Reviewing Tobin's patches for getting pointers out early before
entropy has been established, I noticed that there's a lone smp_mb() in
the code. As with most lone memory barriers, this one appears to be
incorrectly used.
We currently basically have this:
get_random_bytes(&ptr_key, sizeof(ptr_key));
/*
* have_filled_random_ptr_key==true is dependent on get_random_bytes().
* ptr_to_id() needs to see have_filled_random_ptr_key==true
* after get_random_bytes() returns.
*/
smp_mb();
WRITE_ONCE(have_filled_random_ptr_key, true);
And later we have:
if (unlikely(!have_filled_random_ptr_key))
return string(buf, end, "(ptrval)", spec);
/* Missing memory barrier here. */
hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
As the CPU can perform speculative loads, we could have a situation
with the following:
CPU0 CPU1
---- ----
load ptr_key = 0
store ptr_key = random
smp_mb()
store have_filled_random_ptr_key
load have_filled_random_ptr_key = true
BAD BAD BAD! (you're so bad!)
Because nothing prevents CPU1 from loading ptr_key before loading
have_filled_random_ptr_key.
But this race is very unlikely, but we can't keep an incorrect smp_mb() in
place. Instead, replace the have_filled_random_ptr_key with a static_branch
not_filled_random_ptr_key, that is initialized to true and changed to false
when we get enough entropy. If the update happens in early boot, the
static_key is updated immediately, otherwise it will have to wait till
entropy is filled and this happens in an interrupt handler which can't
enable a static_key, as that requires a preemptible context. In that case, a
work_queue is used to enable it, as entropy already took too long to
establish in the first place waiting a little more shouldn't hurt anything.
The benefit of using the static key is that the unlikely branch in
vsprintf() now becomes a nop.
Link: http://lkml.kernel.org/r/20180515100558.21df515e@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: ad67b74d2469d ("printk: hash addresses printed with %p")
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Use the updated memcpy_mcsafe() implementation to define
copy_user_mcsafe() and copy_to_iter_mcsafe(). The most significant
difference from typical copy_to_iter() is that the ITER_KVEC and
ITER_BVEC iterator types can fail to complete a full transfer.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: hch@lst.de
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/152539239150.31796.9189779163576449784.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If we have multiple callers of sbq_wake_up(), we can end up in a
situation where the wait_cnt will continually go more and more
negative. Consider the case where our wake batch is 1, hence
wait_cnt will start out as 1.
wait_cnt == 1
CPU0 CPU1
atomic_dec_return(), cnt == 0
atomic_dec_return(), cnt == -1
cmpxchg(-1, 0) (succeeds)
[wait_cnt now 0]
cmpxchg(0, 1) (fails)
This ends up with wait_cnt being 0, we'll wakeup immediately
next time. Going through the same loop as above again, and
we'll have wait_cnt -1.
For the case where we have a larger wake batch, the only
difference is that the starting point will be higher. We'll
still end up with continually smaller batch wakeups, which
defeats the purpose of the rolling wakeups.
Always reset the wait_cnt to the batch value. Then it doesn't
matter who wins the race. But ensure that whomever does win
the race is the one that increments the ws index and wakes up
our batch count, loser gets to call __sbq_wake_up() again to
account his wakeups towards the next active wait state index.
Fixes: 6c0ca7ae292a ("sbitmap: fix wakeup hang after sbq resize")
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
- just one little fix from Jean to avoid a harmless but very annoying
warning, especially for the drm code
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Merge tag 'dma-mapping-4.17-5' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fix from Christoph Hellwig:
"Just one little fix from Jean to avoid a harmless but very annoying
warning, especially for the drm code"
* tag 'dma-mapping-4.17-5' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: silent unwanted warning "buffer is full"
If DMA_ATTR_NO_WARN is passed to swiotlb_alloc_buffer(), it should be
passed further down to swiotlb_tbl_map_single(). Otherwise we escape
half of the warnings but still log the other half.
This is one of the multiple causes of spurious warnings reported at:
https://bugs.freedesktop.org/show_bug.cgi?id=104082
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 0176adb00406 ("swiotlb: refactor coherent buffer allocation")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christian König <christian.koenig@amd.com>
Cc: Michel Dänzer <michel@daenzer.net>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: stable@vger.kernel.org # v4.16
test_find_first_bit() is intentionally sub-optimal, and may cause soft
lockup due to long time of run on some systems. So decrease length of
bitmap to traverse to avoid lockup.
With the change below, time of test execution doesn't exceed 0.2 seconds
on my testing system.
Link: http://lkml.kernel.org/r/20180420171949.15710-1-ynorov@caviumnetworks.com
Fixes: 4441fca0a27f5 ("lib: test module for find_*_bit() functions")
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make sure the user passed the right value to
sbitmap_queue_min_shallow_depth().
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The sbitmap queue wake batch is calculated such that once allocations
start blocking, all of the bits which are already allocated must be
enough to fulfill the batch counters of all of the waitqueues. However,
the shallow allocation depth can break this invariant, since we block
before our full depth is being utilized. Add
sbitmap_queue_min_shallow_depth(), which saves the minimum shallow depth
the sbq will use, and update sbq_calc_wake_batch() to take it into
account.
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
swiotlb use physical address of bounce buffer when do map and unmap,
therefore, related comment should be updated.
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This way we have one central definition of it, and user can select it as
needed. The new option is not user visible, which is the behavior
it had in most architectures, with a few notable exceptions:
- On x86_64 and mips/loongson3 it used to be user selectable, but
defaulted to y. It now is unconditional, which seems like the right
thing for 64-bit architectures without guaranteed availablity of
IOMMUs.
- on powerpc the symbol is user selectable and defaults to n, but
many boards select it. This change assumes no working setup
required a manual selection, but if that turned out to be wrong
we'll have to add another select statement or two for the respective
boards.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Define this symbol if the architecture either uses 64-bit pointers or the
PHYS_ADDR_T_64BIT is set. This covers 95% of the old arch magic. We only
need an additional select for Xen on ARM (why anyway?), and we now always
set ARCH_DMA_ADDR_T_64BIT on mips boards with 64-bit physical addressing
instead of only doing it when highmem is set.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: James Hogan <jhogan@kernel.org>
This way we have one central definition of it, and user can select it as
needed. Note that we now also always select it when CONFIG_DMA_API_DEBUG
is select, which fixes some incorrect checks in a few network drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
This way we have one central definition of it, and user can select it as
needed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
This way we have one central definition of it, and user can select it as
needed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
This avoids selecting IOMMU_HELPER just for this function. And we only
use it once or twice in normal builds so this often even is a size
reduction.
Signed-off-by: Christoph Hellwig <hch@lst.de>
This function is only used by built-in code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
This code is only used by sparc, and all new iommu drivers should use the
drivers/iommu/ framework. Also remove the unused exports.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
There is no arch specific code required for dma-debug, so there is no
need to opt into the support either.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Only used by the AMD GART and Intel VT-D drivers, which must be built in.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Just keep a single variable with a descriptive name instead of two
with confusing names.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Most mainstream architectures are using 65536 entries, so lets stick to
that. If someone is really desperate to override it that can still be
done through <asm/dma-mapping.h>, but I'd rather see a really good
rationale for that.
dma_debug_init is now called as a core_initcall, which for many
architectures means much earlier, and provides dma-debug functionality
earlier in the boot process. This should be safe as it only relies
on the memory allocator already being available.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Minor conflict, a CHECK was placed into an if() statement
in net-next, whilst a newline was added to that CHECK
call in 'net'. Thanks to Daniel for the merge resolution.
Signed-off-by: David S. Miller <davem@davemloft.net>
This was used by the ide, scsi and networking code in the past to
determine if they should bounce payloads. Now that the dma mapping
always have to support dma to all physical memory (thanks to swiotlb
for non-iommu systems) there is no need to this crude hack any more.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Palmer Dabbelt <palmer@sifive.com> (for riscv)
Reviewed-by: Jens Axboe <axboe@kernel.dk>
As the recent swiotlb bug revealed, we seem to have given up the direct
DMA allocation too early and felt back to swiotlb allocation. The reason
is that swiotlb allocator expected that dma_direct_alloc() would try
harder to get pages even below 64bit DMA mask with GFP_DMA32, but the
function doesn't do that but only deals with GFP_DMA case.
This patch adds a similar fallback reallocation with GFP_DMA32 as we've
done with GFP_DMA. The condition is that the coherent mask is smaller
than 64bit (i.e. some address limitation), and neither GFP_DMA nor
GFP_DMA32 is set beforehand.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Smatch complains here:
lib/swiotlb.c:730 swiotlb_alloc_buffer()
warn: variable dereferenced before check 'dev' (see line 716)
"dev" isn't ever NULL in this function so we can just remove the check.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Remove all eBPF tests involving LD_ABS/LD_IND from test_bpf.ko. Reason
is that the eBPF tests from test_bpf module do not go via BPF verifier
and therefore any instruction rewrites from verifier cannot take place.
Therefore, move them into test_verifier which runs out of user space,
so that verfier can rewrite LD_ABS/LD_IND internally in upcoming patches.
It will have the same effect since runtime tests are also performed from
there. This also allows to finally unexport bpf_skb_vlan_{push,pop}_proto
and keep it internal to core kernel.
Additionally, also add further cBPF LD_ABS/LD_IND test coverage into
test_bpf.ko suite.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Make n signed to avoid leaking the pages array if __pipe_get_pages()
fails to allocate any pages.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It returns -EFAULT and happens to be a helper for pipe_get_pages()
whose return type is ssize_t.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The result was printing the warning only when we were explicitly asked
not to.
Cc: stable@vger.kernel.org
Fixes: 0176adb004065d6815a8e67946752df4cd947c5b "swiotlb: refactor
coherent buffer allocation"
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
commit 07e98962fa77 ("kobject: Send hotplug events in all network namespaces")
enabled sending hotplug events into all network namespaces back in 2010.
Over time the set of uevents that get sent into all network namespaces has
shrunk. We have now reached the point where hotplug events for all devices
that carry a namespace tag are filtered according to that namespace.
Specifically, they are filtered whenever the namespace tag of the kobject
does not match the namespace tag of the netlink socket.
Currently, only network devices carry namespace tags (i.e. network
namespace tags). Hence, uevents for network devices only show up in the
network namespace such devices are created in or moved to.
However, any uevent for a kobject that does not have a namespace tag
associated with it will not be filtered and we will broadcast it into all
network namespaces. This behavior stopped making sense when user namespaces
were introduced.
This patch simplifies and fixes couple of things:
- Split codepath for sending uevents by kobject namespace tags:
1. Untagged kobjects - uevent_net_broadcast_untagged():
Untagged kobjects will be broadcast into all uevent sockets recorded
in uevent_sock_list, i.e. into all network namespacs owned by the
intial user namespace.
2. Tagged kobjects - uevent_net_broadcast_tagged():
Tagged kobjects will only be broadcast into the network namespace they
were tagged with.
Handling of tagged kobjects in 2. does not cause any semantic changes.
This is just splitting out the filtering logic that was handled by
kobj_bcast_filter() before.
Handling of untagged kobjects in 1. will cause a semantic change. The
reasons why this is needed and ok have been discussed in [1]. Here is a
short summary:
- Userspace ignores uevents from network namespaces that are not owned by
the intial user namespace:
Uevents are filtered by userspace in a user namespace because the
received uid != 0. Instead the uid associated with the event will be
65534 == "nobody" because the global root uid is not mapped.
This means we can safely and without introducing regressions modify the
kernel to not send uevents into all network namespaces whose owning
user namespace is not the initial user namespace because we know that
userspace will ignore the message because of the uid anyway.
I have a) verified that is is true for every udev implementation out
there b) that this behavior has been present in all udev
implementations from the very beginning.
- Thundering herd:
Broadcasting uevents into all network namespaces introduces significant
overhead.
All processes that listen to uevents running in non-initial user
namespaces will end up responding to uevents that will be meaningless
to them. Mainly, because non-initial user namespaces cannot easily
manage devices unless they have a privileged host-process helping them
out. This means that there will be a thundering herd of activity when
there shouldn't be any.
- Removing needless overhead/Increasing performance:
Currently, the uevent socket for each network namespace is added to the
global variable uevent_sock_list. The list itself needs to be protected
by a mutex. So everytime a uevent is generated the mutex is taken on
the list. The mutex is held *from the creation of the uevent (memory
allocation, string creation etc. until all uevent sockets have been
handled*. This is aggravated by the fact that for each uevent socket
that has listeners the mc_list must be walked as well which means we're
talking O(n^2) here. Given that a standard Linux workload usually has
quite a lot of network namespaces and - in the face of containers - a
lot of user namespaces this quickly becomes a performance problem (see
"Thundering herd" above). By just recording uevent sockets of network
namespaces that are owned by the initial user namespace we
significantly increase performance in this codepath.
- Injecting uevents:
There's a valid argument that containers might be interested in
receiving device events especially if they are delegated to them by a
privileged userspace process. One prime example are SR-IOV enabled
devices that are explicitly designed to be handed of to other users
such as VMs or containers.
This use-case can now be correctly handled since
commit 692ec06d7c92 ("netns: send uevent messages"). This commit
introduced the ability to send uevents from userspace. As such we can
let a sufficiently privileged (CAP_SYS_ADMIN in the owning user
namespace of the network namespace of the netlink socket) userspace
process make a decision what uevents should be sent. This removes the
need to blindly broadcast uevents into all user namespaces and provides
a performant and safe solution to this problem.
- Filtering logic:
This patch filters by *owning user namespace of the network namespace a
given task resides in* and not by user namespace of the task per se.
This means if the user namespace of a given task is unshared but the
network namespace is kept and is owned by the initial user namespace a
listener that is opening the uevent socket in that network namespace
can still listen to uevents.
- Fix permission for tagged kobjects:
Network devices that are created or moved into a network namespace that
is owned by a non-initial user namespace currently are send with
INVALID_{G,U}ID in their credentials. This means that all current udev
implementations in userspace will ignore the uevent they receive for
them. This has lead to weird bugs whereby new devices showing up in such
network namespaces were not recognized and did not get IPs assigned etc.
This patch adjusts the permission to the appropriate {g,u}id in the
respective user namespace. This way udevd is able to correctly handle
such devices.
- Simplify filtering logic:
do_one_broadcast() already ensures that only listeners in mc_list receive
uevents that have the same network namespace as the uevent socket itself.
So the filtering logic in kobj_bcast_filter is not needed (see [3]). This
patch therefore removes kobj_bcast_filter() and replaces
netlink_broadcast_filtered() with the simpler netlink_broadcast()
everywhere.
[1]: https://lkml.org/lkml/2018/4/4/739
[2]: https://lkml.org/lkml/2018/4/26/767
[3]: https://lkml.org/lkml/2018/4/26/738
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds alloc_uevent_skb() in preparation for follow up patches.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Merge tag 'errseq-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux
Pull errseq infrastructure fix from Jeff Layton:
"The PostgreSQL developers recently had a spirited discussion about the
writeback error handling in Linux, and reached out to us about a
behavoir change to the code that bit them when the errseq_t changes
were merged.
When we changed to using errseq_t for tracking writeback errors, we
lost the ability for an application to see a writeback error that
occurred before the open on which the fsync was issued. This was
problematic for PostgreSQL which offloads fsync calls to a completely
separate process from the DB writers.
This patch restores that ability. If the errseq_t value in the inode
does not have the SEEN flag set, then we just return 0 for the sample.
That ensures that any recorded error is always delivered at least
once.
Note that we might still lose the error if the inode gets evicted from
the cache before anything can reopen it, but that was the case before
errseq_t was merged. At LSF/MM we had some discussion about keeping
inodes with unreported writeback errors around in the cache for longer
(possibly indefinitely), but that's really a separate problem"
* tag 'errseq-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
errseq: Always report a writeback error once
Here are some small driver core and firmware fixes for 4.17-rc3
There's a kobject WARN() removal to make syzkaller a lot happier about
some "normal" error paths that it keeps hitting, which should reduce the
number of false-positives we have been getting recently.
There's also some fimware test and documentation fixes, and the
coredump() function signature change that needed to happen after -rc1
before drivers started to take advantage of it.
All of these have been in linux-next with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg Kroah-Hartman:
"Here are some small driver core and firmware fixes for 4.17-rc3
There's a kobject WARN() removal to make syzkaller a lot happier about
some "normal" error paths that it keeps hitting, which should reduce
the number of false-positives we have been getting recently.
There's also some fimware test and documentation fixes, and the
coredump() function signature change that needed to happen after -rc1
before drivers started to take advantage of it.
All of these have been in linux-next with no reported issues"
* tag 'driver-core-4.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
firmware: some documentation fixes
selftests:firmware: fixes a call to a wrong function name
kobject: don't use WARN for registration failures
firmware: Fix firmware documentation for recent file renames
test_firmware: fix setting old custom fw path back on exit, second try
test_firmware: Install all scripts
drivers: change struct device_driver::coredump() return type to void
The errseq_t infrastructure assumes that errors which occurred before
the file descriptor was opened are of no interest to the application.
This turns out to be a regression for some applications, notably Postgres.
Before errseq_t, a writeback error would be reported exactly once (as
long as the inode remained in memory), so Postgres could open a file,
call fsync() and find out whether there had been a writeback error on
that file from another process.
This patch changes the errseq infrastructure to report errors to all
file descriptors which are opened after the error occurred, but before
it was reported to any file descriptor. This restores the user-visible
behaviour.
Cc: stable@vger.kernel.org
Fixes: 5660e13d2fd6 ("fs: new infrastructure for writeback error handling and reporting")
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
To get rid of the variable length arrays on stack in the RS decoder it's
necessary to allocate the decoder buffers per control structure instance.
All usage sites have been checked for potential parallel decoder usage and
fixed where necessary. Kees confirmed that the pstore decoding is strictly
single threaded so there should be no surprises.
Allocate them in the rs control structure sized depending on the number of
roots for the chosen codec and adapt the decoder code to make use of them.
Document the fact that decode operations based on a particular rs control
instance cannot run in parallel and the caller has to ensure that as it's
not possible to provide a proper locking construct which fits all use
cases.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Andrew Morton <akpm@linuxfoundation.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
The decoder library uses variable length arrays on stack. To get rid of
them it would be simple to allocate fixed length arrays on stack, but those
might become rather large. The other solution is to allocate the buffers in
the rs control structure, but this cannot be done as long as the structure
can be shared by several users. Sharing is desired because the RS polynom
tables are large and initialization is time consuming.
To solve this split the codec information out of the control structure and
have a pointer to a shared codec in it. Instantiate the control structure
for each user, create a new codec if no shareable is avaiable yet. Adjust
all affected usage sites to the new scheme.
This allows to add per instance decoder buffers to the control structure
later on.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Boris Brezillon <boris.brezillon@bootlin.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Andrew Morton <akpm@linuxfoundation.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
The four error path labels in rs_init() can be reduced to one by allocating
the struct with kzalloc so the pointers in the struct are NULL and can be
unconditionally handed in to kfree() because they either point to an
allocation or are NULL.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Now that SPDX identifiers are in place, remove the GPL boiler plate
text. Leave the notices which document that Phil Karn granted permission in
place (encode/decode source code). The modified files are code written for
the kernel by me.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Andrew Morton <akpm@linuxfoundation.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
The Reed-Solomon library is based on code from Phil Karn who granted
permission to import it into the kernel under the GPL V2.
See commit 15b5423757a7 ("Shared Reed-Solomon ECC library") in the history
git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
...
The encoder/decoder code is lifted from the GPL'd userspace RS-library
written by Phil Karn. I modified/wrapped it to provide the different
functions which we need in the MTD/NAND code.
...
Signed-Off-By: Thomas Gleixner <tglx@linutronix.de>
Signed-Off-By: David Woodhouse <dwmw2@infradead.org>
"No objections at all. Just keep the authorship notices." -- Phil Karn
Add the proper SPDX identifiers according to
Documentation/process/license-rules.rst.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Andrew Morton <akpm@linuxfoundation.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Instead of mixing the whitespace cleanup into functional changes, mop it up
first.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Andrew Morton <akpm@linuxfoundation.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
The rslib usage in dm/verity_fec is broken because init_rs() can nest in
GFP_NOIO mempool allocations as init_rs() is invoked from the mempool alloc
callback.
Provide a variant which takes gfp_t flags as argument.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
When a walk of an rhashtable is interrupted with rhastable_walk_stop()
and then rhashtable_walk_start(), the location to restart from is based
on a 'skip' count in the current hash chain, and this can be incorrect
if insertions or deletions have happened. This does not happen when
the walk is not stopped and started as iter->p is a placeholder which
is safe to use while holding the RCU read lock.
In rhashtable_walk_start() we can revalidate that 'p' is still in the
same hash chain. If it isn't then the current method is still used.
With this patch, if a rhashtable walker ensures that the current
object remains in the table over a stop/start period (possibly by
elevating the reference count if that is sufficient), it can be sure
that a walk will not miss objects that were in the hashtable for the
whole time of the walk.
rhashtable_walk_start() may not find the object even though it is
still in the hashtable if a rehash has moved it to a new table. In
this case it will (eventually) get -EAGAIN and will need to proceed
through the whole table again to be sure to see everything at least
once.
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The documentation claims that when rhashtable_walk_start_check()
detects a resize event, it will rewind back to the beginning
of the table. This is not true. We need to set ->slot and
->skip to be zero for it to be true.
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Neither rhashtable_walk_enter() or rhltable_walk_enter() sleep, though
they do take a spinlock without irq protection.
So revise the comments to accurately state the contexts in which
these functions can be called.
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When these are included into arch Kconfig files, maintaining
alphabetical ordering of the selects means these get split up. To allow
for keeping things tidier and alphabetical, rename the selects to
GENERIC_LIB_*
Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-riscv@lists.infradead.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/19049/
Signed-off-by: James Hogan <jhogan@kernel.org>
As part of the MIPS conversion to use the generic GCC library routines,
Matt Redfearn discovered that I'd missed a notrace on __ucmpdi2(). This
patch rectifies the problem.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Matt Redfearn <matt.redfearn@mips.com>
Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/19048/
Signed-off-by: James Hogan <jhogan@kernel.org>
When an allocation with lower dma_coherent mask fails, dma_direct_alloc()
retries the allocation with GFP_DMA. But, this is useless for
architectures that hav no ZONE_DMA.
Fix it by adding the check of CONFIG_ZONE_DMA before retrying the
allocation.
Fixes: 95f183916d4b ("dma-direct: retry allocations using GFP_DMA for small masks")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
