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  1. 22 9月, 2010 2 次提交
  3. 21 9月, 2010 3 次提交
    • V
      cfq-iosched: fix a kernel OOPs when usb key is inserted · 180be2a0
      由 Vivek Goyal 提交于 
      Mike reported a kernel crash when a usb key hotplug is performed while all
kernel thrads are not in a root cgroup and are running in one of the child
cgroups of blkio controller.

	BUG: unable to handle kernel NULL pointer dereference at 0000002c
	IP: [<c11c7b08>] cfq_get_queue+0x232/0x412
	*pde = 00000000
	Oops: 0000 [#1] PREEMPT
	last sysfs file: /sys/devices/pci0000:00/0000:00:1d.7/usb2/2-1/2-1:1.0/host3/scsi_host/host3/uevent

	[..]
	Pid: 30039, comm: scsi_scan_3 Not tainted 2.6.35.2-fg.roam #1 Volvi2                         /Aspire 4315
	EIP: 0060:[<c11c7b08>] EFLAGS: 00010086 CPU: 0
	EIP is at cfq_get_queue+0x232/0x412
	EAX: f705f9c0 EBX: e977abac ECX: 00000000 EDX: 00000000
	ESI: f00da400 EDI: f00da4ec EBP: e977a800 ESP: dff8fd00
	 DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
	Process scsi_scan_3 (pid: 30039, ti=dff8e000 task=f6b6c9a0 task.ti=dff8e000)
	Stack:
	 00000000 00000000 00000001 01ff0000 f00da508 00000000 f00da524 f00da540
	<0> e7994940 dd631750 f705f9c0 e977a820 e977ac44 f00da4d0 00000001 f6b6c9a0
	<0> 00000010 00008010 0000000b 00000000 00000001 e977a800 dd76fac0 00000246
	Call Trace:
	 [<c11c7f10>] ? cfq_set_request+0x228/0x34c
	 [<c11c7ce8>] ? cfq_set_request+0x0/0x34c
	 [<c11bb3b9>] ? elv_set_request+0xf/0x1c
	 [<c11bdd51>] ? get_request+0x1ad/0x22f
	 [<c11bddf2>] ? get_request_wait+0x1f/0x11a
	 [<c11d013b>] ? kvasprintf+0x33/0x3b
	 [<c127b537>] ? scsi_execute+0x1d/0x103
	 [<c127b675>] ? scsi_execute_req+0x58/0x83
	 [<c127c391>] ? scsi_probe_and_add_lun+0x188/0x7c2
	 [<c12718c6>] ? attribute_container_add_device+0x15/0xfa
	 [<c11c95d1>] ? kobject_get+0xf/0x13
	 [<c126d1db>] ? get_device+0x10/0x14
	 [<c127be93>] ? scsi_alloc_target+0x217/0x24d
	 [<c127cbd8>] ? __scsi_scan_target+0x95/0x480
	 [<c10204eb>] ? dequeue_entity+0x14/0x1fe
	 [<c1020491>] ? update_curr+0x165/0x1ab
	 [<c1020491>] ? update_curr+0x165/0x1ab
	 [<c127d00d>] ? scsi_scan_channel+0x4a/0x76
	 [<c127d0b0>] ? scsi_scan_host_selected+0x77/0xad
	 [<c127d13c>] ? do_scan_async+0x0/0x11a
	 [<c127d137>] ? do_scsi_scan_host+0x51/0x56
	 [<c127d13c>] ? do_scan_async+0x0/0x11a
	 [<c127d14a>] ? do_scan_async+0xe/0x11a
	 [<c127d13c>] ? do_scan_async+0x0/0x11a
	 [<c10354c5>] ? kthread+0x5e/0x63
	 [<c1035467>] ? kthread+0x0/0x63
	 [<c1002af6>] ? kernel_thread_helper+0x6/0x10
	Code: 44 24 1c 54 83 44 24 18 54 83 fa 03 75 94 8b 06 c7 86 64 02 00 00 01 00 00 00 83 e0 03 09 f0 89 06 8b 44 24 28 8b 90 58 01 00 00 <8b> 42 2c 85 c0 75 03 8b 42 08 8d 54 24 48 52 8d 4c 24 50 51 68
	EIP: [<c11c7b08>] cfq_get_queue+0x232/0x412 SS:ESP 0068:dff8fd00
	CR2: 000000000000002c
	---[ end trace 9a88306573f69b12 ]---

The problem here is that we don't have bdi->dev information available when
thread does some IO.  Hence when dev_name() tries to access bdi->dev, it
crashes.

This problem does not happen if kernel threads are in root group as root
group is statically allocated at device initialization time and we don't
hit this piece of code.

Fix it by delaying the filling of major and minor number information of
device in blk_group.  Initially a blk_group is created with 0 as device
information and this information is filled later once some more IO comes
in from same group.
Reported-by: NMike Kazantsev <mk.fraggod@gmail.com>
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      180be2a0
    • B
      block: fix blk_rq_map_kern bio direction flag · a45dc2d2
      由 Benny Halevy 提交于 
      This bug was introduced in 7b6d91da
"block: unify flags for struct bio and struct request"

Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      a45dc2d2
    • D
      cciss: freeing uninitialized data on error path · b0722cb1
      由 Dan Carpenter 提交于 
      The "h->scatter_list" is allocated inside a for loop.  If any of those
allocations fail, then the rest of the list is uninitialized data.  When
we free it we should start from the top and free backwards so that we
don't call kfree() on uninitialized pointers.

Also if the allocation for "h->scatter_list" fails then we would get an
Oops here.  I should have noticed this when I send: 4ee69851 "cciss:
handle allocation failure."  but I didn't.  Sorry about that.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      b0722cb1
  5. 20 9月, 2010 5 次提交
  7. 19 9月, 2010 10 次提交
    • A
      alpha: deal with multiple simultaneously pending signals · 494486a1
      由 Al Viro 提交于 
      Unlike the other targets, alpha sets _one_ sigframe and
buggers off until the next syscall/interrupt, even if
more signals are pending.  It leads to quite a few unpleasant
inconsistencies, starting with SIGSEGV potentially arriving
not where it should and including e.g. mess with sigsuspend();
consider two pending signals blocked until sigsuspend()
unblocks them.  We pick the first one; then, if we are hit
by interrupt while in the handler, we process the second one
as well.  If we are not, and if no syscalls had been made,
we get out of the first handler and leave the second signal
pending; normally sigreturn() would've picked it anyway, but
here it starts with restoring the original mask and voila -
the second signal is blocked again.  On everything else we
get both delivered consistently.

It's actually easy to fix; the only thing to watch out for
is prevention of double syscall restart.  Fortunately, the
idea I've nicked from arm fix by rmk works just fine...

Testcase demonstrating the behaviour in question; on alpha
we get one or both flags set (usually one), on everything
else both are always set.
	#include <signal.h>
	#include <stdio.h>
	int had1, had2;
	void f1(int sig) { had1 = 1; }
	void f2(int sig) { had2 = 1; }
	main()
	{
		sigset_t set1, set2;
		sigemptyset(&set1);
		sigemptyset(&set2);
		sigaddset(&set2, 1);
		sigaddset(&set2, 2);
		signal(1, f1);
		signal(2, f2);
		sigprocmask(SIG_SETMASK, &set2, NULL);
		raise(1);
		raise(2);
		sigsuspend(&set1);
		printf("had1:%d had2:%d\n", had1, had2);
	}
Tested-by: NMichael Cree <mcree@orcon.net.nz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      494486a1
    • A
      alpha: fix a 14 years old bug in sigreturn tracing · 53293638
      由 Al Viro 提交于 
      The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL,
all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support.

What happens is direct return to ret_from_syscall, in order to bypass
mangling of a3 (error indicator) and prevent other mutilations of
registers (e.g. by syscall restart).  That's fine, but... the entire
TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall
stopping/notifying the tracer is after the syscall.  And the normal
path we are forcibly switching to doesn't have it.

So we end up with *one* stop in traced sigreturn() vs. two in other
syscalls.  And yes, strace is visibly broken by that; try to strace
the following
	#include <signal.h>
	#include <stdio.h>
	void f(int sig) {}
	main()
	{
		signal(SIGHUP, f);
		raise(SIGHUP);
		write(1, "eeeek\n", 6);
	}
and watch the show.  The
	close(1)                                = 405
in the end of strace output is coming from return value of write() (6 ==
__NR_close on alpha) and syscall number of exit_group() (__NR_exit_group ==
405 there).

The fix is fairly simple - the only thing we end up missing is the call
of syscall_trace() and we can tell whether we'd been called from the
SYSCALL_TRACE path by checking ra value.  Since we are setting the
switch_stack up (that's what sys_sigreturn() does), we have the right
environment for calling syscall_trace() - just before we call
undo_switch_stack() and return.  Since undo_switch_stack() will overwrite
s0 anyway, we can use it to store the result of "has it been called from
SYSCALL_TRACE path?" check.  The same thing applies in rt_sigreturn().
Tested-by: NMichael Cree <mcree@orcon.net.nz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      53293638
    • A
      alpha: unb0rk sigsuspend() and rt_sigsuspend() · 392fb6e3
      由 Al Viro 提交于 
      Old code used to set regs->r0 and regs->r19 to force the right
return value.  Leaving that after switch to ERESTARTNOHAND
was a Bad Idea(tm), since now that screws the restart - if we
hit the case when get_signal_to_deliver() returns 0, we will
step back to syscall insn, with v0 set to EINTR and a3 to 1.
The latter won't matter, since EINTR is 4, aka __NR_write.

Testcase:

	#include <signal.h>
	#define _GNU_SOURCE
	#include <unistd.h>
	#include <sys/syscall.h>

	main()
	{
		sigset_t mask;
		sigemptyset(&mask);
		sigaddset(&mask, SIGCONT);
		sigprocmask(SIG_SETMASK, &mask, NULL);
		kill(0, SIGCONT);
		syscall(__NR_sigsuspend, 1, "b0rken\n", 7);
	}

results on alpha in immediate message to stdout...

Fix is obvious; moreover, since we don't need regs anymore, we can
switch to normal prototypes for these guys and lose the wrappers.
Even better, rt_sigsuspend() is identical to generic version in
kernel/signal.c now.
Tested-by: NMichael Cree <mcree@orcon.net.nz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      392fb6e3
    • A
      alpha: belated ERESTART_RESTARTBLOCK race fix · 2deba1bd
      由 Al Viro 提交于 
      same thing as had been done on other targets back in 2003 -
move setting ->restart_block.fn into {rt_,}sigreturn().
Tested-by: NMichael Cree <mcree@orcon.net.nz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      2deba1bd
    • M
      alpha: Shift perf event pending work earlier in timer interrupt · bdc8b891
      由 Michael Cree 提交于 
      Pending work from the performance event subsystem is executed in
the timer interrupt.  This patch shifts the call to
perf_event_do_pending() before the call to update_process_times()
as the latter may call back into the perf event subsystem and it
is prudent to have the pending work executed first.
Signed-off-by: NMichael Cree <mcree@orcon.net.nz>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      bdc8b891
    • M
      alpha: wire up fanotify and prlimit64 syscalls · 531f0474
      由 Mikael Pettersson 提交于 
      The 2.6.36-rc kernel added three new system calls:
fanotify_init, fanotify_mark, and prlimit64.  This
patch wires them up on Alpha.

Built and booted on an XP900.  Untested beyond that.
Signed-off-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      531f0474
    • A
      alpha: kill big kernel lock · 12e750d9
      由 Arnd Bergmann 提交于 
      All uses of the BKL on alpha are totally bogus, nothing
is really protected by this. Remove the remaining users
so we don't have to mark alpha as 'depends on BKL'.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: linux-alpha@vger.kernel.org
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      12e750d9
    • T
      alpha: fix build breakage in asm/cacheflush.h · b97f897d
      由 Tejun Heo 提交于 
      Alpha SMP flush_icache_user_range() is implemented as an inline
function inside include/asm/cacheflush.h.  It dereferences @current
but doesn't include linux/sched.h and thus causes build failure if
linux/sched.h wasn't included previously.  Fix it by including the
needed header file explicitly.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      b97f897d
    • M
      alpha: remove unnecessary cast from void* in assignment. · af96f8a3
      由 matt mooney 提交于 
      Acked-by: NJan-Benedict Glaw <jbglaw@lug-owl.de>
Signed-off-by: Nmatt mooney <mfm@muteddisk.com>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      af96f8a3
    • J
      alpha: Use static const char * const where possible · 31019075
      由 Joe Perches 提交于 
      Acked-by: NRichard Henderson  <rth@twiddle.net>
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NMatt Turner <mattst88@gmail.com>
      31019075
  9. 18 9月, 2010 12 次提交
  11. 17 9月, 2010 8 次提交