The current approach to filling tmpbuffer with completion candidates is
confusing, with the buffer management being especially hard to reason
about. That's because it doesn't copy the completion canidate into
tmpbuffer, instead of copies a whole bunch of other nonsense and then
runs the completion search from the middle of tmpbuffer!

Change this to copy nothing but the completion candidate into tmpbuffer.

Pretty much everything else in this patch is renaming to reflect the
above change:

    s/p_tmp/tmpbuffer/
    s/buf_size/sizeof(tmpbuffer)/

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

At several points in kdb_read() there are variants of the following
code pattern (with offsets slightly altered):

    memcpy(tmpbuffer, cp, lastchar - cp);
    memcpy(cp-1, tmpbuffer, lastchar - cp);
    *(--lastchar) = '\0';

There is no need to use tmpbuffer here, since we can use memmove() instead
so refactor in the obvious way. Additionally the strings that are being
copied are already properly terminated so let's also change the code so
that the library calls also move the terminator.

Changing how the terminators are managed has no functional effect for now
but might allow us to retire lastchar at a later point. lastchar, although
stored as a pointer, is functionally equivalent to caching strlen(buffer).

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

Currently when the current line should be removed from the display
kdb_read() uses memset() to fill a temporary buffer with spaces.
The problem is not that this could be trivially implemented using a
format string rather than open coding it. The real problem is that
it is possible, on systems with a long kdb_prompt_str, to write past
the end of the tmpbuffer.

Happily, as mentioned above, this can be trivially implemented using a
format string. Make it so!

Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

The code that handles case 14 (down) and case 16 (up) has been copy and
pasted despite being byte-for-byte identical. Combine them.

Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

Currently, if the cursor position is not at the end of the command buffer
and the user uses the Tab-complete functions, then the console does not
leave the cursor in the correct position.

For example consider the following buffer with the cursor positioned
at the ^:

md kdb_pro 10
          ^

Pressing tab should result in:

md kdb_prompt_str 10
                 ^

However this does not happen. Instead the cursor is placed at the end
(after then 10) and further cursor movement redraws incorrectly. The
same problem exists when we double-Tab but in a different part of the
code.

Fix this by sending a carriage return and then redisplaying the text to
the left of the cursor.

Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

Currently when kdb_read() needs to reposition the cursor it uses copy and
paste code that works by injecting an '\0' at the cursor position before
delivering a carriage-return and reprinting the line (which stops at the
'\0').

Tidy up the code by hoisting the copy and paste code into an appropriately
named function. Additionally let's replace the '\0' injection with a
proper field width parameter so that the string will be abridged during
formatting instead.

Cc: stable@vger.kernel.org # Not a bug fix but it is needed for later bug fixes
Tested-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

Currently, when the user attempts symbol completion with the Tab key, kdb
will use strncpy() to insert the completed symbol into the command buffer.
Unfortunately it passes the size of the source buffer rather than the
destination to strncpy() with predictably horrible results. Most obviously
if the command buffer is already full but cp, the cursor position, is in
the middle of the buffer, then we will write past the end of the supplied
buffer.

Fix this by replacing the dubious strncpy() calls with memmove()/memcpy()
calls plus explicit boundary checks to make sure we have enough space
before we start moving characters around.

Reported-by: Justin Stitt <justinstitt@google.com>
Closes: https://lore.kernel.org/all/CAFhGd8qESuuifuHsNjFPR-Va3P80bxrw+LqvC8deA8GziUJLpw@mail.gmail.com/


Cc: stable@vger.kernel.org
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Tested-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

Inspired by a patch from [Justin][1] I took a closer look at kdb_read().

Despite Justin's patch being a (correct) one-line manipulation it was a
tough patch to review because the surrounding code was hard to read and
it looked like there were unfixed problems.

This series isn't enough to make kdb_read() beautiful but it does make
it shorter, easier to reason about and fixes two buffer overflows and a
screen redraw problem!

[1]: https://lore.kernel.org/all/20240403-strncpy-kernel-debug-kdb-kdb_io-c-v1-1-7f78a08e9ff4@google.com/



# Describe the purpose of this series. The information you put here
# will be used by the project maintainer to make a decision whether
# your patches should be reviewed, and in what priority order. Please be
# very detailed and link to any relevant discussions or sites that the
# maintainer can review to better understand your proposed changes. If you
# only have a single patch in your series, the contents of the cover
# letter will be appended to the "under-the-cut" portion of the patch.

# Lines starting with # will be removed from the cover letter. You can
# use them to add notes or reminders to yourself. If you want to use
# markdown headers in your cover letter, start the line with ">#".

# You can add trailers to the cover letter. Any email addresses found in
# these trailers will be added to the addresses specified/generated
# during the b4 send stage. You can also run "b4 prep --auto-to-cc" to
# auto-populate the To: and Cc: trailers based on the code being
# modified.

To: Jason Wessel <jason.wessel@windriver.com>
To: Douglas Anderson <dianders@chromium.org>
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

---
Changes in v3:
- EDITME: describe what is new in this series revision.
- EDITME: use bulletpoints and terse descriptions.
- Link to v2: https://lore.kernel.org/r/20240422-kgdb_read_refactor-v2-0-ed51f7d145fe@linaro.org

Changes in v2:
- No code changes!
- I belatedly realized that one of the cleanups actually fixed a buffer
  overflow so there are changes to Cc: (to add stable@...) and to one
  of the patch descriptions.
- Link to v1: https://lore.kernel.org/r/20240416-kgdb_read_refactor-v1-0-b18c2d01076d@linaro.org

--- b4-submit-tracking ---
# This section is used internally by b4 prep for tracking purposes.
{
  "series": {
    "revision": 3,
    "change-id": "20240415-kgdb_read_refactor-2ea2dfc15dbb",
    "prefixes": [],
    "history": {
      "v1": [
        "20240416-kgdb_read_refactor-v1-0-b18c2d01076d@linaro.org"
      ],
      "v2": [
        "20240422-kgdb_read_refactor-v2-0-ed51f7d145fe@linaro.org"
      ]
    }
  }
}

Inspired by a patch from [Justin][1] I took a closer look at kdb_read().

Despite Justin's patch being a (correct) one-line mechanical manipulation
it was a tough patch to review because the surrounding code was hard
to read, even by kdb standards!

This series isn't enough to make kdb_read() beautiful but it does make
it shorter, easier to reason about and fixes a buffer overflow!

[1]: https://lore.kernel.org/all/20240403-strncpy-kernel-debug-kdb-kdb_io-c-v1-1-7f78a08e9ff4@google.com/



# Describe the purpose of this series. The information you put here
# will be used by the project maintainer to make a decision whether
# your patches should be reviewed, and in what priority order. Please be
# very detailed and link to any relevant discussions or sites that the
# maintainer can review to better understand your proposed changes. If you
# only have a single patch in your series, the contents of the cover
# letter will be appended to the "under-the-cut" portion of the patch.

# Lines starting with # will be removed from the cover letter. You can
# use them to add notes or reminders to yourself. If you want to use
# markdown headers in your cover letter, start the line with ">#".

# You can add trailers to the cover letter. Any email addresses found in
# these trailers will be added to the addresses specified/generated
# during the b4 send stage. You can also run "b4 prep --auto-to-cc" to
# auto-populate the To: and Cc: trailers based on the code being
# modified.

To: Jason Wessel <jason.wessel@windriver.com>
To: Douglas Anderson <dianders@chromium.org>
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>


--- b4-submit-tracking ---
# This section is used internally by b4 prep for tracking purposes.
{
  "series": {
    "revision": 1,
    "change-id": "20240415-kgdb_read_refactor-2ea2dfc15dbb",
    "prefixes": []
  }
}

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>

Pull tracing fixes from Steven Rostedt:

 - Fix the buffer_percent accounting as it is dependent on three
   variables:

     1) pages_read - number of subbuffers read
     2) pages_lost - number of subbuffers lost due to overwrite
     3) pages_touched - number of pages that a writer entered

   These three counters only increment, and to know how many active
   pages there are on the buffer at any given time, the pages_read and
   pages_lost are subtracted from pages_touched.

   But the pages touched was incremented whenever any writer went to the
   next subbuffer even if it wasn't the only one, so it was incremented
   more than it should be causing the counter for how many subbuffers
   currently have content incorrect, which caused the buffer_percent
   that holds waiters until the ring buffer is filled to a given
   percentage to wake up early.

 - Fix warning of unused functions when PERF_EVENTS is not configured in

 - Replace bad tab with space in Kconfig for FTRACE_RECORD_RECURSION_SIZE

 - Fix to some kerneldoc function comments in eventfs code.

* tag 'trace-v6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Only update pages_touched when a new page is touched
  tracing: hide unused ftrace_event_id_fops
  tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entry
  eventfs: Fix kernel-doc comments to functions

Pull MIPS fix from Thomas Bogendoerfer:
 "Fix for syscall_get_nr() to make it work even if tracing is disabled"

* tag 'mips-fixes_6.9_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: scall: Save thread_info.syscall unconditionally on entry

Pull drm fixes from Dave Airlie:
 "Looks like everyone woke up after holidays, this weeks pull has a
  bunch of stuff all over, 2 weeks worth of amdgpu is a lot of it, then
  i915/xe have a few, a bunch of msm fixes, then some scattered driver
  fixes.

  I expect things will settle down for rc5.

  client:
   - Protect connector modes with mode_config mutex

  ast:
   - Fix soft lockup

  host1x:
   - Do not setup DMA for virtual addresses

  ivpu:
   - Fix deadlock in context_xa
   - PCI fixes
   - Fixes to error handling

  nouveau:
   - gsp: Fix OOB access
   - Fix casting

  panfrost:
   - Fix error path in MMU code

  qxl:
   - Revert "drm/qxl: simplify qxl_fence_wait"

  vmwgfx:
   - Enable DMA for SEV mappings

  i915:
   - Couple CDCLK programming fixes
   - HDCP related fix
   - 4 Bigjoiner related fixes
   - Fix for a circular locking around GuC on reset+wedged case

  xe:
   - Fix double display mutex initializations
   - Fix u32 -> u64 implicit conversions
   - Fix RING_CONTEXT_CONTROL not marked as masked

  msm:
   - DP refcount leak fix on disconnect
   - Add missing newlines to prints in msm_fb and msm_kms
   - fix dpu debugfs entry permissions
   - Fix the interface table for the catalog of X1E80100
   - fix irq message printing
   - Bindings fix to add DP node as child of mdss for mdss node
   - Minor typo fix in DP driver API which handles port status change
   - fix CHRASHDUMP_READ()
   - fix HHB (highest bank bit) for a619 to fix UBWC corruption

  amdgpu:
   - GPU reset fixes
   - Fix some confusing logging
   - UMSCH fix
   - Aborted suspend fix
   - DCN 3.5 fixes
   - S4 fix
   - MES logging fixes
   - SMU 14 fixes
   - SDMA 4.4.2 fix
   - KASAN fix
   - SMU 13.0.10 fix
   - VCN partition fix
   - GFX11 fixes
   - DWB fixes
   - Plane handling fix
   - FAMS fix
   - DCN 3.1.6 fix
   - VSC SDP fixes
   - OLED panel fix
   - GFX 11.5 fix

  amdkfd:
   - GPU reset fixes
   - fix ioctl integer overflow"

* tag 'drm-fixes-2024-04-12' of https://gitlab.freedesktop.org/drm/kernel: (65 commits)
  amdkfd: use calloc instead of kzalloc to avoid integer overflow
  drm/xe: Label RING_CONTEXT_CONTROL as masked
  drm/xe/xe_migrate: Cast to output precision before multiplying operands
  drm/xe/hwmon: Cast result to output precision on left shift of operand
  drm/xe/display: Fix double mutex initialization
  drm/amdgpu: differentiate external rev id for gfx 11.5.0
  drm/amd/display: Adjust dprefclk by down spread percentage.
  drm/amd/display: Set VSC SDP Colorimetry same way for MST and SST
  drm/amd/display: Program VSC SDP colorimetry for all DP sinks >= 1.4
  drm/amd/display: fix disable otg wa logic in DCN316
  drm/amd/display: Do not recursively call manual trigger programming
  drm/amd/display: always reset ODM mode in context when adding first plane
  drm/amdgpu: fix incorrect number of active RBs for gfx11
  drm/amd/display: Return max resolution supported by DWB
  amd/amdkfd: sync all devices to wait all processes being evicted
  drm/amdgpu: clear set_q_mode_offs when VM changed
  drm/amdgpu: Fix VCN allocation in CPX partition
  drm/amd/pm: fix the high voltage issue after unload
  drm/amd/display: Skip on writeback when it's not applicable
  drm/amdgpu: implement IRQ_STATE_ENABLE for SDMA v4.4.2
  ...

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't implement uname().

Fixes: 6d029c25 ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240412123536.GA32444@redhat.com
Closes: https://lore.kernel.org/all/f0523b3a-ea08-4615-b0fb-5b504a2d39df@sirena.org.uk/

While monitoring the throttle time of IO from iocost, it's found that
such time is always zero after the io_schedule() from ioc_rqos_throttle,
for example, with the following debug patch:

+       printk("%s-%d: %s enter %llu\n", current->comm, current->pid, __func__, blk_time_get_ns());
        while (true) {
                set_current_state(TASK_UNINTERRUPTIBLE);
                if (wait.committed)
                        break;
                io_schedule();
        }
+       printk("%s-%d: %s exit  %llu\n", current->comm, current->pid, __func__, blk_time_get_ns());

It can be observerd that blk_time_get_ns() always return the same time:

[ 1068.096579] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.272587] fio-1268: ioc_rqos_throttle exit  1067901962288
[ 1068.274389] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.472690] fio-1268: ioc_rqos_throttle exit  1067901962288
[ 1068.474485] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.672656] fio-1268: ioc_rqos_throttle exit  1067901962288
[ 1068.674451] fio-1268: ioc_rqos_throttle enter 1067901962288
[ 1068.872655] fio-1268: ioc_rqos_throttle exit  1067901962288

And I think the root cause is that 'PF_BLOCK_TS' is always cleared
by blk_flush_plug() before scheduel(), hence blk_plug_invalidate_ts()
will never be called:

blk_time_get_ns
 plug->cur_ktime = ktime_get_ns();
 current->flags |= PF_BLOCK_TS;

io_schedule:
 io_schedule_prepare
  blk_flush_plug
   __blk_flush_plug
    /* the flag is cleared, while time is not */
    current->flags &= ~PF_BLOCK_TS;
 schedule
 sched_update_worker
  /* the flag is not set, hence plug->cur_ktime is not cleared */
  if (tsk->flags & PF_BLOCK_TS)
   blk_plug_invalidate_ts()

blk_time_get_ns
 /* got the time stashed before schedule */
 return plug->cur_ktime;

Fix the problem by clearing cached time in __blk_flush_plug().

Fixes: 06b23f92 ("block: update cached timestamp post schedule/preemption")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240411032349.3051233-2-yukuai1@huaweicloud.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>

Building with clang results in the following warning:

  posix_timers.c:69:6: warning: absolute value function 'abs' given an
      argument of type 'long long' but has parameter of type 'int' which may
      cause truncation of value [-Wabsolute-value]
        if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
            ^
So switch to using llabs() instead.

Fixes: 0bc4b0cf ("selftests: add basic posix timers selftests")
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240410232637.4135564-3-jstultz@google.com

After commit 6d029c25 ("selftests/timers/posix_timers: Reimplement
check_timer_distribution()"), clang warns:

  tools/testing/selftests/timers/../kselftest.h:398:6: warning: variable 'major' is used uninitialized whenever '||' condition is true [-Wsometimes-uninitialized]
    398 |         if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2)
        |             ^~~~~~~~~~~~
  tools/testing/selftests/timers/../kselftest.h:401:9: note: uninitialized use occurs here
    401 |         return major > min_major || (major == min_major && minor >= min_minor);
        |                ^~~~~
  tools/testing/selftests/timers/../kselftest.h:398:6: note: remove the '||' if its condition is always false
    398 |         if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2)
        |             ^~~~~~~~~~~~~~~
  tools/testing/selftests/timers/../kselftest.h:395:20: note: initialize the variable 'major' to silence this warning
    395 |         unsigned int major, minor;
        |                           ^
        |                            = 0

This is a false positive because if uname() fails, ksft_exit_fail_msg()
will be called, which unconditionally calls exit(), a noreturn function.
However, clang does not know that ksft_exit_fail_msg() will call exit() at
the point in the pipeline that the warning is emitted because inlining has
not occurred, so it assumes control flow will resume normally after
ksft_exit_fail_msg() is called.

Make it clear to clang that all of the functions that call exit()
unconditionally in kselftest.h are noreturn transitively by marking them
explicitly with '__attribute__((__noreturn__))', which clears up the
warning above and any future warnings that may appear for the same reason.

Fixes: 6d029c25 ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Reported-by: John Stultz <jstultz@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240411-mark-kselftest-exit-funcs-noreturn-v1-1-b027c948f586@kernel.org
Closes: https://lore.kernel.org/all/20240410232637.4135564-2-jstultz@google.com/

After commit 6d029c25 ("selftests/timers/posix_timers: Reimplement
check_timer_distribution()") the following warning occurs when building
with an older gcc:

posix_timers.c:250:2: warning: format not a string literal and no format arguments [-Wformat-security]
  250 |  ksft_print_msg(errmsg);
      |  ^~~~~~~~~~~~~~

Fix this up by changing it to ksft_print_msg("%s", errmsg)

Fixes: 6d029c25 ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Justin Stitt <justinstitt@google.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240410232637.4135564-1-jstultz@google.com