAGER state
we do not want to crash the kernel in a kdb_printf/printk.

CC: Tim Bird <tim.bird@am.sony.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
      78724b8e
  3. 23 3月, 2012 7 次提交
  5. 19 3月, 2012 2 次提交
  7. 18 3月, 2012 2 次提交
    • L
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · c579bc7e
      由 Linus Torvalds 提交于 
      Pull networking changes from David Miller:
 "1) icmp6_dst_alloc() returns NULL instead of ERR_PTR() leading to
     crashes, particularly during shutdown.  Reported by Dave Jones and
     fixed by Eric Dumazet.

  2) hyperv and wimax/i2400m return NETDEV_TX_BUSY when they have
     already freed the SKB, which causes crashes as to the caller this
     means requeue the packet.  Fixes from Eric Dumazet.

  3) usbnet driver doesn't allocate the right amount of headroom on
     fresh RX SKBs, fix from Eric Dumazet.

  4) Fix regression in ip6_mc_find_dev_rcu(), as an RCU lookup it
     abolutely should not take a reference to 'dev', this leads to
     leaks.  Fix from RonQing Li.

  5) Fix netfilter ctnetlink race between delete and timeout expiration.
     From Pablo Neira Ayuso.

  6) Revert SFQ change which causes regressions, specifically queueing
     to tail can lead to unavoidable flow starvation.  From Eric
     Dumazet.

  7) Fix a memory leak and a crash on corrupt firmware files in bnx2x,
     from Michal Schmidt."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  netfilter: ctnetlink: fix race between delete and timeout expiration
  ipv6: Don't dev_hold(dev) in ip6_mc_find_dev_rcu.
  wimax/i2400m: fix erroneous NETDEV_TX_BUSY use
  net/hyperv: fix erroneous NETDEV_TX_BUSY use
  net/usbnet: reserve headroom on rx skbs
  bnx2x: fix memory leak in bnx2x_init_firmware()
  bnx2x: fix a crash on corrupt firmware file
  sch_sfq: revert dont put new flow at the end of flows
  ipv6: fix icmp6_dst_alloc()
      c579bc7e
    • L
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 96ee0499
      由 Linus Torvalds 提交于 
      Pull perf fixes from Ingo Molnar.

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools, x86: Build perf on older user-space as well
  perf tools: Use scnprintf where applicable
  perf tools: Incorrect use of snprintf results in SEGV
      96ee0499
  9. 17 3月, 2012 9 次提交
  11. 16 3月, 2012 17 次提交