linux-toradex.git/kernel/sys.c, branch v3.8.12

PM / reboot: call syscore_shutdown() after disable_nonboot_cpus()

2013-04-17T04:48:28+00:00

commit 6f389a8f1dd22a24f3d9afc2812b30d639e94625 upstream.

As commit 40dc166c (PM / Core: Introduce struct syscore_ops for core
subsystems PM) say, syscore_ops operations should be carried with one
CPU on-line and interrupts disabled. However, after commit f96972f2d
(kernel/sys.c: call disable_nonboot_cpus() in kernel_restart()),
syscore_shutdown() is called before disable_nonboot_cpus(), so break
the rules. We have a MIPS machine with a 8259A PIC, and there is an
external timer (HPET) linked at 8259A. Since 8259A has been shutdown
too early (by syscore_shutdown()), disable_nonboot_cpus() runs without
timer interrupt, so it hangs and reboot fails. This patch call
syscore_shutdown() a little later (after disable_nonboot_cpus()) to
avoid reboot failure, this is the same way as poweroff does.

For consistency, add disable_nonboot_cpus() to kernel_halt().

Signed-off-by: Huacai Chen 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cputime: Rename thread_group_times to thread_group_cputime_adjusted

2012-11-28T16:07:57+00:00

We have thread_group_cputime() and thread_group_times(). The naming
doesn't provide enough information about the difference between
these two APIs.

To lower the confusion, rename thread_group_times() to
thread_group_cputime_adjusted(). This name better suggests that
it's a version of thread_group_cputime() that does some stabilization
on the raw cputime values. ie here: scale on top of CFS runtime
stats and bound lower value for monotonicity.

Signed-off-by: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Steven Rostedt 
Cc: Paul Gortmaker

use clamp_t in UNAME26 fix

2012-10-20T01:51:17+00:00

The min/max call needed to have explicit types on some architectures
(e.g. mn10300). Use clamp_t instead to avoid the warning:

  kernel/sys.c: In function 'override_release':
  kernel/sys.c:1287:10: warning: comparison of distinct pointer types lacks a cast [enabled by default]

Reported-by: Fengguang Wu 
Signed-off-by: Kees Cook 
Signed-off-by: Linus Torvalds

kernel/sys.c: fix stack memory content leak via UNAME26

2012-10-19T21:07:47+00:00

Calling uname() with the UNAME26 personality set allows a leak of kernel
stack contents.  This fixes it by defensively calculating the length of
copy_to_user() call, making the len argument unsigned, and initializing
the stack buffer to zero (now technically unneeded, but hey, overkill).

CVE-2012-0957

Reported-by: PaX Team 
Signed-off-by: Kees Cook 
Cc: Andi Kleen 
Cc: PaX Team 
Cc: Brad Spengler 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

poweroff: fix bug in orderly_poweroff()

2012-10-05T18:04:48+00:00

orderly_poweroff is trying to poweroff platform in two steps:

step 1: Call user space application to poweroff
step 2: If user space poweroff fail, then do a force power off if force param
        is set.

The bug here is, step 1 is always successful with param UMH_NO_WAIT, which obey
the design goal of orderly_poweroff.

We have two choices here:
UMH_WAIT_EXEC which means wait for the exec, but not the process;
UMH_WAIT_PROC which means wait for the process to complete.
we need to trade off the two choices:

If using UMH_WAIT_EXEC, there is potential issue comments by Serge E.
Hallyn: The exec will have started, but may for whatever (very unlikely)
reason fail.

If using UMH_WAIT_PROC, there is potential issue comments by Eric W.
Biederman: If the caller is not running in a kernel thread then we can
easily get into a case where the user space caller will block waiting for
us when we are waiting for the user space caller.

Thanks for their excellent ideas, based on the above discussion, we
finally choose UMH_WAIT_EXEC, which is much more safe, if the user
application really fails, we just complain the application itself, it
seems a better choice here.

Signed-off-by: Feng Hong 
Acked-by: Kees Cook 
Acked-by: Serge Hallyn 
Cc: "Eric W. Biederman" 
Acked-by: "Rafael J. Wysocki" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/sys.c: call disable_nonboot_cpus() in kernel_restart()

2012-10-05T18:04:47+00:00

As kernel_power_off() calls disable_nonboot_cpus(), we may also want to
have kernel_restart() call disable_nonboot_cpus().  Doing so can help
machines that require boot cpu be the last alive cpu during reboot to
survive with kernel restart.

This fixes one reboot issue seen on imx6q (Cortex-A9 Quad).  The machine
requires that the restart routine be run on the primary cpu rather than
secondary ones.  Otherwise, the secondary core running the restart
routine will fail to come to online after reboot.

Signed-off-by: Shawn Guo 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

switch simple cases of fget_light to fdget

2012-09-27T02:20:08+00:00

Signed-off-by: Al Viro

switch prctl_set_mm_exe_file() to fget_light()

2012-09-27T01:10:12+00:00

Signed-off-by: Al Viro

kernel/sys.c: avoid argv_free(NULL)

2012-07-31T00:25:13+00:00

If argv_split() failed, the code will end up calling argv_free(NULL).  Fix
it up and clean things up a bit.

Addresses Coverity report 703573.

Cc: Cyrill Gorcunov 
Cc: Kees Cook 
Cc: Serge Hallyn 
Cc: "Eric W. Biederman" 
Cc: WANG Cong 
Cc: Alan Cox 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

prctl: remove redunant assignment of "error" to zero

2012-07-31T00:25:11+00:00

Just setting the "error" to error number is enough on failure and It
doesn't require to set "error" variable to zero in each switch case,
since it was already initialized with zero.  And also removed return 0
in switch case with break statement

Signed-off-by: Sasikantha babu 
Acked-by: Kees Cook 
Acked-by: Serge E. Hallyn 
Cc: Cyrill Gorcunov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds