No functional changes in this patch, just in preparation for carrying
more state then what is being done now, if necessary. While unifying
some of this code, add a generic send setup prep handler that they can
both use.

This gets rid of some manual msghdr and sockaddr on the stack, and makes
it look a bit more like the sendmsg/recvmsg variants. Going forward, more
can get unified on top.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In practice, we just need to recycle a few elements for (by far) most
use cases. Shrink the total size down from 512 to 128, which should be
more than plenty.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

For historical reasons these were special cased, as they were the only
ones that needed cancelation. But now we handle cancelations generally,
and hence there's no need to check for these in
io_ring_ctx_wait_and_kill() when io_uring_try_cancel_requests() handles
both these and the rest as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Just like we run the inline task_work, ensure we also factor in and
run the fallback task_work.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Move CONFIG_PROVE_LOCKING checks inside of io_lockdep_assert_cq_locked()
and kill the else branch.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/bbf33c429c9f6d7207a8fe66d1a5866ec2c99850.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Make io_req_complete_post() to push all IORING_SETUP_IOPOLL requests
to task_work, it's much cleaner and should normally happen. We couldn't
do it before because there was a possibility of looping in

complete_post() -> tw -> complete_post() -> ...

Also, unexport the function and inline __io_req_complete_post().
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/ea19c032ace3e0dd96ac4d991a063b0188037014.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

task_work execution is now always locked, and we shouldn't get into
io_req_complete_post() from them. That means that complete_post() is
always called out of the original task context and we don't even need to
check current.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/24ec27f27db0d8f58c974d8118dca1d345314ddc.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_post_aux_cqe(), which is used for multishot requests, delays
completions by putting CQEs into a temporary array for the purpose
completion lock/flush batching.

DEFER_TASKRUN doesn't need any locking, so for it we can put completions
directly into the CQ and defer post completion handling with a flag.
That leaves !DEFER_TASKRUN, which is not that interesting / hot for
multishot requests, so have conditional locking with deferred flush
for them.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/b1d05a81fd27aaa2a07f9860af13059e7ad7a890.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

The restriction on multishot execution context disallowing io-wq is
driven by rules of io_fill_cqe_req_aux(), it should only be called in
the master task context, either from the syscall path or in task_work.
Since task_work now always takes the ctx lock implying
IO_URING_F_COMPLETE_DEFER, we can just assume that the function is
always called with its defer argument set to true.

Kill the argument. Also rename the function for more consistency as
"fill" in CQE related functions was usually meant for raw interfaces
only copying data into the CQ without any locking, waking the user
and other accounting "post" functions take care of.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/93423d106c33116c7d06bf277f651aa68b427328.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

ctx is always locked for task_work now, so get rid of struct
io_tw_state::locked. Note I'm stopping one step before removing
io_tw_state altogether, which is not empty, because it still serves the
purpose of indicating which function is a tw callback and forcing users
not to invoke them carelessly out of a wrong context. The removal can
always be done later.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/e95e1ea116d0bfa54b656076e6a977bc221392a4.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

We can run normal task_work without locking the ctx, however we try to
lock anyway and most handlers prefer or require it locked. It might have
been interesting to multi-submitter ring with high contention completing
async read/write requests via task_work, however that will still need to
go through io_req_complete_post() and potentially take the lock for
rsrc node putting or some other case.

In other words, it's hard to care about it, so alawys force the locking.
The case described would also because of various io_uring caches.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/6ae858f2ef562e6ed9f13c60978c0d48926954ba.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

kiocb_done() should care to specifically redirecting requests to io-wq.
Remove the hopping to tw to then queue an io-wq, return -EAGAIN and let
the core code io_uring handle offloading.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/413564e550fe23744a970e1783dfa566291b0e6f.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

NVMe is making up issue_flags, which is a no-no in general, and to make
matters worse, they are completely the wrong ones. For a pure polled
request, which it does check for, we're already inside the
ctx->uring_lock when the completions are run off io_do_iopoll(). Hence
the correct flag would be '0' rather than IO_URING_F_UNLOCKED.
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add comments warning users that they're only allowed to pass issue_flags
that were given from io_uring.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/82ff8a45f2c3eb5f3a04a33f0692e5e4a1320455.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

!IO_URING_F_UNLOCKED does not translate to availability of the deferred
completion infra, IO_URING_F_COMPLETE_DEFER does, that what we should
pass and look for to use io_req_complete_defer() and other variants.

Luckily, it's not a real problem as two wrongs actually made it right,
at least as far as io_uring_cmd_work() goes.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/aef76d34fe9410df8ecc42a14544fd76cd9d8b9e.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_uring cmd converts struct io_tw_state to issue_flags and later back
to io_tw_state, it's awfully ill-fated, not to mention that intermediate
issue_flags state is not correct.

Get rid of the last conversion, drag through tw everything that came
with IO_URING_F_UNLOCKED, and replace io_req_complete_defer() with a
direct call to io_req_complete_defer(), at least for the time being.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/c53fa3df749752bd058cf6f824a90704822d6bcc.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_uring_try_cancel_uring_cmd() is a part of the cmd handling so let's
move it closer to all cmd bits into uring_cmd.c
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/43a3937af4933655f0fd9362c381802f804f43de.1710799188.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull sysfs fix from Al Viro:
 "Get rid of lockdep false positives around sysfs/overlayfs

  syzbot has uncovered a class of lockdep false positives for setups
  with sysfs being one of the backing layers in overlayfs. The root
  cause is that of->mutex allocated when opening a sysfs file read-only
  (which overlayfs might do) is confused with of->mutex of a file opened
  writable (held in write to sysfs file, which overlayfs won't do).

  Assigning them separate lockdep classes fixes that bunch and it's
  obviously safe"

* tag 'pull-sysfs-annotation-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  kernfs: annotate different lockdep class for of->mutex of writable files

Pull misc x86 fixes from Ingo Molnar:

 - Follow up fixes for the BHI mitigations code

 - Fix !SPECULATION_MITIGATIONS bug not turning off mitigations as
   expected

 - Work around an APIC emulation bug when the kernel is built with Clang
   and run as a SEV guest

 - Follow up x86 topology fixes

* tag 'x86-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/amd: Move TOPOEXT enablement into the topology parser
  x86/cpu/amd: Make the NODEID_MSR union actually work
  x86/cpu/amd: Make the CPUID 0x80000008 parser correct
  x86/bugs: Replace CONFIG_SPECTRE_BHI_{ON,OFF} with CONFIG_MITIGATION_SPECTRE_BHI
  x86/bugs: Remove CONFIG_BHI_MITIGATION_AUTO and spectre_bhi=auto
  x86/bugs: Clarify that syscall hardening isn't a BHI mitigation
  x86/bugs: Fix BHI handling of RRSBA
  x86/bugs: Rename various 'ia32_cap' variables to 'x86_arch_cap_msr'
  x86/bugs: Cache the value of MSR_IA32_ARCH_CAPABILITIES
  x86/bugs: Fix BHI documentation
  x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n
  x86/topology: Don't update cpu_possible_map in topo_set_cpuids()
  x86/bugs: Fix return type of spectre_bhi_state()
  x86/apic: Force native_apic_mem_read() to use the MOV instruction

Pull timer fixes from Ingo Molnar:

 - Address a (valid) W=1 build warning

 - Fix timer self-tests

 - Annotate a KCSAN warning wrt. accesses to the tick_do_timer_cpu
   global variable

 - Address a !CONFIG_BUG build warning

* tag 'timers-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests: kselftest: Fix build failure with NOLIBC
  selftests: timers: Fix abs() warning in posix_timers test
  selftests: kselftest: Mark functions that unconditionally call exit() as __noreturn
  selftests: timers: Fix posix_timers ksft_print_msg() warning
  selftests: timers: Fix valid-adjtimex signed left-shift undefined behavior
  bug: Fix no-return-statement warning with !CONFIG_BUG
  timekeeping: Use READ/WRITE_ONCE() for tick_do_timer_cpu
  selftests/timers/posix_timers: Reimplement check_timer_distribution()
  irqflags: Explicitly ignore lockdep_hrtimer_exit() argument

Pull perf event fix from Ingo Molnar:
 "Fix the x86 PMU multi-counter code returning invalid data in certain
  circumstances"

* tag 'perf-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Fix out of range data

Pull locking fix from Ingo Molnar:
 "Fix a PREEMPT_RT build bug"

* tag 'locking-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking: Make rwsem_assert_held_write_nolockdep() build with PREEMPT_RT=y

Pull irq fix from Ingo Molnar:
 "Fix a bug in the GIC irqchip driver"

* tag 'irq-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Fix VSYNC referencing an unmapped VPE on GIC v4.1

Pull virtio bugfixes from Michael Tsirkin:
 "Some small, obvious (in hindsight) bugfixes:

   - new ioctl in vhost-vdpa has a wrong # - not too late to fix

   - vhost has apparently been lacking an smp_rmb() - due to code
     duplication :( The duplication will be fixed in the next merge
     cycle, this is a minimal fix

   - an error message in vhost talks about guest moving used index -
     which of course never happens, guest only ever moves the available
     index

   - i2c-virtio didn't set the driver owner so it did not get refcounted
     correctly"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: correct misleading printing information
  vhost-vdpa: change ioctl # for VDPA_GET_VRING_SIZE
  virtio: store owner from modules with register_virtio_driver()
  vhost: Add smp_rmb() in vhost_enable_notify()
  vhost: Add smp_rmb() in vhost_vq_avail_empty()

Pull dma-mapping fixes from Christoph Hellwig:

 - fix up swiotlb buffer padding even more (Petr Tesarik)

 - fix for partial dma_sync on swiotlb (Michael Kelley)

 - swiotlb debugfs fix (Dexuan Cui)

* tag 'dma-maping-6.9-2024-04-14' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: do not set total_used to 0 in swiotlb_create_debugfs_files()
  swiotlb: fix swiotlb_bounce() to do partial sync's correctly
  swiotlb: extend buffer pre-padding to alloc_align_mask if necessary

The writable file /sys/power/resume may call vfs lookup helpers for
arbitrary paths and readonly files can be read by overlayfs from vfs
helpers when sysfs is a lower layer of overalyfs.

To avoid a lockdep warning of circular dependency between overlayfs
inode lock and kernfs of->mutex, use a different lockdep class for
writable and readonly kernfs files.

Reported-by: syzbot+9a5b0ced8b1bfb238b56@syzkaller.appspotmail.com
Fixes: 0fedefd4 ("kernfs: sysfs: support custom llseek method for sysfs entries")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull ata fixes from Damien Le Moal:

 - Add the mask_port_map parameter to the ahci driver. This is a
   follow-up to the recent snafu with the ASMedia controller and its
   virtual port hidding port-multiplier devices. As ASMedia confirmed
   that there is no way to determine if these slow-to-probe virtual
   ports are actually representing the ports of a port-multiplier
   devices, this new parameter allow masking ports to significantly
   speed up probing during system boot, resulting in shorter boot times.

 - A fix for an incorrect handling of a port unlock in
   ata_scsi_dev_rescan().

 - Allow command duration limits to be detected for ACS-4 devices are
   there are such devices out in the field.

* tag 'ata-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
  ata: libata-core: Allow command duration limits detection for ACS-4 drives
  ata: libata-scsi: Fix ata_scsi_dev_rescan() error path
  ata: ahci: Add mask_port_map module parameter

Pull zonefs fix from Damien Le Moal:

 - Suppress a coccicheck warning using str_plural()

* tag 'zonefs-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
  zonefs: Use str_plural() to fix Coccinelle warning

Pull smb client fixes from Steve French:

 - fix for oops in cifs_get_fattr of deleted files

 - fix for the remote open counter going negative in some directory
   lease cases

 - fix for mkfifo to instantiate dentry to avoid possible crash

 - important fix to allow handling key rotation for mount and remount
   (ie cases that are becoming more common when password that was used
   for the mount will expire soon but will be replaced by new password)

* tag 'v6.9-rc3-SMB3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: fix broken reconnect when password changing on the server by allowing password rotation
  smb: client: instantiate when creating SFU files
  smb3: fix Open files on server counter going negative
  smb: client: fix NULL ptr deref in cifs_mark_open_handles_for_deleted_file()

Even though the command duration limits (CDL) feature was first added
in ACS-5 (major version 12), there are some ACS-4 (major version 11)
drives that implement CDL as well.

IDENTIFY_DEVICE, SUPPORTED_CAPABILITIES, and CURRENT_SETTINGS log pages
are mandatory in the ACS-4 standard so it should be safe to read these
log pages on older drives implementing the ACS-4 standard.

Fixes: 62e4a60e ("scsi: ata: libata: Detect support for command duration limits")
Cc: stable@vger.kernel.org
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

Commit 0c76106c ("scsi: sd: Fix TCG OPAL unlock on system resume")
incorrectly handles failures of scsi_resume_device() in
ata_scsi_dev_rescan(), leading to a double call to
spin_unlock_irqrestore() to unlock a device port. Fix this by redefining
the goto labels used in case of errors and only unlock the port
scsi_scan_mutex when scsi_resume_device() fails.

Bug found with the Smatch static checker warning:

	drivers/ata/libata-scsi.c:4774 ata_scsi_dev_rescan()
	error: double unlocked 'ap->lock' (orig line 4757)
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 0c76106c ("scsi: sd: Fix TCG OPAL unlock on system resume")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>

Pull arm64 fix from Catalin Marinas:
 "Fix the TLBI RANGE operand calculation causing live migration under
  KVM/arm64 to miss dirty pages due to stale TLB entries"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: tlb: Fix TLBI RANGE operand

Pull SoC fixes from Arnd Bergmann:
 "The device tree changes this time are all for NXP i.MX platforms,
  addressing issues with clocks and regulators on i.MX7 and i.MX8.

  The old OMAP2 based Nokia N8x0 tablet get a couple of code fixes for
  regressions that came in.

  The ARM SCMI and FF-A firmware interfaces get a couple of minor bug
  fixes.

  A regression fix for RISC-V cache management addresses a problem with
  probe order on Sifive cores"

* tag 'soc-fixes-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (23 commits)
  MAINTAINERS: Change Krzysztof Kozlowski's email address
  arm64: dts: imx8qm-ss-dma: fix can lpcg indices
  arm64: dts: imx8-ss-dma: fix can lpcg indices
  arm64: dts: imx8-ss-dma: fix adc lpcg indices
  arm64: dts: imx8-ss-dma: fix pwm lpcg indices
  arm64: dts: imx8-ss-dma: fix spi lpcg indices
  arm64: dts: imx8-ss-conn: fix usb lpcg indices
  arm64: dts: imx8-ss-lsio: fix pwm lpcg indices
  ARM: dts: imx7s-warp: Pass OV2680 link-frequencies
  ARM: dts: imx7-mba7: Use 'no-mmc' property
  arm64: dts: imx8-ss-conn: fix usdhc wrong lpcg clock order
  arm64: dts: freescale: imx8mp-venice-gw73xx-2x: fix USB vbus regulator
  arm64: dts: freescale: imx8mp-venice-gw72xx-2x: fix USB vbus regulator
  cache: sifive_ccache: Partially convert to a platform driver
  firmware: arm_scmi: Make raw debugfs entries non-seekable
  firmware: arm_scmi: Fix wrong fastchannel initialization
  firmware: arm_ffa: Fix the partition ID check in ffa_notification_info_get()
  ARM: OMAP2+: fix USB regression on Nokia N8x0
  mmc: omap: restore original power up/down steps
  mmc: omap: fix deferred probe
  ...

Pull iommu fixes from Joerg Roedel:

 - Intel VT-d Fixes:
     - Allocate local memory for PRQ page
     - Fix WARN_ON in iommu probe path
     - Fix wrong use of pasid config

 - AMD IOMMU Fixes:
     - Lock inversion fix
     - Log message severity fix
     - Disable SNP when v2 page-tables are used

 - Mediatek driver:
     - Fix module autoloading

* tag 'iommu-fixes-v6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Change log message severity
  iommu/vt-d: Fix WARN_ON in iommu probe path
  iommu/vt-d: Allocate local memory for page request queue
  iommu/vt-d: Fix wrong use of pasid config
  iommu: mtk: fix module autoloading
  iommu/amd: Do not enable SNP when V2 page table is enabled
  iommu/amd: Fix possible irq lock inversion dependency issue

Pull pci fixes from Bjorn Helgaas:

 - Revert a quirk that prevented Secondary Bus Reset for LSI / Agere
   FW643.

   We thought the device was broken, but the reset does work correctly
   on other platforms, and the reset avoids leaking data out of VMs
   (Bjorn Helgaas)

 - Update MAINTAINERS to reflect that Gustavo Pimentel is no longer
   reachable (Manivannan Sadhasivam)

* tag 'pci-v6.9-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  Revert "PCI: Mark LSI FW643 to avoid bus reset"
  MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer

Pull block fixes from Jens Axboe:

 - MD pull request via Song:
       - UAF fix (Yu)

 - Avoid out-of-bounds shift in blk-iocost (Rik)

 - Fix for q->blkg_list corruption (Ming)

 - Relax virt boundary mask/size segment checking (Ming)

* tag 'block-6.9-20240412' of git://git.kernel.dk/linux:
  block: fix that blk_time_get_ns() doesn't update time after schedule
  block: allow device to have both virt_boundary_mask and max segment size
  block: fix q->blkg_list corruption during disk rebind
  blk-iocost: avoid out of bounds shift
  raid1: fix use-after-free for original bio in raid1_write_request()

Pull io_uring fixes from Jens Axboe:

 - Fix for sigmask restoring while waiting for events (Alexey)

 - Typo fix in comment (Haiyue)

 - Fix for a msg_control retstore on SEND_ZC retries (Pavel)

* tag 'io_uring-6.9-20240412' of git://git.kernel.dk/linux:
  io-uring: correct typo in comment for IOU_F_TWQ_LAZY_WAKE
  io_uring/net: restore msg_control on sendzc retry
  io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure

Pull ceph fixes from Ilya Dryomov:
 "Two CephFS fixes marked for stable and a MAINTAINERS update"

* tag 'ceph-for-6.9-rc4' of https://github.com/ceph/ceph-client:
  MAINTAINERS: remove myself as a Reviewer for Ceph
  ceph: switch to use cap_delay_lock for the unlink delay list
  ceph: redirty page before returning AOP_WRITEPAGE_ACTIVATE

Commit d96c3600 ("tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig
entry") removed a hidden tab because it apparently showed breakage in
some third-party kernel config parsing tool.

It wasn't clear what tool it was, but let's make sure it gets fixed.
Because if you can't parse tabs as whitespace, you should not be parsing
the kernel Kconfig files.

In fact, let's make such breakage more obvious than some esoteric ftrace
record size option.  If you can't parse tabs, you can't have page sizes.

Yes, tab-vs-space confusion is sadly a traditional Unix thing, and
'make' is famous for being broken in this regard.  But no, that does not
mean that it's ok.

I'd add more random tabs to our Kconfig files, but I don't want to make
things uglier than necessary.  But it *might* bbe necessary if it turns
out we see more of this kind of silly tooling.

Fixes: d96c3600 ("tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entry")
Link: https://lore.kernel.org/lkml/CAHk-=wj-hLLN_t_m5OL4dXLaxvXKy_axuoJYXif7iczbfgAevQ@mail.gmail.com/Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>