getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.
For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.
This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.
Later, we'll add other information to the struct as it becomes
convenient.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In the old times, the whole idle task was considered
as an RCU quiescent state. But as RCU became more and
more successful overtime, some RCU read side critical
section have been added even in the code of some
architectures idle tasks, for tracing for example.
So nowadays, rcu_idle_enter() and rcu_idle_exit() must
be called by the architecture to tell RCU about the part
in the idle loop that doesn't make use of rcu read side
critical sections, typically the part that puts the CPU
in low power mode.
This is necessary for RCU to find the quiescent states in
idle in order to complete grace periods.
Add this missing pair of calls in the m32r's idle loop.
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: <stable@vger.kernel.org> # 3.3+
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:
arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to. This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel(). A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().
do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.
Further kernel_execve() and sys_execve() need to be changed to match.
This has been test built on x86_64, frv, arm and mips.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark arguments to certain system calls as being const where they should be but
aren't. The list includes:
(*) The filename arguments of various stat syscalls, execve(), various utimes
syscalls and some mount syscalls.
(*) The filename arguments of some syscall helpers relating to the above.
(*) The buffer argument of various write syscalls.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
m32r: PTRACE_SINGLESTEP sets PT_DTRACE, it is never used except cleared
after do_execve().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Hirokazu Takata <takata@linux-m32r.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Additional fixes for processors without ISA_DSP_LEVEL2. sigcontext_t does not
have dummy_acc1h, dummy_acc1l members any longer.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Here is a patch to support a reboot function for M3A-2170(Mappi-III)
evaluation board.
Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
)
From: Adrian Bunk <bunk@stusta.de>
- create one common dump_thread() prototype in kernel.h
- dump_thread() is only used in fs/binfmt_aout.c and can therefore be
removed on all architectures where CONFIG_BINFMT_AOUT is not
available
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The problem. It is expected that /sbin/halt -p works exactly like
/sbin/halt, when the kernel does not implement power off functionality.
The kernel can do a lot of work in the reboot notifiers and in
device_shutdown before we even get to machine_power_off. Some of that
shutdown is not safe if you are leaving the power on, and it definitely
gets in the way of using sysrq or pressing ctrl-alt-del. Since the
shutdown happens in generic code there is no way to fix this in
architecture specific code :(
Some machines are kernel oopsing today because of this.
The simple solution is to turn LINUX_REBOOT_CMD_POWER_OFF into
LINUX_REBOOT_CMD_HALT if power_off functionality is not implemented.
This has the unfortunate side effect of disabling the power off
functionality on architectures that leave pm_power_off to null and still
implement something in machine_power_off. And it will break the build on
some architectures that don't have a pm_power_off variable at all.
On both counts I say tough.
For architectures like alpha that don't implement the pm_power_off variable
pm_power_off is declared in linux/pm.h and it is a generic part of our
power management code, and all architectures should implement it.
For architectures like parisc that have a default power off method in
machine_power_off if pm_power_off is not implemented or fails. It is easy
enough to set the pm_power_off variable. And nothing bad happens there,
the machines just stop powering off.
The current semantics are impossible without a flag at the top level so we
can avoid the problem code if a power off is not implemented. pm_power_off
is as good a flag as any with the bonus that it works without modification
on at least x86, x86_64, powerpc, and ppc today.
Andrew can you pick this up and put this in the mm tree. Kernels that
don't compile or don't power off seem saner than kernels that oops or
panic. Until we get the arch specific patches for the problem
architectures this probably isn't smart to push into the stable kernel.
Unfortunately I don't have the time at the moment to walk through every
architecture and make them work. And even if I did I couldn't test it :(
From: Hirokazu Takata <takata@linux-m32r.org>
Add pm_power_off() for build fix of arch/m32r/kernel/process.c.
From: Miklos Szeredi <miklos@szeredi.hu>
UML build fix
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Hayato Fujiwara <fujiwara@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Run idle threads with preempt disabled.
Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?
Might fix the CPU hotplugging hang which Nigel Cunningham noted.
We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.
After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep. The CPU will continue executing
previous idle and have no chance to call play_dead.
By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.
From: alexs <ashepard@u.washington.edu>
PPC build fix
From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
MIPS build fix
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
machine_restart, machine_halt and machine_power_off are machine
specific hooks deep into the reboot logic, that modules
have no business messing with. Usually code should be calling
kernel_restart, kernel_halt, kernel_power_off, or
emergency_restart. So don't export machine_restart,
machine_halt, and machine_power_off so we can catch buggy users.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Jeff Layton