Instead of BUG_ON(in_interrupt()), since that doesn't check for all
the newfangled stuff like preempt.
Note that this is valid since the console_sem is essentially used like
a real mutex with only two twists:
- we allow trylock from hardirq context
- across suspend/resume we lock the logical console_lock, but drop the
semaphore protecting the locking state.
Now that doesn't guarantee that no one is playing tricks in
single-thread atomic contexts at suspend/resume/boot time, but
- I couldn't find anything suspicious with some grepping,
- might_sleep shouldn't die,
- and I think the upside of catching more potential issues is worth
the risk of getting a might_sleep backtrace that would have been
save (and then dealing with that fallout).
Cc: Dave Airlie <airlied@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dave Airlie recently discovered a locking bug in the fbcon layer,
where a timer_del_sync (for the blinking cursor) deadlocks with the
timer itself, since both (want to) hold the console_lock:
https://lkml.org/lkml/2012/8/21/36
Unfortunately the console_lock isn't a plain mutex and hence has no
lockdep support. Which resulted in a few days wasted of tracking down
this bug (complicated by the fact that printk doesn't show anything
when the console is locked) instead of noticing the bug much earlier
with the lockdep splat.
Hence I've figured I need to fix that for the next deadlock involving
console_lock - and with kms/drm growing ever more complex locking
that'll eventually happen.
Now the console_lock has rather funky semantics, so after a quick irc
discussion with Thomas Gleixner and Dave Airlie I've quickly ditched
the original idead of switching to a real mutex (since it won't work)
and instead opted to annotate the console_lock with lockdep
information manually.
There are a few special cases:
- The console_lock state is protected by the console_sem, and usually
grabbed/dropped at _lock/_unlock time. But the suspend/resume code
drops the semaphore without dropping the console_lock (see
suspend_console/resume_console). But since the same thread that did
the suspend will do the resume, we don't need to fix up anything.
- In the printk code there's a special trylock, only used to kick off
the logbuffer printk'ing in console_unlock. But all that happens
while lockdep is disable (since printk does a few other evil
tricks). So no issue there, either.
- The console_lock can also be acquired form irq context (but only
with a trylock). lockdep already handles that.
This all leaves us with annotating the normal console_lock, _unlock
and _trylock functions.
And yes, it works - simply unloading a drm kms driver resulted in
lockdep complaining about the deadlock in fbcon_deinit:
======================================================
[ INFO: possible circular locking dependency detected ]
3.6.0-rc2+ #552 Not tainted
-------------------------------------------------------
kms-reload/3577 is trying to acquire lock:
((&info->queue)){+.+...}, at: [<ffffffff81058c70>] wait_on_work+0x0/0xa7
but task is already holding lock:
(console_lock){+.+.+.}, at: [<ffffffff81264686>] bind_con_driver+0x38/0x263
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (console_lock){+.+.+.}:
[<ffffffff81087440>] lock_acquire+0x95/0x105
[<ffffffff81040190>] console_lock+0x59/0x5b
[<ffffffff81209cb6>] fb_flashcursor+0x2e/0x12c
[<ffffffff81057c3e>] process_one_work+0x1d9/0x3b4
[<ffffffff810584a2>] worker_thread+0x1a7/0x24b
[<ffffffff8105ca29>] kthread+0x7f/0x87
[<ffffffff813b1204>] kernel_thread_helper+0x4/0x10
-> #0 ((&info->queue)){+.+...}:
[<ffffffff81086cb3>] __lock_acquire+0x999/0xcf6
[<ffffffff81087440>] lock_acquire+0x95/0x105
[<ffffffff81058cab>] wait_on_work+0x3b/0xa7
[<ffffffff81058dd6>] __cancel_work_timer+0xbf/0x102
[<ffffffff81058e33>] cancel_work_sync+0xb/0xd
[<ffffffff8120a3b3>] fbcon_deinit+0x11c/0x1dc
[<ffffffff81264793>] bind_con_driver+0x145/0x263
[<ffffffff81264a45>] unbind_con_driver+0x14f/0x195
[<ffffffff8126540c>] store_bind+0x1ad/0x1c1
[<ffffffff8127cbb7>] dev_attr_store+0x13/0x1f
[<ffffffff8116d884>] sysfs_write_file+0xe9/0x121
[<ffffffff811145b2>] vfs_write+0x9b/0xfd
[<ffffffff811147b7>] sys_write+0x3e/0x6b
[<ffffffff813b0039>] system_call_fastpath+0x16/0x1b
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(console_lock);
lock((&info->queue));
lock(console_lock);
lock((&info->queue));
*** DEADLOCK ***
v2: Mark the lockdep_map static, noticed by Jani Nikula.
Cc: Dave Airlie <airlied@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <fengguang.wu@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Emit the magic string that indicates a module has a signature after the
signature data instead of before it. This allows module_sig_check() to
be made simpler and faster by the elimination of the search for the
magic string. Instead we just need to do a single memcmp().
This works because at the end of the signature data there is the
fixed-length signature information block. This block then falls
immediately prior to the magic number.
From the contents of the information block, it is trivial to calculate
the size of the signature data and thus the size of the actual module
data.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_pid_ns() operates in a recursive fashion:
free_pid_ns(parent)
put_pid_ns(parent)
kref_put(&ns->kref, free_pid_ns);
free_pid_ns
thus if there was a huge nesting of namespaces the userspace may trigger
avalanche calling of free_pid_ns leading to kernel stack exhausting and a
panic eventually.
This patch turns the recursion into an iterative loop.
Based on a patch by Andrew Vagin.
[akpm@linux-foundation.org: export put_pid_ns() to modules]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <pageexec@freemail.hu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The console_cpu_notify() function runs with interrupts disabled in the
CPU_DYING case. It therefore cannot block, for example, as will happen
when it calls console_lock(). Therefore, remove the CPU_DYING leg of
the switch statement to avoid this problem.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull module signing support from Rusty Russell:
"module signing is the highlight, but it's an all-over David Howells frenzy..."
Hmm "Magrathea: Glacier signing key". Somebody has been reading too much HHGTTG.
* 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (37 commits)
X.509: Fix indefinite length element skip error handling
X.509: Convert some printk calls to pr_devel
asymmetric keys: fix printk format warning
MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checking
MODSIGN: Make mrproper should remove generated files.
MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certs
MODSIGN: Use the same digest for the autogen key sig as for the module sig
MODSIGN: Sign modules during the build process
MODSIGN: Provide a script for generating a key ID from an X.509 cert
MODSIGN: Implement module signature checking
MODSIGN: Provide module signing public keys to the kernel
MODSIGN: Automatically generate module signing keys if missing
MODSIGN: Provide Kconfig options
MODSIGN: Provide gitignore and make clean rules for extra files
MODSIGN: Add FIPS policy
module: signature checking hook
X.509: Add a crypto key parser for binary (DER) X.509 certificates
MPILIB: Provide a function to read raw data into an MPI
X.509: Add an ASN.1 decoder
X.509: Add simple ASN.1 grammar compiler
...
Cleanups
Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
Add module event hooks for simplified debugging with gdb
Fixes
Fix kdb to stop paging with 'q' on bta and dmesg
Fix for data that scrolls off the vga console due to line wrapping
when using the kdb pager
New
The debug core registers for kernel module events which allows a
kernel aware gdb to automatically load symbols and break on entry
to a kernel module
Allow kgdboc=kdb to setup kdb on the vga console
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Merge tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb
Pull KGDB/KDB fixes and cleanups from Jason Wessel:
"Cleanups
- Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
- Add module event hooks for simplified debugging with gdb
Fixes
- Fix kdb to stop paging with 'q' on bta and dmesg
- Fix for data that scrolls off the vga console due to line wrapping
when using the kdb pager
New
- The debug core registers for kernel module events which allows a
kernel aware gdb to automatically load symbols and break on entry
to a kernel module
- Allow kgdboc=kdb to setup kdb on the vga console"
* tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
tty/console: fix warnings in drivers/tty/serial/kgdboc.c
kdb,vt_console: Fix missed data due to pager overruns
kdb: Fix dmesg/bta scroll to quit with 'q'
kgdboc: Accept either kbd or kdb to activate the vga + keyboard kdb shell
kgdb,x86: fix warning about unused variable
mips,kgdb: fix recursive page fault with CONFIG_KPROBES
kgdb: Add module event hooks
Pull perf updates from Ingo Molnar:
"This tree includes some late late perf items that missed the first
round:
tools:
- Bash auto completion improvements, now we can auto complete the
tools long options, tracepoint event names, etc, from Namhyung Kim.
- Look up thread using tid instead of pid in 'perf sched'.
- Move global variables into a perf_kvm struct, from David Ahern.
- Hists refactorings, preparatory for improved 'diff' command, from
Jiri Olsa.
- Hists refactorings, preparatory for event group viewieng work, from
Namhyung Kim.
- Remove double negation on optional feature macro definitions, from
Namhyung Kim.
- Remove several cases of needless global variables, on most
builtins.
- misc fixes
kernel:
- sysfs support for IBS on AMD CPUs, from Robert Richter.
- Support for an upcoming Intel CPU, the Xeon-Phi / Knights Corner
HPC blade PMU, from Vince Weaver.
- misc fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
perf: Fix perf_cgroup_switch for sw-events
perf: Clarify perf_cpu_context::active_pmu usage by renaming it to ::unique_pmu
perf/AMD/IBS: Add sysfs support
perf hists: Add more helpers for hist entry stat
perf hists: Move he->stat.nr_events initialization to a template
perf hists: Introduce struct he_stat
perf diff: Removing the total_period argument from output code
perf tool: Add hpp interface to enable/disable hpp column
perf tools: Removing hists pair argument from output path
perf hists: Separate overhead and baseline columns
perf diff: Refactor diff displacement possition info
perf hists: Add struct hists pointer to struct hist_entry
perf tools: Complete tracepoint event names
perf/x86: Add support for Intel Xeon-Phi Knights Corner PMU
perf evlist: Remove some unused methods
perf evlist: Introduce add_newtp method
perf kvm: Move global variables into a perf_kvm struct
perf tools: Convert to BACKTRACE_SUPPORT
perf tools: Long option completion support for each subcommands
perf tools: Complete long option names of perf command
...
Pull third pile of kernel_execve() patches from Al Viro:
"The last bits of infrastructure for kernel_thread() et.al., with
alpha/arm/x86 use of those. Plus sanitizing the asm glue and
do_notify_resume() on alpha, fixing the "disabled irq while running
task_work stuff" breakage there.
At that point the rest of kernel_thread/kernel_execve/sys_execve work
can be done independently for different architectures. The only
pending bits that do depend on having all architectures converted are
restrictred to fs/* and kernel/* - that'll obviously have to wait for
the next cycle.
I thought we'd have to wait for all of them done before we start
eliminating the longjump-style insanity in kernel_execve(), but it
turned out there's a very simple way to do that without flagday-style
changes."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
alpha: switch to saner kernel_execve() semantics
arm: switch to saner kernel_execve() semantics
x86, um: convert to saner kernel_execve() semantics
infrastructure for saner ret_from_kernel_thread semantics
make sure that kernel_thread() callbacks call do_exit() themselves
make sure that we always have a return path from kernel_execve()
ppc: eeh_event should just use kthread_run()
don't bother with kernel_thread/kernel_execve for launching linuxrc
alpha: get rid of switch_stack argument of do_work_pending()
alpha: don't bother passing switch_stack separately from regs
alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c
alpha: simplify TIF_NEED_RESCHED handling
Pull third pile of VFS updates from Al Viro:
"Stuff from Jeff Layton, mostly. Sanitizing interplay between audit
and namei, removing a lot of insanity from audit_inode() mess and
getting things ready for his ESTALE patchset."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
procfs: don't need a PATH_MAX allocation to hold a string representation of an int
vfs: embed struct filename inside of names_cache allocation if possible
audit: make audit_inode take struct filename
vfs: make path_openat take a struct filename pointer
vfs: turn do_path_lookup into wrapper around struct filename variant
audit: allow audit code to satisfy getname requests from its names_list
vfs: define struct filename and have getname() return it
vfs: unexport getname and putname symbols
acct: constify the name arg to acct_on
vfs: allocate page instead of names_cache buffer in mount_block_root
audit: overhaul __audit_inode_child to accomodate retrying
audit: optimize audit_compare_dname_path
audit: make audit_compare_dname_path use parent_len helper
audit: remove dirlen argument to audit_compare_dname_path
audit: set the name_len in audit_inode for parent lookups
audit: add a new "type" field to audit_names struct
audit: reverse arguments to audit_inode_child
audit: no need to walk list in audit_inode if name is NULL
audit: pass in dentry to audit_copy_inode wherever possible
audit: remove unnecessary NULL ptr checks from do_path_lookup
Keep a pointer to the audit_names "slot" in struct filename.
Have all of the audit_inode callers pass a struct filename ponter to
audit_inode instead of a string pointer. If the aname field is already
populated, then we can skip walking the list altogether and just use it
directly.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
...and fix up the callers. For do_file_open_root, just declare a
struct filename on the stack and fill out the .name field. For
do_filp_open, make it also take a struct filename pointer, and fix up its
callers to call it appropriately.
For filp_open, add a variant that takes a struct filename pointer and turn
filp_open into a wrapper around it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently, if we call getname() on a userland string more than once,
we'll get multiple copies of the string and multiple audit_names
records.
Add a function that will allow the audit_names code to satisfy getname
requests using info from the audit_names list, avoiding a new allocation
and audit_names records.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
* allow kernel_execve() leave the actual return to userland to
caller (selected by CONFIG_GENERIC_KERNEL_EXECVE). Callers
updated accordingly.
* architecture that does select GENERIC_KERNEL_EXECVE in its
Kconfig should have its ret_from_kernel_thread() do this:
call schedule_tail
call the callback left for it by copy_thread(); if it ever
returns, that's because it has just done successful kernel_execve()
jump to return from syscall
IOW, its only difference from ret_from_fork() is that it does call the
callback.
* such an architecture should also get rid of ret_from_kernel_execve()
and __ARCH_WANT_KERNEL_EXECVE
This is the last part of infrastructure patches in that area - from
that point on work on different architectures can live independently.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull timer core update from Thomas Gleixner:
- Bug fixes (one for a longstanding dead loop issue)
- Rework of time related vsyscalls
- Alarm timer updates
- Jiffies updates to remove compile time dependencies
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Cast raw_interval to u64 to avoid shift overflow
timers: Fix endless looping between cascade() and internal_add_timer()
time/jiffies: bring back unconditional LATCH definition
time: Convert x86_64 to using new update_vsyscall
time: Only do nanosecond rounding on GENERIC_TIME_VSYSCALL_OLD systems
time: Introduce new GENERIC_TIME_VSYSCALL
time: Convert CONFIG_GENERIC_TIME_VSYSCALL to CONFIG_GENERIC_TIME_VSYSCALL_OLD
time: Move update_vsyscall definitions to timekeeper_internal.h
time: Move timekeeper structure to timekeeper_internal.h for vsyscall changes
jiffies: Remove compile time assumptions about CLOCK_TICK_RATE
jiffies: Kill unused TICK_USEC_TO_NSEC
alarmtimer: Rename alarmtimer_remove to alarmtimer_dequeue
alarmtimer: Remove unused helpers & defines
alarmtimer: Use hrtimer per-alarm instead of per-base
alarmtimer: Implement minimum alarm interval for allowing suspend
Pull scheduler fixes from Ingo Molnar:
"A CPU hotplug related crash fix and a nohz accounting fixlet."
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Update sched_domains_numa_masks[][] when new cpus are onlined
sched: Ensure 'sched_domains_numa_levels' is safe to use in other functions
nohz: Fix one jiffy count too far in idle cputime
Pull RCU fixes from Ingo Molnar:
"This tree includes a shutdown/cpu-hotplug deadlock fix and a
documentation fix."
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu: Advise most users not to enable RCU user mode
rcu: Grace-period initialization excludes only RCU notifier
It is possible to miss data when using the kdb pager. The kdb pager
does not pay attention to the maximum column constraint of the screen
or serial terminal. This result is not incrementing the shown lines
correctly and the pager will print more lines that fit on the screen.
Obviously that is less than useful when using a VGA console where you
cannot scroll back.
The pager will now look at the kdb_buffer string to see how many
characters are printed. It might not be perfect considering you can
output ASCII that might move the cursor position, but it is a
substantially better approximation for viewing dmesg and trace logs.
This also means that the vt screen needs to set the kdb COLUMNS
variable.
Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
If you press 'q' the pager should exit instead of printing everything
from dmesg which can really bog down a 9600 baud serial link.
The same is true for the bta command.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Allow gdb to auto load kernel modules when it is attached,
which makes it trivially easy to debug module init functions
or pre-set breakpoints in a kernel module that has not loaded yet.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
In order to accomodate retrying path-based syscalls, we need to add a
new "type" argument to audit_inode_child. This will tell us whether
we're looking for a child entry that represents a create or a delete.
If we find a parent, don't automatically assume that we need to create a
new entry. Instead, use the information we have to try to find an
existing entry first. Update it if one is found and create a new one if
not.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In the cases where we already know the length of the parent, pass it as
a parm so we don't need to recompute it. In the cases where we don't
know the length, pass in AUDIT_NAME_FULL (-1) to indicate that it should
be determined.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently, this gets set mostly by happenstance when we call into
audit_inode_child. While that might be a little more efficient, it seems
wrong. If the syscall ends up failing before audit_inode_child ever gets
called, then you'll have an audit_names record that shows the full path
but has the parent inode info attached.
Fix this by passing in a parent flag when we call audit_inode that gets
set to the value of LOOKUP_PARENT. We can then fix up the pathname for
the audit entry correctly from the get-go.
While we're at it, clean up the no-op macro for audit_inode in the
!CONFIG_AUDITSYSCALL case.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For now, we just have two possibilities:
UNKNOWN: for a new audit_names record that we don't know anything about yet
NORMAL: for everything else
In later patches, we'll add other types so we can distinguish and update
records created under different circumstances.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Most of the callers get called with an inode and dentry in the reverse
order. The compiler then has to reshuffle the arg registers and/or
stack in order to pass them on to audit_inode_child.
Reverse those arguments for a micro-optimization.
Reported-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If name is NULL then the condition in the loop will never be true. Also,
with this change, we can eliminate the check for n->name == NULL since
the equivalence check will never be true if it is.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In some cases, we were passing in NULL even when we have a dentry.
Reported-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
- Complement the Nomadik pinctrl driver with alternate Cx functions
so it handles all oddities.
- A patch to the IRQdomain to reform the simple irqdomain to handle
IRQ descriptor allocation dynamically.
- Use the above feature in the Nomadik pin controller.
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Merge tag 'pinctrl-for-3.7-late' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull second set of pinctrl patches from Linus Walleij:
"Here is a late pinctrl pull request with stuff that wasn't quite
tested at the first pull request.
The main reason to not hold off is that the modifications to
irq_domain_add_simple() as reviewed by Rob Herring introduce new
infrastructure for irqdomains that will be useful for the next cycle:
instead of sprinkling irq descriptor allocation all over the kernel
wherever a "legacy" domain is registered, which is necessary for any
platform using sparse IRQs, and many irq chips are say GPIO
controllers which may be used with several systems, some with sparse
IRQs some not, we push this into the irq_domain_add_simple() so we can
atleast do mistakes in one place.
The irq_domain_add_simple() is currently unused in the kernel, so I
need to provide a user. The Nomadik stuff that goes with are changes
to the driver I use day-to-day to make use of this facility (and a
dependency), so see it as a way to eat my own dogfood: if this blows
up the egg hits my face.
A second round of pinctrl patches for v3.7:
- Complement the Nomadik pinctrl driver with alternate Cx functions
so it handles all oddities.
- A patch to the IRQdomain to reform the simple irqdomain to handle
IRQ descriptor allocation dynamically.
- Use the above feature in the Nomadik pin controller."
* tag 'pinctrl-for-3.7-late' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl/nomadik: use simple or linear IRQ domain
irqdomain: augment add_simple() to allocate descs
pinctrl/nomadik: support other alternate-C functions
Pull pile 2 of vfs updates from Al Viro:
"Stuff in this one - assorted fixes, lglock tidy-up, death to
lock_super().
There'll be a VFS pile tomorrow (with patches from Jeff Layton,
sanitizing getname() and related parts of audit and preparing for
ESTALE fixes), but I'd rather push the stuff in this one ASAP - some
of the bugs closed here are quite unpleasant."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: bogus warnings in fs/namei.c
consitify do_mount() arguments
lglock: add DEFINE_STATIC_LGLOCK()
lglock: make the per_cpu locks static
lglock: remove unused DEFINE_LGLOCK_LOCKDEP()
MAX_LFS_FILESIZE definition for 64bit needs LL...
tmpfs,ceph,gfs2,isofs,reiserfs,xfs: fix fh_len checking
vfs: drop lock/unlock super
ufs: drop lock/unlock super
sysv: drop lock/unlock super
hpfs: drop lock/unlock super
fat: drop lock/unlock super
ext3: drop lock/unlock super
exofs: drop lock/unlock super
dup3: Return an error when oldfd == newfd.
fs: handle failed audit_log_start properly
fs: prevent use after free in auditing when symlink following was denied
Pull pile 2 of execve and kernel_thread unification work from Al Viro:
"Stuff in there: kernel_thread/kernel_execve/sys_execve conversions for
several more architectures plus assorted signal fixes and cleanups.
There'll be more (in particular, real fixes for the alpha
do_notify_resume() irq mess)..."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (43 commits)
alpha: don't open-code trace_report_syscall_{enter,exit}
Uninclude linux/freezer.h
m32r: trim masks
avr32: trim masks
tile: don't bother with SIGTRAP in setup_frame
microblaze: don't bother with SIGTRAP in setup_rt_frame()
mn10300: don't bother with SIGTRAP in setup_frame()
frv: no need to raise SIGTRAP in setup_frame()
x86: get rid of duplicate code in case of CONFIG_VM86
unicore32: remove pointless test
h8300: trim _TIF_WORK_MASK
parisc: decide whether to go to slow path (tracesys) based on thread flags
parisc: don't bother looping in do_signal()
parisc: fix double restarts
bury the rest of TIF_IRET
sanitize tsk_is_polling()
bury _TIF_RESTORE_SIGMASK
unicore32: unobfuscate _TIF_WORK_MASK
mips: NOTIFY_RESUME is not needed in TIF masks
mips: merge the identical "return from syscall" per-ABI code
...
Conflicts:
arch/arm/include/asm/thread_info.h
Most of them never returned anyway - only two functions had to be
changed. That allows to simplify their callers a whole lot.
Note that this does *not* apply to kthread_run() callbacks - all of
those had been called from the same kernel_thread() callback, which
did do_exit() already. This is strictly about very few low-level
kernel_thread() callbacks (there are only 6 of those, mostly as part
of kthread.h and kmod.h exported mechanisms, plus kernel_init()
itself).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It doesn't, because the clean targets don't include kernel/Makefile, and
because two files were missing from the list.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Place an indication that the certificate should use utf8 strings into the
x509.genkey template generated by kernel/Makefile.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Use the same digest type for the autogenerated key signature as for the module
signature so that the hash algorithm is guaranteed to be present in the kernel.
Without this, the X.509 certificate loader may reject the X.509 certificate so
generated because it was self-signed and the signature will be checked against
itself - but this won't work if the digest algorithm must be loaded as a
module.
The symptom is that the key fails to load with the following message emitted
into the kernel log:
MODSIGN: Problem loading in-kernel X.509 certificate (-65)
the error in brackets being -ENOPKG. What you should see is something like:
MODSIGN: Loaded cert 'Magarathea: Glacier signing key: 9588321144239a119d3406d4c4cf1fbae1836fa0'
Note that this doesn't apply to certificates that are not self-signed as we
don't check those currently as they require the parent CA certificate to be
available.
Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Check the signature on the module against the keys compiled into the kernel or
available in a hardware key store.
Currently, only RSA keys are supported - though that's easy enough to change,
and the signature is expected to contain raw components (so not a PGP or
PKCS#7 formatted blob).
The signature blob is expected to consist of the following pieces in order:
(1) The binary identifier for the key. This is expected to match the
SubjectKeyIdentifier from an X.509 certificate. Only X.509 type
identifiers are currently supported.
(2) The signature data, consisting of a series of MPIs in which each is in
the format of a 2-byte BE word sizes followed by the content data.
(3) A 12 byte information block of the form:
struct module_signature {
enum pkey_algo algo : 8;
enum pkey_hash_algo hash : 8;
enum pkey_id_type id_type : 8;
u8 __pad;
__be32 id_length;
__be32 sig_length;
};
The three enums are defined in crypto/public_key.h.
'algo' contains the public-key algorithm identifier (0->DSA, 1->RSA).
'hash' contains the digest algorithm identifier (0->MD4, 1->MD5, 2->SHA1,
etc.).
'id_type' contains the public-key identifier type (0->PGP, 1->X.509).
'__pad' should be 0.
'id_length' should contain in the binary identifier length in BE form.
'sig_length' should contain in the signature data length in BE form.
The lengths are in BE order rather than CPU order to make dealing with
cross-compilation easier.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor Kconfig fix)
Include a PGP keyring containing the public keys required to perform module
verification in the kernel image during build and create a special keyring
during boot which is then populated with keys of crypto type holding the public
keys found in the PGP keyring.
These can be seen by root:
[root@andromeda ~]# cat /proc/keys
07ad4ee0 I----- 1 perm 3f010000 0 0 crypto modsign.0: RSA 87b9b3bd []
15c7f8c3 I----- 1 perm 1f030000 0 0 keyring .module_sign: 1/4
...
It is probably worth permitting root to invalidate these keys, resulting in
their removal and preventing further modules from being loaded with that key.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Automatically generate keys for module signing if they're absent so that
allyesconfig doesn't break. The builder should consider generating their own
key and certificate, however, so that the keys are appropriately named.
The private key for the module signer should be placed in signing_key.priv
(unencrypted!) and the public key in an X.509 certificate as signing_key.x509.
If a transient key is desired for signing the modules, a config file for
'openssl req' can be placed in x509.genkey, looking something like the
following:
[ req ]
default_bits = 4096
distinguished_name = req_distinguished_name
prompt = no
x509_extensions = myexts
[ req_distinguished_name ]
O = Magarathea
CN = Glacier signing key
emailAddress = slartibartfast@magrathea.h2g2
[ myexts ]
basicConstraints=critical,CA:FALSE
keyUsage=digitalSignature
subjectKeyIdentifier=hash
authorityKeyIdentifier=hash
The build process will use this to configure:
openssl req -new -nodes -utf8 -sha1 -days 36500 -batch \
-x509 -config x509.genkey \
-outform DER -out signing_key.x509 \
-keyout signing_key.priv
to generate the key.
Note that it is required that the X.509 certificate have a subjectKeyIdentifier
and an authorityKeyIdentifier. Without those, the certificate will be
rejected. These can be used to check the validity of a certificate.
Note that 'make distclean' will remove signing_key.{priv,x509} and x509.genkey,
whether or not they were generated automatically.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If we're in FIPS mode, we should panic if we fail to verify the signature on a
module or we're asked to load an unsigned module in signature enforcing mode.
Possibly FIPS mode should automatically enable enforcing mode.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We do a very simple search for a particular string appended to the module
(which is cache-hot and about to be SHA'd anyway). There's both a config
option and a boot parameter which control whether we accept or fail with
unsigned modules and modules that are signed with an unknown key.
If module signing is enabled, the kernel will be tainted if a module is
loaded that is unsigned or has a signature for which we don't have the
key.
(Useful feedback and tweaks by David Howells <dhowells@redhat.com>)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Currently we rely on all IRQ chip instances to dynamically
allocate their IRQ descriptors unless they use the linear
IRQ domain. So for irqdomain_add_legacy() and
irqdomain_add_simple() the caller need to make sure that
descriptors are allocated.
Let's slightly augment the yet unused irqdomain_add_simple()
to also allocate descriptors as a means to simplify usage
and avoid code duplication throughout the kernel.
We warn if descriptors cannot be allocated, e.g. if a
platform has the bad habit of hogging descriptors at boot
time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
audit_log_start() may return NULL, this is unchecked by the caller in
audit_log_link_denied() and could cause a NULL ptr deref.
Introduced by commit a51d9eaa ("fs: add link restriction audit reporting").
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull generic execve() changes from Al Viro:
"This introduces the generic kernel_thread() and kernel_execve()
functions, and switches x86, arm, alpha, um and s390 over to them."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
s390: convert to generic kernel_execve()
s390: switch to generic kernel_thread()
s390: fold kernel_thread_helper() into ret_from_fork()
s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
um: switch to generic kernel_thread()
x86, um/x86: switch to generic sys_execve and kernel_execve
x86: split ret_from_fork
alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
alpha: switch to generic kernel_thread()
alpha: switch to generic sys_execve()
arm: get rid of execve wrapper, switch to generic execve() implementation
arm: optimized current_pt_regs()
arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
generic sys_execve()
generic kernel_execve()
new helper: current_pt_regs()
preparation for generic kernel_thread()
um: kill thread->forking
um: let signal_delivered() do SIGTRAP on singlestepping into handler
...
We fixed a bunch of integer overflows in timekeeping code during the 3.6
cycle. I did an audit based on that and found this potential overflow.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: John Stultz <johnstul@us.ibm.com>
Link: http://lkml.kernel.org/r/20121009071823.GA19159@elgon.mountain
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Adding two (or more) timers with large values for "expires" (they have
to reside within tv5 in the same list) leads to endless looping
between cascade() and internal_add_timer() in case CONFIG_BASE_SMALL
is one and jiffies are crossing the value 1 << 18. The bug was
introduced between 2.6.11 and 2.6.12 (and survived for quite some
time).
This patch ensures that when cascade() is called timers within tv5 are
not added endlessly to their own list again, instead they are added to
the next lower tv level tv4 (as expected).
Signed-off-by: Christian Hildner <christian.hildner@siemens.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Link: http://lkml.kernel.org/r/98673C87CB31274881CFFE0B65ECC87B0F5FC1963E@DEFTHW99EA4MSX.ww902.siemens.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
