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* linux-linaro-lsk-v4.4: (361 commits)
Linux 4.4.135
Revert "vti4: Don't override MTU passed on link creation via IFLA_MTU"
Linux 4.4.134
s390/ftrace: use expoline for indirect branches
kdb: make "mdr" command repeat
Bluetooth: btusb: Add device ID for RTL8822BE
ASoC: samsung: i2s: Ensure the RCLK rate is properly determined
regulator: of: Add a missing 'of_node_put()' in an error handling path of 'of_regulator_match()'
scsi: lpfc: Fix frequency of Release WQE CQEs
scsi: lpfc: Fix soft lockup in lpfc worker thread during LIP testing
scsi: lpfc: Fix issue_lip if link is disabled
netlabel: If PF_INET6, check sk_buff ip header version
selftests/net: fixes psock_fanout eBPF test case
perf report: Fix memory corruption in --branch-history mode --branch-history
perf tests: Use arch__compare_symbol_names to compare symbols
x86/apic: Set up through-local-APIC mode on the boot CPU if 'noapic' specified
drm/rockchip: Respect page offset for PRIME mmap calls
MIPS: Octeon: Fix logging messages with spurious periods after newlines
audit: return on memory error to avoid null pointer dereference
crypto: sunxi-ss - Add MODULE_ALIAS to sun4i-ss
...
Conflicts:
arch/arm64/include/asm/assembler.h
Rebase LTS commit 348f043ab6c6
("arm64: Add work around for Arm Cortex-A55 Erratum 1024718").
fs/f2fs/namei.c
Rebase LTS commit 03bb7588942a
("do d_instantiate/unlock_new_inode combinations safely")
fs/proc/base.c
Trivial typo.
kernel/auditsc.c
Rebase LTS commit 9bb698bedebf
("audit: move calcs after alloc and check when logging set loginuid").
kernel/time/timekeeping.c
Rebase changes from AOSP commit 28850c79d071
("BACKPORT: time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting"), and
1d35c0438678 ("BACKPORT: time: Clean up CLOCK_MONOTONIC_RAW time handling").
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
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commit 8f89c007b6dec16a1793cb88de88fcc02117bbbc upstream.
shmat()'s SHM_REMAP option forbids passing a nil address for; this is in
fact the very first thing we check for. Andrea reported that for
SHM_RND|SHM_REMAP cases we can end up bypassing the initial addr check,
but we need to check again if the address was rounded down to nil. As
of this patch, such cases will return -EINVAL.
Link: http://lkml.kernel.org/r/20180503204934.kk63josdu6u53fbd@linux-n805
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a73ab244f0dad8fffb3291b905f73e2d3eaa7c00 upstream.
Patch series "ipc/shm: shmat() fixes around nil-page".
These patches fix two issues reported[1] a while back by Joe and Andrea
around how shmat(2) behaves with nil-page.
The first reverts a commit that it was incorrectly thought that mapping
nil-page (address=0) was a no no with MAP_FIXED. This is not the case,
with the exception of SHM_REMAP; which is address in the second patch.
I chose two patches because it is easier to backport and it explicitly
reverts bogus behaviour. Both patches ought to be in -stable and ltp
testcases need updated (the added testcase around the cve can be
modified to just test for SHM_RND|SHM_REMAP).
[1] lkml.kernel.org/r/20180430172152.nfa564pvgpk3ut7p@linux-n805
This patch (of 2):
Commit 95e91b831f87 ("ipc/shm: Fix shmat mmap nil-page protection")
worked on the idea that we should not be mapping as root addr=0 and
MAP_FIXED. However, it was reported that this scenario is in fact
valid, thus making the patch both bogus and breaks userspace as well.
For example X11's libint10.so relies on shmat(1, SHM_RND) for lowmem
initialization[1].
[1] https://cgit.freedesktop.org/xorg/xserver/tree/hw/xfree86/os-support/linux/int10/linux.c#n347
Link: http://lkml.kernel.org/r/20180503203243.15045-2-dave@stgolabs.net
Fixes: 95e91b831f87 ("ipc/shm: Fix shmat mmap nil-page protection")
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Joe Lawrence <joe.lawrence@redhat.com>
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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* linux-linaro-lsk-v4.4: (515 commits)
Linux 4.4.132
perf/x86: Fix possible Spectre-v1 indexing for x86_pmu::event_map()
perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[]
perf/x86/msr: Fix possible Spectre-v1 indexing in the MSR driver
perf/x86/cstate: Fix possible Spectre-v1 indexing for pkg_msr
perf/x86: Fix possible Spectre-v1 indexing for hw_perf_event cache_*
tracing/uprobe_event: Fix strncpy corner case
Revert "Bluetooth: btusb: Fix quirk for Atheros 1525/QCA6174"
atm: zatm: Fix potential Spectre v1
net: atm: Fix potential Spectre v1
can: kvaser_usb: Increase correct stats counter in kvaser_usb_rx_can_msg()
tracing: Fix regex_match_front() to not over compare the test string
libata: Apply NOLPM quirk for SanDisk SD7UB3Q*G1001 SSDs
rfkill: gpio: fix memory leak in probe error path
xfrm_user: fix return value from xfrm_user_rcv_msg
f2fs: fix a dead loop in f2fs_fiemap()
bdi: Fix oops in wb_workfn()
tcp: fix TCP_REPAIR_QUEUE bound checking
perf: Remove superfluous allocation error check
soreuseport: initialise timewait reuseport field
...
Conflicts:
arch/s390/kernel/module.c
arch/x86/kernel/kprobes/core.c
fs/proc/task_mmu.c
net/ipv6/route.c
Trivial conflicts between AOSP/LSK and backported/rebased LTS changes.
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
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commit 3f05317d9889ab75c7190dcd39491d2a97921984 upstream.
syzbot reported a use-after-free of shm_file_data(file)->file->f_op in
shm_get_unmapped_area(), called via sys_remap_file_pages().
Unfortunately it couldn't generate a reproducer, but I found a bug which
I think caused it. When remap_file_pages() is passed a full System V
shared memory segment, the memory is first unmapped, then a new map is
created using the ->vm_file. Between these steps, the shm ID can be
removed and reused for a new shm segment. But, shm_mmap() only checks
whether the ID is currently valid before calling the underlying file's
->mmap(); it doesn't check whether it was reused. Thus it can use the
wrong underlying file, one that was already freed.
Fix this by making the "outer" shm file (the one that gets put in
->vm_file) hold a reference to the real shm file, and by making
__shm_open() require that the file associated with the shm ID matches
the one associated with the "outer" file.
Taking the reference to the real shm file is needed to fully solve the
problem, since otherwise sfd->file could point to a freed file, which
then could be reallocated for the reused shm ID, causing the wrong shm
segment to be mapped (and without the required permission checks).
Commit 1ac0b6dec656 ("ipc/shm: handle removed segments gracefully in
shm_mmap()") almost fixed this bug, but it didn't go far enough because
it didn't consider the case where the shm ID is reused.
The following program usually reproduces this bug:
#include <stdlib.h>
#include <sys/shm.h>
#include <sys/syscall.h>
#include <unistd.h>
int main()
{
int is_parent = (fork() != 0);
srand(getpid());
for (;;) {
int id = shmget(0xF00F, 4096, IPC_CREAT|0700);
if (is_parent) {
void *addr = shmat(id, NULL, 0);
usleep(rand() % 50);
while (!syscall(__NR_remap_file_pages, addr, 4096, 0, 0, 0));
} else {
usleep(rand() % 50);
shmctl(id, IPC_RMID, NULL);
}
}
}
It causes the following NULL pointer dereference due to a 'struct file'
being used while it's being freed. (I couldn't actually get a KASAN
use-after-free splat like in the syzbot report. But I think it's
possible with this bug; it would just take a more extraordinary race...)
BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
PGD 0 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 9 PID: 258 Comm: syz_ipc Not tainted 4.16.0-05140-gf8cf2f16a7c95 #189
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
RIP: 0010:d_inode include/linux/dcache.h:519 [inline]
RIP: 0010:touch_atime+0x25/0xd0 fs/inode.c:1724
[...]
Call Trace:
file_accessed include/linux/fs.h:2063 [inline]
shmem_mmap+0x25/0x40 mm/shmem.c:2149
call_mmap include/linux/fs.h:1789 [inline]
shm_mmap+0x34/0x80 ipc/shm.c:465
call_mmap include/linux/fs.h:1789 [inline]
mmap_region+0x309/0x5b0 mm/mmap.c:1712
do_mmap+0x294/0x4a0 mm/mmap.c:1483
do_mmap_pgoff include/linux/mm.h:2235 [inline]
SYSC_remap_file_pages mm/mmap.c:2853 [inline]
SyS_remap_file_pages+0x232/0x310 mm/mmap.c:2769
do_syscall_64+0x64/0x1a0 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ebiggers@google.com: add comment]
Link: http://lkml.kernel.org/r/20180410192850.235835-1-ebiggers3@gmail.com
Link: http://lkml.kernel.org/r/20180409043039.28915-1-ebiggers3@gmail.com
Reported-by: syzbot+d11f321e7f1923157eac80aa990b446596f46439@syzkaller.appspotmail.com
Fixes: c8d78c1823f4 ("mm: replace remap_file_pages() syscall with emulation")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 999898355e08ae3b92dfd0a08db706e0c6703d30 upstream.
When LONG_MIN is passed to msgrcv, one would expect to recieve any
message. But convert_mode does *msgtyp = -*msgtyp and -LONG_MIN is
undefined. In particular, with my gcc -LONG_MIN produces -LONG_MIN
again.
So handle this case properly by assigning LONG_MAX to *msgtyp if
LONG_MIN was specified as msgtyp to msgrcv.
This code:
long msg[] = { 100, 200 };
int m = msgget(IPC_PRIVATE, IPC_CREAT | 0644);
msgsnd(m, &msg, sizeof(msg), 0);
msgrcv(m, &msg, sizeof(msg), LONG_MIN, 0);
produces currently nothing:
msgget(IPC_PRIVATE, IPC_CREAT|0644) = 65538
msgsnd(65538, {100, "\310\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"}, 16, 0) = 0
msgrcv(65538, ...
Except a UBSAN warning:
UBSAN: Undefined behaviour in ipc/msg.c:745:13
negation of -9223372036854775808 cannot be represented in type 'long int':
With the patch, I see what I expect:
msgget(IPC_PRIVATE, IPC_CREAT|0644) = 0
msgsnd(0, {100, "\310\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"}, 16, 0) = 0
msgrcv(0, {100, "\310\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"}, 16, -9223372036854775808, 0) = 16
Link: http://lkml.kernel.org/r/20161024082633.10148-1-jslaby@suse.cz
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f991af3daabaecff34684fd51fac80319d1baad1 upstream.
The retry logic for netlink_attachskb() inside sys_mq_notify()
is nasty and vulnerable:
1) The sock refcnt is already released when retry is needed
2) The fd is controllable by user-space because we already
release the file refcnt
so we when retry but the fd has been just closed by user-space
during this small window, we end up calling netlink_detachskb()
on the error path which releases the sock again, later when
the user-space closes this socket a use-after-free could be
triggered.
Setting 'sock' to NULL here should be sufficient to fix it.
Reported-by: GeneBlue <geneblue.mail@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 95e91b831f87ac8e1f8ed50c14d709089b4e01b8 upstream.
The issue is described here, with a nice testcase:
https://bugzilla.kernel.org/show_bug.cgi?id=192931
The problem is that shmat() calls do_mmap_pgoff() with MAP_FIXED, and
the address rounded down to 0. For the regular mmap case, the
protection mentioned above is that the kernel gets to generate the
address -- arch_get_unmapped_area() will always check for MAP_FIXED and
return that address. So by the time we do security_mmap_addr(0) things
get funky for shmat().
The testcase itself shows that while a regular user crashes, root will
not have a problem attaching a nil-page. There are two possible fixes
to this. The first, and which this patch does, is to simply allow root
to crash as well -- this is also regular mmap behavior, ie when hacking
up the testcase and adding mmap(... |MAP_FIXED). While this approach
is the safer option, the second alternative is to ignore SHM_RND if the
rounded address is 0, thus only having MAP_SHARED flags. This makes the
behavior of shmat() identical to the mmap() case. The downside of this
is obviously user visible, but does make sense in that it maintains
semantics after the round-down wrt 0 address and mmap.
Passes shm related ltp tests.
Link: http://lkml.kernel.org/r/1486050195-18629-1-git-send-email-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Gareth Evans <gareth.evans@contextis.co.uk>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This allows filesystems to use their mount private data to
influence the permssions they return in permission2. It has
been separated into a new call to avoid disrupting current
permission users.
Change-Id: I9d416e3b8b6eca84ef3e336bd2af89ddd51df6ca
Signed-off-by: Daniel Rosenberg <drosen@google.com>
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commit 5864a2fd3088db73d47942370d0f7210a807b9bc upstream.
Commit 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") introduced a
race:
sem_lock has a fast path that allows parallel simple operations.
There are two reasons why a simple operation cannot run in parallel:
- a non-simple operations is ongoing (sma->sem_perm.lock held)
- a complex operation is sleeping (sma->complex_count != 0)
As both facts are stored independently, a thread can bypass the current
checks by sleeping in the right positions. See below for more details
(or kernel bugzilla 105651).
The patch fixes that by creating one variable (complex_mode)
that tracks both reasons why parallel operations are not possible.
The patch also updates stale documentation regarding the locking.
With regards to stable kernels:
The patch is required for all kernels that include the
commit 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") (3.10?)
The alternative is to revert the patch that introduced the race.
The patch is safe for backporting, i.e. it makes no assumptions
about memory barriers in spin_unlock_wait().
Background:
Here is the race of the current implementation:
Thread A: (simple op)
- does the first "sma->complex_count == 0" test
Thread B: (complex op)
- does sem_lock(): This includes an array scan. But the scan can't
find Thread A, because Thread A does not own sem->lock yet.
- the thread does the operation, increases complex_count,
drops sem_lock, sleeps
Thread A:
- spin_lock(&sem->lock), spin_is_locked(sma->sem_perm.lock)
- sleeps before the complex_count test
Thread C: (complex op)
- does sem_lock (no array scan, complex_count==1)
- wakes up Thread B.
- decrements complex_count
Thread A:
- does the complex_count test
Bug:
Now both thread A and thread C operate on the same array, without
any synchronization.
Fixes: 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()")
Link: http://lkml.kernel.org/r/1469123695-5661-1-git-send-email-manfred@colorfullife.com
Reported-by: <felixh@informatik.uni-bremen.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <1vier1@web.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9b24fef9f0410fb5364245d6cc2bd044cc064007 upstream.
Commit 53dad6d3a8e5 ("ipc: fix race with LSMs") updated ipc_rcu_putref()
to receive rcu freeing function but used generic ipc_rcu_free() instead
of msg_rcu_free() which does security cleaning.
Running LTP msgsnd06 with kmemleak gives the following:
cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff88003c0a11f8 (size 8):
comm "msgsnd06", pid 1645, jiffies 4294672526 (age 6.549s)
hex dump (first 8 bytes):
1b 00 00 00 01 00 00 00 ........
backtrace:
kmemleak_alloc+0x23/0x40
kmem_cache_alloc_trace+0xe1/0x180
selinux_msg_queue_alloc_security+0x3f/0xd0
security_msg_queue_alloc+0x2e/0x40
newque+0x4e/0x150
ipcget+0x159/0x1b0
SyS_msgget+0x39/0x40
entry_SYSCALL_64_fastpath+0x13/0x8f
Manfred Spraul suggested to fix sem.c as well and Davidlohr Bueso to
only use ipc_rcu_free in case of security allocation failure in newary()
Fixes: 53dad6d3a8e ("ipc: fix race with LSMs")
Link: http://lkml.kernel.org/r/1470083552-22966-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1ac0b6dec656f3f78d1c3dd216fad84cb4d0a01e upstream.
remap_file_pages(2) emulation can reach file which represents removed
IPC ID as long as a memory segment is mapped. It breaks expectations of
IPC subsystem.
Test case (rewritten to be more human readable, originally autogenerated
by syzkaller[1]):
#define _GNU_SOURCE
#include <stdlib.h>
#include <sys/ipc.h>
#include <sys/mman.h>
#include <sys/shm.h>
#define PAGE_SIZE 4096
int main()
{
int id;
void *p;
id = shmget(IPC_PRIVATE, 3 * PAGE_SIZE, 0);
p = shmat(id, NULL, 0);
shmctl(id, IPC_RMID, NULL);
remap_file_pages(p, 3 * PAGE_SIZE, 0, 7, 0);
return 0;
}
The patch changes shm_mmap() and code around shm_lock() to propagate
locking error back to caller of shm_mmap().
[1] http://github.com/google/syzkaller
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d0edd8528362 ("ipc: convert invalid scenarios to use WARN_ON") relaxed the
nil dst parameter check, originally being a full BUG_ON. However, this
check seems quite unnecessary when the only purpose is for
ceckpoint/restore (MSG_COPY flag):
o The copy variable is set initially to nil, apparently as a way of
ensuring that prepare_copy is previously called. Which is in fact done,
unconditionally at the beginning of do_msgrcv.
o There is no concurrency with 'copy' (stack allocated in do_msgrcv).
Furthermore, any errors in 'copy' (and thus prepare_copy/copy_msg) should
always handled by IS_ERR() family. Therefore remove this check altogether
as it can never occur with the current users.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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As reported by Dmitry Vyukov, we really shouldn't do ipc_addid() before
having initialized the IPC object state. Yes, we initialize the IPC
object in a locked state, but with all the lockless RCU lookup work,
that IPC object lock no longer means that the state cannot be seen.
We already did this for the IPC semaphore code (see commit e8577d1f0329:
"ipc/sem.c: fully initialize sem_array before making it visible") but we
clearly forgot about msg and shm.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Considering Linus' past rants about the (ab)use of BUG in the kernel, I
took a look at how we deal with such calls in ipc. Given that any errors
or corruption in ipc code are most likely contained within the set of
processes participating in the broken mechanisms, there aren't really many
strong fatal system failure scenarios that would require a BUG call.
Also, if something is seriously wrong, ipc might not be the place for such
a BUG either.
1. For example, recently, a customer hit one of these BUG_ONs in shm
after failing shm_lock(). A busted ID imho does not merit a BUG_ON,
and WARN would have been better.
2. MSG_COPY functionality of posix msgrcv(2) for checkpoint/restore.
I don't see how we can hit this anyway -- at least it should be IS_ERR.
The 'copy' arg from do_msgrcv is always set by calling prepare_copy()
first and foremost. We could also probably drop this check altogether.
Either way, it does not merit a BUG_ON.
3. No ->fault() callback for the fs getting the corresponding page --
seems selfish to make the system unusable.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
sem_lock() did not properly pair memory barriers:
!spin_is_locked() and spin_unlock_wait() are both only control barriers.
The code needs an acquire barrier, otherwise the cpu might perform read
operations before the lock test.
As no primitive exists inside <include/spinlock.h> and since it seems
noone wants another primitive, the code creates a local primitive within
ipc/sem.c.
With regards to -stable:
The change of sem_wait_array() is a bugfix, the change to sem_lock() is a
nop (just a preprocessor redefinition to improve the readability). The
bugfix is necessary for all kernels that use sem_wait_array() (i.e.:
starting from 3.10).
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Kirill Tkhai <ktkhai@parallels.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
After we acquire the sma->sem_perm lock in exit_sem(), we are protected
against a racing IPC_RMID operation. Also at that point, we are the last
user of sem_undo_list. Therefore it isn't required that we acquire or use
ulp->lock.
Signed-off-by: Herton R. Krzesinski <herton@redhat.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Rafael Aquini <aquini@redhat.com>
CC: Aristeu Rozanski <aris@redhat.com>
Cc: David Jeffery <djeffery@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
set exits
The current semaphore code allows a potential use after free: in
exit_sem we may free the task's sem_undo_list while there is still
another task looping through the same semaphore set and cleaning the
sem_undo list at freeary function (the task called IPC_RMID for the same
semaphore set).
For example, with a test program [1] running which keeps forking a lot
of processes (which then do a semop call with SEM_UNDO flag), and with
the parent right after removing the semaphore set with IPC_RMID, and a
kernel built with CONFIG_SLAB, CONFIG_SLAB_DEBUG and
CONFIG_DEBUG_SPINLOCK, you can easily see something like the following
in the kernel log:
Slab corruption (Not tainted): kmalloc-64 start=ffff88003b45c1c0, len=64
000: 6b 6b 6b 6b 6b 6b 6b 6b 00 6b 6b 6b 6b 6b 6b 6b kkkkkkkk.kkkkkkk
010: ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........
Prev obj: start=ffff88003b45c180, len=64
000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ
010: ff ff ff ff ff ff ff ff c0 fb 01 37 00 88 ff ff ...........7....
Next obj: start=ffff88003b45c200, len=64
000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ
010: ff ff ff ff ff ff ff ff 68 29 a7 3c 00 88 ff ff ........h).<....
BUG: spinlock wrong CPU on CPU#2, test/18028
general protection fault: 0000 [#1] SMP
Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib]
CPU: 2 PID: 18028 Comm: test Not tainted 4.2.0-rc5+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
RIP: spin_dump+0x53/0xc0
Call Trace:
spin_bug+0x30/0x40
do_raw_spin_unlock+0x71/0xa0
_raw_spin_unlock+0xe/0x10
freeary+0x82/0x2a0
? _raw_spin_lock+0xe/0x10
semctl_down.clone.0+0xce/0x160
? __do_page_fault+0x19a/0x430
? __audit_syscall_entry+0xa8/0x100
SyS_semctl+0x236/0x2c0
? syscall_trace_leave+0xde/0x130
entry_SYSCALL_64_fastpath+0x12/0x71
Code: 8b 80 88 03 00 00 48 8d 88 60 05 00 00 48 c7 c7 a0 2c a4 81 31 c0 65 8b 15 eb 40 f3 7e e8 08 31 68 00 4d 85 e4 44 8b 4b 08 74 5e <45> 8b 84 24 88 03 00 00 49 8d 8c 24 60 05 00 00 8b 53 04 48 89
RIP [<ffffffff810d6053>] spin_dump+0x53/0xc0
RSP <ffff88003750fd68>
---[ end trace 783ebb76612867a0 ]---
NMI watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [test:18053]
Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib]
CPU: 3 PID: 18053 Comm: test Tainted: G D 4.2.0-rc5+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014
RIP: native_read_tsc+0x0/0x20
Call Trace:
? delay_tsc+0x40/0x70
__delay+0xf/0x20
do_raw_spin_lock+0x96/0x140
_raw_spin_lock+0xe/0x10
sem_lock_and_putref+0x11/0x70
SYSC_semtimedop+0x7bf/0x960
? handle_mm_fault+0xbf6/0x1880
? dequeue_task_fair+0x79/0x4a0
? __do_page_fault+0x19a/0x430
? kfree_debugcheck+0x16/0x40
? __do_page_fault+0x19a/0x430
? __audit_syscall_entry+0xa8/0x100
? do_audit_syscall_entry+0x66/0x70
? syscall_trace_enter_phase1+0x139/0x160
SyS_semtimedop+0xe/0x10
SyS_semop+0x10/0x20
entry_SYSCALL_64_fastpath+0x12/0x71
Code: 47 10 83 e8 01 85 c0 89 47 10 75 08 65 48 89 3d 1f 74 ff 7e c9 c3 0f 1f 44 00 00 55 48 89 e5 e8 87 17 04 00 66 90 c9 c3 0f 1f 00 <55> 48 89 e5 0f 31 89 c1 48 89 d0 48 c1 e0 20 89 c9 48 09 c8 c9
Kernel panic - not syncing: softlockup: hung tasks
I wasn't able to trigger any badness on a recent kernel without the
proper config debugs enabled, however I have softlockup reports on some
kernel versions, in the semaphore code, which are similar as above (the
scenario is seen on some servers running IBM DB2 which uses semaphore
syscalls).
The patch here fixes the race against freeary, by acquiring or waiting
on the sem_undo_list lock as necessary (exit_sem can race with freeary,
while freeary sets un->semid to -1 and removes the same sem_undo from
list_proc or when it removes the last sem_undo).
After the patch I'm unable to reproduce the problem using the test case
[1].
[1] Test case used below:
#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#define NSEM 1
#define NSET 5
int sid[NSET];
void thread()
{
struct sembuf op;
int s;
uid_t pid = getuid();
s = rand() % NSET;
op.sem_num = pid % NSEM;
op.sem_op = 1;
op.sem_flg = SEM_UNDO;
semop(sid[s], &op, 1);
exit(EXIT_SUCCESS);
}
void create_set()
{
int i, j;
pid_t p;
union {
int val;
struct semid_ds *buf;
unsigned short int *array;
struct seminfo *__buf;
} un;
/* Create and initialize semaphore set */
for (i = 0; i < NSET; i++) {
sid[i] = semget(IPC_PRIVATE , NSEM, 0644 | IPC_CREAT);
if (sid[i] < 0) {
perror("semget");
exit(EXIT_FAILURE);
}
}
un.val = 0;
for (i = 0; i < NSET; i++) {
for (j = 0; j < NSEM; j++) {
if (semctl(sid[i], j, SETVAL, un) < 0)
perror("semctl");
}
}
/* Launch threads that operate on semaphore set */
for (i = 0; i < NSEM * NSET * NSET; i++) {
p = fork();
if (p < 0)
perror("fork");
if (p == 0)
thread();
}
/* Free semaphore set */
for (i = 0; i < NSET; i++) {
if (semctl(sid[i], NSEM, IPC_RMID))
perror("IPC_RMID");
}
/* Wait for forked processes to exit */
while (wait(NULL)) {
if (errno == ECHILD)
break;
};
}
int main(int argc, char **argv)
{
pid_t p;
srand(time(NULL));
while (1) {
p = fork();
if (p < 0) {
perror("fork");
exit(EXIT_FAILURE);
}
if (p == 0) {
create_set();
goto end;
}
/* Wait for forked processes to exit */
while (wait(NULL)) {
if (errno == ECHILD)
break;
};
}
end:
return 0;
}
[akpm@linux-foundation.org: use normal comment layout]
Signed-off-by: Herton R. Krzesinski <herton@redhat.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Rafael Aquini <aquini@redhat.com>
CC: Aristeu Rozanski <aris@redhat.com>
Cc: David Jeffery <djeffery@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The shm implementation internally uses shmem or hugetlbfs inodes for shm
segments. As these inodes are never directly exposed to userspace and
only accessed through the shm operations which are already hooked by
security modules, mark the inodes with the S_PRIVATE flag so that inode
security initialization and permission checking is skipped.
This was motivated by the following lockdep warning:
======================================================
[ INFO: possible circular locking dependency detected ]
4.2.0-0.rc3.git0.1.fc24.x86_64+debug #1 Tainted: G W
-------------------------------------------------------
httpd/1597 is trying to acquire lock:
(&ids->rwsem){+++++.}, at: shm_close+0x34/0x130
but task is already holding lock:
(&mm->mmap_sem){++++++}, at: SyS_shmdt+0x4b/0x180
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&mm->mmap_sem){++++++}:
lock_acquire+0xc7/0x270
__might_fault+0x7a/0xa0
filldir+0x9e/0x130
xfs_dir2_block_getdents.isra.12+0x198/0x1c0 [xfs]
xfs_readdir+0x1b4/0x330 [xfs]
xfs_file_readdir+0x2b/0x30 [xfs]
iterate_dir+0x97/0x130
SyS_getdents+0x91/0x120
entry_SYSCALL_64_fastpath+0x12/0x76
-> #2 (&xfs_dir_ilock_class){++++.+}:
lock_acquire+0xc7/0x270
down_read_nested+0x57/0xa0
xfs_ilock+0x167/0x350 [xfs]
xfs_ilock_attr_map_shared+0x38/0x50 [xfs]
xfs_attr_get+0xbd/0x190 [xfs]
xfs_xattr_get+0x3d/0x70 [xfs]
generic_getxattr+0x4f/0x70
inode_doinit_with_dentry+0x162/0x670
sb_finish_set_opts+0xd9/0x230
selinux_set_mnt_opts+0x35c/0x660
superblock_doinit+0x77/0xf0
delayed_superblock_init+0x10/0x20
iterate_supers+0xb3/0x110
selinux_complete_init+0x2f/0x40
security_load_policy+0x103/0x600
sel_write_load+0xc1/0x750
__vfs_write+0x37/0x100
vfs_write+0xa9/0x1a0
SyS_write+0x58/0xd0
entry_SYSCALL_64_fastpath+0x12/0x76
...
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reported-by: Morten Stevens <mstevens@fedoraproject.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
account
A while back, the message queue implementation in the kernel was
improved to use btrees to speed up retrieval of messages, in commit
d6629859b36d ("ipc/mqueue: improve performance of send/recv").
That patch introducing the improved kernel handling of message queues
(using btrees) has, as a by-product, changed the meaning of the QSIZE
field in the pseudo-file created for the queue. Before, this field
reflected the size of the user-data in the queue. Since, it also takes
kernel data structures into account. For example, if 13 bytes of user
data are in the queue, on my machine the file reports a size of 61
bytes.
There was some discussion on this topic before (for example
https://lkml.org/lkml/2014/10/1/115). Commenting on a th lkml, Michael
Kerrisk gave the following background
(https://lkml.org/lkml/2015/6/16/74):
The pseudofiles in the mqueue filesystem (usually mounted at
/dev/mqueue) expose fields with metadata describing a message
queue. One of these fields, QSIZE, as originally implemented,
showed the total number of bytes of user data in all messages in
the message queue, and this feature was documented from the
beginning in the mq_overview(7) page. In 3.5, some other (useful)
work happened to break the user-space API in a couple of places,
including the value exposed via QSIZE, which now includes a measure
of kernel overhead bytes for the queue, a figure that renders QSIZE
useless for its original purpose, since there's no way to deduce
the number of overhead bytes consumed by the implementation.
(The other user-space breakage was subsequently fixed.)
This patch removes the accounting of kernel data structures in the
queue. Reporting the size of these data-structures in the QSIZE field
was a breaking change (see Michael's comment above). Without the QSIZE
field reporting the total size of user-data in the queue, there is no
way to deduce this number.
It should be noted that the resource limit RLIMIT_MSGQUEUE is counted
against the worst-case size of the queue (in both the old and the new
implementation). Therefore, the kernel overhead accounting in QSIZE is
not necessary to help the user understand the limitations RLIMIT imposes
on the processes.
Signed-off-by: Marcus Gelderie <redmnic@gmail.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: John Duffy <jb_duffy@btinternet.com>
Cc: Arto Bendiken <arto@bendiken.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
In ipc_obtain_object_check we return -EIDRM when a bogus sequence number
is detected via ipc_checkid, while the ipc manpages state the following
return codes for such errors:
EIDRM <ID> points to a removed identifier.
EINVAL Invalid <ID> value, or unaligned, etc.
EIDRM should only be returned upon a RMID call (->deleted check), and thus
return EINVAL for wrong seq. This difference in semantics has also caused
real bugs, ie: https://bugzilla.redhat.com/show_bug.cgi?id=246509
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The ipc_lock helper is used by all forms of sysv ipc to acquire the ipc
object's spinlock. Upon error (bogus identifier), we always return
-EINVAL, whether the problem be in the idr path or because we raced with a
task performing RMID. For the later, however, all ipc related manpages,
state the that for:
EIDRM <ID> points to a removed identifier.
And return:
EINVAL Invalid <ID> value, or unaligned, etc.
Which (EINVAL) should only return once the ipc resource is deleted. For
all types of ipc this is done immediately upon a RMID command. However,
shared memory behaves slightly different as it can merely mark a segment
for deletion, and delay the actual freeing until there are no more active
consumers. Per shmctl(IPC_RMID) manpage:
""
Mark the segment to be destroyed. The segment will only actually
be destroyed after the last process detaches it (i.e., when the
shm_nattch member of the associated structure shmid_ds is zero).
""
Unlike ipc_lock, paths that behave "correctly", at least per the manpage,
involve controlling the ipc resource via *ctl(), doing the exact same
validity check as ipc_lock after right acquiring the spinlock:
if (!ipc_valid_object()) {
err = -EIDRM;
goto out_unlock;
}
Thus make ipc_lock consistent with the rest of ipc code and return -EIDRM
in ipc_lock when !ipc_valid_object().
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
... to ipc_obtain_object_idr, which is more meaningful and makes the code
slightly easier to follow.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
We currently use a full barrier on the sender side to to avoid receiver
tasks disappearing on us while still performing on the sender side wakeup.
We lack however, the proper CPU-CPU interactions pairing on the receiver
side which busy-waits for the message. Similarly, we do not need a full
smp_mb, and can relax the semantics for the writer and reader sides of the
message. This is safe as we are only ordering loads and stores to r_msg.
And in both smp_wmb and smp_rmb, there are no stores after the calls
_anyway_.
This obviously applies for pipelined_send and expunge_all, for EIRDM when
destroying a queue.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Upon every shm_lock call, we BUG_ON if an error was returned, indicating
racing either in idr or in shm_destroy. Move this logic into the locking.
[akpm@linux-foundation.org: simplify code]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Use kvfree() instead of open-coding it.
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This patch moves the wakeup_process() invocation so it is not done under
the info->lock by making use of a lockless wake_q. With this change, the
waiter is woken up once it is STATE_READY and it does not need to loop
on SMP if it is still in STATE_PENDING. In the timeout case we still need
to grab the info->lock to verify the state.
This change should also avoid the introduction of preempt_disable() in -rt
which avoids a busy-loop which pools for the STATE_PENDING -> STATE_READY
change if the waiter has a higher priority compared to the waker.
Additionally, this patch micro-optimizes wq_sleep by using the cheaper
cousin of set_current_state(TASK_INTERRUPTABLE) as we will block no
matter what, thus get rid of the implied barrier.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: George Spelvin <linux@horizon.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Mason <clm@fb.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1430748166.1940.17.camel@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
"d_inode() annotations from David Howells (sat in for-next since before
the beginning of merge window) + four assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
RCU pathwalk breakage when running into a symlink overmounting something
fix I_DIO_WAKEUP definition
direct-io: only inc/dec inode->i_dio_count for file systems
fs/9p: fix readdir()
VFS: assorted d_backing_inode() annotations
VFS: fs/inode.c helpers: d_inode() annotations
VFS: fs/cachefiles: d_backing_inode() annotations
VFS: fs library helpers: d_inode() annotations
VFS: assorted weird filesystems: d_inode() annotations
VFS: normal filesystems (and lustre): d_inode() annotations
VFS: security/: d_inode() annotations
VFS: security/: d_backing_inode() annotations
VFS: net/: d_inode() annotations
VFS: net/unix: d_backing_inode() annotations
VFS: kernel/: d_inode() annotations
VFS: audit: d_backing_inode() annotations
VFS: Fix up some ->d_inode accesses in the chelsio driver
VFS: Cachefiles should perform fs modifications on the top layer only
VFS: AF_UNIX sockets should call mknod on the top layer only
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The seq_printf return value, because it's frequently misused,
will eventually be converted to void.
See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to
seq_has_overflowed() and make public")
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Call __set_current_state() instead of assigning the new state directly.
These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments, keeping
track of who changed the state.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile #2 from Al Viro:
"Next pile (and there'll be one or two more).
The large piece in this one is getting rid of /proc/*/ns/* weirdness;
among other things, it allows to (finally) make nameidata completely
opaque outside of fs/namei.c, making for easier further cleanups in
there"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
coda_venus_readdir(): use file_inode()
fs/namei.c: fold link_path_walk() call into path_init()
path_init(): don't bother with LOOKUP_PARENT in argument
fs/namei.c: new helper (path_cleanup())
path_init(): store the "base" pointer to file in nameidata itself
make default ->i_fop have ->open() fail with ENXIO
make nameidata completely opaque outside of fs/namei.c
kill proc_ns completely
take the targets of /proc/*/ns/* symlinks to separate fs
bury struct proc_ns in fs/proc
copy address of proc_ns_ops into ns_common
new helpers: ns_alloc_inum/ns_free_inum
make proc_ns_operations work with struct ns_common * instead of void *
switch the rest of proc_ns_operations to working with &...->ns
netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
common object embedded into various struct ....ns
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Andrew Morton noted
http://lkml.kernel.org/r/20141104142027.a7a0d010772d84560b445f59@linux-foundation.org
that the shmdt uses inode->i_size outside of i_mutex being held.
There is one more case in shm.c in shm_destroy(). This converts
both users over to use i_size_read().
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is a highly-contrived scenario. But, a single shmdt() call can be
induced in to unmapping memory from mulitple shm segments. Example code
is here:
http://www.sr71.net/~dave/intel/shmfun.c
The fix is pretty simple: Record the 'struct file' for the first VMA we
encounter and then stick to it. Decline to unmap anything not from the
same file and thus the same segment.
I found this by inspection and the odds of anyone hitting this in practice
are pretty darn small.
Lightly tested, but it's a pretty small patch.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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SysV can be abused to allocate locked kernel memory. For most systems, a
small limit doesn't make sense, see the discussion with regards to SHMMAX.
Therefore: increase MSGMNI to the maximum supported.
And: If we ignore the risk of locking too much memory, then an automatic
scaling of MSGMNI doesn't make sense. Therefore the logic can be removed.
The code preserves auto_msgmni to avoid breaking any user space applications
that expect that the value exists.
Notes:
1) If an administrator must limit the memory allocations, then he can set
MSGMNI as necessary.
Or he can disable sysv entirely (as e.g. done by Android).
2) MSGMAX and MSGMNB are intentionally not increased, as these values are used
to control latency vs. throughput:
If MSGMNB is large, then msgsnd() just returns and more messages can be queued
before a task switch to a task that calls msgrcv() is forced.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When I fixed bugs in the sem_lock() logic, I was more conservative than
necessary. Therefore it is safe to replace the smp_mb() with smp_rmb().
And: With smp_rmb(), semop() syscalls are up to 10% faster.
The race we must protect against is:
sem->lock is free
sma->complex_count = 0
sma->sem_perm.lock held by thread B
thread A:
A: spin_lock(&sem->lock)
B: sma->complex_count++; (now 1)
B: spin_unlock(&sma->sem_perm.lock);
A: spin_is_locked(&sma->sem_perm.lock);
A: XXXXX memory barrier
A: if (sma->complex_count == 0)
Thread A must read the increased complex_count value, i.e. the read must
not be reordered with the read of sem_perm.lock done by spin_is_locked().
Since it's about ordering of reads, smp_rmb() is sufficient.
[akpm@linux-foundation.org: update sem_lock() comment, from Davidlohr]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS changes from Al Viro:
"First pile out of several (there _definitely_ will be more). Stuff in
this one:
- unification of d_splice_alias()/d_materialize_unique()
- iov_iter rewrite
- killing a bunch of ->f_path.dentry users (and f_dentry macro).
Getting that completed will make life much simpler for
unionmount/overlayfs, since then we'll be able to limit the places
sensitive to file _dentry_ to reasonably few. Which allows to have
file_inode(file) pointing to inode in a covered layer, with dentry
pointing to (negative) dentry in union one.
Still not complete, but much closer now.
- crapectomy in lustre (dead code removal, mostly)
- "let's make seq_printf return nothing" preparations
- assorted cleanups and fixes
There _definitely_ will be more piles"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
copy_from_iter_nocache()
new helper: iov_iter_kvec()
csum_and_copy_..._iter()
iov_iter.c: handle ITER_KVEC directly
iov_iter.c: convert copy_to_iter() to iterate_and_advance
iov_iter.c: convert copy_from_iter() to iterate_and_advance
iov_iter.c: get rid of bvec_copy_page_{to,from}_iter()
iov_iter.c: convert iov_iter_zero() to iterate_and_advance
iov_iter.c: convert iov_iter_get_pages_alloc() to iterate_all_kinds
iov_iter.c: convert iov_iter_get_pages() to iterate_all_kinds
iov_iter.c: convert iov_iter_npages() to iterate_all_kinds
iov_iter.c: iterate_and_advance
iov_iter.c: macros for iterating over iov_iter
kill f_dentry macro
dcache: fix kmemcheck warning in switch_names
new helper: audit_file()
nfsd_vfs_write(): use file_inode()
ncpfs: use file_inode()
kill f_dentry uses
lockd: get rid of ->f_path.dentry->d_sb
...
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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take struct ns_common *, for now simply wrappers around proc_{alloc,free}_inum()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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We can do that now. And kill ->inum(), while we are at it - all instances
are identical.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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for now - just move corresponding ->proc_inum instances over there
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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ipc_addid() makes a new ipc identifier visible to everyone. New objects
start as locked, so that the caller can complete the initialization
after the call. Within struct sem_array, at least sma->sem_base and
sma->sem_nsems are accessed without any locks, therefore this approach
doesn't work.
Thus: Move the ipc_addid() to the end of the initialization.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reported-by: Rik van Riel <riel@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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... for situations when we don't have any candidate in pathnames - basically,
in descriptor-based syscalls.
[Folded the build fix for !CONFIG_AUDITSYSCALL configs from Chen Gang]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Resolve some shadow warnings produced in W=2 builds by changing the name
of some parameters and local variables. Change instances of "s64"
because that clashes with the well-known typedef. Also change a local
variable with the name "up" because that clashes with the name of of the
"up" function for semaphores. These are hazards so eliminate the
hazards by renaming them.
Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Using __seq_open_private() removes boilerplate code from
sysvipc_proc_open().
The resultant code is shorter and easier to follow.
However, please note that __seq_open_private() call kzalloc() rather than
kmalloc() which may affect timing due to the memory initialisation
overhead.
Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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