The mmu-gather operation 'tlb_flush_mmu()' has done two things: the
actual tlb flush operation, and the batched freeing of the pages that
the TLB entries pointed at.
This splits the operation into separate phases, so that the forced
batched flushing done by zap_pte_range() can now do the actual TLB flush
while still holding the page table lock, but delay the batched freeing
of all the pages to after the lock has been dropped.
This in turn allows us to avoid a race condition between
set_page_dirty() (as called by zap_pte_range() when it finds a dirty
shared memory pte) and page_mkclean(): because we now flush all the
dirty page data from the TLB's while holding the pte lock,
page_mkclean() will be held up walking the (recently cleaned) page
tables until after the TLB entries have been flushed from all CPU's.
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The reverse case of this race (you must msync before read) is
well known. This is the not so common one.
It can be triggered only on systems which do a lot of task
switching and only at UML startup. If you are starting 200+ UMLs
~ 0.5% will always die without this fix.
Signed-off-by: Anton Ivanov <antivano@cisco.com>
[rw: minor whitespace fixes]
Signed-off-by: Richard Weinberger <richard@nod.at>
UML does not handle sigpipe. As a result when running it under
expect or redirecting the IO from the console to an external program
it will crash if the program stops or exits.
Signed-off-by: Anton Ivanov <antivano@cisco.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Inferring the mount hierarchy correctly from /proc/mounts is hard when MS_MOVE
may have been used, and the previous code did it wrongly. This change simplifies
the logic to only require that /dev/shm be _on_ tmpfs (which can be checked
trivially with statfs) rather than that it be a _mountpoint_ of tmpfs, since
there isn't a compelling reason to be that strict. We also now check for tmpfs
on whatever directory we ultimately use so that the user is better informed.
This change also moves the more standard TMPDIR environment variable check ahead
of the others.
Applies to 3.12.
Signed-off-by: Tristan Schmelcher <tschmelcher@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
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
...
arch_align_stack() moved to asm/exec.h, so change the comment referring to
asm/system.h which no longer exists.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
"Here is my initial pull request for the networking subsystem during
this merge window:
1) Support for ESN in AH (RFC 4302) from Fan Du.
2) Add full kernel doc for ethtool command structures, from Ben
Hutchings.
3) Add BCM7xxx PHY driver, from Florian Fainelli.
4) Export computed TCP rate information in netlink socket dumps, from
Eric Dumazet.
5) Allow IPSEC SA to be dumped partially using a filter, from Nicolas
Dichtel.
6) Convert many drivers to pci_enable_msix_range(), from Alexander
Gordeev.
7) Record SKB timestamps more efficiently, from Eric Dumazet.
8) Switch to microsecond resolution for TCP round trip times, also
from Eric Dumazet.
9) Clean up and fix 6lowpan fragmentation handling by making use of
the existing inet_frag api for it's implementation.
10) Add TX grant mapping to xen-netback driver, from Zoltan Kiss.
11) Auto size SKB lengths when composing netlink messages based upon
past message sizes used, from Eric Dumazet.
12) qdisc dumps can take a long time, add a cond_resched(), From Eric
Dumazet.
13) Sanitize netpoll core and drivers wrt. SKB handling semantics.
Get rid of never-used-in-tree netpoll RX handling. From Eric W
Biederman.
14) Support inter-address-family and namespace changing in VTI tunnel
driver(s). From Steffen Klassert.
15) Add Altera TSE driver, from Vince Bridgers.
16) Optimizing csum_replace2() so that it doesn't adjust the checksum
by checksumming the entire header, from Eric Dumazet.
17) Expand BPF internal implementation for faster interpreting, more
direct translations into JIT'd code, and much cleaner uses of BPF
filtering in non-socket ocntexts. From Daniel Borkmann and Alexei
Starovoitov"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1976 commits)
netpoll: Use skb_irq_freeable to make zap_completion_queue safe.
net: Add a test to see if a skb is freeable in irq context
qlcnic: Fix build failure due to undefined reference to `vxlan_get_rx_port'
net: ptp: move PTP classifier in its own file
net: sxgbe: make "core_ops" static
net: sxgbe: fix logical vs bitwise operation
net: sxgbe: sxgbe_mdio_register() frees the bus
Call efx_set_channels() before efx->type->dimension_resources()
xen-netback: disable rogue vif in kthread context
net/mlx4: Set proper build dependancy with vxlan
be2net: fix build dependency on VxLAN
mac802154: make csma/cca parameters per-wpan
mac802154: allow only one WPAN to be up at any given time
net: filter: minor: fix kdoc in __sk_run_filter
netlink: don't compare the nul-termination in nla_strcmp
can: c_can: Avoid led toggling for every packet.
can: c_can: Simplify TX interrupt cleanup
can: c_can: Store dlc private
can: c_can: Reduce register access
can: c_can: Make the code readable
...
Replace dev_kfree_skb with dev_consume_skb_any in uml_net_start_xmit
as it can be called in hard irq and other contexts.
dev_consume_skb_any is used as uml_net_start_xmit typically
consumes (not drops) packets.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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>
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>
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>
Pull UML changes from Richard Weinberger:
"This time only various cleanups and housekeeping patches"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: hostfs: make functions static
um: Include generic barrier.h
um: Removed unused attributes from thread_struct
Pull networking updates from David Miller:
1) BPF debugger and asm tool by Daniel Borkmann.
2) Speed up create/bind in AF_PACKET, also from Daniel Borkmann.
3) Correct reciprocal_divide and update users, from Hannes Frederic
Sowa and Daniel Borkmann.
4) Currently we only have a "set" operation for the hw timestamp socket
ioctl, add a "get" operation to match. From Ben Hutchings.
5) Add better trace events for debugging driver datapath problems, also
from Ben Hutchings.
6) Implement auto corking in TCP, from Eric Dumazet. Basically, if we
have a small send and a previous packet is already in the qdisc or
device queue, defer until TX completion or we get more data.
7) Allow userspace to manage ipv6 temporary addresses, from Jiri Pirko.
8) Add a qdisc bypass option for AF_PACKET sockets, from Daniel
Borkmann.
9) Share IP header compression code between Bluetooth and IEEE802154
layers, from Jukka Rissanen.
10) Fix ipv6 router reachability probing, from Jiri Benc.
11) Allow packets to be captured on macvtap devices, from Vlad Yasevich.
12) Support tunneling in GRO layer, from Jerry Chu.
13) Allow bonding to be configured fully using netlink, from Scott
Feldman.
14) Allow AF_PACKET users to obtain the VLAN TPID, just like they can
already get the TCI. From Atzm Watanabe.
15) New "Heavy Hitter" qdisc, from Terry Lam.
16) Significantly improve the IPSEC support in pktgen, from Fan Du.
17) Allow ipv4 tunnels to cache routes, just like sockets. From Tom
Herbert.
18) Add Proportional Integral Enhanced packet scheduler, from Vijay
Subramanian.
19) Allow openvswitch to mmap'd netlink, from Thomas Graf.
20) Key TCP metrics blobs also by source address, not just destination
address. From Christoph Paasch.
21) Support 10G in generic phylib. From Andy Fleming.
22) Try to short-circuit GRO flow compares using device provided RX
hash, if provided. From Tom Herbert.
The wireless and netfilter folks have been busy little bees too.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2064 commits)
net/cxgb4: Fix referencing freed adapter
ipv6: reallocate addrconf router for ipv6 address when lo device up
fib_frontend: fix possible NULL pointer dereference
rtnetlink: remove IFLA_BOND_SLAVE definition
rtnetlink: remove check for fill_slave_info in rtnl_have_link_slave_info
qlcnic: update version to 5.3.55
qlcnic: Enhance logic to calculate msix vectors.
qlcnic: Refactor interrupt coalescing code for all adapters.
qlcnic: Update poll controller code path
qlcnic: Interrupt code cleanup
qlcnic: Enhance Tx timeout debugging.
qlcnic: Use bool for rx_mac_learn.
bonding: fix u64 division
rtnetlink: add missing IFLA_BOND_AD_INFO_UNSPEC
sfc: Use the correct maximum TX DMA ring size for SFC9100
Add Shradha Shah as the sfc driver maintainer.
net/vxlan: Share RX skb de-marking and checksum checks with ovs
tulip: cleanup by using ARRAY_SIZE()
ip_tunnel: clear IPCB in ip_tunnel_xmit() in case dst_link_failure() is called
net/cxgb4: Don't retrieve stats during recovery
...
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On UML SUBARCH can be x86, x86_64 and i386 and if it is x86
we use uname -m to select a defconfig.
Therefore we can no longer use -mcmodel=large only if SUBARCH
is x86_64.
Reported-and-tested-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
We cannot use print_stack_trace because the name conflicts
with linux/stacktrace.h.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Pull UML changes from Richard Weinberger:
"This pile contains a nice defconfig cleanup, a rewritten stack
unwinder and various cleanups"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Remove unused declarations from <as-layout.h>
um: remove used STDIO_CONSOLE Kconfig param
um/vdso: add .gitignore for a couple of targets
arch/um: make it work with defconfig and x86_64
um: Make kstack_depth_to_print conform to arch/x86
um: Get rid of thread_struct->saved_task
um: Make stack trace reliable against kernel mode faults
um: Rewrite show_stack()
Pull irq cleanups from Ingo Molnar:
"This is a multi-arch cleanup series from Thomas Gleixner, which we
kept to near the end of the merge window, to not interfere with
architecture updates.
This series (motivated by the -rt kernel) unifies more aspects of IRQ
handling and generalizes PREEMPT_ACTIVE"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
preempt: Make PREEMPT_ACTIVE generic
sparc: Use preempt_schedule_irq
ia64: Use preempt_schedule_irq
m32r: Use preempt_schedule_irq
hardirq: Make hardirq bits generic
m68k: Simplify low level interrupt handling code
genirq: Prevent spurious detection for unconditionally polled interrupts
_end is used, but it's already provided by <asm/sections.h>, so use that.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Richard Weinberger <richard@nod.at>
This removes the STDIO_CONSOLE Kconfig parameter which
is defined but no longer used anywhere in the makefiles and source code.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
arch/um/defconfig only lists one default configuration, and that applies
only to the i386 architecture. Replace it with two minimal
configuration files generated using `make savedefconfig`:
i386_defconfig and x86_64_defconfig
The build scripts now require two updates:
1. um's Kconfig (arch/x86/um/Kconfig) should specify an ARCH_DEFCONFIG
section explicitly pointing to these scripts if the required
variables are set. Take care to remove the DEFCONFIG_LIST section
defined in the included file arch/um/Kconfig.common.
2. um's Makefile (arch/um/Makefile) should set KBUILD_DEFCONFIG properly
for the top-level Makefile to pick up. Copy the logic in
arch/x86/Makefile to properly pick the defconfig file depending on
the actual architecture; except we're working with $SUBARCH here,
instead of $ARCH.
Now, you can do:
$ ARCH=um make defconfig
$ ARCH=um make
and successfully build User-Mode Linux on an x86_64 box in default
configuration.
Cc: Richard Weinberger <richard@nod.at>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
As UML uses an alternative signal stack we cannot use
the current stack pointer for stack dumping if UML itself
dies by SIGSEGV. To bypass this issue we save regs taken
from mcontext in our segv handler into thread_struct and
use these regs to obtain the stack pointer in show_stack().
Signed-off-by: Richard Weinberger <richard@nod.at>
Currently on UML stack traces are not very reliable and both
x86 and x86_64 have their on implementations.
This patch unifies both and adds support to outline unreliable
functions calls.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Resolve cherry-picking conflicts:
Conflicts:
mm/huge_memory.c
mm/memory.c
mm/mprotect.c
See this upstream merge commit for more details:
52469b4fcd Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We don't cap the size of buffer from the user so we could write past the
end of the array here. Only root can write to this file.
Reported-by: Nico Golde <nico@ngolde.de>
Reported-by: Fabian Yamaguchi <fabs@goesec.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to prepare to per-arch implementations of preempt_count move
the required bits into an asm-generic header and use this for all
archs.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-h5j0c1r3e3fk015m30h8f1zx@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Unlike global OOM handling, memory cgroup code will invoke the OOM killer
in any OOM situation because it has no way of telling faults occuring in
kernel context - which could be handled more gracefully - from
user-triggered faults.
Pass a flag that identifies faults originating in user space from the
architecture-specific fault handlers to generic code so that memcg OOM
handling can be improved.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel faults are expected to handle OOM conditions gracefully (gup,
uaccess etc.), so they should never invoke the OOM killer. Reserve this
for faults triggered in user context when it is the only option.
Most architectures already do this, fix up the remaining few.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These handlers are not optional and need in our case
dummy implementions to avoid NULL pointer bugs within
the irq core code.
Reported-and-tested-by: Toralf Foester <toralf.foerster@gmx.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
If UML is not run by a shell it can happen that UML
will kill unrelated proceses upon a fatal exit because
it issues a kill(0, ...).
To prevent such oddities we create a new session in main().
Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Richard reported that some UML processes survive if the UML
main process receives a SIGTERM.
This issue was caused by a wrongly placed signal(SIGTERM, SIG_DFL)
in init_new_thread_signals().
It disabled the UML exit handler accidently for some processes.
The correct solution is to disable the fatal handler for all
UML helper threads/processes.
Such that last_ditch_exit() does not get called multiple times
and all processes can exit due to SIGTERM.
Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Just a clean-up patch to remove the open coded
variants and to ensure that all requests are submitted the
same way.
Signed-off-by: Richard Weinberger <richard@nod.at>
UML's block device driver does not support write barriers,
to support this this patch adds REQ_FLUSH suppport.
Every time the block layer sends a REQ_FLUSH we fsync() now
our backing file to guarantee data consistency.
Reported-and-tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
UML needs it's own probe_kernel_read() to handle kernel
mode faults correctly.
The implementation uses mincore() on the host side to detect
whether a page is owned by the UML kernel process.
This fixes also a possible crash when sysrq-t is used.
Starting with 3.10 sysrq-t calls probe_kernel_read() to
read details from the kernel workers. As kernel worker are
completely async pointers may turn NULL while reading them.
Cc: <stian@nixia.no>
Cc: <tj@kernel.org>
Cc: <stable@vger.kernel.org> # 3.10.x
Signed-off-by: Richard Weinberger <richard@nod.at>
Ben Tebulin reported:
"Since v3.7.2 on two independent machines a very specific Git
repository fails in 9/10 cases on git-fsck due to an SHA1/memory
failures. This only occurs on a very specific repository and can be
reproduced stably on two independent laptops. Git mailing list ran
out of ideas and for me this looks like some very exotic kernel issue"
and bisected the failure to the backport of commit 53a59fc67f ("mm:
limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").
That commit itself is not actually buggy, but what it does is to make it
much more likely to hit the partial TLB invalidation case, since it
introduces a new case in tlb_next_batch() that previously only ever
happened when running out of memory.
The real bug is that the TLB gather virtual memory range setup is subtly
buggered. It was introduced in commit 597e1c3580 ("mm/mmu_gather:
enable tlb flush range in generic mmu_gather"), and the range handling
was already fixed at least once in commit e6c495a96c ("mm: fix the TLB
range flushed when __tlb_remove_page() runs out of slots"), but that fix
was not complete.
The problem with the TLB gather virtual address range is that it isn't
set up by the initial tlb_gather_mmu() initialization (which didn't get
the TLB range information), but it is set up ad-hoc later by the
functions that actually flush the TLB. And so any such case that forgot
to update the TLB range entries would potentially miss TLB invalidates.
Rather than try to figure out exactly which particular ad-hoc range
setup was missing (I personally suspect it's the hugetlb case in
zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
did), this patch just gets rid of the problem at the source: make the
TLB range information available to tlb_gather_mmu(), and initialize it
when initializing all the other tlb gather fields.
This makes the patch larger, but conceptually much simpler. And the end
result is much more understandable; even if you want to play games with
partial ranges when invalidating the TLB contents in chunks, now the
range information is always there, and anybody who doesn't want to
bother with it won't introduce subtle bugs.
Ben verified that this fixes his problem.
Reported-bisected-and-tested-by: Ben Tebulin <tebulin@googlemail.com>
Build-testing-by: Stephen Rothwell <sfr@canb.auug.org.au>
Build-testing-by: Richard Weinberger <richard.weinberger@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we use both struct siginfo and siginfo_t.
Let's use struct siginfo internally to avoid ongoing
compiler warning. We are allowed to do so because
struct siginfo and siginfo_t are equivalent.
Signed-off-by: Richard Weinberger <richard@nod.at>
which_tmpdir did the wrong thing if /dev/shm was a symlink (e.g., to /run/shm),
if there were multiple mounts on top of each other, if the mount(s) were
obscured by a later mount, or if /dev/shm was a prefix of another mount point.
This fixes these cases. Applies to 3.9.6.
Signed-off-by: Tristan Schmelcher <tschmelcher@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
If we die within a stub handler we only way to reliable
kill the (obviously) dying uml guest process is killing
it's host twin on the host side.
Signed-off-by: Richard Weinberger <richard@nod.at>
Ensure that a process cannot destroy his stub pages with
using MADV_DONTNEED and friends.
Reported-by: toralf.foerster@gmx.de
Signed-off-by: Richard Weinberger <richard@nod.at>
In case of an error it must not return -EFAULT.
Return 0 like all other archs do.
Reported-by: toralf.foerster@gmx.de
Signed-off-by: Richard Weinberger <richard@nod.at>
Prepare for removing num_physpages and simplify mem_init().
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Normalize global variables exported by vmlinux.lds to conform usage
guidelines from include/asm-generic/sections.h.
1) Use _text to mark the start of the kernel image including the head
text, and _stext to mark the start of the .text section.
2) Export mandatory global variables __bss_stop.
3) Adjust __init_begin and __init_end to avoid acrossing .text and
.data sections.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
