Commit Graph

1287 Commits

Author SHA1 Message Date
Linus Torvalds 9abd09acd6 parisc: 'renameat2()' doesn't need (or have) a separate compat system call
The 'renameat2()' system call was incorrectly added as a ENTRY_COMP() in
the parisc system call table by commit 18e480aa07 ("parisc: add
renameat2 syscall").  That causes a link-time error due to there not
being any compat version of that system call:

  arch/parisc/kernel/built-in.o: In function `sys_call_table':
  (.rodata+0xad0): undefined reference to `compat_sys_renameat2'
  make: *** [vmlinux] Error 1

Easily fixed by marking the system call as being the same for compat as
for native by using ENTRY_SAME() instead of ENTRY_COMP().

Reported-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-23 09:23:51 -07:00
Miklos Szeredi 18e480aa07 parisc: add renameat2 syscall
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Helge Deller <deller@gmx.de>
2014-05-20 10:59:37 +02:00
Linus Torvalds 6ed8bf82fe Merge branch 'parisc-3.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:
 "There are two patches in here:

  The first patch greatly improves latency and corrects the memory
  ordering in our light-weight atomic locking syscall.

  The second patch ratelimits printing of userspace segfaults in the
  same way as it's done on other platforms.  This fixes a possible DOS
  on parisc since it prevents the syslog to grow too fast.  For example,
  when the debian acl2 package was built on our debian buildd servers,
  this package produced lots of gigabytes in syslog in very short time
  and thus filled our harddisks, which then turned the server nearly
  completely unaccessible and unresponsive"

* 'parisc-3.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Improve LWS-CAS performance
  parisc: ratelimit userspace segfault printing
2014-05-20 14:35:28 +09:00
John David Anglin c776cd89fc parisc: Improve LWS-CAS performance
The attached change significantly improves the performance of the LWS-CAS code
in syscall.S.
This allows a number of packages to build (e.g., zeromq3, gtest and libxs)
that previously failed because slow LWS-CAS performance under contention. In
particular, interrupts taken while the lock was taken degraded performance
significantly.

The change does the following:

1) Disables interrupts around the CAS operation, and
2) Changes the loads and stores to use the ordered completer, "o", on
PA 2.0. "o" and "ma" with a zero offset are equivalent. The latter is
accepted on both PA 1.X and 2.0.

The use of ordered loads and stores probably makes no difference on all
existing hardware, but it seemed pedantically correct. In particular, the CAS
operation must complete before LDCW lock is released. As written before, a
processor could reorder the operations.

I don't believe the period interrupts are disabled is long enough to
significantly increase interrupt latency. For example, the TLB insert code is
longer. Worst case is a memory fault in the CAS operation.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 3.13+
Signed-off-by: Helge Deller <deller@gmx.de>
2014-05-15 21:12:26 +02:00
Helge Deller fef47e2a2e parisc: ratelimit userspace segfault printing
Ratelimit printing of userspace segfaults and make it runtime
configurable via the /proc/sys/debug/exception-trace variable. This
should resolve syslog from growing way too fast and thus prevents
possible system service attacks.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+
2014-05-15 21:12:15 +02:00
Helge Deller 042d27acb6 parisc,metag: Do not hardcode maximum userspace stack size
This patch affects only architectures where the stack grows upwards
(currently parisc and metag only). On those do not hardcode the maximum
initial stack size to 1GB for 32-bit processes, but make it configurable
via a config option.

The main problem with the hardcoded stack size is, that we have two
memory regions which grow upwards: stack and heap. To keep most of the
memory available for heap in a flexmap memory layout, it makes no sense
to hard allocate up to 1GB of the memory for stack which can't be used
as heap then.

This patch makes the stack size for 32-bit processes configurable and
uses 80MB as default value which has been in use during the last few
years on parisc and which hasn't showed any problems yet.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin <dave.anglin@bell.net>
2014-05-15 00:01:41 +01:00
James Hogan d71f290b4e metag: Reduce maximum stack size to 256MB
Specify the maximum stack size for arches where the stack grows upward
(parisc and metag) in asm/processor.h rather than hard coding in
fs/exec.c so that metag can specify a smaller value of 256MB rather than
1GB.

This fixes a BUG on metag if the RLIMIT_STACK hard limit is increased
beyond a safe value by root. E.g. when starting a process after running
"ulimit -H -s unlimited" it will then attempt to use a stack size of the
maximum 1GB which is far too big for metag's limited user virtual
address space (stack_top is usually 0x3ffff000):

BUG: failure at fs/exec.c:589/shift_arg_pages()!

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # only needed for >= v3.9 (arch/metag)
2014-05-15 00:00:35 +01:00
Linus Torvalds b5f3c61d06 Merge branch 'parisc-3.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:
 "Drop the architecture-specifc value for_STK_LIM_MAX to fix stack
  related problems with GNU make"

* 'parisc-3.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Use generic uapi/asm/resource.h file
  parisc: remove _STK_LIM_MAX override
2014-05-01 15:54:44 -07:00
Helge Deller 8a415e534d parisc: Use generic uapi/asm/resource.h file
Signed-off-by: Helge Deller <deller@gmx.de>
2014-05-01 19:29:26 +02:00
John David Anglin e0d8898d76 parisc: remove _STK_LIM_MAX override
There are only a couple of architectures that override _STK_LIM_MAX to
a non-infinity value. This changes the stack allocation semantics in
subtle ways. For example, GNU make changes its stack allocation to the
hard maximum defined by _STK_LIM_MAX. As a results, threads executed
by processes running under make are allocated a stack size of
_STK_LIM_MAX rather than a sensible default value. This causes various
thread stress tests to fail when they can't muster more than about 50
threads.

The attached change implements the default behavior used by the
majority of architectures.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
Cc: stable@vger.kernel.org # 3.14
Signed-off-by: Helge Deller <deller@gmx.de>
2014-05-01 19:28:44 +02:00
Linus Torvalds 81cef0fe19 Merge branch 'parisc-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc updates from Helge Deller:
 "There are two major changes in this patchset:

  The major fix is that the epoll_pwait() syscall for 32bit userspace
  was not using the compat wrapper on a 64bit kernel.

  Secondly we changed the value of SHMLBA from 4MB to PAGE_SIZE to
  reflect that we can actually mmap to any multiple of PAGE_SIZE.  The
  only thing which needs care is that shared mmaps need to be mapped at
  the same offset inside the 4MB cache window"

* 'parisc-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: fix epoll_pwait syscall on compat kernel
  parisc: change value of SHMLBA from 0x00400000 to PAGE_SIZE
  parisc: Replace __get_cpu_var uses for address calculation
2014-04-17 13:21:35 -07:00
Helge Deller ab3e55b119 parisc: fix epoll_pwait syscall on compat kernel
This bug was detected with the libio-epoll-perl debian package where the
test case IO-Ppoll-compat.t failed.

Signed-off-by: Helge Deller <deller@gmx.de>
CC: stable@kernel.org   # 3.0+
2014-04-13 15:07:57 +02:00
Helge Deller 0ef36bd2b3 parisc: change value of SHMLBA from 0x00400000 to PAGE_SIZE
On parisc, SHMLBA was defined to 0x00400000 (4MB) to reflect that we need to
take care of our caches for shared mappings. But actually, we can map a file at
any multiple address of PAGE_SIZE, so let us correct that now with a value of
PAGE_SIZE for SHMLBA.  Instead we now take care of this cache colouring via the
constant SHM_COLOUR while we map shared pages.

Signed-off-by: Helge Deller <deller@gmx.de>
CC: Jeroen Roovers <jer@gentoo.org>
CC: John David Anglin <dave.anglin@bell.net>
CC: Carlos O'Donell <carlos@systemhalted.org>
Cc: stable@kernel.org [3.13+]
2014-04-13 15:00:53 +02:00
Linus Torvalds 0b747172dc Merge git://git.infradead.org/users/eparis/audit
Pull audit updates from Eric Paris.

* git://git.infradead.org/users/eparis/audit: (28 commits)
  AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC
  audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range
  audit: do not cast audit_rule_data pointers pointlesly
  AUDIT: Allow login in non-init namespaces
  audit: define audit_is_compat in kernel internal header
  kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c
  sched: declare pid_alive as inline
  audit: use uapi/linux/audit.h for AUDIT_ARCH declarations
  syscall_get_arch: remove useless function arguments
  audit: remove stray newline from audit_log_execve_info() audit_panic() call
  audit: remove stray newlines from audit_log_lost messages
  audit: include subject in login records
  audit: remove superfluous new- prefix in AUDIT_LOGIN messages
  audit: allow user processes to log from another PID namespace
  audit: anchor all pid references in the initial pid namespace
  audit: convert PPIDs to the inital PID namespace.
  pid: get pid_t ppid of task in init_pid_ns
  audit: rename the misleading audit_get_context() to audit_take_context()
  audit: Add generic compat syscall support
  audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
  ...
2014-04-12 12:38:53 -07:00
Christoph Lameter 496252f787 parisc: Replace __get_cpu_var uses for address calculation
Convert to the use of this_cpu_ptr().

Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Helge Deller <deller@gmx.de>
2014-04-03 20:50:33 +02:00
Linus Torvalds 683b6c6f82 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq code updates from Thomas Gleixner:
 "The irq department proudly presents:

   - Another tree wide sweep of irq infrastructure abuse.  Clear winner
     of the trainwreck engineering contest was:
         #include "../../../kernel/irq/settings.h"

   - Tree wide update of irq_set_affinity() callbacks which miss a cpu
     online check when picking a single cpu out of the affinity mask.

   - Tree wide consolidation of interrupt statistics.

   - Updates to the threaded interrupt infrastructure to allow explicit
     wakeup of the interrupt thread and a variant of synchronize_irq()
     which synchronizes only the hard interrupt handler.  Both are
     needed to replace the homebrewn thread handling in the mmc/sdhci
     code.

   - New irq chip callbacks to allow proper support for GPIO based irqs.
     The GPIO based interrupts need to request/release GPIO resources
     from request/free_irq.

   - A few new ARM interrupt chips.  No revolutionary new hardware, just
     differently wreckaged variations of the scheme.

   - Small improvments, cleanups and updates all over the place"

I was hoping that that trainwreck engineering contest was a April Fools'
joke.  But no.

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (68 commits)
  irqchip: sun7i/sun6i: Disable NMI before registering the handler
  ARM: sun7i/sun6i: dts: Fix IRQ number for sun6i NMI controller
  ARM: sun7i/sun6i: irqchip: Update the documentation
  ARM: sun7i/sun6i: dts: Add NMI irqchip support
  ARM: sun7i/sun6i: irqchip: Add irqchip driver for NMI controller
  genirq: Export symbol no_action()
  arm: omap: Fix typo in ams-delta-fiq.c
  m68k: atari: Fix the last kernel_stat.h fallout
  irqchip: sun4i: Simplify sun4i_irq_ack
  irqchip: sun4i: Use handle_fasteoi_irq for all interrupts
  genirq: procfs: Make smp_affinity values go+r
  softirq: Add linux/irq.h to make it compile again
  m68k: amiga: Add linux/irq.h to make it compile again
  irqchip: sun4i: Don't ack IRQs > 0, fix acking of IRQ 0
  irqchip: sun4i: Fix a comment about mask register initialization
  irqchip: sun4i: Fix irq 0 not working
  genirq: Add a new IRQCHIP_EOI_THREADED flag
  genirq: Document IRQCHIP_ONESHOT_SAFE flag
  ARM: sunxi: dt: Convert to the new irq controller compatibles
  irqchip: sunxi: Change compatibles
  ...
2014-04-01 11:22:57 -07:00
Linus Torvalds 462bf234a8 Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking updates from Ingo Molnar:
 "The biggest change is the MCS spinlock generalization changes from Tim
  Chen, Peter Zijlstra, Jason Low et al.  There's also lockdep
  fixes/enhancements from Oleg Nesterov, in particular a false negative
  fix related to lockdep_set_novalidate_class() usage"

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  locking/mutex: Fix debug checks
  locking/mutexes: Add extra reschedule point
  locking/mutexes: Introduce cancelable MCS lock for adaptive spinning
  locking/mutexes: Unlock the mutex without the wait_lock
  locking/mutexes: Modify the way optimistic spinners are queued
  locking/mutexes: Return false if task need_resched() in mutex_can_spin_on_owner()
  locking: Move mcs_spinlock.h into kernel/locking/
  m68k: Skip futex_atomic_cmpxchg_inatomic() test
  futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test
  Revert "sched/wait: Suppress Sparse 'variable shadowing' warning"
  lockdep: Change lockdep_set_novalidate_class() to use _and_name
  lockdep: Change mark_held_locks() to check hlock->check instead of lockdep_no_validate
  lockdep: Don't create the wrong dependency on hlock->check == 0
  lockdep: Make held_lock->check and "int check" argument bool
  locking/mcs: Allow architecture specific asm files to be used for contended case
  locking/mcs: Order the header files in Kbuild of each architecture in alphabetical order
  sched/wait: Suppress Sparse 'variable shadowing' warning
  hung_task/Documentation: Fix hung_task_warnings description
  locking/mcs: Allow architectures to hook in to contended paths
  locking/mcs: Micro-optimize the MCS code, add extra comments
  ...
2014-03-31 10:59:39 -07:00
Will Deacon a34fe10750 parisc: locks: remove redundant arch_*_relax operations
Now that the arch_{spin,read,write}_relax macros default to cpu_relax(),
remove the redundant definitions for parisc.

Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Helge Deller <deller@gmx.de>
2014-03-23 17:01:23 +01:00
Helge Deller e9af8b7aba parisc: wire up sys_utimes
We seem to be nearly the only platform which does not provide the
sys_utimes syscall.  Adding it now makes our life much easier with
userspace applications (like dietlibc and e2fsprogs) since we then
behave like all other platforms too and don't need extra patches which
are hard to get upstream anyway because we are not a mainstream
architecture.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13
2014-03-23 16:57:13 +01:00
John David Anglin 4b02a72a26 parisc: Remove unused CONFIG_PARISC_TMPALIAS code
The attached change removes the unused and experimental
CONFIG_PARISC_TMPALIAS code. It doesn't work and I don't believe it will
ever be used.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
2014-03-23 16:46:30 +01:00
AKASHI Takahiro 7a01772128 audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL
Currently AUDITSYSCALL has a long list of architecture depencency:
       depends on AUDIT && (X86 || PARISC || PPC || S390 || IA64 || UML ||
		SPARC64 || SUPERH || (ARM && AEABI && !OABI_COMPAT) || ALPHA)
The purpose of this patch is to replace it with HAVE_ARCH_AUDITSYSCALL
for simplicity.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com> (arm)
Acked-by: Richard Guy Briggs <rgb@redhat.com> (audit)
Acked-by: Matt Turner <mattst88@gmail.com> (alpha)
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-03-20 10:11:10 -04:00
Thomas Gleixner 1ed71e59bc parisc: Validate online cpus in irq_set_affinity() callbacks
The [user space] interface does not filter out offline cpus. It merily
guarantees that the mask contains at least one online cpu.

So the selector in the irq chip implementation needs to make sure to
pick only an online cpu because otherwise:

     Offline Core 1
     Set affinity to 0xe (is valid due to online mask 0xd)
     cpumask_first will pick core 1, which is offline

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Link: http://lkml.kernel.org/r/20140304203100.859489993@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-03-12 13:07:41 +01:00
Tim Chen ddf1d169c0 locking/mcs: Allow architecture specific asm files to be used for contended case
This patch allows each architecture to add its specific assembly optimized
arch_mcs_spin_lock_contended and arch_mcs_spinlock_uncontended for
MCS lock and unlock functions.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: AswinChandramouleeswaran <aswin@hp.com>
Cc: George Spelvin <linux@horizon.com>
Cc: Rik vanRiel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: MichelLespinasse <walken@google.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Figo.zhang" <figo1802@gmail.com>
Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1390347382.3138.67.camel@schen9-DESK
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-09 21:18:52 +01:00
Tim Chen b119fa61d4 locking/mcs: Order the header files in Kbuild of each architecture in alphabetical order
We perform a clean up of the Kbuid files in each architecture.
We order the files in each Kbuild in alphabetical order
by running the below script.

for i in arch/*/include/asm/Kbuild
do
        cat $i | gawk '/^generic-y/ {
                i = 3;
                do {
                        for (; i <= NF; i++) {
                                if ($i == "\\") {
                                        getline;
                                        i = 1;
                                        continue;
                                }
                                if ($i != "")
                                        hdr[$i] = $i;
                        }
                        break;
                } while (1);
                next;
        }
        // {
                print $0;
        }
        END {
                n = asort(hdr);
                for (i = 1; i <= n; i++)
                        print "generic-y += " hdr[i];
        }' > ${i}.sorted;
        mv ${i}.sorted $i;
done

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
Cc: AswinChandramouleeswaran <aswin@hp.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "Figo.zhang" <figo1802@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: George Spelvin <linux@horizon.com>
Cc: MichelLespinasse <walken@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
[ Fixed build bug. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-09 21:17:50 +01:00
Linus Torvalds c4ad8f98be execve: use 'struct filename *' for executable name passing
This changes 'do_execve()' to get the executable name as a 'struct
filename', and to free it when it is done.  This is what the normal
users want, and it simplifies and streamlines their error handling.

The controlled lifetime of the executable name also fixes a
use-after-free problem with the trace_sched_process_exec tracepoint: the
lifetime of the passed-in string for kernel users was not at all
obvious, and the user-mode helper code used UMH_WAIT_EXEC to serialize
the pathname allocation lifetime with the execve() having finished,
which in turn meant that the trace point that happened after
mm_release() of the old process VM ended up using already free'd memory.

To solve the kernel string lifetime issue, this simply introduces
"getname_kernel()" that works like the normal user-space getname()
function, except with the source coming from kernel memory.

As Oleg points out, this also means that we could drop the tcomm[] array
from 'struct linux_binprm', since the pathname lifetime now covers
setup_new_exec().  That would be a separate cleanup.

Reported-by: Igor Zhbanov <i.zhbanov@samsung.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-05 12:54:53 -08:00