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commit 95389b08d93d5c06ec63ab49bd732b0069b7c35e upstream.
This fixes CVE-2014-3631.
It is possible for an associative array to end up with a shortcut node at the
root of the tree if there are more than fan-out leaves in the tree, but they
all crowd into the same slot in the lowest level (ie. they all have the same
first nibble of their index keys).
When assoc_array_gc() returns back up the tree after scanning some leaves, it
can fall off of the root and crash because it assumes that the back pointer
from a shortcut (after label ascend_old_tree) must point to a normal node -
which isn't true of a shortcut node at the root.
Should we find we're ascending rootwards over a shortcut, we should check to
see if the backpointer is zero - and if it is, we have completed the scan.
This particular bug cannot occur if the root node is not a shortcut - ie. if
you have fewer than 17 keys in a keyring or if you have at least two keys that
sit into separate slots (eg. a keyring and a non keyring).
This can be reproduced by:
ring=`keyctl newring bar @s`
for ((i=1; i<=18; i++)); do last_key=`keyctl newring foo$i $ring`; done
keyctl timeout $last_key 2
Doing this:
echo 3 >/proc/sys/kernel/keys/gc_delay
first will speed things up.
If we do fall off of the top of the tree, we get the following oops:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
IP: [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540
PGD dae15067 PUD cfc24067 PMD 0
Oops: 0000 [#1] SMP
Modules linked in: xt_nat xt_mark nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_rpfilter ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_ni
CPU: 0 PID: 26011 Comm: kworker/0:1 Not tainted 3.14.9-200.fc20.x86_64 #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: events key_garbage_collector
task: ffff8800918bd580 ti: ffff8800aac14000 task.ti: ffff8800aac14000
RIP: 0010:[<ffffffff8136cea7>] [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540
RSP: 0018:ffff8800aac15d40 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8800aaecacc0
RDX: ffff8800daecf440 RSI: 0000000000000001 RDI: ffff8800aadc2bc0
RBP: ffff8800aac15da8 R08: 0000000000000001 R09: 0000000000000003
R10: ffffffff8136ccc7 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000070 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88011fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000018 CR3: 00000000db10d000 CR4: 00000000000006f0
Stack:
ffff8800aac15d50 0000000000000011 ffff8800aac15db8 ffffffff812e2a70
ffff880091a00600 0000000000000000 ffff8800aadc2bc3 00000000cd42c987
ffff88003702df20 ffff88003702dfa0 0000000053b65c09 ffff8800aac15fd8
Call Trace:
[<ffffffff812e2a70>] ? keyring_detect_cycle_iterator+0x30/0x30
[<ffffffff812e3e75>] keyring_gc+0x75/0x80
[<ffffffff812e1424>] key_garbage_collector+0x154/0x3c0
[<ffffffff810a67b6>] process_one_work+0x176/0x430
[<ffffffff810a744b>] worker_thread+0x11b/0x3a0
[<ffffffff810a7330>] ? rescuer_thread+0x3b0/0x3b0
[<ffffffff810ae1a8>] kthread+0xd8/0xf0
[<ffffffff810ae0d0>] ? insert_kthread_work+0x40/0x40
[<ffffffff816ffb7c>] ret_from_fork+0x7c/0xb0
[<ffffffff810ae0d0>] ? insert_kthread_work+0x40/0x40
Code: 08 4c 8b 22 0f 84 bf 00 00 00 41 83 c7 01 49 83 e4 fc 41 83 ff 0f 4c 89 65 c0 0f 8f 5a fe ff ff 48 8b 45 c0 4d 63 cf 49 83 c1 02 <4e> 8b 34 c8 4d 85 f6 0f 84 be 00 00 00 41 f6 c6 01 0f 84 92
RIP [<ffffffff8136cea7>] assoc_array_gc+0x2f7/0x540
RSP <ffff8800aac15d40>
CR2: 0000000000000018
---[ end trace 1129028a088c0cbd ]---
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 27419604f51a97d497853f14142c1059d46eb597 upstream.
An edit script should be considered inaccessible by a function once it has
called assoc_array_apply_edit() or assoc_array_cancel_edit().
However, assoc_array_gc() is accessing the edit script just after the
gc_complete: label.
Reported-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
cc: shemming@brocade.com
cc: paulmck@linux.vnet.ibm.com
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c75b53af2f0043aff500af0a6f878497bef41bca upstream.
I use btree from 3.14-rc2 in my own module. When the btree module is
removed, a warning arises:
kmem_cache_destroy btree_node: Slab cache still has objects
CPU: 13 PID: 9150 Comm: rmmod Tainted: GF O 3.14.0-rc2 #1
Hardware name: Inspur NF5270M3/NF5270M3, BIOS CHEETAH_2.1.3 09/10/2013
Call Trace:
dump_stack+0x49/0x5d
kmem_cache_destroy+0xcf/0xe0
btree_module_exit+0x10/0x12 [btree]
SyS_delete_module+0x198/0x1f0
system_call_fastpath+0x16/0x1b
The cause is that it doesn't release the last btree node, when height = 1
and fill = 1.
[akpm@linux-foundation.org: remove unneeded test of NULL]
Signed-off-by: Minfei Huang <huangminfei@ucloud.cn>
Cc: Joern Engel <joern@logfs.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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 4a3a99045177369700c60d074c0e525e8093b0fc upstream.
Jan points out that I forgot to make the needed fixes to the
lz4_uncompress_unknownoutputsize() function to mirror the changes done
in lz4_decompress() with regards to potential pointer overflows.
The only in-kernel user of this function is the zram code, which only
takes data from a valid compressed buffer that it made itself, so it's
not a big issue. But due to external kernel modules using this
function, it's better to be safe here.
Reported-by: Jan Beulich <JBeulich@suse.com>
Cc: "Don A. Bailey" <donb@securitymouse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 4148c1f67abf823099b2d7db6851e4aea407f5ee upstream.
There is one other possible overrun in the lz4 code as implemented by
Linux at this point in time (which differs from the upstream lz4
codebase, but will get synced at in a future kernel release.) As
pointed out by Don, we also need to check the overflow in the data
itself.
While we are at it, replace the odd error return value with just a
"simple" -1 value as the return value is never used for anything other
than a basic "did this work or not" check.
Reported-by: "Don A. Bailey" <donb@securitymouse.com>
Reported-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3afb69cb5572b3c8c898c00880803cf1a49852c4 upstream.
idr_replace() open-codes the logic to calculate the maximum valid ID
given the height of the idr tree; unfortunately, the open-coded logic
doesn't account for the fact that the top layer may have unused slots
and over-shifts the limit to zero when the tree is at its maximum
height.
The following test code shows it fails to replace the value for
id=((1<<27)+42):
static void test5(void)
{
int id;
DEFINE_IDR(test_idr);
#define TEST5_START ((1<<27)+42) /* use the highest layer */
printk(KERN_INFO "Start test5\n");
id = idr_alloc(&test_idr, (void *)1, TEST5_START, 0, GFP_KERNEL);
BUG_ON(id != TEST5_START);
TEST_BUG_ON(idr_replace(&test_idr, (void *)2, TEST5_START) != (void *)1);
idr_destroy(&test_idr);
printk(KERN_INFO "End of test5\n");
}
Fix the bug by using idr_max() which correctly takes into account the
maximum allowed shift.
sub_alloc() shares the same problem and may incorrectly fail with
-EAGAIN; however, this bug doesn't affect correct operation because
idr_get_empty_slot(), which already uses idr_max(), retries with the
increased @id in such cases.
[tj@kernel.org: Updated patch description.]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@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 206204a1162b995e2185275167b22468c00d6b36 upstream.
Given some pathologically compressed data, lz4 could possibly decide to
wrap a few internal variables, causing unknown things to happen. Catch
this before the wrapping happens and abort the decompression.
Reported-by: "Don A. Bailey" <donb@securitymouse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 206a81c18401c0cde6e579164f752c4b147324ce upstream.
The lzo decompressor can, if given some really crazy data, possibly
overrun some variable types. Modify the checking logic to properly
detect overruns before they happen.
Reported-by: "Don A. Bailey" <donb@securitymouse.com>
Tested-by: "Don A. Bailey" <donb@securitymouse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit bfc5184b69cf9eeb286137640351c650c27f118a ]
Any process is able to send netlink messages with leftover bytes.
Make the warning rate-limited to prevent too much log spam.
The warning is supposed to help find userspace bugs, so print the
triggering command name to implicate the buggy program.
[v2: Use pr_warn_ratelimited instead of printk_ratelimited.]
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e39435ce68bb4685288f78b1a7e24311f7ef939f upstream.
I got a bug report yesterday from Laszlo Ersek in which he states that
his kvm instance fails to suspend. Laszlo bisected it down to this
commit 1cf7e9c68fe8 ("virtio_blk: blk-mq support") where virtio-blk is
converted to use the blk-mq infrastructure.
After digging a bit, it became clear that the issue was with the queue
drain. blk-mq tracks queue usage in a percpu counter, which is
incremented on request alloc and decremented when the request is freed.
The initial hunt was for an inconsistency in blk-mq, but everything
seemed fine. In fact, the counter only returned crazy values when
suspend was in progress.
When a CPU is unplugged, the percpu counters merges that CPU state with
the general state. blk-mq takes care to register a hotcpu notifier with
the appropriate priority, so we know it runs after the percpu counter
notifier. However, the percpu counter notifier only merges the state
when the CPU is fully gone. This leaves a state transition where the
CPU going away is no longer in the online mask, yet it still holds
private values. This means that in this state, percpu_counter_sum()
returns invalid results, and the suspend then hangs waiting for
abs(dead-cpu-value) requests to complete which of course will never
happen.
Fix this by clearing the state earlier, so we never have a case where
the CPU isn't in online mask but still holds private state. This bug
has been there since forever, I guess we don't have a lot of users where
percpu counters needs to be reliable during the suspend cycle.
Signed-off-by: Jens Axboe <axboe@fb.com>
Reported-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.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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[ Upstream commit 8b7b932434f5eee495b91a2804f5b64ebb2bc835 ]
nla_strcmp compares the string length plus one, so it's implicitly
including the nul-termination in the comparison.
int nla_strcmp(const struct nlattr *nla, const char *str)
{
int len = strlen(str) + 1;
...
d = memcmp(nla_data(nla), str, len);
However, if NLA_STRING is used, userspace can send us a string without
the nul-termination. This is a problem since the string
comparison will not match as the last byte may be not the
nul-termination.
Fix this by skipping the comparison of the nul-termination if the
attribute data is nul-terminated. Suggested by Thomas Graf.
Cc: Florian Westphal <fw@strlen.de>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Commit 4af712e8df ("random32: add prandom_reseed_late() and call when
nonblocking pool becomes initialized") has added a late reseed stage
that happens as soon as the nonblocking pool is marked as initialized.
This fails in the case that the nonblocking pool gets initialized
during __prandom_reseed()'s call to get_random_bytes(). In that case
we'd double back into __prandom_reseed() in an attempt to do a late
reseed - deadlocking on 'lock' early on in the boot process.
Instead, just avoid even waiting to do a reseed if a reseed is already
occuring.
Fixes: 4af712e8df99 ("random32: add prandom_reseed_late() and call when nonblocking pool becomes initialized")
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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built-in ROM fonts
STI console is used on parisc and m68k HP machines. This patch partly reverts
my previous commit and as such restores the fonts for the m68k machines.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13
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Running fsx on tmpfs with concurrent memhog-swapoff-swapon, lots of
BUG: sleeping function called from invalid context at kernel/fork.c:606
in_atomic(): 0, irqs_disabled(): 0, pid: 1394, name: swapoff
1 lock held by swapoff/1394:
#0: (rcu_read_lock){.+.+.+}, at: [<ffffffff812520a1>] radix_tree_locate_item+0x1f/0x2b6
followed by
================================================
[ BUG: lock held when returning to user space! ]
3.14.0-rc1 #3 Not tainted
------------------------------------------------
swapoff/1394 is leaving the kernel with locks still held!
1 lock held by swapoff/1394:
#0: (rcu_read_lock){.+.+.+}, at: [<ffffffff812520a1>] radix_tree_locate_item+0x1f/0x2b6
after which the system recovered nicely.
Whoops, I long ago forgot the rcu_read_unlock() on one unlikely branch.
Fixes e504f3fdd63d ("tmpfs radix_tree: locate_item to speed up swapoff")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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While debug_dma_assert_idle() checks if a given *page* is actively
undergoing dma the valid granularity of a dma mapping is a *cacheline*.
Sander's testing shows that the warning message "DMA-API: exceeded 7
overlapping mappings of pfn..." is falsely triggering. The test is
simply mapping multiple cachelines in a given page.
Ultimately we want overlap tracking to be valid as it is a real api
violation, so we need to track active mappings by cachelines. Update
the active dma tracking to use the page-frame-relative cacheline of the
mapping as the key, and update debug_dma_assert_idle() to check for all
possible mapped cachelines for a given page.
However, the need to track active mappings is only relevant when the
dma-mapping is writable by the device. In fact it is fairly standard
for read-only mappings to have hundreds or thousands of overlapping
mappings at once. Limiting the overlap tracking to writable
(!DMA_TO_DEVICE) eliminates this class of false-positive overlap
reports.
Note, the radix gang lookup is sub-optimal. It would be best if it
stopped fetching entries once the search passed a page boundary.
Nevertheless, this implementation does not perturb the original net_dma
failing case. That is to say the extra overhead does not show up in
terms of making the failing case pass due to a timing change.
References:
http://marc.info/?l=linux-netdev&m=139232263419315&w=2
http://marc.info/?l=linux-netdev&m=139217088107122&w=2
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Reported-by: Dave Jones <davej@redhat.com>
Tested-by: Dave Jones <davej@redhat.com>
Tested-by: Sander Eikelenboom <linux@eikelenboom.it>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull block IO fixes from Jens Axboe:
"Second round of updates and fixes for 3.14-rc2. Most of this stuff
has been queued up for a while. The notable exception is the blk-mq
changes, which are naturally a bit more in flux still.
The pull request contains:
- Two bug fixes for the new immutable vecs, causing crashes with raid
or swap. From Kent.
- Various blk-mq tweaks and fixes from Christoph. A fix for
integrity bio's from Nic.
- A few bcache fixes from Kent and Darrick Wong.
- xen-blk{front,back} fixes from David Vrabel, Matt Rushton, Nicolas
Swenson, and Roger Pau Monne.
- Fix for a vec miscount with integrity vectors from Martin.
- Minor annotations or fixes from Masanari Iida and Rashika Kheria.
- Tweak to null_blk to do more normal FIFO processing of requests
from Shlomo Pongratz.
- Elevator switching bypass fix from Tejun.
- Softlockup in blkdev_issue_discard() fix when !CONFIG_PREEMPT from
me"
* 'for-linus' of git://git.kernel.dk/linux-block: (31 commits)
block: add cond_resched() to potentially long running ioctl discard loop
xen-blkback: init persistent_purge_work work_struct
blk-mq: pair blk_mq_start_request / blk_mq_requeue_request
blk-mq: dont assume rq->errors is set when returning an error from ->queue_rq
block: Fix cloning of discard/write same bios
block: Fix type mismatch in ssize_t_blk_mq_tag_sysfs_show
blk-mq: rework flush sequencing logic
null_blk: use blk_complete_request and blk_mq_complete_request
virtio_blk: use blk_mq_complete_request
blk-mq: rework I/O completions
fs: Add prototype declaration to appropriate header file include/linux/bio.h
fs: Mark function as static in fs/bio-integrity.c
block/null_blk: Fix completion processing from LIFO to FIFO
block: Explicitly handle discard/write same segments
block: Fix nr_vecs for inline integrity vectors
blk-mq: Add bio_integrity setup to blk_mq_make_request
blk-mq: initialize sg_reserved_size
blk-mq: handle dma_drain_size
blk-mq: divert __blk_put_request for MQ ops
blk-mq: support at_head inserations for blk_execute_rq
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Peter Anvin:
"Quite a varied little collection of fixes. Most of them are
relatively small or isolated; the biggest one is Mel Gorman's fixes
for TLB range flushing.
A couple of AMD-related fixes (including not crashing when given an
invalid microcode image) and fix a crash when compiled with gcov"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, microcode, AMD: Unify valid container checks
x86, hweight: Fix BUG when booting with CONFIG_GCOV_PROFILE_ALL=y
x86/efi: Allow mapping BGRT on x86-32
x86: Fix the initialization of physnode_map
x86, cpu hotplug: Fix stack frame warning in check_irq_vectors_for_cpu_disable()
x86/intel/mid: Fix X86_INTEL_MID dependencies
arch/x86/mm/srat: Skip NUMA_NO_NODE while parsing SLIT
mm, x86: Revisit tlb_flushall_shift tuning for page flushes except on IvyBridge
x86: mm: change tlb_flushall_shift for IvyBridge
x86/mm: Eliminate redundant page table walk during TLB range flushing
x86/mm: Clean up inconsistencies when flushing TLB ranges
mm, x86: Account for TLB flushes only when debugging
x86/AMD/NB: Fix amd_set_subcaches() parameter type
x86/quirks: Add workaround for AMD F16h Erratum792
x86, doc, kconfig: Fix dud URL for Microcode data
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* Avoid WARN_ON() when mapping BGRT on Baytrail (EFI 32-bit).
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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Commit d61931d89b, "x86: Add optimized popcnt variants" introduced
compile flag -fcall-saved-rdi for lib/hweight.c. When combined with
options -fprofile-arcs and -O2, this flag causes gcc to generate
broken constructor code. As a result, a 64 bit x86 kernel compiled
with CONFIG_GCOV_PROFILE_ALL=y prints message "gcov: could not create
file" and runs into sproadic BUGs during boot.
The gcc people indicate that these kinds of problems are endemic when
using ad hoc calling conventions. It is therefore best to treat any
file compiled with ad hoc calling conventions as an isolated
environment and avoid things like profiling or coverage analysis,
since those subsystems assume a "normal" calling conventions.
This patch avoids the bug by excluding lib/hweight.o from coverage
profiling.
Reported-by: Meelis Roos <mroos@linux.ee>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/52F3A30C.7050205@linux.vnet.ibm.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
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It really isn't very interesting to have DEBUG_INFO when doing compile
coverage stuff (you wouldn't want to run the result anyway, that's kind
of the whole point of COMPILE_TEST), and it currently makes the build
take longer and use much more disk space for "all{yes,mod}config".
There's somewhat active discussion about this still, and we might end up
with some new config option for things like this (Andi points out that
the silly X86_DECODER_SELFTEST option also slows down the normal
coverage tests hugely), but I'm starting the ball rolling with this
simple one-liner.
DEBUG_INFO isn't that noticeable if you have tons of memory and a good
IO subsystem, but it hurts you a lot if you don't - for very little
upside for the common use.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The built-in ROM fonts lack many necessary ASCII characters, which is
why it makes sens to prefer the Linux fonts instead if they are
available. This makes consoles on STI graphics cards which are not
supported by the stifb driver (e.g. Visualize FXe) looks much nicer.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13
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git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
"The highlights this round include:
- add support for SCSI Referrals (Hannes)
- add support for T10 DIF into target core (nab + mkp)
- add support for T10 DIF emulation in FILEIO + RAMDISK backends (Sagi + nab)
- add support for T10 DIF -> bio_integrity passthrough in IBLOCK backend (nab)
- prep changes to iser-target for >= v3.15 T10 DIF support (Sagi)
- add support for qla2xxx N_Port ID Virtualization - NPIV (Saurav + Quinn)
- allow percpu_ida_alloc() to receive task state bitmask (Kent)
- fix >= v3.12 iscsi-target session reset hung task regression (nab)
- fix >= v3.13 percpu_ref se_lun->lun_ref_active race (nab)
- fix a long-standing network portal creation race (Andy)"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (51 commits)
target: Fix percpu_ref_put race in transport_lun_remove_cmd
target/iscsi: Fix network portal creation race
target: Report bad sector in sense data for DIF errors
iscsi-target: Convert gfp_t parameter to task state bitmask
iscsi-target: Fix connection reset hang with percpu_ida_alloc
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask
iscsi-target: Pre-allocate more tags to avoid ack starvation
qla2xxx: Configure NPIV fc_vport via tcm_qla2xxx_npiv_make_lport
qla2xxx: Enhancements to enable NPIV support for QLOGIC ISPs with TCM/LIO.
qla2xxx: Fix scsi_host leak on qlt_lport_register callback failure
IB/isert: pass scatterlist instead of cmd to fast_reg_mr routine
IB/isert: Move fastreg descriptor creation to a function
IB/isert: Avoid frwr notation, user fastreg
IB/isert: seperate connection protection domains and dma MRs
tcm_loop: Enable DIF/DIX modes in SCSI host LLD
target/rd: Add DIF protection into rd_execute_rw
target/rd: Add support for protection SGL setup + release
target/rd: Refactor rd_build_device_space + rd_release_device_space
target/file: Add DIF protection support to fd_execute_rw
target/file: Add DIF protection init/format support
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
"This is a pretty big pull, and most of these changes have been
floating in btrfs-next for a long time. Filipe's properties work is a
cool building block for inheriting attributes like compression down on
a per inode basis.
Jeff Mahoney kicked in code to export filesystem info into sysfs.
Otherwise, lots of performance improvements, cleanups and bug fixes.
Looks like there are still a few other small pending incrementals, but
I wanted to get the bulk of this in first"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (149 commits)
Btrfs: fix spin_unlock in check_ref_cleanup
Btrfs: setup inode location during btrfs_init_inode_locked
Btrfs: don't use ram_bytes for uncompressed inline items
Btrfs: fix btrfs_search_slot_for_read backwards iteration
Btrfs: do not export ulist functions
Btrfs: rework ulist with list+rb_tree
Btrfs: fix memory leaks on walking backrefs failure
Btrfs: fix send file hole detection leading to data corruption
Btrfs: add a reschedule point in btrfs_find_all_roots()
Btrfs: make send's file extent item search more efficient
Btrfs: fix to catch all errors when resolving indirect ref
Btrfs: fix protection between walking backrefs and root deletion
btrfs: fix warning while merging two adjacent extents
Btrfs: fix infinite path build loops in incremental send
btrfs: undo sysfs when open_ctree() fails
Btrfs: fix snprintf usage by send's gen_unique_name
btrfs: fix defrag 32-bit integer overflow
btrfs: sysfs: list the NO_HOLES feature
btrfs: sysfs: don't show reserved incompat feature
btrfs: call permission checks earlier in ioctls and return EPERM
...
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steal_tags only happens when free tags is more than half of the total
tags. This is too strict and can cause live lock. I found that if one
cpu has free tags, but other cpu can't steal (thread is bound to
specific cpus), threads which want to allocate tags are always
sleeping. I found this when I run next patch, but this could happen
without it I think.
I did performance test too with null_blk. Two cases (each cpu has enough
percpu tags, or total tags are limited), no performance changes were
observed.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Commit 0abdd7a81b7e ("dma-debug: introduce debug_dma_assert_idle()") was
reworked to expand the overlap counter to the full range expressable by
3 tag bits, but it has a thinko in treating the overlap counter as a
pure reference count for the entry.
Instead of deleting when the reference-count drops to zero, we need to
delete when the overlap-count drops below zero. Also, when detecting
overflow we can just test the overlap-count > MAX rather than applying
special meaning to 0.
Regression report available here:
http://marc.info/?l=linux-netdev&m=139073373932386&w=2
This patch, now tested on the original net_dma case, sees the expected
handful of reports before the eventual data corruption occurs.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
In the gen_pool_dma_alloc() the dma pointer can be NULL and while
assigning gen_pool_virt_to_phys(pool, vaddr) to dma caused the following
crash on da850 evm:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
Internal error: Oops: 805 [#1] PREEMPT ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Tainted: G W 3.13.0-rc1-00001-g0609e45-dirty #5
task: c4830000 ti: c4832000 task.ti: c4832000
PC is at gen_pool_dma_alloc+0x30/0x3c
LR is at gen_pool_virt_to_phys+0x74/0x80
Process swapper, call trace:
gen_pool_dma_alloc+0x30/0x3c
davinci_pm_probe+0x40/0xa8
platform_drv_probe+0x1c/0x4c
driver_probe_device+0x98/0x22c
__driver_attach+0x8c/0x90
bus_for_each_dev+0x6c/0x8c
bus_add_driver+0x124/0x1d4
driver_register+0x78/0xf8
platform_driver_probe+0x20/0xa4
davinci_init_late+0xc/0x14
init_machine_late+0x1c/0x28
do_one_initcall+0x34/0x15c
kernel_init_freeable+0xe4/0x1ac
kernel_init+0x8/0xec
This patch fixes the above.
[akpm@linux-foundation.org: update kerneldoc]
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Nicolin Chen <b42378@freescale.com>
Cc: Joe Perches <joe@perches.com>
Cc: Sachin Kamat <sachin.kamat@linaro.org>
Cc: <stable@vger.kernel.org> [3.13.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
struct kobj_attribute implements the baseline attribute functionality
that can be used all over the place. We should export the ops associated
with it.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>
|
|
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This fixes following scenario:
$ echo 'file dynamic_debug.c line 1-123 +p' > /sys/kernel/debug/dynamic_debug/control
-bash: echo: write error: Invalid argument
$ dmesg | grep dynamic_debug
dynamic_debug:ddebug_parse_query: last-line:123 < 1st-line:1
dynamic_debug:ddebug_parse_query: query parse failed
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
parse_lineno() returns either negative error code or zero. We don't
need to print something here because if parse_lineno fails it will print
error message.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The new memblock_virt APIs are used to replaced old bootmem API.
We need to allocate page below 4G for swiotlb.
That should fix regression on Andrew's system that is using swiotlb.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb bug-fixes from Konrad Rzeszutek Wilk:
- Don't DoS with 'swiotlb is full' message.
- Documentation update.
* tag 'stable/for-linus-3.14-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
swiotlb: Don't DoS us with 'swiotlb buffer is full' (v2)
swiotlb: update format
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394
Pull firewire updates from Stefan Richter:
"IEEE 1394 (FireWire) subsystem changes:
- make remote debugging over 1394 a runtime option instead of a
buildtime option
- extend remote debug access past the 4 GB barrier on respectively
capable hardware
- documentation update"
* tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
firewire: Enable remote DMA above 4 GB
firewire: ohci: Turn remote DMA support into a module parameter
Documentation/: update FireWire debugging documentation
|
|
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
...
|
|
This patch addresses a bug where connection reset would hang
indefinately once percpu_ida_alloc() was starved for tags, due
to the fact that it always assumed uninterruptible sleep mode.
So now make percpu_ida_alloc() check for signal_pending_state() for
making interruptible sleep optional, and convert iscsit_allocate_cmd()
to set TASK_INTERRUPTIBLE for GFP_KERNEL, or TASK_RUNNING for
GFP_ATOMIC.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
|
|
"ret", being set to -1 early on, gets cleared by the first invocation of
lz4_decompress()/lz4_decompress_unknownoutputsize(), and hence subsequent
failures wouldn't be noticed by the caller without setting it back to -1
right after those calls.
Reported-by: Matthew Daley <mattjd@gmail.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Avoid making the rb_node the first entry to catch some bugs around NULL
checking the rb_node.
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
To help avoid an architecture failing to correctly check kernel/user
boundaries when handling copy_to_user, copy_from_user, put_user, or
get_user, perform some simple tests and fail to load if any of them
behave unexpectedly.
Specifically, this is to make sure there is a way to notice if things
like what was fixed in commit 8404663f81d2 ("ARM: 7527/1: uaccess:
explicitly check __user pointer when !CPU_USE_DOMAINS") ever regresses
again, for any architecture.
Additionally, adds new "user" selftest target, which loads this module.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This is a pair of test modules I'd like to see in the tree. Instead of
putting these in lkdtm, where I've been adding various tests that trigger
crashes, these don't make sense there since they need to be either
distinctly separate, or their pass/fail state don't need to crash the
machine.
These live in lib/ for now, along with a few other in-kernel test modules,
and use the slightly more common "test_" naming convention, instead of
"test-". We should likely standardize on the former:
$ find . -name 'test_*.c' | grep -v /tools/ | wc -l
4
$ find . -name 'test-*.c' | grep -v /tools/ | wc -l
2
The first is entirely a no-op module, designed to allow simple testing of
the module loading and verification interface. It's useful to have a
module that has no other uses or dependencies so it can be reliably used
for just testing module loading and verification.
The second is a module that exercises the user memory access functions, in
an effort to make sure that we can quickly catch any regressions in
boundary checking (e.g. like what was recently fixed on ARM).
This patch (of 2):
When doing module loading verification tests (for example, with module
signing, or LSM hooks), it is very handy to have a module that can be
built on all systems under test, isn't auto-loaded at boot, and has no
device or similar dependencies. This creates the "test_module.ko" module
for that purpose, which only reports its load and unload to printk.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
+EXPORT_SYMBOL(memparse);
WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
+EXPORT_SYMBOL(get_option);
WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
+EXPORT_SYMBOL(get_options);
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Levente Kurusa <levex@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
WARNING: space prohibited between function name and open parenthesis '('
+int get_option (char **str, int *pint)
WARNING: space prohibited between function name and open parenthesis '('
+ *pint = simple_strtol (cur, str, 0);
ERROR: trailing whitespace
+ $
WARNING: please, no spaces at the start of a line
+ $
WARNING: space prohibited between function name and open parenthesis '('
+ res = get_option ((char **)&str, ints + i);
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
We can't reach the cleanup code unless the flag KSTRTOX_OVERFLOW is not
set, so there's not no point in clearing a bit that we know is not set.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Acked-by: Levente Kurusa <levex@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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dma_addr_t's can be either u32 or u64 depending on a CONFIG option.
There are a few hundred dma_addr_t's printed via either cast to unsigned
long long, unsigned long or no cast at all.
Add %pad to be able to emit them without the cast.
Update Documentation/printk-formats.txt too.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: "Shevchenko, Andriy" <andriy.shevchenko@intel.com>
Cc: Rob Landley <rob@landley.net>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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Add wildcard '*'(matches zero or more characters) and '?' (matches one
character) support when qurying debug flags.
Now we can open debug messages using keywords. eg:
1. open debug logs in all usb drivers
echo "file drivers/usb/* +p" > <debugfs>/dynamic_debug/control
2. open debug logs for usb xhci code
echo "file *xhci* +p" > <debugfs>/dynamic_debug/control
Signed-off-by: Du, Changbin <changbin.du@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Cc: Du, Changbin <changbin.du@gmail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
match_wildcard function is a simple implementation of wildcard
matching algorithm. It only supports two usual wildcardes:
'*' - matches zero or more characters
'?' - matches one character
This algorithm is safe since it is non-recursive.
Signed-off-by: Du, Changbin <changbin.du@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This patch changes percpu_ida_alloc() + callers to accept task state
bitmask for prepare_to_wait() for code like target/iscsi that needs
it for interruptible sleep, that is provided in a subsequent patch.
It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep
waiting for a new tag, or TASK_RUNNING when the caller cannot sleep,
and is forced to return a negative value when no tags are available.
v2 changes:
- Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes
- Drop signal_pending_state() call
v3 changes:
- Only call prepare_to_wait() + finish_wait() when != TASK_RUNNING
(PeterZ)
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
|
|
The associative array code creates unnecessary and potentially
problematic global variable 'status'. Remove it since never used.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Jakub Zawadzki noticed that some divisions by reciprocal_divide()
were not correct [1][2], which he could also show with BPF code
after divisions are transformed into reciprocal_value() for runtime
invariance which can be passed to reciprocal_divide() later on;
reverse in BPF dump ended up with a different, off-by-one K in
some situations.
This has been fixed by Eric Dumazet in commit aee636c4809fa5
("bpf: do not use reciprocal divide"). This follow-up patch
improves reciprocal_value() and reciprocal_divide() to work in
all cases by using Granlund and Montgomery method, so that also
future use is safe and without any non-obvious side-effects.
Known problems with the old implementation were that division by 1
always returned 0 and some off-by-ones when the dividend and divisor
where very large. This seemed to not be problematic with its
current users, as far as we can tell. Eric Dumazet checked for
the slab usage, we cannot surely say so in the case of flex_array.
Still, in order to fix that, we propose an extension from the
original implementation from commit 6a2d7a955d8d resp. [3][4],
by using the algorithm proposed in "Division by Invariant Integers
Using Multiplication" [5], Torbjörn Granlund and Peter L.
Montgomery, that is, pseudocode for q = n/d where q, n, d is in
u32 universe:
1) Initialization:
int l = ceil(log_2 d)
uword m' = floor((1<<32)*((1<<l)-d)/d)+1
int sh_1 = min(l,1)
int sh_2 = max(l-1,0)
2) For q = n/d, all uword:
uword t = (n*m')>>32
q = (t+((n-t)>>sh_1))>>sh_2
The assembler implementation from Agner Fog [6] also helped a lot
while implementing. We have tested the implementation on x86_64,
ppc64, i686, s390x; on x86_64/haswell we're still half the latency
compared to normal divide.
Joint work with Daniel Borkmann.
[1] http://www.wireshark.org/~darkjames/reciprocal-buggy.c
[2] http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c
[3] https://gmplib.org/~tege/division-paper.pdf
[4] http://homepage.cs.uiowa.edu/~jones/bcd/divide.html
[5] http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1.2556
[6] http://www.agner.org/optimize/asmlib.zip
Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Jesse Gross <jesse@nicira.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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