This patch disables translation(dma-remapping) before its initialization
if it is already enabled.
This is needed for kexec/kdump boot. If dma-remapping is enabled in the
first kernel, it need to be disabled before initializing its page table
during second kernel boot. Wei Hu also reported that this is needed
when second kernel boots with intel_iommu=off.
Basically iommu->gcmd is used to know whether translation is enabled or
disabled, but it is always zero at boot time even when translation is
enabled since iommu->gcmd is initialized without considering such a
case. Therefor this patch synchronizes iommu->gcmd value with global
command register when iommu structure is allocated.
Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
[wyj: Backported to 3.4: adjust context] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit 554086d ("x86_32, entry: Do syscall exit work on badsys
(CVE-2014-4508)") introduced a regression in the x86_32 syscall entry
code, resulting in syscall() not returning proper errors for undefined
syscalls on CPUs supporting the sysenter feature.
The following code:
> int result = syscall(666);
> printf("result=%d errno=%d error=%s\n", result, errno, strerror(errno));
results in:
> result=666 errno=0 error=Success
Obviously, the syscall return value is the called syscall number, but it
should have been an ENOSYS error. When run under ptrace it behaves
correctly, which makes it hard to debug in the wild:
> result=-1 errno=38 error=Function not implemented
The %eax register is the return value register. For debugging via ptrace
the syscall entry code stores the complete register context on the
stack. The badsys handlers only store the ENOSYS error code in the
ptrace register set and do not set %eax like a regular syscall handler
would. The old resume_userspace call chain contains code that clobbers
%eax and it restores %eax from the ptrace registers afterwards. The same
goes for the ptrace-enabled call chain. When ptrace is not used, the
syscall return value is the passed-in syscall number from the untouched
%eax register.
Use %eax as the return value register in syscall_badsys and
sysenter_badsys, like a real syscall handler does, and have the caller
push the value onto the stack for ptrace access.
1871ee134b73 ("libata: support the ata host which implements a queue
depth less than 32") directly used ata_port->scsi_host->can_queue from
ata_qc_new() to determine the number of tags supported by the host;
unfortunately, SAS controllers doing SATA don't initialize ->scsi_host
leading to the following oops.
Fix it by introducing ata_host->n_tags which is initialized to
ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to
scsi_host_template->can_queue in ata_host_register() for !SAS ones.
As SAS hosts are never registered, this will give them the same
ATA_MAX_QUEUE - 1 as before. Note that we can't use
scsi_host->can_queue directly for SAS hosts anyway as they can go
higher than the libata maximum.
Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> Reported-by: Jesse Brandeburg <jesse.brandeburg@gmail.com> Reported-by: Peter Hurley <peter@hurleysoftware.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Fixes: 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32") Cc: Kevin Hao <haokexin@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The sata on fsl mpc8315e is broken after the commit 8a4aeec8d2d6
("libata/ahci: accommodate tag ordered controllers"). The reason is
that the ata controller on this SoC only implement a queue depth of
16. When issuing the commands in tag order, all the commands in tag
16 ~ 31 are mapped to tag 0 unconditionally and then causes the sata
malfunction. It makes no senses to use a 32 queue in software while
the hardware has less queue depth. So consider the queue depth
implemented by the hardware when requesting a command tag.
Fixes: 8a4aeec8d2d6 ("libata/ahci: accommodate tag ordered controllers") Signed-off-by: Kevin Hao <haokexin@gmail.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit 248ac0e1943a ("mm/vmalloc: remove guard page from between vmap
blocks") had the side effect of making vmap_area.va_end member point to
the next vmap_area.va_start. This was creating an artificial reference
to vmalloc'ed objects and kmemleak was rarely reporting vmalloc() leaks.
This patch marks the vmap_area containing pointers explicitly and
reduces the min ref_count to 2 as vm_struct still contains a reference
to the vmalloc'ed object. The kmemleak add_scan_area() function has
been improved to allow a SIZE_MAX argument covering the rest of the
object (for simpler calling sites).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ULONG_MAX is often used to check for integer overflow when calculating
allocation size. While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.
This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.
Signed-off-by: Xi Wang <xi.wang@gmail.com> Acked-by: Alex Elder <elder@dreamhost.com> Cc: David Airlie <airlied@linux.ie> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit 455bd4c430b0 ("ARM: 7668/1: fix memset-related crashes caused by
recent GCC (4.7.2) optimizations") attempted to fix a compliance issue
with the memset return value. However the memset itself became broken
by that patch for misaligned pointers.
This fixes the above by branching over the entry code from the
misaligned fixup code to avoid reloading the original pointer.
Also, because the function entry alignment is wrong in the Thumb mode
compilation, that fixup code is moved to the end.
While at it, the entry instructions are slightly reworked to help dual
issue pipelines.
Signed-off-by: Nicolas Pitre <nico@linaro.org> Tested-by: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.
GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.
This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:
Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).
Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:
Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".
Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Dirk Behme <dirk.behme@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit 4a705fef9862 ("hugetlb: fix copy_hugetlb_page_range() to handle
migration/hwpoisoned entry") changed the order of
huge_ptep_set_wrprotect() and huge_ptep_get(), which leads to breakage
in some workloads like hugepage-backed heap allocation via libhugetlbfs.
This patch fixes it.
Fixes 4a705fef9862 ("hugetlb: fix copy_hugetlb_page_range() to handle
migration/hwpoisoned entry"), so is applicable to -stable kernels which
include it.
The tot_stats estimator is started only when CONFIG_SYSCTL
is defined. But it is stopped without checking CONFIG_SYSCTL.
Fix the crash by moving ip_vs_stop_estimator into
ip_vs_control_net_cleanup_sysctl.
The change is needed after commit 14e405461e664b
("IPVS: Add __ip_vs_control_{init,cleanup}_sysctl()") from 2.6.39.
Reported-by: Jet Chen <jet.chen@intel.com> Tested-by: Jet Chen <jet.chen@intel.com> Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
In __ioremap_caller() (the guts of ioremap), we loop over the range of
pfns being remapped and checks each one individually with page_is_ram().
For large ioremaps, this can be very slow. For example, we have a
device with a 256 GiB PCI BAR, and ioremapping this BAR can take 20+
seconds -- sometimes long enough to trigger the soft lockup detector!
Internally, page_is_ram() calls walk_system_ram_range() on a single
page. Instead, we can make a single call to walk_system_ram_range()
from __ioremap_caller(), and do our further checks only for any RAM
pages that we find. For the common case of MMIO, this saves an enormous
amount of work, since the range being ioremapped doesn't intersect
system RAM at all.
With this change, ioremap on our 256 GiB BAR takes less than 1 second.
This patch fixes I/O errors with the sym53c8xx_2 driver when the disk
returns QUEUE FULL status.
When the controller encounters an error (including QUEUE FULL or BUSY
status), it aborts all not yet submitted requests in the function
sym_dequeue_from_squeue.
This function aborts them with DID_SOFT_ERROR.
If the disk has full tag queue, the request that caused the overflow is
aborted with QUEUE FULL status (and the scsi midlayer properly retries
it until it is accepted by the disk), but the sym53c8xx_2 driver aborts
the following requests with DID_SOFT_ERROR --- for them, the midlayer
does just a few retries and then signals the error up to sd.
The result is that disk returning QUEUE FULL causes request failures.
The error was reproduced on 53c895 with COMPAQ BD03685A24 disk
(rebranded ST336607LC) with command queue 48 or 64 tags. The disk has
64 tags, but under some access patterns it return QUEUE FULL when there
are less than 64 pending tags. The SCSI specification allows returning
QUEUE FULL anytime and it is up to the host to retry.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is not safe to use LAR to filter when to go down the espfix path,
because the LDT is per-process (rather than per-thread) and another
thread might change the descriptors behind our back. Fortunately it
is always *safe* (if a bit slow) to go down the espfix path, and a
32-bit LDT stack segment is extremely rare.
These functions are used in some PCI drivers with big-endian
MMIO space.
Admittedly it is almost certain that no one this side of the
Moon would use such a card in an Alpha but it does get us
closer to being able to build allyesconfig or allmodconfig,
and it enables the Debian default generic config to build.
Tested-by: Raúl Porcel <armin76@gentoo.org> Signed-off-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Ben Hutchings [Sun, 3 Aug 2014 16:45:10 +0000 (17:45 +0100)]
score: Add missing #include <linux/export.h>
There is no upstream commit for this, as arch/score/kernel/init_task.c
has been replaced by generic code and <linux/export.h> is included
indirectly by arch/score/mm/init.c.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Score: The commit is for compiling successfully. The modifications include: 1. Kconfig of Score: we don't support ioremap 2. Missed headfile including 3. There are some errors in other people's commit not checked by us, we fix it now 3.1 arch/score/kernel/entry.S: wrong instructions 3.2 arch/score/kernel/process.c : just some typos
Signed-off-by: Lennox Wu <lennox.wu@gmail.com>
[bwh: Backported to 3.2:
- Drop addition of 'select HAVE_GENERIC_HARDIRQS' which was not removed here
- Drop inapplicale change to copy_thread()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Bugfix for following error messages:
lib/iomap.c: In function 'pci_iomap':
lib/iomap.c:274: error: implicit declaration of function 'ioremap_nocache'
lib/iomap.c:274: warning: return makes pointer from integer without a cast
shmem_fault() is the actual culprit in trinity's hole-punch starvation,
and the most significant cause of such problems: since a page faulted is
one that then appears page_mapped(), needing unmap_mapping_range() and
i_mmap_mutex to be unmapped again.
But it is not the only way in which a page can be brought into a hole in
the radix_tree while that hole is being punched; and Vlastimil's testing
implies that if enough other processors are busy filling in the hole,
then shmem_undo_range() can be kept from completing indefinitely.
shmem_file_splice_read() is the main other user of SGP_CACHE, which can
instantiate shmem pagecache pages in the read-only case (without holding
i_mutex, so perhaps concurrently with a hole-punch). Probably it's
silly not to use SGP_READ already (using the ZERO_PAGE for holes): which
ought to be safe, but might bring surprises - not a change to be rushed.
shmem_read_mapping_page_gfp() is an internal interface used by
drivers/gpu/drm GEM (and next by uprobes): it should be okay. And
shmem_file_read_iter() uses the SGP_DIRTY variant of SGP_CACHE, when
called internally by the kernel (perhaps for a stacking filesystem,
which might rely on holes to be reserved): it's unclear whether it could
be provoked to keep hole-punch busy or not.
We could apply the same umbrella as now used in shmem_fault() to
shmem_file_splice_read() and the others; but it looks ugly, and use over
a range raises questions - should it actually be per page? can these get
starved themselves?
The origin of this part of the problem is my v3.1 commit d0823576bf4b
("mm: pincer in truncate_inode_pages_range"), once it was duplicated
into shmem.c. It seemed like a nice idea at the time, to ensure
(barring RCU lookup fuzziness) that there's an instant when the entire
hole is empty; but the indefinitely repeated scans to ensure that make
it vulnerable.
Revert that "enhancement" to hole-punch from shmem_undo_range(), but
retain the unproblematic rescanning when it's truncating; add a couple
of comments there.
Remove the "indices[0] >= end" test: that is now handled satisfactorily
by the inner loop, and mem_cgroup_uncharge_start()/end() are too light
to be worth avoiding here.
But if we do not always loop indefinitely, we do need to handle the case
of swap swizzled back to page before shmem_free_swap() gets it: add a
retry for that case, as suggested by Konstantin Khlebnikov; and for the
case of page swizzled back to swap, as suggested by Johannes Weiner.
Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lukas Czerner <lczerner@redhat.com> Cc: Dave Jones <davej@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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit f00cdc6df7d7 ("shmem: fix faulting into a hole while it's
punched") was buggy: Sasha sent a lockdep report to remind us that
grabbing i_mutex in the fault path is a no-no (write syscall may already
hold i_mutex while faulting user buffer).
We tried a completely different approach (see following patch) but that
proved inadequate: good enough for a rational workload, but not good
enough against trinity - which forks off so many mappings of the object
that contention on i_mmap_mutex while hole-puncher holds i_mutex builds
into serious starvation when concurrent faults force the puncher to fall
back to single-page unmap_mapping_range() searches of the i_mmap tree.
So return to the original umbrella approach, but keep away from i_mutex
this time. We really don't want to bloat every shmem inode with a new
mutex or completion, just to protect this unlikely case from trinity.
So extend the original with wait_queue_head on stack at the hole-punch
end, and wait_queue item on the stack at the fault end.
This involves further use of i_lock to guard against the races: lockdep
has been happy so far, and I see fs/inode.c:unlock_new_inode() holds
i_lock around wake_up_bit(), which is comparable to what we do here.
i_lock is more convenient, but we could switch to shmem's info->lock.
This issue has been tagged with CVE-2014-4171, which will require commit f00cdc6df7d7 and this and the following patch to be backported: we
suggest to 3.1+, though in fact the trinity forkbomb effect might go
back as far as 2.6.16, when madvise(,,MADV_REMOVE) came in - or might
not, since much has changed, with i_mmap_mutex a spinlock before 3.0.
Anyone running trinity on 3.0 and earlier? I don't think we need care.
Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lukas Czerner <lczerner@redhat.com> Cc: Dave Jones <davej@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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Trinity finds that mmap access to a hole while it's punched from shmem
can prevent the madvise(MADV_REMOVE) or fallocate(FALLOC_FL_PUNCH_HOLE)
from completing, until the reader chooses to stop; with the puncher's
hold on i_mutex locking out all other writers until it can complete.
It appears that the tmpfs fault path is too light in comparison with its
hole-punching path, lacking an i_data_sem to obstruct it; but we don't
want to slow down the common case.
Extend shmem_fallocate()'s existing range notification mechanism, so
shmem_fault() can refrain from faulting pages into the hole while it's
punched, waiting instead on i_mutex (when safe to sleep; or repeatedly
faulting when not).
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Dave Jones <davej@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>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The current cursor is reallocated when retrying the allocation, so
the existing cursor needs to be destroyed in both the restart and
the failure cases.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When we fail to find an matching extent near the requested extent
specification during a left-right distance search in
xfs_alloc_ag_vextent_near, we fail to free the original cursor that
we used to look up the XFS_BTNUM_CNT tree and hence leak it.
Reported-by: Chris J Arges <chris.j.arges@canonical.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The ulog messages leak heap bytes by the means of padding bytes and
incompletely filled string arrays. Fix those by memset(0)'ing the
whole struct before filling it.
Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The PSW mask check of the PTRACE_POKEUSR_AREA command is incorrect.
For the default user_mode=home address space layout the psw_user_bits
variable has the home space address-space-control bits set. But the
PSW_MASK_USER contains PSW_MASK_ASC, the ptrace validity check for the
PSW mask will therefore always fail.
Fixes CVE-2014-3534
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If CONFIG_NO_HZ=n tick_nohz_get_sleep_length() returns NSEC_PER_SEC/HZ.
If CONFIG_NO_HZ=y and the nohz functionality is disabled via the
command line option "nohz=off" or not enabled due to missing hardware
support, then tick_nohz_get_sleep_length() returns 0. That happens
because ts->sleep_length is never set in that case.
Set it to NSEC_PER_SEC/HZ when the NOHZ mode is inactive.
Reported-by: Michal Hocko <mhocko@suse.cz> Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When running RHEL6 userspace on a current upstream kernel, "ip link"
fails to show VF information.
The reason is a kernel<->userspace API change introduced by commit 88c5b5ce5cb57 ("rtnetlink: Call nlmsg_parse() with correct header length"),
after which the kernel does not see iproute2's IFLA_EXT_MASK attribute
in the netlink request.
iproute2 adjusted for the API change in its commit 63338dca4513
("libnetlink: Use ifinfomsg instead of rtgenmsg in rtnl_wilddump_req_filter").
The problem has been noticed before:
http://marc.info/?l=linux-netdev&m=136692296022182&w=2
(Subject: Re: getting VF link info seems to be broken in 3.9-rc8)
We can do better than tell those with old userspace to upgrade. We can
recognize the old iproute2 in the kernel by checking the netlink message
length. Even when including the IFLA_EXT_MASK attribute, its netlink
message is shorter than struct ifinfomsg.
With this patch "ip link" shows VF information in both old and new
iproute2 versions.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
There is a benign buffer overflow in ip_options_compile spotted by
AddressSanitizer[1] :
Its benign because we always can access one extra byte in skb->head
(because header is followed by struct skb_shared_info), and in this case
this byte is not even used.
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
*_result[len] is parsed as *(_result[len]) which is not at all what we
want to touch here.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Fixes: 84a7c0b1db1c ("dns_resolver: assure that dns_query() result is null-terminated") Signed-off-by: David S. Miller <davem@davemloft.net>
dns_query() credulously assumes that keys are null-terminated and
returns a copy of a memory block that is off by one.
Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Nothing cleans up the objects created by
vnet_new(), they are completely leaked.
vnet_exit(), after doing the vio_unregister_driver() to clean
up ports, should call a helper function that iterates over vnet_list
and cleans up those objects. This includes unregister_netdevice()
as well as free_netdev().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> Reviewed-by: Karl Volz <karl.volz@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
While working on some other SCTP code, I noticed that some
structures shared with user space are leaking uninitialized
stack or heap buffer. In particular, struct sctp_sndrcvinfo
has a 2 bytes hole between .sinfo_flags and .sinfo_ppid that
remains unfilled by us in sctp_ulpevent_read_sndrcvinfo() when
putting this into cmsg. But also struct sctp_remote_error
contains a 2 bytes hole that we don't fill but place into a skb
through skb_copy_expand() via sctp_ulpevent_make_remote_error().
Both structures are defined by the IETF in RFC6458:
* Section 5.3.2. SCTP Header Information Structure:
A remote peer may send an Operation Error message to its peer.
This message indicates a variety of error conditions on an
association. The entire ERROR chunk as it appears on the wire
is included in an SCTP_REMOTE_ERROR event. Please refer to the
SCTP specification [RFC4960] and any extensions for a list of
possible error formats. An SCTP error notification has the
following format:
Fix this by setting both to 0 before filling them out. We also
have other structures shared between user and kernel space in
SCTP that contains holes (e.g. struct sctp_paddrthlds), but we
copy that buffer over from user space first and thus don't need
to care about it in that cases.
While at it, we can also remove lengthy comments copied from
the draft, instead, we update the comment with the correct RFC
number where one can look it up.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Setting just skb->sk without taking its reference and setting a
destructor is invalid. However, in the places where this was done, skb
is used in a way not requiring skb->sk setting. So dropping the setting
of skb->sk.
Thanks to Eric Dumazet <eric.dumazet@gmail.com> for correct solution.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79441 Reported-by: Ed Martin <edman007@edman007.com> Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
1) create socket, bind and then setsockopt for add mc group.
mreq.imr_multiaddr.s_addr = inet_addr("255.0.0.37");
mreq.imr_interface.s_addr = inet_addr("192.168.1.2");
setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
2) drop the mc group for this socket.
mreq.imr_multiaddr.s_addr = inet_addr("255.0.0.37");
mreq.imr_interface.s_addr = inet_addr("0.0.0.0");
setsockopt(sockfd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
3) and then drop the socket, I found the mc group was still used by the dev:
netstat -g
Interface RefCnt Group
--------------- ------ ---------------------
eth2 1 255.0.0.37
Normally even though the IP_DROP_MEMBERSHIP return error, the mc group still need
to be released for the netdev when drop the socket, but this process was broken when
route default is NULL, the reason is that:
The ip_mc_leave_group() will choose the in_dev by the imr_interface.s_addr, if input addr
is NULL, the default route dev will be chosen, then the ifindex is got from the dev,
then polling the inet->mc_list and return -ENODEV, but if the default route dev is NULL,
the in_dev and ifIndex is both NULL, when polling the inet->mc_list, the mc group will be
released from the mc_list, but the dev didn't dec the refcnt for this mc group, so
when dropping the socket, the mc_list is NULL and the dev still keep this group.
v1->v2: According Hideaki's suggestion, we should align with IPv6 (RFC3493) and BSDs,
so I add the checking for the in_dev before polling the mc_list, make sure when
we remove the mc group, dec the refcnt to the real dev which was using the mc address.
The problem would never happened again.
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
skb_cow called in vlan_reorder_header does not free the skb when it failed,
and vlan_reorder_header returns NULL to reset original skb when it is called
in vlan_untag, lead to a memory leak.
Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If there is an MSS change (or misbehaving receiver) that causes a SACK
to arrive that covers the end of an skb but is less than one MSS, then
tcp_match_skb_to_sack() was rounding up pkt_len to the full length of
the skb ("Round if necessary..."), then chopping all bytes off the skb
and creating a zero-byte skb in the write queue.
This was visible now because the recently simplified TLP logic in bef1909ee3ed1c ("tcp: fixing TLP's FIN recovery") could find that 0-byte
skb at the end of the write queue, and now that we do not check that
skb's length we could send it as a TLP probe.
Previously we would find the new_len > skb->len check failing, so we
would fall through and set pkt_len = new_len = 4000 and chop off
pkt_len of 4000 from the 4000-byte skb, leaving a 0-byte segment
afterward in the write queue.
With this new commit, we notice that the new new_len >= skb->len check
succeeds, so that we return without trying to fragment.
Fixes: adb92db857ee ("tcp: Make SACK code to split only at mss boundaries") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Ilpo Jarvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When using USB 3.0 pen drive with the [AMD] FCH USB XHCI Controller
[1022:7814], the second hotplugging will experience the USB 3.0 pen
drive is recognized as high-speed device. After bisecting the kernel,
I found the commit number 41e7e056cdc662f704fa9262e5c6e213b4ab45dd
(USB: Allow USB 3.0 ports to be disabled.) causes the bug. After doing
some experiments, the bug can be fixed by avoiding executing the function
hub_usb3_port_disable(). Because the port status with [AMD] FCH USB
XHCI Controlleris [1022:7814] is already in RxDetect
(I tried printing out the port status before setting to Disabled state),
it's reasonable to check the port status before really executing
hub_usb3_port_disable().
Fixes: 41e7e056cdc6 (USB: Allow USB 3.0 ports to be disabled.) Signed-off-by: Gavin Guo <gavin.guo@canonical.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: use hub device as context for dev_dbg(),
as hub ports are not devices in their own right] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
In some cases we fetch the edid in the detect() callback
in order to determine what sort of monitor is connected.
If that happens, don't fetch the edid again in the get_modes()
callback or we will leak the edid.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Temperature limit registers are signed. Limits therefore need
to be clamped to (-128, 127) degrees C and not to (0, 255)
degrees C.
Without this fix, writing a limit of 128 degrees C sets the
actual limit to -128 degrees C.
Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Axel Lin <axel.lin@ingics.com>
[bwh: Backported to 3.2: driver was using SENSORS_LIMIT(), which we can
replace with clamp_val()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The optimistic spin code assumes regular stores and cmpxchg() play nice;
this is found to not be true for at least: parisc, sparc32, tile32,
metag-lock1, arc-!llsc and hexagon.
There is further wreckage, but this in particular seemed easy to
trigger, so blacklist this.
Opt in for known good archs.
Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Jason Low <jason.low2@hp.com> Cc: Waiman Long <waiman.long@hp.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: John David Anglin <dave.anglin@bell.net> Cc: James Hogan <james.hogan@imgtec.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2:
- Adjust context
- Drop arm64 change] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
nr_switches is unsigned long and do_div truncates it to 32 bits, which
means it can test non-zero on e.g. x86-64 and be truncated to zero for
division.
Fix the problem by using div64_ul() instead.
As a side effect calculations of avg_atom for big nr_switches are now correct.
Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1402750809-31991-1-git-send-email-mguzik@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ring_buffer_poll_wait() should always put the poll_table to its wait_queue
even there is immediate data available. Otherwise, the following epoll and
read sequence will eventually hang forever:
1. Put some data to make the trace_pipe ring_buffer read ready first
2. epoll_ctl(efd, EPOLL_CTL_ADD, trace_pipe_fd, ee)
3. epoll_wait()
4. read(trace_pipe_fd) till EAGAIN
5. Add some more data to the trace_pipe ring_buffer
6. epoll_wait() -> this epoll_wait() will block forever
~ During the epoll_ctl(efd, EPOLL_CTL_ADD,...) call in step 2,
ring_buffer_poll_wait() returns immediately without adding poll_table,
which has poll_table->_qproc pointing to ep_poll_callback(), to its
wait_queue.
~ During the epoll_wait() call in step 3 and step 6,
ring_buffer_poll_wait() cannot add ep_poll_callback() to its wait_queue
because the poll_table->_qproc is NULL and it is how epoll works.
~ When there is new data available in step 6, ring_buffer does not know
it has to call ep_poll_callback() because it is not in its wait queue.
Hence, block forever.
Other poll implementation seems to call poll_wait() unconditionally as the very
first thing to do. For example, tcp_poll() in tcp.c.
Link: http://lkml.kernel.org/p/20140610060637.GA14045@devbig242.prn2.facebook.com Fixes: 2a2cc8f7c4d0 "ftrace: allow the event pipe to be polled" Reviewed-by: Chris Mason <clm@fb.com> Signed-off-by: Martin Lau <kafai@fb.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[bwh: Backported to 3.2: the poll implementation looks rather different
but does have a conditional return before and after the poll_wait() call;
delete the return before it.] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The l2tp [get|set]sockopt() code has fallen back to the UDP functions
for socket option levels != SOL_PPPOL2TP since day one, but that has
never actually worked, since the l2tp socket isn't an inet socket.
As David Miller points out:
"If we wanted this to work, it'd have to look up the tunnel and then
use tunnel->sk, but I wonder how useful that would be"
Since this can never have worked so nobody could possibly have depended
on that functionality, just remove the broken code and return -EINVAL.
Reported-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: James Chapman <jchapman@katalix.com> Acked-by: David Miller <davem@davemloft.net> Cc: Phil Turnbull <phil.turnbull@oracle.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If there are error flags in the aux transaction return
-EIO rather than -EBUSY. -EIO restarts the whole transaction
while -EBUSY jus retries. Fixes problematic aux transfers.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[bwh: Backported to 3.2: error code is returned directly here] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
There's a race condition between the atomic_dec_and_test(&io->count)
in dec_count() and the waking of the sync_io() thread. If the thread
is spuriously woken immediately after the decrement it may exit,
making the on stack io struct invalid, yet the dec_count could still
be using it.
Fix this race by using a completion in sync_io() and dec_count().
Reported-by: Minfei Huang <huangminfei@ucloud.cn> Signed-off-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com>
[bwh: Backported to 3.2: use wait_for_completion() as wait_for_completion_io()
is not available] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
To properly re-initialize SR-IOV it is necessary to reset the device
even if it is already down. Not doing this may result in Tx unit hangs.
Signed-off-by: Stefan Assmann <sassmann@kpanic.de> Tested-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Sharvil noticed with the posix timer_settime interface, using the
CLOCK_REALTIME_ALARM or CLOCK_BOOTTIME_ALARM clockid, if the users
tried to specify a relative time timer, it would incorrectly be
treated as absolute regardless of the state of the flags argument.
This patch corrects this, properly checking the absolute/relative flag,
as well as adds further error checking that no invalid flag bits are set.
Reported-by: Sharvil Nanavati <sharvil@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Link: http://lkml.kernel.org/r/1404767171-6902-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
It is customary to clamp limits instead of bailing out with an error
if a configured limit is out of the range supported by the driver.
This simplifies limit configuration, since the user will not typically
know chip and/or driver specific limits.
Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If the number in "user_id=N" or "group_id=N" mount options was larger than
INT_MAX then fuse returned EINVAL.
Fix this to handle all valid uid/gid values.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
[bwh: Backported to 3.2: no user namespace conversion] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Upper limit for write operations to temperature limit registers
was clamped to a fractional value. However, limit registers do
not support fractional values. As a result, upper limits of 127.5
degrees C or higher resulted in a rounded limit of 128 degrees C.
Since limit registers are signed, this was stored as -128 degrees C.
Clamp limits to (-55, +127) degrees C to solve the problem.
Value on writes to auto_temp[12]_min and auto_temp[12]_max were not
clamped at all, but masked. As a result, out-of-range writes resulted
in a more or less arbitrary limit. Clamp those attributes to (0, 127)
degrees C for more predictable results.
Cc: Axel Lin <axel.lin@ingics.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[bwh: Backported to 3.2:
- Adjust context
- Driver was using SENSORS_LIMIT(), which we can replace with clamp_val()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Some machines (eg. Lenovo Z480) ECs are not stable during boot up
and causes battery driver fails to be loaded due to failure of getting
battery information from EC sometimes. After several retries, the
operation will work. This patch is to retry to get battery information 5
times if the first try fails.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=75581 Reported-and-tested-by: naszar <naszar@ya.ru> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: acpi_battery_update() doesn't take a second parameter] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
There is a race condition in ec_transaction_completed().
When ec_transaction_completed() is called in the GPE handler, it could
return true because of (ec->curr == NULL). Then the wake_up() invocation
could complete the next command unexpectedly since there is no lock between
the 2 invocations. With the previous cleanup, the IBF=0 waiter race need
not be handled any more. It's now safe to return a flag from
advance_condition() to indicate the requirement of wakeup, the flag is
returned from a locked context.
The ec_transaction_completed() is now only invoked by the ec_poll() where
the ec->curr is ensured to be different from NULL.
After cleaning up, the EVT_SCI=1 check should be moved out of the wakeup
condition so that an EVT_SCI raised with (ec->curr == NULL) can trigger a
QR_SC command.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
After we've added the first command byte write into advance_transaction(),
the IBF=0 waiter is duplicated with the command completion waiter
implemented in the ec_poll() because:
If IBF=1 blocked the first command byte write invoked in the task
context ec_poll(), it would be kicked off upon IBF=0 interrupt or timed
out and retried again in the task context.
Remove this seperate and duplicate IBF=0 waiter. By doing so we can
reduce the overall number of times to access the EC_SC(R) status
register.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Move the first command byte write into advance_transaction() so that all
EC register accesses that can affect the command processing state machine
can happen in this asynchronous state machine advancement function.
The advance_transaction() function then can be a complete implementation
of an asyncrhonous transaction for a single command so that:
1. The first command byte can be written in the interrupt context;
2. The command completion waiter can also be used to wait the first command
byte's timeout;
3. In BURST mode, the follow-up command bytes can be written in the
interrupt context directly, so that it doesn't need to return to the
task context. Returning to the task context reduces the throughput of
the BURST mode and in the worst cases where the system workload is very
high, this leads to the hardware driven automatic BURST mode exit.
In order not to increase memory consumption, convert 'done' into 'flags'
to contain multiple indications:
1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition,
indicating the completion of the command transaction.
2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first
command byte. A new command can utilize this flag to compete for the
right of accessing the underlying hardware. There is a follow-up bug
fix that has utilized this new flag.
The 2 flags are important because it also reflects a key concept of IO
programs' design used in the system softwares. Normally an IO program
running in the kernel should first be implemented in the asynchronous way.
And the 2 flags are the most common way to implement its synchronous
operations on top of the asynchronous operations:
1. POLL: This flag can be used to block until the asynchronous operations
can happen.
2. COMPLETE: This flag can be used to block until the asynchronous
operations have completed.
By constructing code cleanly in this way, many difficult problems can be
solved smoothly.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2:
- Adjust context
- s/ec->lock/ec->curr_lock/] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Currently when advance_transaction() is called in EC interrupt handler,
if there is nothing driver can do with the interrupt, it will be taken
as a false one.
But this is not always true, as there may be a SCI EC interrupt fired
during normal read/write operation, which should not be counted as a
false one. This patch fixes the problem.
Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The advance_transaction() will be invoked from the IRQ context GPE handler
and the task context ec_poll(). The handling of this function is locked so
that the EC state machine are ensured to be advanced sequentially.
But there is a problem. Before invoking advance_transaction(), EC_SC(R) is
read. Then for advance_transaction(), there could be race condition around
the lock from both contexts. The first one reading the register could fail
this race and when it passes the stale register value to the state machine
advancement code, the hardware condition is totally different from when
the register is read. And the hardware accesses determined from the wrong
hardware status can break the EC state machine. And there could be cases
that the functionalities of the platform firmware are seriously affected.
For example:
1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may
be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the
hardware will either refuse to respond a next EC_SC(W) write of the next
command or discard the current WR_EC command when it receives a EC_SC(W)
write of the next command.
2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the
EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write.
The next EC_DATA(R) could never be responded by the hardware. This is
the root cause of the reported issue.
Fix this issue by moving the EC_SC(R) access into the lock so that we can
ensure that the state machine is advanced consistently.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk> Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org> Reported-by: Barton Xu <tank.xuhan@gmail.com> Tested-by: Steffen Weber <steffen.weber@gmail.com> Tested-by: Arthur Chen <axchen@nvidia.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2:
- Adjust context
- Use PREFIX in log message] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
A bug was introduced by commit b76b51ba0cef ('ACPI / EC: Add more debug
info and trivial code cleanup') that erroneously caused the struct member
to be accessed before acquiring the required lock. This change fixes
it by ensuring the lock acquisition is done first.
Found by Aaron Durbin <adurbin@chromium.org>
Fixes: b76b51ba0cef ('ACPI / EC: Add more debug info and trivial code cleanup')
References: http://crbug.com/319019 Signed-off-by: Puneet Kumar <puneetster@chromium.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org>
[olof: Commit message reworded a bit] Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Add more debug info for EC transaction debugging, like the interrupt
status register value, the detail info of a EC transaction.
Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Corsair USB Dongles are shipped with Corsair AXi series PSUs.
These are cp210x serial usb devices, so make driver detect these.
I have a program, that can get information from these PSUs.
Tested with 2 different dongles shipped with Corsair AX860i and
AX1200i units.
Signed-off-by: Andras Kovacs <andras@sth.sze.hu> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Writing to fanX_div does not clear the cache. As a result, reading
from fanX_div may return the old value for up to two seconds
after writing a new value.
This patch ensures the fan_div cache is updated in set_fan_div().
Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit "drm/vmwgfx: correct fb_fix_screeninfo.line_length", while fixing a
vmwgfx fbdev bug, also writes the pitch to a supposedly read-only register:
SVGA_REG_BYTES_PER_LINE, while it should be (and also in fact is) written to
SVGA_REG_PITCHLOCK.
This patch is Cc'd stable because of the unknown effects writing to this
register might have, particularly on older device versions.
v2: Updated log message.
Cc: Christopher Friedt <chrisfriedt@gmail.com> Tested-by: Christopher Friedt <chrisfriedt@gmail.com> Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Reviewed-by: Jakob Bornecrantz <jakob@vmware.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
We should always prefer to use full RTS protection. Using
CTS to self gives a meaningless improvement, but this flow
is much harder for the firmware which is likely to have
issues with it.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[bwh: Backported to 3.2:
- Adjust filename
- Condition for RXON_FLG_SELF_CTS_EN in iwlagn_commit_rxon() was different] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Calling xen_console_resume() in xen_suspend() causes a warning because
it locks irq_mapping_update_lock (a mutex) and this may sleep. If a
userspace process is using the evtchn device then this mutex may be
locked at the point of the stop_machine() call and
xen_console_resume() would then deadlock.
Resuming the console after stop_machine() returns avoids this
deadlock.
Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When we write to a degraded array which has a bitmap, we
make sure the relevant bit in the bitmap remains set when
the write completes (so a 're-add' can quickly rebuilt a
temporarily-missing device).
If, immediately after such a write starts, we incorporate a spare,
commence recovery, and skip over the region where the write is
happening (because the 'needs recovery' flag isn't set yet),
then that write will not get to the new device.
Once the recovery finishes the new device will be trusted, but will
have incorrect data, leading to possible corruption.
We cannot set the 'needs recovery' flag when we start the write as we
do not know easily if the write will be "degraded" or not. That
depends on details of the particular raid level and particular write
request.
This patch fixes a corruption issue of long standing and so it
suitable for any -stable kernel. It applied correctly to 3.0 at
least and will minor editing to earlier kernels.
Reported-by: Bill <billstuff2001@sbcglobal.net> Tested-by: Bill <billstuff2001@sbcglobal.net> Link: http://lkml.kernel.org/r/53A518BB.60709@sbcglobal.net Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Currently, any NMI is falsely handled by a NMI handler of NMI watchdog
if CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR is set.
For example, we use external NMI to make system panic to get crash
dump, but in this case, the external NMI is falsely handled do to the
issue.
This commit deals with the issue simply by ignoring CondChgd bit.
Here is explanation in detail.
On x86 NMI watchdog uses performance monitoring feature to
periodically signal NMI each time performance counter gets overflowed.
intel_pmu_handle_irq() is called as a NMI_LOCAL handler from a NMI
handler of NMI watchdog, perf_event_nmi_handler(). It identifies an
owner of a given NMI by looking at overflow status bits in
MSR_CORE_PERF_GLOBAL_STATUS MSR. If some of the bits are set, then it
handles the given NMI as its own NMI.
The problem is that the intel_pmu_handle_irq() doesn't distinguish
CondChgd bit from other bits. Unlike the other status bits, CondChgd
bit doesn't represent overflow status for performance counters. Thus,
CondChgd bit cannot be thought of as a mark indicating a given NMI is
NMI watchdog's.
As a result, if CondChgd bit is set, any NMI is falsely handled by the
NMI handler of NMI watchdog. Also, if type of the falsely handled NMI
is either NMI_UNKNOWN, NMI_SERR or NMI_IO_CHECK, the corresponding
action is never performed until CondChgd bit is cleared.
I noticed this behavior on systems with Ivy Bridge processors: Intel
Xeon CPU E5-2630 v2 and Intel Xeon CPU E7-8890 v2. On both systems,
CondChgd bit in MSR_CORE_PERF_GLOBAL_STATUS MSR has already been set
in the beginning at boot. Then the CondChgd bit is immediately cleared
by next wrmsr to MSR_CORE_PERF_GLOBAL_CTRL MSR and appears to remain
0.
On the other hand, on older processors such as Nehalem, Xeon E7540,
CondChgd bit is not set in the beginning at boot.
I'm not sure about exact behavior of CondChgd bit, in particular when
this bit is set. Although I read Intel System Programmer's Manual to
figure out that, the descriptions I found are:
In 18.9.1:
"The MSR_PERF_GLOBAL_STATUS MSR also provides a ¡sticky bit¢ to
indicate changes to the state of performancmonitoring hardware"
In Table 35-2 IA-32 Architectural MSRs
63 CondChg: status bits of this register has changed.
These are different from the bahviour I see on the actual system as I
explained above.
At least, I think ignoring CondChgd bit should be enough for NMI
watchdog perspective.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20140625.103503.409316067.d.hatayama@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs. This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Michael Büsch <m@bues.ch> Tested-by: Michael Büsch <m@bues.ch> Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2:
- Adjust context
- Use sd_printk() not sd_first_printk()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
It appears that no one ever run ffs-test on a big-endian machine,
since it used cpu-endianess for fs_count and hs_count fields which
should be in little-endian format. Fix by wrapping the numbers in
cpu_to_le32.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
An NFS operation that creates a new symlink includes the symlink data,
which is xdr-encoded as a length followed by the data plus 0 to 3 bytes
of zero-padding as required to reach a 4-byte boundary.
The vfs, on the other hand, wants null-terminated data.
The simple way to handle this would be by copying the data into a newly
allocated buffer with space for the final null.
The current nfsd_symlink code tries to be more clever by skipping that
step in the (likely) case where the byte following the string is already
0.
But that assumes that the byte following the string is ours to look at.
In fact, it might be the first byte of a page that we can't read, or of
some object that another task might modify.
Worse, the NFSv4 code tries to fix the problem by actually writing to
that byte.
In the NFSv2/v3 cases this actually appears to be safe:
- nfs3svc_decode_symlinkargs explicitly null-terminates the data
(after first checking its length and copying it to a new
page).
- NFSv2 limits symlinks to 1k. The buffer holding the rpc
request is always at least a page, and the link data (and
previous fields) have maximum lengths that prevent the request
from reaching the end of a page.
In the NFSv4 case the CREATE op is potentially just one part of a long
compound so can end up on the end of a page if you're unlucky.
The minimal fix here is to copy and null-terminate in the NFSv4 case.
The nfsd_symlink() interface here seems too fragile, though. It should
really either do the copy itself every time or just require a
null-terminated string.
Reported-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
It is observed that sometimes Tx packet is downloaded without
adding driver's txpd header. This results in firmware parsing
garbage data as packet length. Sometimes firmware is unable
to read the packet if length comes out as invalid. This stops
further traffic and timeout occurs.
The root cause is uninitialized fields in tx_info(skb->cb) of
packet used to get garbage values. In this case if
MWIFIEX_BUF_FLAG_REQUEUED_PKT flag is mistakenly set, txpd
header was skipped. This patch makes sure that tx_info is
correctly initialized to fix the problem.
Reported-by: Andrew Wiley <wiley.andrew.j@gmail.com> Reported-by: Linus Gasser <list@markas-al-nour.org> Reported-by: Michael Hirsch <hirsch@teufel.de> Tested-by: Xinming Hu <huxm@marvell.com> Signed-off-by: Amitkumar Karwar <akarwar@marvell.com> Signed-off-by: Maithili Hinge <maithili@marvell.com> Signed-off-by: Avinash Patil <patila@marvell.com> Signed-off-by: Bing Zhao <bzhao@marvell.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The cause is that cpuset_mems_allowed() try to take
mutex_lock(&callback_mutex) under the rcu_read_lock(which was hold in
__mpol_dup()). And in cpuset_mems_allowed(), the access to cpuset is
under rcu_read_lock, so in __mpol_dup, we can reduce the rcu_read_lock
protection region to protect the access to cpuset only in
current_cpuset_is_being_rebound(). So that we can avoid this bug.
This patch is a temporary solution that just addresses the bug
mentioned above, can not fix the long-standing issue about cpuset.mems
rebinding on fork():
"When the forker's task_struct is duplicated (which includes
->mems_allowed) and it races with an update to cpuset_being_rebound
in update_tasks_nodemask() then the task's mems_allowed doesn't get
updated. And the child task's mems_allowed can be wrong if the
cpuset's nodemask changes before the child has been added to the
cgroup's tasklist."
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Acked-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Add a memory barrier prior to sending a new command to the VIOS
to ensure the VIOS does not receive stale data in the command buffer.
Also add a memory barrier when processing the CRQ for completed commands.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Acked-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
[bwh: Backported to 3.2: as the iSeries code is still present, these
functions have different names and live in rpa_vscsi.c.] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If a CRQ reset is triggered for some reason while in the middle
of performing VSCSI adapter initialization, we don't want to
call the done function for the initialization MAD commands as
this will only result in two threads attempting initialization
at the same time, resulting in failures.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Acked-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The system suspend flow as following:
1, Freeze all user processes and kenrel threads.
2, Try to suspend all devices.
2.1, If pci device is in RPM suspended state, then pci driver will try
to resume it to RPM active state in the prepare stage.
2.2, xhci_resume function calls usb_hcd_resume_root_hub to queue two
workqueue items to resume usb2&usb3 roothub devices.
2.3, Call suspend callbacks of devices.
2.3.1, All suspend callbacks of all hcd's children, including
roothub devices are called.
2.3.2, Finally, hcd_pci_suspend callback is called.
Due to workqueue threads were already frozen in step 1, the workqueue
items can't be scheduled, and the roothub devices can't be resumed in
this flow. The HCD_FLAG_WAKEUP_PENDING flag which is set in
usb_hcd_resume_root_hub won't be cleared. Finally,
hcd_pci_suspend will return -EBUSY, and system suspend fails.
The reason why this issue doesn't show up very often is due to that
choose_wakeup will be called in step 2.3.1. In step 2.3.1, if
udev->do_remote_wakeup is not equal to device_may_wakeup(&udev->dev), then
udev will resume to RPM active for changing the wakeup settings. This
has been a lucky hit which hides this issue.
For some special xHCI controllers which have no USB2 port, then roothub
will not match hub driver due to probe failed. Then its
do_remote_wakeup will be set to zero, and we won't be as lucky.
xhci driver doesn't need to resume roothub devices everytime like in
the above case. It's only needed when there are pending event TRBs.
This patch should be back-ported to kernels as old as 3.2, that
contains the commit f69e3120df82391a0ee8118e0a156239a06b2afb
"USB: XHCI: resume root hubs when the controller resumes"
Signed-off-by: Wang, Yu <yu.y.wang@intel.com> Acked-by: Alan Stern <stern@rowland.harvard.edu>
[use readl() instead of removed xhci_readl(), reword commit message -Mathias] Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When xHCI PCI host is suspended, if do_wakeup is false in xhci_pci_suspend,
xhci_bus_suspend needs to clear all root port wake on bits. Otherwise some Intel
platforms may get a spurious wakeup, even if PCI PME# is disabled.
This patch should be back-ported to kernels as old as 2.6.37, that
contains the commit 9777e3ce907d4cb5a513902a87ecd03b52499569
"USB: xHCI: bus power management implementation".
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The transfer burst count (TBC) field in xhci 1.0 hosts should be set
to the number of bursts needed to transfer all packets in a isoc TD.
Supported values are 0-2 (1 to 3 bursts per service interval).
Formula for TBC calculation is given in xhci spec section 4.11.2.3:
TBC = roundup( Transfer Descriptor Packet Count / Max Burst Size +1 ) - 1
This patch should be applied to stable kernels since 3.0 that contain
the commit 5cd43e33b9519143f06f507dd7cbee6b7a621885
"xhci 1.0: Set transfer burst count field."
Suggested-by: ShiChun Ma <masc2008@qq.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reported-by: Mike Remski <mremski@mutualink.net> Tested-by: Mike Remski <mremski@mutualink.net> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If the descriptors do not need any strings and user space sends empty
set of strings, the ffs->stringtabs field remains NULL. Thus
*ffs->stringtabs in functionfs_bind leads to a NULL pointer
dereferenece.
The bug was introduced by commit [fd7c9a007f: “use usb_string_ids_n()”].
While at it, remove double initialisation of lang local variable in
that function.
ffs->strings_count does not need to be checked in any way since in
the above scenario it will remain zero and usb_string_ids_n() is
a no-operation when colled with 0 argument.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Recent Intel CPUs have 10 variable range MTRRs. Since operating systems
sometime make assumptions on CPUs while they ignore capability MSRs, it is
better for KVM to be consistent with recent CPUs. Reporting more MTRRs than
actually supported has no functional implications.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fix a parser-bug in the omap2 muxing code where muxtable-entries will be
wrongly selected if the requested muxname is a *prefix* of their
m0-entry and they have a matching mN-entry. Fix by additionally checking
that the length of the m0_entry is equal.
For example muxing of "dss_data2.dss_data2" on omap32xx will fail
because the prefix "dss_data2" will match the mux-entries "dss_data2" as
well as "dss_data20", with the suffix "dss_data2" matching m0 (for
dss_data2) and m4 (for dss_data20). Thus both are recognized as signal
path candidates:
This will result in a failure to mux the pin at all:
_omap_mux_get_by_name: Multiple signal paths (2) for dss_data2.dss_data2
Patch should apply to linus' latest master down to rather old linux-2.6
trees.
Signed-off-by: David R. Piegdon <lkml@p23q.org>
[tony@atomide.com: updated description to include full description] Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Ben Hutchings [Sat, 12 Jul 2014 20:00:54 +0000 (21:00 +0100)]
Revert "net: ip, ipv6: handle gso skbs in forwarding path"
This reverts commit caa5344994778a2b4725b2d75c74430f76925e4a, which
was commit fe6cc55f3a9a053482a76f5a6b2257cee51b4663 upstream. In 3.2,
the transport header length is not calculated in the forwarding path,
so skb_gso_network_seglen() returns an incorrect result. We also have
problems due to the local_df flag not being set correctly.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This reverts commit 59d9f389df3cdf72833d5ee17c3fe959b6bdc792, which
was commit ca6c5d4ad216d5942ae544bbf02503041bd802aa upstream. It is a
valid fix, but depends on sk_buff::local_df being set in all the right
cases, which it wasn't in 3.2. We need to defer it unless and until
the other fixes are also backported to 3.2.y.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
skb_segment copies frags around, so we need
to copy them carefully to avoid accessing
user memory after reporting completion to userspace
through a callback.
skb_segment doesn't normally happen on datapath:
TSO needs to be disabled - so disabling zero copy
in this case does not look like a big deal.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2. As skb_segment() only supports page-frags *or* a
frag list, there is no need for the additional frag_skb pointer or the
preparatory renaming.] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Export skb_copy_ubufs so that modules can orphan frags.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Many places do
if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY))
skb_copy_ubufs(skb, gfp_mask);
to copy and invoke frag destructors if necessary.
Add an inline helper for this.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The 'sysret' fastpath does not correctly restore even all regular
registers, much less any segment registers or reflags values. That is
very much part of why it's faster than 'iret'.
Normally that isn't a problem, because the normal ptrace() interface
catches the process using the signal handler infrastructure, which
always returns with an iret.
However, some paths can get caught using ptrace_event() instead of the
signal path, and for those we need to make sure that we aren't going to
return to user space using 'sysret'. Otherwise the modifications that
may have been done to the register set by the tracer wouldn't
necessarily take effect.
Fix it by forcing IRET path by setting TIF_NOTIFY_RESUME from
arch_ptrace_stop_needed() which is invoked from ptrace_stop().