Move the stats fd cleanup code into stats_test() and drop the
superfluous vm_stats_test() and vcpu_stats_test() helpers in order to
decouple creation of the stats file from consuming/testing the file
(deduping code is a bonus).  This will make it easier to test various
edge cases related to stats, e.g. that userspace can dup() a stats fd,
that userspace can have multiple stats files for a singleVM/vCPU, etc.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230711230131.648752-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Use pread() with an explicit offset when reading the header and the header
name for a binary stats fd so that the common helper and the binary stats
test don't subtly rely on the file effectively being untouched, e.g. to
allow multiple reads of the header, name, etc.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230711230131.648752-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Grab a reference to KVM prior to installing VM and vCPU stats file
descriptors to ensure the underlying VM and vCPU objects are not freed
until the last reference to any and all stats fds are dropped.

Note, the stats paths manually invoke fd_install() and so don't need to
grab a reference before creating the file.

Fixes: ce55c049 ("KVM: stats: Support binary stats retrieval for a VCPU")
Fixes: fcfe1bae ("KVM: stats: Support binary stats retrieval for a VM")
Reported-by: Zheng Zhang <zheng.zhang@email.ucr.edu>
Closes: https://lore.kernel.org/all/CAC_GQSr3xzZaeZt85k_RCBd5kfiOve8qXo7a81Cq53LuVQ5r=Q@mail.gmail.com
Cc: stable@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Message-Id: <20230711230131.648752-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

To allow running rseq and KVM's rseq selftests as statically linked
binaries, initialize the various "trampoline" pointers to point directly
at the expect glibc symbols, and skip the dlysm() lookups if the rseq
size is non-zero, i.e. the binary is statically linked *and* the libc
registered its own rseq.

Define weak versions of the symbols so as not to break linking against
libc versions that don't support rseq in any capacity.

The KVM selftests in particular are often statically linked so that they
can be run on targets with very limited runtime environments, i.e. test
machines.

Fixes: 233e667e ("selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35")
Cc: Aaron Lewis <aaronlewis@google.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721223352.2333911-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Now that handle_fastpath_set_msr_irqoff() acquires kvm->srcu, i.e. allows
dereferencing memslots during WRMSR emulation, drop the requirement that
"next RIP" is valid.  In hindsight, acquiring kvm->srcu would have been a
better fix than avoiding the pastpath, but at the time it was thought that
accessing SRCU-protected data in the fastpath was a one-off edge case.

This reverts commit 5c30e810.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721224337.2335137-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Temporarily acquire kvm->srcu for read when potentially emulating WRMSR in
the VM-Exit fastpath handler, as several of the common helpers used during
emulation expect the caller to provide SRCU protection.  E.g. if the guest
is counting instructions retired, KVM will query the PMU event filter when
stepping over the WRMSR.

  dump_stack+0x85/0xdf
  lockdep_rcu_suspicious+0x109/0x120
  pmc_event_is_allowed+0x165/0x170
  kvm_pmu_trigger_event+0xa5/0x190
  handle_fastpath_set_msr_irqoff+0xca/0x1e0
  svm_vcpu_run+0x5c3/0x7b0 [kvm_amd]
  vcpu_enter_guest+0x2108/0x2580

Alternatively, check_pmu_event_filter() could acquire kvm->srcu, but this
isn't the first bug of this nature, e.g. see commit 5c30e810 ("KVM:
SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid").  Providing
protection for the entirety of WRMSR emulation will allow reverting the
aforementioned commit, and will avoid having to play whack-a-mole when new
uses of SRCU-protected structures are inevitably added in common emulation
helpers.

Fixes: dfdeda67 ("KVM: x86/pmu: Prevent the PMU from counting disallowed events")
Reported-by: Greg Thelen <gthelen@google.com>
Reported-by: Aaron Lewis <aaronlewis@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721224337.2335137-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Use vmread_error() to report VM-Fail on VMREAD for the "asm goto" case,
now that trampoline case has yet another wrapper around vmread_error() to
play nice with instrumentation.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721235637.2345403-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Mark vmread_error_trampoline() as noinstr, and add a second trampoline
for the CONFIG_CC_HAS_ASM_GOTO_OUTPUT=n case to enable instrumentation
when handling VM-Fail on VMREAD.  VMREAD is used in various noinstr
flows, e.g. immediately after VM-Exit, and objtool rightly complains that
the call to the error trampoline leaves a no-instrumentation section
without annotating that it's safe to do so.

  vmlinux.o: warning: objtool: vmx_vcpu_enter_exit+0xc9:
  call to vmread_error_trampoline() leaves .noinstr.text section

Note, strictly speaking, enabling instrumentation in the VM-Fail path
isn't exactly safe, but if VMREAD fails the kernel/system is likely hosed
anyways, and logging that there is a fatal error is more important than
*maybe* encountering slightly unsafe instrumentation.
Reported-by: Su Hui <suhui@nfschina.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721235637.2345403-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

As was attempted commit 14717e20 ("kvm: Conditionally register IRQ
bypass consumer"): "if we don't support a mechanism for bypassing IRQs,
don't register as a consumer.  Initially this applied to AMD processors,
but when AVIC support was implemented for assigned devices,
kvm_arch_has_irq_bypass() was always returning true.

We can still skip registering the consumer where enable_apicv
or posted-interrupts capability is unsupported or globally disabled.
This eliminates meaningless dev_info()s when the connect fails
between producer and consumer", such as on Linux hosts where enable_apicv
or posted-interrupts capability is unsupported or globally disabled.

Cc: Alex Williamson <alex.williamson@redhat.com>
Reported-by: Yong He <alexyonghe@tencent.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217379Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20230724111236.76570-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The pid_table of ipiv is the persistent memory allocated by
per-vcpu, which should be counted into the memory cgroup.
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Message-Id: <CAPm50aLxCQ3TQP2Lhc0PX3y00iTRg+mniLBqNDOC=t9CLxMwwA@mail.gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The code was blindly assuming that kvm_cpu_get_interrupt never returns -1
when there is a pending interrupt.

While this should be true, a bug in KVM can still cause this.

If -1 is returned, the code before this patch was converting it to 0xFF,
and 0xFF interrupt was injected to the guest, which results in an issue
which was hard to debug.

Add WARN_ON_ONCE to catch this case and	skip the injection
if this happens again.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20230726135945.260841-4-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

When the APICv is inhibited, the irr_pending optimization is used.

Therefore, when kvm_apic_update_irr sets bits in the IRR,
it must set irr_pending to true as well.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20230726135945.260841-3-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

If APICv is inhibited, then IPIs from peer vCPUs are done by
atomically setting bits in IRR.

This means, that when __kvm_apic_update_irr copies PIR to IRR,
it has to modify IRR atomically as well.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20230726135945.260841-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull tracing fixes from Steven Rostedt:

 - Swapping the ring buffer for snapshotting (for things like irqsoff)
   can crash if the ring buffer is being resized. Disable swapping when
   this happens. The missed swap will be reported to the tracer

 - Report error if the histogram fails to be created due to an error in
   adding a histogram variable, in event_hist_trigger_parse()

 - Remove unused declaration of tracing_map_set_field_descr()

* tag 'trace-v6.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/histograms: Return an error if we fail to add histogram to hist_vars list
  ring-buffer: Do not swap cpu_buffer during resize process
  tracing: Remove unused extern declaration tracing_map_set_field_descr()

Merge tag 'kbuild-fixes-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix stale help text in gconfig

 - Support *.S files in compile_commands.json

 - Flatten KBUILD_CFLAGS

 - Fix external module builds with Rust so that temporary files are
   created in the modules directories instead of the kernel tree

* tag 'kbuild-fixes-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: rust: avoid creating temporary files
  kbuild: flatten KBUILD_CFLAGS
  gen_compile_commands: add assembly files to compilation database
  kconfig: gconfig: correct program name in help text
  kconfig: gconfig: drop the Show Debug Info help text

`rustc` outputs by default the temporary files (i.e. the ones saved
by `-Csave-temps`, such as `*.rcgu*` files) in the current working
directory when `-o` and `--out-dir` are not given (even if
`--emit=x=path` is given, i.e. it does not use those for temporaries).

Since out-of-tree modules are compiled from the `linux` tree,
`rustc` then tries to create them there, which may not be accessible.

Thus pass `--out-dir` explicitly, even if it is just for the temporary
files.

Similarly, do so for Rust host programs too.
Reported-by: Raphael Nestler <raphael.nestler@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1015Reported-by: Andrea Righi <andrea.righi@canonical.com>
Tested-by: Raphael Nestler <raphael.nestler@gmail.com> # non-hostprogs
Tested-by: Andrea Righi <andrea.righi@canonical.com> # non-hostprogs
Fixes: 295d8398 ("kbuild: specify output names separately for each emission type from rustc")
Cc: stable@vger.kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Avoid pKVM finalization if KVM initialization fails

   - Add missing BTI instructions in the hypervisor, fixing an early
     boot failure on BTI systems

   - Handle MMU notifiers correctly for non hugepage-aligned memslots

   - Work around a bug in the architecture where hypervisor timer
     controls have UNKNOWN behavior under nested virt

   - Disable preemption in kvm_arch_hardware_enable(), fixing a kernel
     BUG in cpu hotplug resulting from per-CPU accessor sanity checking

   - Make WFI emulation on GICv4 systems robust w.r.t. preemption,
     consistently requesting a doorbell interrupt on vcpu_put()

   - Uphold RES0 sysreg behavior when emulating older PMU versions

   - Avoid macro expansion when initializing PMU register names,
     ensuring the tracepoints pretty-print the sysreg

  s390:

   - Two fixes for asynchronous destroy

  x86 fixes will come early next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: s390: pv: fix index value of replaced ASCE
  KVM: s390: pv: simplify shutdown and fix race
  KVM: arm64: Fix the name of sys_reg_desc related to PMU
  KVM: arm64: Correctly handle RES0 bits PMEVTYPER<n>_EL0.evtCount
  KVM: arm64: vgic-v4: Make the doorbell request robust w.r.t preemption
  KVM: arm64: Add missing BTI instructions
  KVM: arm64: Correctly handle page aging notifiers for unaligned memslot
  KVM: arm64: Disable preemption in kvm_arch_hardware_enable()
  KVM: arm64: Handle kvm_arm_init failure correctly in finalize_pkvm
  KVM: arm64: timers: Use CNTHCTL_EL2 when setting non-CNTKCTL_EL1 bits

Pull ext4 fixes from Ted Ts'o:
 "Bug and regression fixes for 6.5-rc3 for ext4's mballoc and jbd2's
  checkpoint code"

* tag 'ext4_for_linus-6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix rbtree traversal bug in ext4_mb_use_preallocated
  ext4: fix off by one issue in ext4_mb_choose_next_group_best_avail()
  ext4: correct inline offset when handling xattrs in inode body
  jbd2: remove __journal_try_to_free_buffer()
  jbd2: fix a race when checking checkpoint buffer busy
  jbd2: Fix wrongly judgement for buffer head removing while doing checkpoint
  jbd2: remove journal_clean_one_cp_list()
  jbd2: remove t_checkpoint_io_list
  jbd2: recheck chechpointing non-dirty buffer

Pull smb client fix from Steve French:
 "Add minor debugging improvement.

  The change improves ability to read a network trace to debug problems
  on encrypted connections which are very common (e.g. using wireshark
  or tcpdump).

  That works today with tools like 'smbinfo keys /mnt/file' but requires
  passing in a filename on the mount (see e.g. [1]), but it often makes
  more sense to just pass in the mount point path (ie a directory not a
  filename).

  So this fix was needed to debug some types of problems (an obvious
  example is on an encrypted connection failing operations on an empty
  share or with no files in the root of the directory) - so you can
  simply pass in the 'smbinfo keys <mntpoint>' and get the information
  that wireshark needs"

Link: https://wiki.samba.org/index.php/Wireshark_Decryption [1]

* tag '6.5-rc2-smb3-client-fixes-ver2' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number for cifs.ko
  cifs: allow dumping keys for directories too

Merge tag 'kvm-s390-master-6.5-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

Two fixes for asynchronous destroy

Merge tag 'kvmarm-fixes-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.5, part #1

 - Avoid pKVM finalization if KVM initialization fails

 - Add missing BTI instructions in the hypervisor, fixing an early boot
   failure on BTI systems

 - Handle MMU notifiers correctly for non hugepage-aligned memslots

 - Work around a bug in the architecture where hypervisor timer controls
   have UNKNOWN behavior under nested virt.

 - Disable preemption in kvm_arch_hardware_enable(), fixing a kernel BUG
   in cpu hotplug resulting from per-CPU accessor sanity checking.

 - Make WFI emulation on GICv4 systems robust w.r.t. preemption,
   consistently requesting a doorbell interrupt on vcpu_put()

 - Uphold RES0 sysreg behavior when emulating older PMU versions

 - Avoid macro expansion when initializing PMU register names, ensuring
   the tracepoints pretty-print the sysreg.

Commit 6018b585 ("tracing/histograms: Add histograms to hist_vars if
they have referenced variables") added a check to fail histogram creation
if save_hist_vars() failed to add histogram to hist_vars list. But the
commit failed to set ret to failed return code before jumping to
unregister histogram, fix it.

Link: https://lore.kernel.org/linux-trace-kernel/20230714203341.51396-1-mkhalfella@purestorage.com

Cc: stable@vger.kernel.org
Fixes: 6018b585 ("tracing/histograms: Add histograms to hist_vars if they have referenced variables")
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

When ring_buffer_swap_cpu was called during resize process,
the cpu buffer was swapped in the middle, resulting in incorrect state.
Continuing to run in the wrong state will result in oops.

This issue can be easily reproduced using the following two scripts:
/tmp # cat test1.sh
//#! /bin/sh
for i in `seq 0 100000`
do
         echo 2000 > /sys/kernel/debug/tracing/buffer_size_kb
         sleep 0.5
         echo 5000 > /sys/kernel/debug/tracing/buffer_size_kb
         sleep 0.5
done
/tmp # cat test2.sh
//#! /bin/sh
for i in `seq 0 100000`
do
        echo irqsoff > /sys/kernel/debug/tracing/current_tracer
        sleep 1
        echo nop > /sys/kernel/debug/tracing/current_tracer
        sleep 1
done
/tmp # ./test1.sh &
/tmp # ./test2.sh &

A typical oops log is as follows, sometimes with other different oops logs.

[  231.711293] WARNING: CPU: 0 PID: 9 at kernel/trace/ring_buffer.c:2026 rb_update_pages+0x378/0x3f8
[  231.713375] Modules linked in:
[  231.714735] CPU: 0 PID: 9 Comm: kworker/0:1 Tainted: G        W          6.5.0-rc1-00276-g20edcec2 #15
[  231.716750] Hardware name: linux,dummy-virt (DT)
[  231.718152] Workqueue: events update_pages_handler
[  231.719714] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  231.721171] pc : rb_update_pages+0x378/0x3f8
[  231.722212] lr : rb_update_pages+0x25c/0x3f8
[  231.723248] sp : ffff800082b9bd50
[  231.724169] x29: ffff800082b9bd50 x28: ffff8000825f7000 x27: 0000000000000000
[  231.726102] x26: 0000000000000001 x25: fffffffffffff010 x24: 0000000000000ff0
[  231.728122] x23: ffff0000c3a0b600 x22: ffff0000c3a0b5c0 x21: fffffffffffffe0a
[  231.730203] x20: ffff0000c3a0b600 x19: ffff0000c0102400 x18: 0000000000000000
[  231.732329] x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffe7aa8510
[  231.734212] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000002
[  231.736291] x11: ffff8000826998a8 x10: ffff800082b9baf0 x9 : ffff800081137558
[  231.738195] x8 : fffffc00030e82c8 x7 : 0000000000000000 x6 : 0000000000000001
[  231.740192] x5 : ffff0000ffbafe00 x4 : 0000000000000000 x3 : 0000000000000000
[  231.742118] x2 : 00000000000006aa x1 : 0000000000000001 x0 : ffff0000c0007208
[  231.744196] Call trace:
[  231.744892]  rb_update_pages+0x378/0x3f8
[  231.745893]  update_pages_handler+0x1c/0x38
[  231.746893]  process_one_work+0x1f0/0x468
[  231.747852]  worker_thread+0x54/0x410
[  231.748737]  kthread+0x124/0x138
[  231.749549]  ret_from_fork+0x10/0x20
[  231.750434] ---[ end trace 0000000000000000 ]---
[  233.720486] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[  233.721696] Mem abort info:
[  233.721935]   ESR = 0x0000000096000004
[  233.722283]   EC = 0x25: DABT (current EL), IL = 32 bits
[  233.722596]   SET = 0, FnV = 0
[  233.722805]   EA = 0, S1PTW = 0
[  233.723026]   FSC = 0x04: level 0 translation fault
[  233.723458] Data abort info:
[  233.723734]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[  233.724176]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  233.724589]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  233.725075] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000104943000
[  233.725592] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[  233.726231] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[  233.726720] Modules linked in:
[  233.727007] CPU: 0 PID: 9 Comm: kworker/0:1 Tainted: G        W          6.5.0-rc1-00276-g20edcec2 #15
[  233.727777] Hardware name: linux,dummy-virt (DT)
[  233.728225] Workqueue: events update_pages_handler
[  233.728655] pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  233.729054] pc : rb_update_pages+0x1a8/0x3f8
[  233.729334] lr : rb_update_pages+0x154/0x3f8
[  233.729592] sp : ffff800082b9bd50
[  233.729792] x29: ffff800082b9bd50 x28: ffff8000825f7000 x27: 0000000000000000
[  233.730220] x26: 0000000000000000 x25: ffff800082a8b840 x24: ffff0000c0102418
[  233.730653] x23: 0000000000000000 x22: fffffc000304c880 x21: 0000000000000003
[  233.731105] x20: 00000000000001f4 x19: ffff0000c0102400 x18: ffff800082fcbc58
[  233.731727] x17: 0000000000000000 x16: 0000000000000001 x15: 0000000000000001
[  233.732282] x14: ffff8000825fe0c8 x13: 0000000000000001 x12: 0000000000000000
[  233.732709] x11: ffff8000826998a8 x10: 0000000000000ae0 x9 : ffff8000801b760c
[  233.733148] x8 : fefefefefefefeff x7 : 0000000000000018 x6 : ffff0000c03298c0
[  233.733553] x5 : 0000000000000002 x4 : 0000000000000000 x3 : 0000000000000000
[  233.733972] x2 : ffff0000c3a0b600 x1 : 0000000000000000 x0 : 0000000000000000
[  233.734418] Call trace:
[  233.734593]  rb_update_pages+0x1a8/0x3f8
[  233.734853]  update_pages_handler+0x1c/0x38
[  233.735148]  process_one_work+0x1f0/0x468
[  233.735525]  worker_thread+0x54/0x410
[  233.735852]  kthread+0x124/0x138
[  233.736064]  ret_from_fork+0x10/0x20
[  233.736387] Code: 92400000 910006b5 aa000021 aa0303f7 (f9400060)
[  233.736959] ---[ end trace 0000000000000000 ]---

After analysis, the seq of the error is as follows [1-5]:

int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
			int cpu_id)
{
	for_each_buffer_cpu(buffer, cpu) {
		cpu_buffer = buffer->buffers[cpu];
		//1. get cpu_buffer, aka cpu_buffer(A)
		...
		...
		schedule_work_on(cpu,
		 &cpu_buffer->update_pages_work);
		//2. 'update_pages_work' is queue on 'cpu', cpu_buffer(A) is passed to
		// update_pages_handler, do the update process, set 'update_done' in
		// complete(&cpu_buffer->update_done) and to wakeup resize process.
	//---->
		//3. Just at this moment, ring_buffer_swap_cpu is triggered,
		//cpu_buffer(A) be swaped to cpu_buffer(B), the max_buffer.
		//ring_buffer_swap_cpu is called as the 'Call trace' below.

		Call trace:
		 dump_backtrace+0x0/0x2f8
		 show_stack+0x18/0x28
		 dump_stack+0x12c/0x188
		 ring_buffer_swap_cpu+0x2f8/0x328
		 update_max_tr_single+0x180/0x210
		 check_critical_timing+0x2b4/0x2c8
		 tracer_hardirqs_on+0x1c0/0x200
		 trace_hardirqs_on+0xec/0x378
		 el0_svc_common+0x64/0x260
		 do_el0_svc+0x90/0xf8
		 el0_svc+0x20/0x30
		 el0_sync_handler+0xb0/0xb8
		 el0_sync+0x180/0x1c0
	//<----

	/* wait for all the updates to complete */
	for_each_buffer_cpu(buffer, cpu) {
		cpu_buffer = buffer->buffers[cpu];
		//4. get cpu_buffer, cpu_buffer(B) is used in the following process,
		//the state of cpu_buffer(A) and cpu_buffer(B) is totally wrong.
		//for example, cpu_buffer(A)->update_done will leave be set 1, and will
		//not 'wait_for_completion' at the next resize round.
		  if (!cpu_buffer->nr_pages_to_update)
			continue;

		if (cpu_online(cpu))
			wait_for_completion(&cpu_buffer->update_done);
		cpu_buffer->nr_pages_to_update = 0;
	}
	...
}
	//5. the state of cpu_buffer(A) and cpu_buffer(B) is totally wrong,
	//Continuing to run in the wrong state, then oops occurs.

Link: https://lore.kernel.org/linux-trace-kernel/202307191558478409990@zte.com.cnSigned-off-by: Chen Lin <chen.lin5@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Since commit 08d43a5f ("tracing: Add lock-free tracing_map"),
this is never used, so can be removed.

Link: https://lore.kernel.org/linux-trace-kernel/20230722032123.24664-1-yuehaibing@huawei.com

Cc: <mhiramat@kernel.org>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Make it slightly easier to see which compiler options are added and
removed (and not worry about column limit too!).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Like C source files, tooling can find it useful to have the assembly
source file compilation recorded.

The .S extension appears to used across all architectures.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

During allocations, while looking for preallocations(PA) in the per
inode rbtree, we can't do a direct traversal of the tree because
ext4_mb_discard_group_preallocation() can paralelly mark the pa deleted
and that can cause direct traversal to skip some entries. This was
leading to a BUG_ON() being hit [1] when we missed a PA that could satisfy
our request and ultimately tried to create a new PA that would overlap
with the missed one.

To makes sure we handle that case while still keeping the performance of
the rbtree, we make use of the fact that the only pa that could possibly
overlap the original goal start is the one that satisfies the below
conditions:

  1. It must have it's logical start immediately to the left of
  (ie less than) original logical start.

  2. It must not be deleted

To find this pa we use the following traversal method:

1. Descend into the rbtree normally to find the immediate neighboring
PA. Here we keep descending irrespective of if the PA is deleted or if
it overlaps with our request etc. The goal is to find an immediately
adjacent PA.

2. If the found PA is on right of original goal, use rb_prev() to find
the left adjacent PA.

3. Check if this PA is deleted and keep moving left with rb_prev() until
a non deleted PA is found.

4. This is the PA we are looking for. Now we can check if it can satisfy
the original request and proceed accordingly.

This approach also takes care of having deleted PAs in the tree.

(While we are at it, also fix a possible overflow bug in calculating the
end of a PA)

[1] https://lore.kernel.org/linux-ext4/CA+G9fYv2FRpLqBZf34ZinR8bU2_ZRAUOjKAD3+tKRFaEQHtt8Q@mail.gmail.com/

Cc: stable@kernel.org # 6.4
Fixes: 38727786 ("ext4: Use rbtrees to manage PAs instead of inode i_prealloc_list")
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Ritesh Harjani (IBM) ritesh.list@gmail.com
Tested-by: Ritesh Harjani (IBM) ritesh.list@gmail.com
Link: https://lore.kernel.org/r/edd2efda6a83e6343c5ace9deea44813e71dbe20.1690045963.git.ojaswin@linux.ibm.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

In ext4_mb_choose_next_group_best_avail(), we want the start order to be
1 less than goal length and the min_order to be, at max, 1 more than the
original length. This commit fixes an off by one issue that arose due to
the fact that 1 << fls(n) > (n).

After all the processing:

order = 1 order below goal len
min_order = maximum of the three:-
             - order - trim_order
             - 1 order below B2C(s_stripe)
             - 1 order above original len

Cc: stable@kernel.org
Fixes: 33122aa930 ("ext4: Add allocation criteria 1.5 (CR1_5)")
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230609103403.112807-1-ojaswin@linux.ibm.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

When run on a file system where the inline_data feature has been
enabled, xfstests generic/269, generic/270, and generic/476 cause ext4
to emit error messages indicating that inline directory entries are
corrupted.  This occurs because the inline offset used to locate
inline directory entries in the inode body is not updated when an
xattr in that shared region is deleted and the region is shifted in
memory to recover the space it occupied.  If the deleted xattr precedes
the system.data attribute, which points to the inline directory entries,
that attribute will be moved further up in the region.  The inline
offset continues to point to whatever is located in system.data's former
location, with unfortunate effects when used to access directory entries
or (presumably) inline data in the inode body.

Cc: stable@kernel.org
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Link: https://lore.kernel.org/r/20230522181520.1570360-1-enwlinux@gmail.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

Pull powerpc fixes from Michael Ellerman:

 - Reinstate support for little endian ELFv1 binaries, which it turns
   out still exist in the wild.

 - Revert a change which used asm goto for WARN_ON/__WARN_FLAGS, as it
   lead to dead code generation and seemed to trigger compiler bugs in
   some edge cases.

 - Fix a deadlock in the pseries VAS code, between live migration and
   the driver's mmap handler.

 - Disable KCOV instrumentation in the powerpc KASAN code.

Thanks to Andrew Donnellan, Benjamin Gray, Christophe Leroy, Haren
Myneni, Russell Currey, and Uwe Kleine-König.

* tag 'powerpc-6.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  Revert "powerpc/64s: Remove support for ELFv1 little endian userspace"
  powerpc/kasan: Disable KCOV in KASAN code
  powerpc/512x: lpbfifo: Convert to platform remove callback returning void
  powerpc/crypto: Add gitignore for generated P10 AES/GCM .S files
  Revert "powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto"
  powerpc/pseries/vas: Hold mmap_mutex after mmap lock during window close

From 2.43 to 2.44
Signed-off-by: Steve French <stfrench@microsoft.com>

Dumping the enc/dec keys is a session wide operation.
And it should not matter if the ioctl was run on
a regular file or a directory.

Currently, we obtain the tcon pointer from the
cifs file handle. But since there's no dir open call
in cifs, this is not populated for dirs.

This change allows dumping of session keys using ioctl
even for directories. To do this, we'll now get the
tcon pointer from the superblock, and not from the file
handle.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Pull s390 fixes from Heiko Carstens:

 - Fix per vma lock fault handling: add missing !(fault & VM_FAULT_ERROR)
   check to fault handler to prevent error handling for return values
   that don't indicate an error

 - Use kfree_sensitive() instead of kfree() in paes crypto code to clear
   memory that may contain keys before freeing it

 - Fix reply buffer size calculation for CCA replies in zcrypt device
   driver

* tag 's390-6.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/zcrypt: fix reply buffer calculations for CCA replies
  s390/crypto: use kfree_sensitive() instead of kfree()
  s390/mm: fix per vma lock fault handling

Pull block fixes from Jens Axboe:

 - Fix for loop regressions (Mauricio)

 - Fix a potential stall with batched wakeups in sbitmap (David)

 - Fix for stall with recursive plug flushes (Ross)

 - Skip accounting of empty requests for blk-iocost (Chengming)

 - Remove a dead field in struct blk_mq_hw_ctx (Chengming)

* tag 'block-6.5-2023-07-21' of git://git.kernel.dk/linux:
  loop: do not enforce max_loop hard limit by (new) default
  loop: deprecate autoloading callback loop_probe()
  sbitmap: fix batching wakeup
  blk-iocost: skip empty flush bio in iocost
  blk-mq: delete dead struct blk_mq_hw_ctx->queued field
  blk-mq: Fix stall due to recursive flush plug

Pull io_uring fixes from Jens Axboe:

 - Fix for io-wq not always honoring REQ_F_NOWAIT, if it was set and
   punted directly (eg via DRAIN) (me)

 - Capability check fix (Ondrej)

 - Regression fix for the mmap changes that went into 6.4, which
   apparently broke IA64 (Helge)

* tag 'io_uring-6.5-2023-07-21' of git://git.kernel.dk/linux:
  ia64: mmap: Consider pgoff when searching for free mapping
  io_uring: Fix io_uring mmap() by using architecture-provided get_unmapped_area()
  io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq
  io_uring: don't audit the capability check in io_uring_create()

Pull devicetree fixes from Rob Herring:

 - Fix moortec,mr75203 schema usage of 'multipleOf' keyword

 - Fix regression in systems depending on "of-display" device name

 - Build fix for s390 with CONFIG_PCI=n and OF_EARLY_FLATTREE=y

 - Drop two obsolete serial .txt bindings

* tag 'devicetree-fixes-for-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: serial: Remove obsolete nxp,lpc1850-uart.txt
  dt-bindings: serial: Remove obsolete cavium-uart.txt
  dt-bindings: hwmon: moortec,mr75203: fix multipleOf for coefficients
  of: Preserve "of-display" device name for compatibility
  of: make OF_EARLY_FLATTREE depend on HAS_IOMEM

Pull regmap fixes from Mark Brown:
 "Three fixes here:

   - The issues with accounting for register and padding length on raw
     buses turn out to be quite widespread in custom buses.

     In order to avoid disturbing anything drop the initial fixes and
     fall back to a point fix in the SMBus code where the issue was
     originally noticed, a more substantial refactoring of the API which
     ensures that all buses make the same assumptions will follow.

   - The generic regcache code had been forcing on async I/O which did
     not work with the new maple tree sync code when used with SPI.

     Since that was mainly for the rbtree cache and the assumptions
     about hardware that drove the choice are probably not true any more
     fix this by pushing the enablement of async down into the rbtree
     code.

     This probably also makes cache syncs for systems faster though it's
     not the point.

   - The test code was triggering use of the rbtree and maple tree
     caches with dynamic allocation of nodes since all the testing is
     with RAM backed caches with no I/O performance issues.

     Just disable the locking in the tests to avoid triggering warnings
     when allocation debugging is turned on, it's not really what's
     being tested"

* tag 'regmap-fix-v6.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: Disable locking for RBTREE and MAPLE unit tests
  regcache: Push async I/O request down into the rbtree cache
  regmap: Account for register length in SMBus I/O limits
  regmap: Drop initial version of maximum transfer length fixes

Pull gpio fixes from Bartosz Golaszewski:

 - fix initial value handling for output-only pins in gpio-tps68470

 - fix two resource leaks in gpio-mvebu

* tag 'gpio-fixes-for-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: mvebu: fix irq domain leak
  gpio: mvebu: Make use of devm_pwmchip_add
  gpio: tps68470: Make tps68470_gpio_output() always set the initial value

nxp,lpc1850-uart.txt binding is already covered by 8250.yaml, so remove
it.
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230707221607.1064888-1-robh@kernel.orgSigned-off-by: Rob Herring <robh@kernel.org>