Commit Graph
1323416 Commits
Author SHA1 Message Date
Ming Lei 22465bbac5 blk-mq: move cpuhp callback registering out of q->sysfs_lock
Registering and unregistering cpuhp callback requires global cpu hotplug lock,
which is used everywhere. Meantime q->sysfs_lock is used in block layer
almost everywhere.

It is easy to trigger lockdep warning[1] by connecting the two locks.

Fix the warning by moving blk-mq's cpuhp callback registering out of
q->sysfs_lock. Add one dedicated global lock for covering registering &
unregistering hctx's cpuhp, and it is safe to do so because hctx is
guaranteed to be live if our request_queue is live.

[1] https://lore.kernel.org/lkml/Z04pz3AlvI4o0Mr8@agluck-desk3/

Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Newman <peternewman@google.com>
Cc: Babu Moger <babu.moger@amd.com>
Reported-by: Luck Tony <tony.luck@intel.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20241206111611.978870-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-06 09:48:46 -07:00
Ming Lei 4bf485a7db blk-mq: register cpuhp callback after hctx is added to xarray table
We need to retrieve 'hctx' from xarray table in the cpuhp callback, so the
callback should be registered after this 'hctx' is added to xarray table.

Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Newman <peternewman@google.com>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Luck Tony <tony.luck@intel.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20241206111611.978870-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-06 09:48:46 -07:00
Jens Axboe d64fd5f777 Merge tag 'nvme-6.13-2024-12-05' of git://git.infradead.org/nvme into block-6.13
Pull NVMe fixess from Keith:

"nvme fixes for Linux 6.13

 - Target fix using incorrect zero buffer (Nilay)
 - Device specifc deallocate quirk fixes (Christoph, Keith)
 - Fabrics fix for handling max command target bugs (Maurizio)
 - Cocci fix usage for kzalloc (Yu-Chen)
 - DMA size fix for host memory buffer feature (Christoph)
 - Fabrics queue cleanup fixes (Chunguang)"

* tag 'nvme-6.13-2024-12-05' of git://git.infradead.org/nvme:
  nvme-tcp: simplify nvme_tcp_teardown_io_queues()
  nvme-tcp: no need to quiesce admin_q in nvme_tcp_teardown_io_queues()
  nvme-rdma: unquiesce admin_q before destroy it
  nvme-tcp: fix the memleak while create new ctrl failed
  nvme-pci: don't use dma_alloc_noncontiguous with 0 merge boundary
  nvmet: replace kmalloc + memset with kzalloc for data allocation
  nvme-fabrics: handle zero MAXCMD without closing the connection
  nvme-pci: remove two deallocate zeroes quirks
  nvme: don't apply NVME_QUIRK_DEALLOCATE_ZEROES when DSM is not supported
  nvmet: use kzalloc instead of ZERO_PAGE in nvme_execute_identify_ns_nvm()
2024-12-05 10:14:36 -07:00
Ming Lei 7678abee08 virtio-blk: don't keep queue frozen during system suspend
Commit 4ce6e2db00 ("virtio-blk: Ensure no requests in virtqueues before
deleting vqs.") replaces queue quiesce with queue freeze in virtio-blk's
PM callbacks. And the motivation is to drain inflight IOs before suspending.

block layer's queue freeze looks very handy, but it is also easy to cause
deadlock, such as, any attempt to call into bio_queue_enter() may run into
deadlock if the queue is frozen in current context. There are all kinds
of ->suspend() called in suspend context, so keeping queue frozen in the
whole suspend context isn't one good idea. And Marek reported lockdep
warning[1] caused by virtio-blk's freeze queue in virtblk_freeze().

[1] https://lore.kernel.org/linux-block/ca16370e-d646-4eee-b9cc-87277c89c43c@samsung.com/

Given the motivation is to drain in-flight IOs, it can be done by calling
freeze & unfreeze, meantime restore to previous behavior by keeping queue
quiesced during suspend.

Cc: Yi Sun <yi.sun@unisoc.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: virtualization@lists.linux.dev
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://lore.kernel.org/r/20241112125821.1475793-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-05 10:00:20 -07:00
Chunguang.xu b4e12f5728 nvme-tcp: simplify nvme_tcp_teardown_io_queues()
As nvme_tcp_teardown_io_queues() is the only one caller of
nvme_tcp_destroy_admin_queue(), so we can merge it into
nvme_tcp_teardown_io_queues() to simplify the code.

Signed-off-by: Chunguang.xu <chunguang.xu@shopee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-04 10:15:46 -08:00
Chunguang.xu fdc5664c69 nvme-tcp: no need to quiesce admin_q in nvme_tcp_teardown_io_queues()
As we quiesce admin_q in nvme_tcp_teardown_admin_queue(), so we should no
need to quiesce it in nvme_tcp_reaardown_io_queues(), make things simple.

Signed-off-by: Chunguang.xu <chunguang.xu@shopee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-04 10:15:46 -08:00
Chunguang.xu 5858b68755 nvme-rdma: unquiesce admin_q before destroy it
Kernel will hang on destroy admin_q while we create ctrl failed, such
as following calltrace:

PID: 23644    TASK: ff2d52b40f439fc0  CPU: 2    COMMAND: "nvme"
 #0 [ff61d23de260fb78] __schedule at ffffffff8323bc15
 #1 [ff61d23de260fc08] schedule at ffffffff8323c014
 #2 [ff61d23de260fc28] blk_mq_freeze_queue_wait at ffffffff82a3dba1
 #3 [ff61d23de260fc78] blk_freeze_queue at ffffffff82a4113a
 #4 [ff61d23de260fc90] blk_cleanup_queue at ffffffff82a33006
 #5 [ff61d23de260fcb0] nvme_rdma_destroy_admin_queue at ffffffffc12686ce
 #6 [ff61d23de260fcc8] nvme_rdma_setup_ctrl at ffffffffc1268ced
 #7 [ff61d23de260fd28] nvme_rdma_create_ctrl at ffffffffc126919b
 #8 [ff61d23de260fd68] nvmf_dev_write at ffffffffc024f362
 #9 [ff61d23de260fe38] vfs_write at ffffffff827d5f25
    RIP: 00007fda7891d574  RSP: 00007ffe2ef06958  RFLAGS: 00000202
    RAX: ffffffffffffffda  RBX: 000055e8122a4d90  RCX: 00007fda7891d574
    RDX: 000000000000012b  RSI: 000055e8122a4d90  RDI: 0000000000000004
    RBP: 00007ffe2ef079c0   R8: 000000000000012b   R9: 000055e8122a4d90
    R10: 0000000000000000  R11: 0000000000000202  R12: 0000000000000004
    R13: 000055e8122923c0  R14: 000000000000012b  R15: 00007fda78a54500
    ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

This due to we have quiesced admi_q before cancel requests, but forgot
to unquiesce before destroy it, as a result we fail to drain the
pending requests, and hang on blk_mq_freeze_queue_wait() forever. Here
try to reuse nvme_rdma_teardown_admin_queue() to fix this issue and
simplify the code.

Fixes: 958dc1d32c ("nvme-rdma: add clean action for failed reconnection")
Reported-by: Yingfu.zhou <yingfu.zhou@shopee.com>
Signed-off-by: Chunguang.xu <chunguang.xu@shopee.com>
Signed-off-by: Yue.zhao <yue.zhao@shopee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-04 10:15:46 -08:00
Chunguang.xu fec55c29e5 nvme-tcp: fix the memleak while create new ctrl failed
Now while we create new ctrl failed, we have not free the
tagset occupied by admin_q, here try to fix it.

Fixes: fd1418de10 ("nvme-tcp: avoid open-coding nvme_tcp_teardown_admin_queue()")
Signed-off-by: Chunguang.xu <chunguang.xu@shopee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-04 10:15:46 -08:00
Christoph Hellwig ad0cf42e1f nvme-pci: don't use dma_alloc_noncontiguous with 0 merge boundary
Only call into nvme_alloc_host_mem_single which uses
dma_alloc_noncontiguous when there is non-null dma merge boundary.
Without this we'll call into dma_alloc_noncontiguous for device using
dma-direct, which can work fine as long as the preferred size is below the
MAX_ORDER of the page allocator, but blows up with a warning if it is
too large.

Fixes: 63a5c7a4b4 ("nvme-pci: use dma_alloc_noncontigous if possible")
Reported-by: Leon Romanovsky <leon@kernel.org>
Reported-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
Tested-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-04 09:23:11 -08:00
Yu-Chun Lin 41d826c8a9 nvmet: replace kmalloc + memset with kzalloc for data allocation
cocci warnings: (new ones prefixed by >>)
>> drivers/nvme/target/pr.c:831:8-15: WARNING: kzalloc should be used for data, instead of kmalloc/memset

The pattern of using 'kmalloc' followed by 'memset' is replaced with
'kzalloc', which is functionally equivalent to 'kmalloc' + 'memset',
but more efficient. 'kzalloc' automatically zeroes the allocated
memory, making it a faster and more streamlined solution.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202411301434.LEckbcWx-lkp@intel.com/
Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yu-Chun Lin <eleanor15x@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-04 09:20:00 -08:00
Maurizio Lombardi 88c23a32b8 nvme-fabrics: handle zero MAXCMD without closing the connection
The NVMe specification states that MAXCMD is mandatory
for NVMe-over-Fabrics implementations. However, some NVMe/TCP
and NVMe/FC arrays from major vendors have buggy firmware
that reports MAXCMD as zero in the Identify Controller data structure.

Currently, the implementation closes the connection in such cases,
completely preventing the host from connecting to the target.

Fix the issue by printing a clear error message about the firmware bug
and allowing the connection to proceed. It assumes that the
target supports a MAXCMD value of SQSIZE + 1. If any issues arise,
the user can manually adjust SQSIZE to mitigate them.

Fixes: 4999568184 ("nvme-fabrics: check max outstanding commands")
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-04 09:19:54 -08:00
Liequan Che b2e382ae12 bcache: revert replacing IS_ERR_OR_NULL with IS_ERR again
Commit 028ddcac47 ("bcache: Remove unnecessary NULL point check in
node allocations") leads a NULL pointer deference in cache_set_flush().

1721         if (!IS_ERR_OR_NULL(c->root))
1722                 list_add(&c->root->list, &c->btree_cache);

>From the above code in cache_set_flush(), if previous registration code
fails before allocating c->root, it is possible c->root is NULL as what
it is initialized. __bch_btree_node_alloc() never returns NULL but
c->root is possible to be NULL at above line 1721.

This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this.

Fixes: 028ddcac47 ("bcache: Remove unnecessary NULL point check in node allocations")
Signed-off-by: Liequan Che <cheliequan@inspur.com>
Cc: stable@vger.kernel.org
Cc: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20241202115638.28957-1-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-03 15:06:27 -07:00
Keith Busch b0de5456e2 nvme-pci: remove two deallocate zeroes quirks
The quirk was initially used as a signal to set the discard_zeroes_data
queue limit because there were some use cases that relied on that
behavior. The queue limit no longer exists as every user of it has been
converted to use the write zeroes operation instead.

The quirk now means to use a discard command as an alias to a write
zeroes request. Two of the devices previously using the quirk support
the write zeroes command directly, so these don't need or want to use
discard when the desired operation is to write zeroes.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-03 10:56:27 -08:00
FUJITA Tomonori 3c93e4e4a2 block: rnull: add missing MODULE_DESCRIPTION
Add the missing description to fix the following warning:

WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/block/rnull_mod.o

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20241130094521.193924-1-fujita.tomonori@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-03 06:34:11 -07:00
Peter Zijlstra cdd30ebb1b module: Convert symbol namespace to string literal
Clean up the existing export namespace code along the same lines of
commit 33def8498f ("treewide: Convert macro and uses of __section(foo)
to __section("foo")") and for the same reason, it is not desired for the
namespace argument to be a macro expansion itself.

Scripted using

  git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file;
  do
    awk -i inplace '
      /^#define EXPORT_SYMBOL_NS/ {
        gsub(/__stringify\(ns\)/, "ns");
        print;
        next;
      }
      /^#define MODULE_IMPORT_NS/ {
        gsub(/__stringify\(ns\)/, "ns");
        print;
        next;
      }
      /MODULE_IMPORT_NS/ {
        $0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g");
      }
      /EXPORT_SYMBOL_NS/ {
        if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) {
  	if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ &&
  	    $0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ &&
  	    $0 !~ /^my/) {
  	  getline line;
  	  gsub(/[[:space:]]*\\$/, "");
  	  gsub(/[[:space:]]/, "", line);
  	  $0 = $0 " " line;
  	}

  	$0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/,
  		    "\\1(\\2, \"\\3\")", "g");
        }
      }
      { print }' $file;
  done

Requested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc
Acked-by: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-02 11:34:44 -08:00
Christoph Hellwig 58a0c875ce nvme: don't apply NVME_QUIRK_DEALLOCATE_ZEROES when DSM is not supported
Commit 63dfa10043 ("nvme: move NVME_QUIRK_DEALLOCATE_ZEROES out of
nvme_config_discard") started applying the NVME_QUIRK_DEALLOCATE_ZEROES
quirk even then the Dataset Management is not supported.  It turns out
that there versions of these old Intel SSDs that have DSM support
disabled in the firmware, which will now lead to errors everytime
a Write Zeroes command is issued.  Fix this by checking for DSM support
before applying the quirk.

Reported-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
Fixes: 63dfa10043 ("nvme: move NVME_QUIRK_DEALLOCATE_ZEROES out of nvme_config_discard")
Tested-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-02 10:03:19 -08:00
Nilay Shroff 84909f7dec nvmet: use kzalloc instead of ZERO_PAGE in nvme_execute_identify_ns_nvm()
The nvme_execute_identify_ns_nvm function uses ZERO_PAGE for copying
SG list with all zeros. As ZERO_PAGE would not necessarily return the
virtual-address of the zero page, we need to first convert the page
address to kernel virtual-address and then use it as source address
for copying the data to SG list with all zeros. Using return address
of ZERO_PAGE(0) as source address for copying data to SG list would
fill the target buffer with random/garbage value and causes the
undesired side effect.

As other identify implemenations uses kzalloc for allocating a zero
filled buffer, we decided use kzalloc for allocating a zero filled
buffer in nvme_execute_identify_ns_nvm function and then use this
buffer for copying all zeros to SG list buffers. So esentially, we
now avoid using ZERO_PAGE.

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Fixes: 64a51080ea ("nvmet: implement id ns for nvm command set")
Link: https://lore.kernel.org/all/CAHj4cs8OVyxmn4XTvA=y4uQ3qWpdw-x3M3FSUYr-KpE-nhaFEA@mail.gmail.com/
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-12-02 10:02:47 -08:00
Linus Torvalds e70140ba0d Get rid of 'remove_new' relic from platform driver struct
The continual trickle of small conversion patches is grating on me, and
is really not helping.  Just get rid of the 'remove_new' member
function, which is just an alias for the plain 'remove', and had a
comment to that effect:

  /*
   * .remove_new() is a relic from a prototype conversion of .remove().
   * New drivers are supposed to implement .remove(). Once all drivers are
   * converted to not use .remove_new any more, it will be dropped.
   */

This was just a tree-wide 'sed' script that replaced '.remove_new' with
'.remove', with some care taken to turn a subsequent tab into two tabs
to make things line up.

I did do some minimal manual whitespace adjustment for places that used
spaces to line things up.

Then I just removed the old (sic) .remove_new member function, and this
is the end result.  No more unnecessary conversion noise.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-01 15:12:43 -08:00
Linus Torvalds 40384c840e Linux 6.13-rc1 2024-12-01 14:28:56 -08:00
Linus Torvalds a14bf463e7 Merge tag 'i2c-for-6.13-rc1-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c component probing support from Wolfram Sang:
 "Add OF component probing.

  Some devices are designed and manufactured with some components having
  multiple drop-in replacement options. These components are often
  connected to the mainboard via ribbon cables, having the same signals
  and pin assignments across all options. These may include the display
  panel and touchscreen on laptops and tablets, and the trackpad on
  laptops. Sometimes which component option is used in a particular
  device can be detected by some firmware provided identifier, other
  times that information is not available, and the kernel has to try to
  probe each device.

  Instead of a delicate dance between drivers and device tree quirks,
  this change introduces a simple I2C component probe function. For a
  given class of devices on the same I2C bus, it will go through all of
  them, doing a simple I2C read transfer and see which one of them
  responds. It will then enable the device that responds"

* tag 'i2c-for-6.13-rc1-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  MAINTAINERS: fix typo in I2C OF COMPONENT PROBER
  of: base: Document prefix argument for of_get_next_child_with_prefix()
  i2c: Fix whitespace style issue
  arm64: dts: mediatek: mt8173-elm-hana: Mark touchscreens and trackpads as fail
  platform/chrome: Introduce device tree hardware prober
  i2c: of-prober: Add GPIO support to simple helpers
  i2c: of-prober: Add simple helpers for regulator support
  i2c: Introduce OF component probe function
  of: base: Add for_each_child_of_node_with_prefix()
  of: dynamic: Add of_changeset_update_prop_string
2024-12-01 13:38:24 -08:00
Linus Torvalds 88862eeb47 Merge tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull bprintf() removal from Steven Rostedt:

 - Remove unused bprintf() function, that was added with the rest of the
   "bin-printf" functions.

   These are functions that are used by trace_printk() that allows to
   quickly save the format and arguments into the ring buffer without
   the expensive processing of converting numbers to ASCII. Then on
   output, at a much later time, the ring buffer is read and the string
   processing occurs then. The bprintf() was added for consistency but
   was never used. It can be safely removed.

* tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  printf: Remove unused 'bprintf'
2024-12-01 13:10:51 -08:00
Linus Torvalds f788b5ef1c Merge tag 'timers_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Borislav Petkov:

 - Fix a case where posix timers with a thread-group-wide target would
   miss signals if some of the group's threads are exiting

 - Fix a hang caused by ndelay() calling the wrong delay function
   __udelay()

 - Fix a wrong offset calculation in adjtimex(2) when using ADJ_MICRO
   (microsecond resolution) and a negative offset

* tag 'timers_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-timers: Target group sigqueue to current task only if not exiting
  delay: Fix ndelay() spuriously treated as udelay()
  ntp: Remove invalid cast in time offset math
2024-12-01 12:41:21 -08:00
Linus Torvalds 63f4993b79 Merge tag 'irq_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Borislav Petkov:

 - Move the ->select callback to the correct ops structure in
   irq-mvebu-sei to fix some Marvell Armada platforms

 - Add a workaround for Hisilicon ITS erratum 162100801 which can cause
   some virtual interrupts to get lost

 - More platform_driver::remove() conversion

* tag 'irq_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Switch back to struct platform_driver::remove()
  irqchip/gicv3-its: Add workaround for hip09 ITS erratum 162100801
  irqchip/irq-mvebu-sei: Move misplaced select() callback to SEI CP domain
2024-12-01 12:37:58 -08:00
Linus Torvalds 58ac609b99 Merge tag 'x86_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:

 - Add a terminating zero end-element to the array describing AMD CPUs
   affected by erratum 1386 so that the matching loop actually
   terminates instead of going off into the weeds

 - Update the boot protocol documentation to mention the fact that the
   preferred address to load the kernel to is considered in the
   relocatable kernel case too

 - Flush the memory buffer containing the microcode patch after applying
   microcode on AMD Zen1 and Zen2, to avoid unnecessary slowdowns

 - Make sure the PPIN CPU feature flag is cleared on all CPUs if PPIN
   has been disabled

* tag 'x86_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU/AMD: Terminate the erratum_1386_microcode array
  x86/Documentation: Update algo in init_size description of boot protocol
  x86/microcode/AMD: Flush patch buffer mapping after application
  x86/mm: Carve out INVLPG inline asm for use by others
  x86/cpu: Fix PPIN initialization
2024-12-01 12:35:37 -08:00
Linus Torvalds 9022ed0e7e strscpy: write destination buffer only once
The point behind strscpy() was to once and for all avoid all the
problems with 'strncpy()' and later broken "fixed" versions like
strlcpy() that just made things worse.

So strscpy not only guarantees NUL-termination (unlike strncpy), it also
doesn't do unnecessary padding at the destination.  But at the same time
also avoids byte-at-a-time reads and writes by _allowing_ some extra NUL
writes - within the size, of course - so that the whole copy can be done
with word operations.

It is also stable in the face of a mutable source string: it explicitly
does not read the source buffer multiple times (so an implementation
using "strnlen()+memcpy()" would be wrong), and does not read the source
buffer past the size (like the mis-design that is strlcpy does).

Finally, the return value is designed to be simple and unambiguous: if
the string cannot be copied fully, it returns an actual negative error,
making error handling clearer and simpler (and the caller already knows
the size of the buffer).  Otherwise it returns the string length of the
result.

However, there was one final stability issue that can be important to
callers: the stability of the destination buffer.

In particular, the same way we shouldn't read the source buffer more
than once, we should avoid doing multiple writes to the destination
buffer: first writing a potentially non-terminated string, and then
terminating it with NUL at the end does not result in a stable result
buffer.

Yes, it gives the right result in the end, but if the rule for the
destination buffer was that it is _always_ NUL-terminated even when
accessed concurrently with updates, the final byte of the buffer needs
to always _stay_ as a NUL byte.

[ Note that "final byte is NUL" here is literally about the final byte
  in the destination array, not the terminating NUL at the end of the
  string itself. There is no attempt to try to make concurrent reads and
  writes give any kind of consistent string length or contents, but we
  do want to guarantee that there is always at least that final
  terminating NUL character at the end of the destination array if it
  existed before ]

This is relevant in the kernel for the tsk->comm[] array, for example.
Even without locking (for either readers or writers), we want to know
that while the buffer contents may be garbled, it is always a valid C
string and always has a NUL character at 'comm[TASK_COMM_LEN-1]' (and
never has any "out of thin air" data).

So avoid any "copy possibly non-terminated string, and terminate later"
behavior, and write the destination buffer only once.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-01 12:17:16 -08:00