Luis Chamberlain [Wed, 10 Nov 2021 00:29:49 +0000 (16:29 -0800)]
block: add __must_check for *add_disk*() callers
Now that we have done a spring cleaning on all drivers and added
error checking / handling, let's keep it that way and ensure
no new drivers fail to stick with it.
When BLKZEROOUT ioctl and data read race, the data read leaves stale
page cache. To avoid the stale page cache, hold invalidate_lock of the
block device file mapping. The stale page cache is observed when
blktests test case block/009 is modified to call "blkdiscard -z" command
and repeated hundreds of times.
This patch can be applied back to the stable kernel version v5.15.y.
Rework is required for older stable kernels.
Fixes: 6297ab839f28 ("block: invalidate the page cache when issuing BLKZEROOUT") Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Cc: stable@vger.kernel.org # v5.15 Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211109104723.835533-3-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
When BLKDISCARD ioctl and data read race, the data read leaves stale
page cache. To avoid the stale page cache, hold invalidate_lock of the
block device file mapping. The stale page cache is observed when
blktests test case block/009 is repeated hundreds of times.
This patch can be applied back to the stable kernel version v5.15.y
with slight patch edit. Rework is required for older stable kernels.
Fixes: 2095031980ac ("block: Invalidate cache on discard v2") Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Cc: stable@vger.kernel.org # v5.15 Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211109104723.835533-2-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linus Torvalds [Tue, 9 Nov 2021 19:24:08 +0000 (11:24 -0800)]
Merge tag 'for-5.16/drivers-2021-11-09' of git://git.kernel.dk/linux-block
Pull more block driver updates from Jens Axboe:
- Last series adding error handling support for add_disk() in drivers.
After this one, and once the SCSI side has been merged, we can
finally annotate add_disk() as must_check. (Luis)
- bcache fixes (Coly)
- zram fixes (Ming)
- ataflop locking fix (Tetsuo)
- nbd fixes (Ye, Yu)
- MD merge via Song
- Cleanup (Yang)
- sysfs fix (Guoqing)
- Misc fixes (Geert, Wu, luo)
* tag 'for-5.16/drivers-2021-11-09' of git://git.kernel.dk/linux-block: (34 commits)
bcache: Revert "bcache: use bvec_virt"
ataflop: Add missing semicolon to return statement
floppy: address add_disk() error handling on probe
ataflop: address add_disk() error handling on probe
block: update __register_blkdev() probe documentation
ataflop: remove ataflop_probe_lock mutex
mtd/ubi/block: add error handling support for add_disk()
block/sunvdc: add error handling support for add_disk()
z2ram: add error handling support for add_disk()
nvdimm/pmem: use add_disk() error handling
nvdimm/pmem: cleanup the disk if pmem_release_disk() is yet assigned
nvdimm/blk: add error handling support for add_disk()
nvdimm/blk: avoid calling del_gendisk() on early failures
nvdimm/btt: add error handling support for add_disk()
nvdimm/btt: use goto error labels on btt_blk_init()
loop: Remove duplicate assignments
drbd: Fix double free problem in drbd_create_device
nvdimm/btt: do not call del_gendisk() if not needed
bcache: fix use-after-free problem in bcache_device_free()
zram: replace fsync_bdev with sync_blockdev
...
Linus Torvalds [Tue, 9 Nov 2021 19:20:07 +0000 (11:20 -0800)]
Merge tag 'for-5.16/block-2021-11-09' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
- Set of fixes for the batched tag allocation (Ming, me)
- add_disk() error handling fix (Luis)
- Nested queue quiesce fixes (Ming)
- Shared tags init error handling fix (Ye)
- Misc cleanups (Jean, Ming, me)
* tag 'for-5.16/block-2021-11-09' of git://git.kernel.dk/linux-block:
nvme: wait until quiesce is done
scsi: make sure that request queue queiesce and unquiesce balanced
scsi: avoid to quiesce sdev->request_queue two times
blk-mq: add one API for waiting until quiesce is done
blk-mq: don't free tags if the tag_set is used by other device in queue initialztion
block: fix device_add_disk() kobject_create_and_add() error handling
block: ensure cached plug request matches the current queue
block: move queue enter logic into blk_mq_submit_bio()
block: make bio_queue_enter() fast-path available inline
block: split request allocation components into helpers
block: have plug stored requests hold references to the queue
blk-mq: update hctx->nr_active in blk_mq_end_request_batch()
blk-mq: add RQF_ELV debug entry
blk-mq: only try to run plug merge if request has same queue with incoming bio
block: move RQF_ELV setting into allocators
dm: don't stop request queue after the dm device is suspended
block: replace always false argument with 'false'
block: assign correct tag before doing prefetch of request
blk-mq: fix redundant check of !e expression
Linus Torvalds [Tue, 9 Nov 2021 19:16:20 +0000 (11:16 -0800)]
Merge tag 'for-5.16/bdev-size-2021-11-09' of git://git.kernel.dk/linux-block
Pull more bdev size updates from Jens Axboe:
"Two followup changes for the bdev-size series from this merge window:
- Add loff_t cast to bdev_nr_bytes() (Christoph)
- Use bdev_nr_bytes() consistently for the block parts at least (me)"
* tag 'for-5.16/bdev-size-2021-11-09' of git://git.kernel.dk/linux-block:
block: use new bdev_nr_bytes() helper for blkdev_{read,write}_iter()
block: add a loff_t cast to bdev_nr_bytes
Linus Torvalds [Tue, 9 Nov 2021 19:11:37 +0000 (11:11 -0800)]
Merge tag 'io_uring-5.16-2021-11-09' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
"Minor fixes that should go into the 5.16 release:
- Fix max worker setting not working correctly on NUMA (Beld)
- Correctly return current setting for max workers if zeroes are
passed in (Pavel)
- io_queue_sqe_arm_apoll() cleanup, as identified during the initial
merge (Pavel)
- Misc fixes (Nghia, me)"
* tag 'io_uring-5.16-2021-11-09' of git://git.kernel.dk/linux-block:
io_uring: honour zeroes as io-wq worker limits
io_uring: remove dead 'sqe' store
io_uring: remove redundant assignment to ret in io_register_iowq_max_workers()
io-wq: fix max-workers not correctly set on multi-node system
io_uring: clean up io_queue_sqe_arm_apoll
Linus Torvalds [Tue, 9 Nov 2021 19:02:04 +0000 (11:02 -0800)]
Merge tag 'for-5.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
- Add DM core support for emitting audit events through the audit
subsystem. Also enhance both the integrity and crypt targets to emit
events to via dm-audit.
- Various other simple code improvements and cleanups.
* tag 'for-5.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm table: log table creation error code
dm: make workqueue names device-specific
dm writecache: Make use of the helper macro kthread_run()
dm crypt: Make use of the helper macro kthread_run()
dm verity: use bvec_kmap_local in verity_for_bv_block
dm log writes: use memcpy_from_bvec in log_writes_map
dm integrity: use bvec_kmap_local in __journal_read_write
dm integrity: use bvec_kmap_local in integrity_metadata
dm: add add_disk() error handling
dm: Remove redundant flush_workqueue() calls
dm crypt: log aead integrity violations to audit subsystem
dm integrity: log audit events for dm-integrity target
dm: introduce audit event module for device mapper
Linus Torvalds [Tue, 9 Nov 2021 18:56:41 +0000 (10:56 -0800)]
Merge tag 'dma-mapping-5.16' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
"Just a small set of changes this time. The request dma_direct_alloc
cleanups are still under review and haven't made the cut.
Summary:
- convert sparc32 to the generic dma-direct code
- use bitmap_zalloc (Christophe JAILLET)"
* tag 'dma-mapping-5.16' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: use 'bitmap_zalloc()' when applicable
sparc32: use DMA_DIRECT_REMAP
sparc32: remove dma_make_coherent
sparc32: remove the call to dma_make_coherent in arch_dma_free
Linus Torvalds [Tue, 9 Nov 2021 18:51:12 +0000 (10:51 -0800)]
Merge tag 'ovl-update-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
- Fix a regression introduced in the last cycle
- Fix a use-after-free in the AIO path
- Fix a bogus warning reported by syzbot
* tag 'ovl-update-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: fix filattr copy-up failure
ovl: fix warning in ovl_create_real()
ovl: fix use after free in struct ovl_aio_req
Linus Torvalds [Tue, 9 Nov 2021 18:34:06 +0000 (10:34 -0800)]
Merge tag 'for-linus-5.16-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux
Pull orangefs fixes from Mike Marshall:
- fix sb refcount leak when allocate sb info failed (Chenyuan Mi)
- fix error return code of orangefs_revalidate_lookup() (Jia-Ju Bai)
- remove redundant initialization of variable ret (Colin Ian King)
* tag 'for-linus-5.16-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
orangefs: Fix sb refcount leak when allocate sb info failed.
fs: orangefs: fix error return code of orangefs_revalidate_lookup()
orangefs: Remove redundant initialization of variable ret
Linus Torvalds [Tue, 9 Nov 2021 18:30:13 +0000 (10:30 -0800)]
Merge tag '9p-for-5.16-rc1' of git://github.com/martinetd/linux
Pull 9p updates from Dominique Martinet:
"Fixes, netfs read support and checkpatch rewrite:
- fix syzcaller uninitialized value usage after missing error check
- add module autoloading based on transport name
- convert cached reads to use netfs helpers
- adjust readahead based on transport msize
- and many, many checkpatch.pl warning fixes..."
* tag '9p-for-5.16-rc1' of git://github.com/martinetd/linux:
9p: fix a bunch of checkpatch warnings
9p: set readahead and io size according to maxsize
9p p9mode2perm: remove useless strlcpy and check sscanf return code
9p v9fs_parse_options: replace simple_strtoul with kstrtouint
9p: fix file headers
fs/9p: fix indentation and Add missing a blank line after declaration
fs/9p: fix warnings found by checkpatch.pl
9p: fix minor indentation and codestyle
fs/9p: cleanup: opening brace at the beginning of the next line
9p: Convert to using the netfs helper lib to do reads and caching
fscache_cookie_enabled: check cookie is valid before accessing it
net/9p: autoload transport modules
9p/net: fix missing error check in p9_check_errors
Linus Torvalds [Tue, 9 Nov 2021 18:11:53 +0000 (10:11 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
"87 patches.
Subsystems affected by this patch series: mm (pagecache and hugetlb),
procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs,
init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork,
sysvfs, kcov, gdb, resource, selftests, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits)
ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL
ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
selftests/kselftest/runner/run_one(): allow running non-executable files
virtio-mem: disallow mapping virtio-mem memory via /dev/mem
kernel/resource: disallow access to exclusive system RAM regions
kernel/resource: clean up and optimize iomem_is_exclusive()
scripts/gdb: handle split debug for vmlinux
kcov: replace local_irq_save() with a local_lock_t
kcov: avoid enable+disable interrupts if !in_task()
kcov: allocate per-CPU memory on the relevant node
Documentation/kcov: define `ip' in the example
Documentation/kcov: include types.h in the example
sysv: use BUILD_BUG_ON instead of runtime check
kernel/fork.c: unshare(): use swap() to make code cleaner
seq_file: fix passing wrong private data
seq_file: move seq_escape() to a header
signal: remove duplicate include in signal.h
crash_dump: remove duplicate include in crash_dump.h
crash_dump: fix boolreturn.cocci warning
hfs/hfsplus: use WARN_ON for sanity check
...
ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
This commit removes the requirement to be root to modify sem_next_id,
msg_next_id and shm_next_id and checks checkpoint_restore_ns_capable
instead.
Since those files are specific to the IPC namespace, there is no reason
they should require root privileges. This is similar to ns_last_pid,
which also only checks checkpoint_restore_ns_capable.
[akpm@linux-foundation.org: ipc/ipc_sysctl.c needs capability.h for checkpoint_restore_ns_capable()]
Link: https://lkml.kernel.org/r/20210916163717.3179496-1-mclapinski@google.com Signed-off-by: Michal Clapinski <mclapinski@google.com> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Manfred Spraul <manfred@colorfullife.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When running a test program, 'run_one()' checks if the program has the
execution permission and fails if it doesn't. However, it's easy to
mistakenly lose the permissions, as some common tools like 'diff' don't
support the permission change well[1]. Compared to that, making mistakes
in the test program's path would only rare, as those are explicitly listed
in 'TEST_PROGS'. Therefore, it might make more sense to resolve the
situation on our own and run the program.
For this reason, this commit makes the test program runner function still
print the warning message but to try parsing the interpreter of the
program and to explicitly run it with the interpreter, in this case.
virtio-mem: disallow mapping virtio-mem memory via /dev/mem
We don't want user space to be able to map virtio-mem device memory
directly (e.g., via /dev/mem) in order to have guarantees that in a sane
setup we'll never accidentially access unplugged memory within the
device-managed region of a virtio-mem device, just as required by the
virtio-spec.
As soon as the virtio-mem driver is loaded, the device region is visible
in /proc/iomem via the parent device region. From that point on user
space is aware of the device region and we want to disallow mapping
anything inside that region (where we will dynamically (un)plug memory)
until the driver has been unloaded cleanly and e.g., another driver might
take over.
By creating our parent IORESOURCE_SYSTEM_RAM resource with
IORESOURCE_EXCLUSIVE, we will disallow any /dev/mem access to our device
region until the driver was unloaded cleanly and removed the parent
region. This will work even though only some memory blocks are actually
currently added to Linux and appear as busy in the resource tree.
So access to the region from user space is only possible
a) if we don't load the virtio-mem driver.
b) after unloading the virtio-mem driver cleanly.
Don't build virtio-mem if access to /dev/mem cannot be restricticted -- if
we have CONFIG_DEVMEM=y but CONFIG_STRICT_DEVMEM is not set.
Link: https://lkml.kernel.org/r/20210920142856.17758-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Jason Wang <jasowang@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/resource: disallow access to exclusive system RAM regions
virtio-mem dynamically exposes memory inside a device memory region as
system RAM to Linux, coordinating with the hypervisor which parts are
actually "plugged" and consequently usable/accessible.
On the one hand, the virtio-mem driver adds/removes whole memory blocks,
creating/removing busy IORESOURCE_SYSTEM_RAM resources, on the other
hand, it logically (un)plugs memory inside added memory blocks,
dynamically either exposing them to the buddy or hiding them from the
buddy and marking them PG_offline.
In contrast to physical devices, like a DIMM, the virtio-mem driver is
required to actually make use of any of the device-provided memory,
because it performs the handshake with the hypervisor. virtio-mem
memory cannot simply be access via /dev/mem without a driver.
There is no safe way to:
a) Access plugged memory blocks via /dev/mem, as they might contain
unplugged holes or might get silently unplugged by the virtio-mem
driver and consequently turned inaccessible.
b) Access unplugged memory blocks via /dev/mem because the virtio-mem
driver is required to make them actually accessible first.
The virtio-spec states that unplugged memory blocks MUST NOT be written,
and only selected unplugged memory blocks MAY be read. We want to make
sure, this is the case in sane environments -- where the virtio-mem driver
was loaded.
We want to make sure that in a sane environment, nobody "accidentially"
accesses unplugged memory inside the device managed region. For example,
a user might spot a memory region in /proc/iomem and try accessing it via
/dev/mem via gdb or dumping it via something else. By the time the mmap()
happens, the memory might already have been removed by the virtio-mem
driver silently: the mmap() would succeeed and user space might
accidentially access unplugged memory.
So once the driver was loaded and detected the device along the
device-managed region, we just want to disallow any access via /dev/mem to
it.
In an ideal world, we would mark the whole region as busy ("owned by a
driver") and exclude it; however, that would be wrong, as we don't really
have actual system RAM at these ranges added to Linux ("busy system RAM").
Instead, we want to mark such ranges as "not actual busy system RAM but
still soft-reserved and prepared by a driver for future use."
Let's teach iomem_is_exclusive() to reject access to any range with
"IORESOURCE_SYSTEM_RAM | IORESOURCE_EXCLUSIVE", even if not busy and even
if "iomem=relaxed" is set. Introduce EXCLUSIVE_SYSTEM_RAM to make it
easier for applicable drivers to depend on this setting in their Kconfig.
For now, there are no applicable ranges and we'll modify virtio-mem next
to properly set IORESOURCE_EXCLUSIVE on the parent resource container it
creates to contain all actual busy system RAM added via
add_memory_driver_managed().
Link: https://lkml.kernel.org/r/20210920142856.17758-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Jason Wang <jasowang@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/resource: clean up and optimize iomem_is_exclusive()
Patch series "virtio-mem: disallow mapping virtio-mem memory via /dev/mem", v5.
Let's add the basic infrastructure to exclude some physical memory regions
marked as "IORESOURCE_SYSTEM_RAM" completely from /dev/mem access, even
though they are not marked IORESOURCE_BUSY and even though "iomem=relaxed"
is set. Resource IORESOURCE_EXCLUSIVE for that purpose instead of adding
new flags to express something similar to "soft-busy" or "not busy yet,
but already prepared by a driver and not to be mapped by user space".
Use it for virtio-mem, to disallow mapping any virtio-mem memory via
/dev/mem to user space after the virtio-mem driver was loaded.
This patch (of 3):
We end up traversing subtrees of ranges we are not interested in; let's
optimize this case, skipping such subtrees, cleaning up the function a
bit.
For example, in the following configuration (/proc/iomem):
We don't have to look at any children of "0009d000-000fffff : Reserved"
if we can just skip these 15 items directly because the parent range is
not of interest.
Link: https://lkml.kernel.org/r/20210920142856.17758-1-david@redhat.com Link: https://lkml.kernel.org/r/20210920142856.17758-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is related to two previous changes. Commit 6b77697dca0a
("scripts/gdb: find vmlinux where it was before") and commit a5e8c18f9bb4
("scripts/gdb: handle split debug").
Although Chrome OS has been using the debug suffix for modules for a
while, it has just recently started using it for vmlinux as well. That
means we've now got to improve the detection of "vmlinux" to also handle
that it might end with ".debug".
Link: https://lkml.kernel.org/r/20211028151120.v2.1.Ie6bd5a232f770acd8c9ffae487a02170bad3e963@changeid Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kcov: replace local_irq_save() with a local_lock_t
The kcov code mixes local_irq_save() and spin_lock() in
kcov_remote_{start|end}(). This creates a warning on PREEMPT_RT because
local_irq_save() disables interrupts and spin_lock_t is turned into a
sleeping lock which can not be acquired in a section with disabled
interrupts.
The kcov_remote_lock is used to synchronize the access to the hash-list
kcov_remote_map. The local_irq_save() block protects access to the
per-CPU data kcov_percpu_data.
There is no compelling reason to change the lock type to raw_spin_lock_t
to make it work with local_irq_save(). Changing it would require to
move memory allocation (in kcov_remote_add()) and deallocation outside
of the locked section.
Adding an unlimited amount of entries to the hashlist will increase the
IRQ-off time during lookup. It could be argued that this is debug code
and the latency does not matter. There is however no need to do so and
it would allow to use this facility in an RT enabled build.
Using a local_lock_t instead of local_irq_save() has the befit of adding
a protection scope within the source which makes it obvious what is
protected. On a !PREEMPT_RT && !LOCKDEP build the local_lock_irqsave()
maps directly to local_irq_save() so there is overhead at runtime.
Replace the local_irq_save() section with a local_lock_t.
Link: https://lkml.kernel.org/r/20210923164741.1859522-6-bigeasy@linutronix.de Link: https://lore.kernel.org/r/20210830172627.267989-6-bigeasy@linutronix.de Reported-by: Clark Williams <williams@redhat.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Marco Elver <elver@google.com> Tested-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kcov: avoid enable+disable interrupts if !in_task()
kcov_remote_start() may need to allocate memory in the in_task() case
(otherwise per-CPU memory has been pre-allocated) and therefore requires
enabled interrupts.
The interrupts are enabled before checking if the allocation is required
so if no allocation is required then the interrupts are needlessly enabled
and disabled again.
Enable interrupts only if memory allocation is performed.
Link: https://lkml.kernel.org/r/20210923164741.1859522-5-bigeasy@linutronix.de Link: https://lore.kernel.org/r/20210830172627.267989-5-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Marco Elver <elver@google.com> Tested-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Clark Williams <williams@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/kcov: include types.h in the example
Patch series "kcov: PREEMPT_RT fixup + misc", v2.
The last patch in series is follow-up to address the PREEMPT_RT issue
within in kcov reported by Clark [1]. Patches 1-3 are smaller things that
I noticed while staring at it. Patch 4 is small change which makes
replacement in #5 simpler / more obvious.
The first example code has includes at the top, the following two
example share that part. The last example (remote coverage collection)
requires the linux/types.h header file due its __aligned_u64 usage.
Add the linux/types.h to the top most example and a comment that the
header files from above are required as it is done in the second
example.
Pavel Skripkin [Tue, 9 Nov 2021 02:35:25 +0000 (18:35 -0800)]
sysv: use BUILD_BUG_ON instead of runtime check
There were runtime checks about sizes of struct v7_super_block and struct
sysv_inode. If one of these checks fail the kernel will panic. Since
these values are known at compile time let's use BUILD_BUG_ON(), because
it's a standard mechanism for validation checking at build time
Link: https://lkml.kernel.org/r/20210813123020.22971-1-paskripkin@gmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Muchun Song [Tue, 9 Nov 2021 02:35:19 +0000 (18:35 -0800)]
seq_file: fix passing wrong private data
DEFINE_PROC_SHOW_ATTRIBUTE() is supposed to be used to define a series
of functions and variables to register proc file easily. And the users
can use proc_create_data() to pass their own private data and get it
via seq->private in the callback. Unfortunately, the proc file system
use PDE_DATA() to get private data instead of inode->i_private. So fix
it. Fortunately, there only one user of it which does not pass any
private data, so this bug does not break any in-tree codes.
Link: https://lkml.kernel.org/r/20211029032638.84884-1-songmuchun@bytedance.com Fixes: 72e086d9fe20 ("proc: convert everything to "struct proc_ops"") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Florent Revest <revest@chromium.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ye Guojin [Tue, 9 Nov 2021 02:35:10 +0000 (18:35 -0800)]
crash_dump: remove duplicate include in crash_dump.h
In crash_dump.h, header file <linux/pgtable.h> is included twice. This
duplication was introduced in commit f844577d34a6("mm: reorder includes
after introduction of linux/pgtable.h") where the order of the header
files is adjusted, while the old one was not removed.
Clean it up here.
Link: https://lkml.kernel.org/r/20211020090659.1038877-1-ye.guojin@zte.com.cn Signed-off-by: Ye Guojin <ye.guojin@zte.com.cn> Reported-by: Zeal Robot <zealci@zte.com.cn> Acked-by: Baoquan He <bhe@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Changcheng Deng <deng.changcheng@zte.com.cn> Cc: Simon Horman <horms@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arnd Bergmann [Tue, 9 Nov 2021 02:35:04 +0000 (18:35 -0800)]
hfs/hfsplus: use WARN_ON for sanity check
gcc warns about a couple of instances in which a sanity check exists but
the author wasn't sure how to react to it failing, which makes it look
like a possible bug:
fs/hfsplus/inode.c: In function 'hfsplus_cat_read_inode':
fs/hfsplus/inode.c:503:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
503 | /* panic? */;
| ^
fs/hfsplus/inode.c:524:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
524 | /* panic? */;
| ^
fs/hfsplus/inode.c: In function 'hfsplus_cat_write_inode':
fs/hfsplus/inode.c:582:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
582 | /* panic? */;
| ^
fs/hfsplus/inode.c:608:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
608 | /* panic? */;
| ^
fs/hfs/inode.c: In function 'hfs_write_inode':
fs/hfs/inode.c:464:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
464 | /* panic? */;
| ^
fs/hfs/inode.c:485:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
485 | /* panic? */;
| ^
panic() is probably not the correct choice here, but a WARN_ON
seems appropriate and avoids the compile-time warning.
Link: https://lkml.kernel.org/r/20210927102149.1809384-1-arnd@kernel.org Link: https://lore.kernel.org/all/20210322223249.2632268-1-arnd@kernel.org/ Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Harkes [Tue, 9 Nov 2021 02:34:45 +0000 (18:34 -0800)]
coda: avoid doing bad things on inode type changes during revalidation
When Coda discovers an inconsistent object, it turns it into a symlink.
However we can't just follow this change in the kernel on an existing file
or directory inode that may still have references.
This patch removes the inconsistent inode from the inode hash and
allocates a new inode for the symlink object.
Link: https://lkml.kernel.org/r/20210908140308.18491-7-jaharkes@cs.cmu.edu Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Jing Yangyang <jing.yangyang@zte.com.cn> Cc: Xin Tan <tanxin.ctf@gmail.com> Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn> Cc: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Harkes [Tue, 9 Nov 2021 02:34:42 +0000 (18:34 -0800)]
coda: avoid hidden code duplication in rename
We were actually fixing up the directory mtime in both branches after the
negative dentry test, it was just that one branch was only flagging the
directory inodes to refresh their attributes while the other branch used
the optional optimization to set mtime to the current time and not go back
to the Coda client.
Link: https://lkml.kernel.org/r/20210908140308.18491-6-jaharkes@cs.cmu.edu Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Jing Yangyang <jing.yangyang@zte.com.cn> Cc: Xin Tan <tanxin.ctf@gmail.com> Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn> Cc: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Harkes [Tue, 9 Nov 2021 02:34:39 +0000 (18:34 -0800)]
coda: avoid flagging NULL inodes
Somehow we hit a negative dentry in coda_rename even after checking with
d_really_is_positive. Maybe something raced and turned the new_dentry
negative while we were fixing up directory link counts.
Link: https://lkml.kernel.org/r/20210908140308.18491-5-jaharkes@cs.cmu.edu Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Jing Yangyang <jing.yangyang@zte.com.cn> Cc: Xin Tan <tanxin.ctf@gmail.com> Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn> Cc: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Harkes [Tue, 9 Nov 2021 02:34:33 +0000 (18:34 -0800)]
coda: check for async upcall request using local state
Originally flagged by Smatch because the code implicitly assumed outSize
is not NULL for non-async upcalls because of a flag that was (not) set in
req->uc_flags.
However req->uc_flags field is in shared state and although the current
code will not allow it to be changed before the async request check the
code is more robust when it tests against the local outSize variable.
Link: https://lkml.kernel.org/r/20210908140308.18491-3-jaharkes@cs.cmu.edu Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Jing Yangyang <jing.yangyang@zte.com.cn> Cc: Xin Tan <tanxin.ctf@gmail.com> Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn> Cc: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Harkes [Tue, 9 Nov 2021 02:34:30 +0000 (18:34 -0800)]
coda: avoid NULL pointer dereference from a bad inode
Patch series "Coda updates for -next".
The following patch series contains some fixes for the Coda kernel module
I've had sitting around and were tested extensively in a development
version of the Coda kernel module that lives outside of the main kernel.
This patch (of 9):
Avoid accessing coda_inode_info from a dentry with a bad inode.
Andrew Halaney [Tue, 9 Nov 2021 02:34:27 +0000 (18:34 -0800)]
init: make unknown command line param message clearer
The prior message is confusing users, which is the exact opposite of the
goal. If the message is being seen, one of the following situations is
happening:
1. the param is misspelled
2. the param is not valid due to the kernel configuration
3. the param is intended for init but isn't after the '--'
delineator on the command line
To make that more clear to the user, explicitly mention "kernel command
line" and also note that the params are still passed to user space to
avoid causing any alarm over params intended for init.
Link: https://lkml.kernel.org/r/20211013223502.96756-1-ahalaney@redhat.com Fixes: a3957777decc ("init: print out unknown kernel parameters") Signed-off-by: Andrew Halaney <ahalaney@redhat.com> Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
yangerkun [Tue, 9 Nov 2021 02:34:24 +0000 (18:34 -0800)]
ramfs: fix mount source show for ramfs
ramfs_parse_param does not parse key "source", and will convert
-ENOPARAM to 0. This will skip vfs_parse_fs_param_source in vfs_parse_fs_param, which
lead always "none" mount source for ramfs.
Fix it by parsing "source" in ramfs_parse_param like cgroup1_parse_param
does.
Kefeng Wang [Tue, 9 Nov 2021 02:34:02 +0000 (18:34 -0800)]
sections: provide internal __is_kernel() and __is_kernel_text() helper
An internal __is_kernel() helper which only check the kernel address
ranges, and an internal __is_kernel_text() helper which only check text
section ranges.
Link: https://lkml.kernel.org/r/20210930071143.63410-7-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Alexander Potapenko <glider@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kefeng Wang [Tue, 9 Nov 2021 02:33:58 +0000 (18:33 -0800)]
x86: mm: rename __is_kernel_text() to is_x86_32_kernel_text()
Commit 8994a854a8c5 ("x86/mm: Rename is_kernel_text to __is_kernel_text"),
add '__' prefix not to get in conflict with existing is_kernel_text() in
<linux/kallsyms.h>.
We will add __is_kernel_text() for the basic kernel text range check in
the next patch, so use private is_x86_32_kernel_text() naming for x86
special check.
Link: https://lkml.kernel.org/r/20210930071143.63410-6-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Alexander Potapenko <glider@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kefeng Wang [Tue, 9 Nov 2021 02:33:54 +0000 (18:33 -0800)]
sections: move is_kernel_inittext() into sections.h
The is_kernel_inittext() and init_kernel_text() are with same
functionality, let's just keep is_kernel_inittext() and move it into
sections.h, then update all the callers.
Link: https://lkml.kernel.org/r/20210930071143.63410-5-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alexander Potapenko <glider@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kefeng Wang [Tue, 9 Nov 2021 02:33:47 +0000 (18:33 -0800)]
kallsyms: fix address-checks for kernel related range
The is_kernel_inittext/is_kernel_text/is_kernel function should not
include the end address(the labels _einittext, _etext and _end) when check
the address range, the issue exists since Linux v2.6.12.
Link: https://lkml.kernel.org/r/20210930071143.63410-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alexander Potapenko <glider@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kefeng Wang [Tue, 9 Nov 2021 02:33:43 +0000 (18:33 -0800)]
kallsyms: remove arch specific text and data check
Patch series "sections: Unify kernel sections range check and use", v4.
There are three head files(kallsyms.h, kernel.h and sections.h) which
include the kernel sections range check, let's make some cleanup and unify
them.
1. cleanup arch specific text/data check and fix address boundary check
in kallsyms.h
2. make all the basic/core kernel range check function into sections.h
3. update all the callers, and use the helper in sections.h to simplify
the code
After this series, we have 5 APIs about kernel sections range check in
sections.h
* is_kernel_rodata() --- already in sections.h
* is_kernel_core_data() --- come from core_kernel_data() in kernel.h
* is_kernel_inittext() --- come from kernel.h and kallsyms.h
* __is_kernel_text() --- add new internal helper
* __is_kernel() --- add new internal helper
Note: For the last two helpers, people should not use directly, consider to
use corresponding function in kallsyms.h.
This patch (of 11):
Remove arch specific text and data check after commit 266577dab10d ("arch:
remove blackfin port"), no need arch-specific text/data check.
Link: https://lkml.kernel.org/r/20210930071143.63410-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20210930071143.63410-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kees Cook [Tue, 9 Nov 2021 02:33:37 +0000 (18:33 -0800)]
binfmt_elf: reintroduce using MAP_FIXED_NOREPLACE
Commit 9dd7ec872d62 ("elf: don't use MAP_FIXED_NOREPLACE for elf
executable mappings") reverted back to using MAP_FIXED to map ELF LOAD
segments because it was found that the segments in some binaries overlap
and can cause MAP_FIXED_NOREPLACE to fail.
The original intent of MAP_FIXED_NOREPLACE in the ELF loader was to
prevent the silent clobbering of an existing mapping (e.g. stack) by
the ELF image, which could lead to exploitable conditions. Quoting
commit 551923430331 ("fs, elf: drop MAP_FIXED usage from elf_map"),
which originally introduced the use of MAP_FIXED_NOREPLACE in the
loader:
Both load_elf_interp and load_elf_binary rely on elf_map to map
segments [to a specific] address and they use MAP_FIXED to enforce
that. This is however [a] dangerous thing prone to silent data
corruption which can be even exploitable.
...
Let's take CVE-2017-1000253 as an example ... we could end up mapping
[the executable] over the existing stack ... The [stack layout] issue
has been fixed since then ... So we should be safe and any [similar]
attack should be impractical. On the other hand this is just too
subtle [an] assumption ... it can break quite easily and [be] hard to
spot.
...
Address this [weakness] by changing MAP_FIXED to the newly added
MAP_FIXED_NOREPLACE. This will mean that mmap will fail if there is
an existing mapping clashing with the requested one [instead of
silently] clobbering it.
Then processing ET_DYN binaries the loader already calculates a total
size for the image when the first segment is mapped, maps the entire
image, and then unmaps the remainder before the remaining segments are
then individually mapped.
To avoid the earlier problems (legitimate overlapping LOAD segments
specified in the ELF), apply the same logic to ET_EXEC binaries as well.
For both ET_EXEC and ET_DYN+INTERP use MAP_FIXED_NOREPLACE for the
initial total size mapping and then use MAP_FIXED to build the final
(possibly legitimately overlapping) mappings. For ET_DYN w/out INTERP,
continue to map at a system-selected address in the mmap region.
Link: https://lkml.kernel.org/r/20210916215947.3993776-1-keescook@chromium.org Link: https://lore.kernel.org/lkml/1595869887-23307-2-git-send-email-anthony.yznaga@oracle.com Co-developed-by: Anthony Yznaga <anthony.yznaga@oracle.com> Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Chen Jingwen <chenjingwen6@huawei.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrei Vagin <avagin@openvz.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thomas Gleixner [Tue, 9 Nov 2021 02:33:25 +0000 (18:33 -0800)]
mm/scatterlist: replace the !preemptible warning in sg_miter_stop()
sg_miter_stop() checks for disabled preemption before unmapping a page
via kunmap_atomic(). The kernel doc mentions under context that
preemption must be disabled if SG_MITER_ATOMIC is set.
There is no active requirement for the caller to have preemption
disabled before invoking sg_mitter_stop(). The sg_mitter_*()
implementation itself has no such requirement.
In fact, preemption is disabled by kmap_atomic() as part of
sg_miter_next() and remains disabled as long as there is an active
SG_MITER_ATOMIC mapping. This is a consequence of kmap_atomic() and not
a requirement for sg_mitter_*() itself.
The user chooses SG_MITER_ATOMIC because it uses the API in a context
where blocking is not possible or blocking is possible but he chooses a
lower weight mapping which is not available on all CPUs and so it might
need less overhead to setup at a price that now preemption will be
disabled.
The kmap_atomic() implementation on PREEMPT_RT does not disable
preemption. It simply disables CPU migration to ensure that the task
remains on the same CPU while the caller remains preemptible. This in
turn triggers the warning in sg_miter_stop() because preemption is
allowed.
The PREEMPT_RT and !PREEMPT_RT implementation of kmap_atomic() disable
pagefaults as a requirement. It is sufficient to check for this instead
of disabled preemption.
Check for disabled pagefault handler in the SG_MITER_ATOMIC case.
Remove the "preemption disabled" part from the kernel doc as the
sg_milter*() implementation does not care.
[bigeasy@linutronix.de: commit description]
Link: https://lkml.kernel.org/r/20211015211409.cqopacv3pxdwn2ty@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lucas De Marchi [Tue, 9 Nov 2021 02:33:19 +0000 (18:33 -0800)]
include/linux/string_helpers.h: add linux/string.h for strlen()
linux/string_helpers.h uses strlen(), so include the correponding header.
Otherwise we get a compilation error if it's not also included by whoever
included the helper.
Imran Khan [Tue, 9 Nov 2021 02:33:16 +0000 (18:33 -0800)]
lib, stackdepot: add helper to print stack entries into buffer
To print stack entries into a buffer, users of stackdepot, first get a
list of stack entries using stack_depot_fetch and then print this list
into a buffer using stack_trace_snprint. Provide a helper in stackdepot
for this purpose. Also change above mentioned users to use this helper.
[imran.f.khan@oracle.com: fix build error] Link: https://lkml.kernel.org/r/20210915175321.3472770-4-imran.f.khan@oracle.com
[imran.f.khan@oracle.com: export stack_depot_snprint() to modules] Link: https://lkml.kernel.org/r/20210916133535.3592491-4-imran.f.khan@oracle.com Link: https://lkml.kernel.org/r/20210915014806.3206938-4-imran.f.khan@oracle.com Signed-off-by: Imran Khan <imran.f.khan@oracle.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jani Nikula <jani.nikula@intel.com> [i915] Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Imran Khan [Tue, 9 Nov 2021 02:33:12 +0000 (18:33 -0800)]
lib, stackdepot: add helper to print stack entries
To print a stack entries, users of stackdepot, first use stack_depot_fetch
to get a list of stack entries and then use stack_trace_print to print
this list. Provide a helper in stackdepot to print stack entries based on
stackdepot handle. Also change above mentioned users to use this helper.
Imran Khan [Tue, 9 Nov 2021 02:33:09 +0000 (18:33 -0800)]
lib, stackdepot: check stackdepot handle before accessing slabs
Patch series "lib, stackdepot: check stackdepot handle before accessing slabs", v2.
PATCH-1: Checks validity of a stackdepot handle before proceeding to
access stackdepot slab/objects.
PATCH-2: Adds a helper in stackdepot, to allow users to print stack
entries just by specifying the stackdepot handle. It also changes such
users to use this new interface.
PATCH-3: Adds a helper in stackdepot, to allow users to print stack
entries into buffers just by specifying the stackdepot handle and
destination buffer. It also changes such users to use this new interface.
This patch (of 3):
stack_depot_save allocates slabs that will be used for storing objects in
future.If this slab allocation fails we may get to a situation where space
allocation for a new stack_record fails, causing stack_depot_save to
return 0 as handle. If user of this handle ends up invoking
stack_depot_fetch with this handle value, current implementation of
stack_depot_fetch will end up using slab from wrong index. To avoid this
check handle value at the beginning.
Lukas Bulwahn [Tue, 9 Nov 2021 02:33:02 +0000 (18:33 -0800)]
MAINTAINERS: rectify entry for INTEL KEEM BAY DRM DRIVER
Commit a1802de40c77 ("drm/kmb: Build files for KeemBay Display driver")
refers to the non-existing file intel,kmb_display.yaml in
Documentation/devicetree/bindings/display/.
Commit 3d60bc24bae3 ("dt-bindings: display: Add support for Intel
KeemBay Display") originating from the same patch series however adds
the file intel,keembay-display.yaml in that directory instead.
So, refer to intel,keembay-display.yaml in the INTEL KEEM BAY DRM DRIVER
section instead.
Link: https://lkml.kernel.org/r/20211026141902.4865-4-lukas.bulwahn@gmail.com Fixes: a1802de40c77 ("drm/kmb: Build files for KeemBay Display driver") Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Anitha Chrisanthus <anitha.chrisanthus@intel.com> Cc: Edmund Dea <edmund.j.dea@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Cc: Punit Agrawal <punit1.agrawal@toshiba.co.jp> Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Wilken Gottwalt <wilken.gottwalt@posteo.net> Cc: Yu Chen <chenyu56@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lukas Bulwahn [Tue, 9 Nov 2021 02:32:59 +0000 (18:32 -0800)]
MAINTAINERS: rectify entry for HIKEY960 ONBOARD USB GPIO HUB DRIVER
Commit 9c78691b3824 ("misc: hisi_hikey_usb: Driver to support onboard
USB gpio hub on Hikey960") refers to the non-existing file
Documentation/devicetree/bindings/misc/hisilicon-hikey-usb.yaml, but
this commit's patch series does not add any related devicetree binding
in misc.
So, just drop this file reference in HIKEY960 ONBOARD USB GPIO HUB DRIVER.
Link: https://lkml.kernel.org/r/20211026141902.4865-3-lukas.bulwahn@gmail.com Fixes: 9c78691b3824 ("misc: hisi_hikey_usb: Driver to support onboard USB gpio hub on Hikey960") Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Anitha Chrisanthus <anitha.chrisanthus@intel.com> Cc: Edmund Dea <edmund.j.dea@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Cc: Punit Agrawal <punit1.agrawal@toshiba.co.jp> Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Wilken Gottwalt <wilken.gottwalt@posteo.net> Cc: Yu Chen <chenyu56@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lukas Bulwahn [Tue, 9 Nov 2021 02:32:55 +0000 (18:32 -0800)]
MAINTAINERS: rectify entry for ARM/TOSHIBA VISCONTI ARCHITECTURE
Patch series "Rectify file references for dt-bindings in MAINTAINERS", v5.
A patch series that cleans up some file references for dt-bindings in
MAINTAINERS.
This patch (of 4):
Commit 67665d18e056 ("MAINTAINERS: Add information for Toshiba Visconti
ARM SoCs") refers to the non-existing file toshiba,tmpv7700-pinctrl.yaml
in ./Documentation/devicetree/bindings/pinctrl/. Commit 2d2994479b53
("pinctrl: Add DT bindings for Toshiba Visconti TMPV7700 SoC")
originating from the same patch series however adds the file
toshiba,visconti-pinctrl.yaml in that directory instead.
So, refer to toshiba,visconti-pinctrl.yaml in the ARM/TOSHIBA VISCONTI
ARCHITECTURE section instead.
Link: https://lkml.kernel.org/r/20211026141902.4865-1-lukas.bulwahn@gmail.com Link: https://lkml.kernel.org/r/20211026141902.4865-2-lukas.bulwahn@gmail.com Fixes: 67665d18e056 ("MAINTAINERS: Add information for Toshiba Visconti ARM SoCs") Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Cc: Rob Herring <robh+dt@kernel.org> Cc: Punit Agrawal <punit1.agrawal@toshiba.co.jp> Cc: Anitha Chrisanthus <anitha.chrisanthus@intel.com> Cc: Wilken Gottwalt <wilken.gottwalt@posteo.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Yu Chen <chenyu56@huawei.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Edmund Dea <edmund.j.dea@intel.com> Cc: Joe Perches <joe@perches.com> Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
_Static_assert() is evaluated already in the compiler's frontend, and
gives a somehat more to-the-point error, compared to the BUILD_BUG_ON
macro, which only fires after the optimizer has had a chance to
eliminate calls to functions marked with __attribute__((error)). In
theory, this might make builds a tiny bit faster.
There's also a little less gunk in the error message emitted:
lib/sort.c: In function `foo':
include/linux/build_bug.h:78:41: error: static assertion failed: "pointer type mismatch in container_of()"
78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
compared to
lib/sort.c: In function `foo':
include/linux/compiler_types.h:322:38: error: call to `__compiletime_assert_2' declared with attribute error: pointer type mismatch in container_of()
322 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
While at it, fix the copy-pasto in container_of_safe().
bottom_half.h needs _THIS_IP_ to be standalone, so split that and
_RET_IP_ out from kernel.h into the new instruction_pointer.h. kernel.h
directly needs them, so include it there and replace the include of
kernel.h with this new file in bottom_half.h.
Link: https://lkml.kernel.org/r/20211028161248.45232-1-andriy.shevchenko@linux.intel.com Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Shevchenko [Tue, 9 Nov 2021 02:32:12 +0000 (18:32 -0800)]
kernel.h: split out container_of() and typeof_member() macros
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt cleaning it up by splitting out container_of() and
typeof_member() macros.
For time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.
Note, there are _a lot_ of headers and modules that include kernel.h
solely for one of these macros and this allows to unburden compiler for
the twisted inclusion paths and to make new code cleaner in the future.
Link: https://lkml.kernel.org/r/20211013170417.87909-3-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Shevchenko [Tue, 9 Nov 2021 02:32:08 +0000 (18:32 -0800)]
kernel.h: drop unneeded <linux/kernel.h> inclusion from other headers
Patch series "kernel.h further split", v5.
kernel.h is a set of something which is not related to each other and
often used in non-crossed compilation units, especially when drivers
need only one or two macro definitions from it.
This patch (of 7):
There is no evidence we need kernel.h inclusion in certain headers.
Drop unneeded <linux/kernel.h> inclusion from other headers.
[sfr@canb.auug.org.au: bottom_half.h needs kernel] Link: https://lkml.kernel.org/r/20211015202908.1c417ae2@canb.auug.org.au Link: https://lkml.kernel.org/r/20211013170417.87909-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20211013170417.87909-2-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stephen Brennan [Tue, 9 Nov 2021 02:32:05 +0000 (18:32 -0800)]
proc: allow pid_revalidate() during LOOKUP_RCU
Problem Description:
When running running ~128 parallel instances of
TZ=/etc/localtime ps -fe >/dev/null
on a 128CPU machine, the %sys utilization reaches 97%, and perf shows
the following code path as being responsible for heavy contention on the
d_lockref spinlock:
The reason is that pid_revalidate() is triggering a drop from RCU to ref
path walk mode. All concurrent path lookups thus try to grab a
reference to the dentry for /proc/, before re-executing pid_revalidate()
and then stepping into the /proc/$pid directory. Thus there is huge
spinlock contention.
This patch allows pid_revalidate() to execute in RCU mode, meaning that
the path lookup can successfully enter the /proc/$pid directory while
still in RCU mode. Later on, the path lookup may still drop into ref
mode, but the contention will be much reduced at this point.
By applying this patch, %sys utilization falls to around 85% under the
same workload, and the number of ps processes executed per unit time
increases by 3x-4x. Although this particular workload is a bit
contrived, we have seen some large collections of eager monitoring
scripts which produced similarly high %sys time due to contention in the
/proc directory.
As a result this patch, Al noted that several procfs methods which were
only called in ref-walk mode could now be called from RCU mode. To
ensure that this patch is safe, I audited all the inode get_link and
permission() implementations, as well as dentry d_revalidate()
implementations, in fs/proc. The purpose here is to ensure that they
either are safe to call in RCU (i.e. don't sleep) or correctly bail out
of RCU mode if they don't support it. My analysis shows that all
at-risk procfs methods are safe to call under RCU, and thus this patch
is safe.
Procfs RCU-walk Analysis:
This analysis is up-to-date with 5.15-rc3. When called under RCU mode,
these functions have arguments as follows:
* get_link() receives a NULL dentry pointer when called in RCU mode.
* permission() receives MAY_NOT_BLOCK in the mode parameter when called
from RCU.
* d_revalidate() receives LOOKUP_RCU in flags.
For the following functions, either they are trivially RCU safe, or they
explicitly bail at the beginning of the function when they run:
proc_ns_get_link (bails out)
proc_get_link (RCU safe)
proc_pid_get_link (bails out)
map_files_d_revalidate (bails out)
map_misc_d_revalidate (bails out)
proc_net_d_revalidate (RCU safe)
proc_sys_revalidate (bails out, also not under /proc/$pid)
tid_fd_revalidate (bails out)
proc_sys_permission (not under /proc/$pid)
The remainder of the functions require a bit more detail:
* proc_fd_permission: RCU safe. All of the body of this function is
under rcu_read_lock(), except generic_permission() which declares
itself RCU safe in its documentation string.
* proc_self_get_link uses GFP_ATOMIC in the RCU case, so it is RCU aware
and otherwise looks safe. The same is true of proc_thread_self_get_link.
* proc_map_files_get_link: calls ns_capable, which calls capable(), and
thus calls into the audit code (see note #1 below). The remainder is
just a call to the trivially safe proc_pid_get_link().
* proc_pid_permission: calls ptrace_may_access(), which appears RCU
safe, although it does call into the "security_ptrace_access_check()"
hook, which looks safe under smack and selinux. Just the audit code is
of concern. Also uses get_task_struct() and put_task_struct(), see
note #2 below.
* proc_tid_comm_permission: Appears safe, though calls put_task_struct
(see note #2 below).
Note #1:
Most of the concern of RCU safety has centered around the audit code.
However, since fd65cc0b954c ("selinux: slow_avc_audit has become
non-blocking"), it's safe to call this code under RCU. So all of the
above are safe by my estimation.
Note #2: get_task_struct() and put_task_struct():
The majority of get_task_struct() is under RCU read lock, and in any
case it is a simple increment. But put_task_struct() is complex, given
that it could at some point free the task struct, and this process has
many steps which I couldn't manually verify. However, several other
places call put_task_struct() under RCU, so it appears safe to use
here too (see kernel/hung_task.c:165 or rcu/tree-stall.h:296)
Patch description:
pid_revalidate() drops from RCU into REF lookup mode. When many threads
are resolving paths within /proc in parallel, this can result in heavy
spinlock contention on d_lockref as each thread tries to grab a
reference to the /proc dentry (and drop it shortly thereafter).
Investigation indicates that it is not necessary to drop RCU in
pid_revalidate(), as no RCU data is modified and the function never
sleeps. So, remove the LOOKUP_RCU check.
Link: https://lkml.kernel.org/r/20211004175629.292270-2-stephen.s.brennan@oracle.com Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
virtio-mem: kdump mode to sanitize /proc/vmcore access
Although virtio-mem currently supports reading unplugged memory in the
hypervisor, this will change in the future, indicated to the device via
a new feature flag.
We similarly sanitized /proc/kcore access recently. [1]
Let's register a vmcore callback, to allow vmcore code to check if a PFN
belonging to a virtio-mem device is either currently plugged and should
be dumped or is currently unplugged and should not be accessed, instead
mapping the shared zeropage or returning zeroes when reading.
This is important when not capturing /proc/vmcore via tools like
"makedumpfile" that can identify logically unplugged virtio-mem memory
via PG_offline in the memmap, but simply by e.g., copying the file.
Distributions that support virtio-mem+kdump have to make sure that the
virtio_mem module will be part of the kdump kernel or the kdump initrd;
dracut was recently [2] extended to include virtio-mem in the generated
initrd. As long as no special kdump kernels are used, this will
automatically make sure that virtio-mem will be around in the kdump
initrd and sanitize /proc/vmcore access -- with dracut.
With this series, we'll send one virtio-mem state request for every ~2
MiB chunk of virtio-mem memory indicated in the vmcore that we intend to
read/map.
In the future, we might want to allow building virtio-mem for kdump mode
only, even without CONFIG_MEMORY_HOTPLUG and friends: this way, we could
support special stripped-down kdump kernels that have many other config
options disabled; we'll tackle that once required. Further, we might
want to try sensing bigger blocks (e.g., memory sections) first before
falling back to device blocks on demand.
Tested with Fedora rawhide, which contains a recent kexec-tools version
(considering "System RAM (virtio_mem)" when creating the vmcore header)
and a recent dracut version (including the virtio_mem module in the
kdump initrd).
Link: https://lkml.kernel.org/r/20210526093041.8800-1-david@redhat.com Link: https://github.com/dracutdevs/dracut/pull/1157 Link: https://lkml.kernel.org/r/20211005121430.30136-10-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Young <dyoung@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc/vmcore: convert oldmem_pfn_is_ram callback to more generic vmcore callbacks
Let's support multiple registered callbacks, making sure that
registering vmcore callbacks cannot fail. Make the callback return a
bool instead of an int, handling how to deal with errors internally.
Drop unused HAVE_OLDMEM_PFN_IS_RAM.
We soon want to make use of this infrastructure from other drivers:
virtio-mem, registering one callback for each virtio-mem device, to
prevent reading unplugged virtio-mem memory.
Handle it via a generic vmcore_cb structure, prepared for future
extensions: for example, once we support virtio-mem on s390x where the
vmcore is completely constructed in the second kernel, we want to detect
and add plugged virtio-mem memory ranges to the vmcore in order for them
to get dumped properly.
Handle corner cases that are unexpected and shouldn't happen in sane
setups: registering a callback after the vmcore has already been opened
(warn only) and unregistering a callback after the vmcore has already been
opened (warn and essentially read only zeroes from that point on).
Link: https://lkml.kernel.org/r/20211005121430.30136-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Young <dyoung@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The callback should deal with errors internally, it doesn't make sense
to expose these via pfn_is_ram(). We'll rework the callbacks next.
Right now we consider errors as if "it's RAM"; no functional change.
Link: https://lkml.kernel.org/r/20211005121430.30136-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Dave Young <dyoung@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86/xen: print a warning when HVMOP_get_mem_type fails
HVMOP_get_mem_type is not expected to fail, "This call failing is
indication of something going quite wrong and it would be good to know
about this." [1]
Let's add a pr_warn_once().
Link: https://lkml.kernel.org/r/3b935aa0-6d85-0bcd-100e-15098add3c4c@oracle.com Link: https://lkml.kernel.org/r/20211005121430.30136-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Young <dyoung@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After removing /dev/kmem, sanitizing /proc/kcore and handling /dev/mem,
this series tackles the last sane way how a VM could accidentially
access logically unplugged memory managed by a virtio-mem device:
/proc/vmcore
When dumping memory via "makedumpfile", PG_offline pages, used by
virtio-mem to flag logically unplugged memory, are already properly
excluded; however, especially when accessing/copying /proc/vmcore "the
usual way", we can still end up reading logically unplugged memory part
of a virtio-mem device.
Patch #1-#3 are cleanups. Patch #4 extends the existing
oldmem_pfn_is_ram mechanism. Patch #5-#7 are virtio-mem refactorings
for patch #8, which implements the virtio-mem logic to query the state
of device blocks.
Patch #8:
"Although virtio-mem currently supports reading unplugged memory in the
hypervisor, this will change in the future, indicated to the device
via a new feature flag. We similarly sanitized /proc/kcore access
recently.
[...]
Distributions that support virtio-mem+kdump have to make sure that the
virtio_mem module will be part of the kdump kernel or the kdump
initrd; dracut was recently [2] extended to include virtio-mem in the
generated initrd. As long as no special kdump kernels are used, this
will automatically make sure that virtio-mem will be around in the
kdump initrd and sanitize /proc/vmcore access -- with dracut"
This is the last remaining bit to support
VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE [3] in the Linux implementation of
virtio-mem.
Note: this is best-effort. We'll never be able to control what runs
inside the second kernel, really, but we also don't have to care: we
only care about sane setups where we don't want our VM getting zapped
once we touch the wrong memory location while dumping. While we usually
expect sane setups to use "makedumfile", nothing really speaks against
just copying /proc/vmcore, especially in environments where HWpoisioning
isn't typically expected. Also, we really don't want to put all our
trust completely on the memmap, so sanitizing also makes sense when just
using "makedumpfile".
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