Commit Graph

1200480 Commits

Author SHA1 Message Date
Christophe JAILLET
7fb0ad1938 s390/ebcdic: fix typo in comment
s/ECBDIC/EBCDIC/ 	(C and B are swapped)

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/08ed63331699177b3354458da66a2f63c0217e49.1686407113.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-27 13:11:35 +02:00
Heiko Carstens
e810487385 s390/diag: fix diagnose 8c description
The comment above diag8c() describes diagnose 210, not diagnose 8c.
Add a proper short description.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-27 13:11:35 +02:00
Masahiro Yamada
305b9f4f7b s390: use obj-y to descend into drivers/s390/
The single build rule does not work with the drivers-y syntax. [1]

Use the standard obj-y syntax. It moves the objects from drivers/s390/
to slightly lower address, but fixes the reported issue.

[1]: https://lore.kernel.org/linux-kbuild/d57ba55f-20a3-b836-783d-b49c8a161b6e@kernel.org/T/#m27f781ab60acadfed8a9e9642f30d5414a5e2df3

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230721171358.3612099-1-masahiroy@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:25 +02:00
Costa Shulyupin
37002bc6b6 docs: move s390 under arch
and fix all in-tree references.

Architecture-specific documentation is being moved into Documentation/arch/
as a way of cleaning up the top-level documentation directory and making
the docs hierarchy more closely match the source hierarchy.

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20230718045550.495428-1-costa.shul@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:24 +02:00
Sven Schnelle
e3123dfb53 s390/tracing: pass struct ftrace_regs to ftrace_trace_function
ftrace_trace_function expects a struct ftrace_regs, but the s390
architecure code passes struct pt_regs. This isn't a problem with the
current code because struct ftrace_regs contains only one member:
struct pt_regs. To avoid issues in the future this should be fixed.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:24 +02:00
Sven Schnelle
5216d853cb s390/hypfs: stop using ENOSYS error code
ENOSYS should only be returned to userspace when a syscall
is not implemented. The only known user, 'hyptop' is not explicitely
checking for -ENOSYS, therefore use EOPNOTSUPP instead. It is very
unlikely that there are other users, so this change should have no
impact on userspace.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:24 +02:00
Alexander Gordeev
e7e828ebeb s390/mm: get rid of VMEM_MAX_PHYS macro
There are no users of VMEM_MAX_PHYS macro left, remove it.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:24 +02:00
Alexander Gordeev
9916bf4eda s390/extmem: improve reporting of -ERANGE error
Interface segment_warning() reports maximum mappable physical
address for -ERANGE error. Currently that address is the value
of VMEM_MAX_PHYS macro, but that well might change. A better
way to obtain that address is calling arch_get_mappable_range()
callback - one that is used by vmem_add_mapping() and generates
-ERANGE error in the first place.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:24 +02:00
Alexander Gordeev
94fd522069 s390/mm: rework arch_get_mappable_range() callback
As per description in mm/memory_hotplug.c platforms should define
arch_get_mappable_range() that provides maximum possible addressable
physical memory range for which the linear mapping could be created.

The current implementation uses VMEM_MAX_PHYS macro as the maximum
mappable physical address and it is simply a cast to vmemmap. Since
the address is in physical address space the natural upper limit of
MAX_PHYSMEM_BITS is honoured:

	vmemmap_start = min(vmemmap_start, 1UL << MAX_PHYSMEM_BITS);

Further, to make sure the identity mapping would not overlay with
vmemmap, the size of identity mapping could be stripped like this:

	ident_map_size = min(ident_map_size, vmemmap_start);

Similarily, any other memory that could be added (e.g DCSS segment)
should not overlay with vmemmap as well and that is prevented by
using vmemmap (VMEM_MAX_PHYS macro) as the upper limit.

However, while the use of VMEM_MAX_PHYS brings the desired result
it actually poses two issues:

1. As described, vmemmap is handled as a physical address, although
   it is actually a pointer to struct page in virtual address space.

2. As vmemmap is a virtual address it could have been located
   anywhere in the virtual address space. However, the desired
   necessity to honour MAX_PHYSMEM_BITS limit prevents that.

Rework arch_get_mappable_range() callback in a way it does not
use VMEM_MAX_PHYS macro and does not confuse the notion of virtual
vs physical address spacees as result. That paves the way for moving
vmemmap elsewhere and optimizing the virtual address space layout.

Introduce max_mappable preserved boot variable and let function
setup_kernel_memory_layout() set it up. As result, the rest of the
code is does not need to know the virtual memory layout specifics.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:23 +02:00
Alexander Gordeev
355e30ca1a s390/mm: remove redundant check against VMEM_MAX_PHYS
The value of ident_map_size could never exceed the value of
vmemmap as secured by setup_kernel_memory_layout() function:

	/* make sure identity map doesn't overlay with vmemmap */
	ident_map_size = min(ident_map_size, vmemmap_start);

Since VMEM_MAX_PHYS macro is set to vmemmap and a newly added
range is checked against ident_map_size in add_memory_merged()
function anyway, the check against VMEM_MAX_PHYS is redundant.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:23 +02:00
Alexander Gordeev
3b53d7b131 s390/dcssblk: fix virtual vs physical address confusion
Fix virtual vs physical address confusion (which currently are the same).

Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:23 +02:00
Alexander Gordeev
04b8698ae8 s390/dcssblk: use IS_ALIGNED() for alignment checks
Use IS_ALIGNED() instead of cumbersome bit manipulations.

Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:23 +02:00
Alexander Gordeev
b9b4568843 s390/kexec: make machine_kexec() depend on CONFIG_KEXEC_CORE
Make machine_kexec.o and relocate_kernel.o depend on
CONFIG_KEXEC_CORE option as other architectures do.

Still generate machine_kexec_reloc.o unconditionally,
since arch_kexec_do_relocs() function is neded by the
decompressor.

Suggested-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:23 +02:00
Sven Schnelle
1256e70a08 s390/ftrace: enable HAVE_FUNCTION_GRAPH_RETVAL
Add support for tracing return values in the function graph tracer.
This requires return_to_handler() to record gpr2 and the frame pointer

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:22 +02:00
Heiko Carstens
3325b4d857 s390/hypfs: factor out filesystem code
The s390_hypfs filesystem is deprecated and shouldn't be used due to its
rather odd semantics. It creates a whole directory structure with static
file contents so a user can read a consistent state while within that
directory.
Writing to its update attribute will remove and rebuild nearly the whole
filesystem, so that again a user can read a consistent state, even if
multiple files need to be read.

Given that this wastes a lot of CPU cycles, and involves a lot of code,
binary interfaces have been added quite a couple of years ago, which simply
pass the binary data to user space, and let user space decode the data.
This is the preferred and only way how the data should be retrieved.

The assumption is that there are no users of the s390_hypfs filesystem.
However instead of just removing the code, and having to revert in case
there are actually users, factor the filesystem code out and make it only
available via a new config option.

This config option is supposed to be disabled. If it turns out there are no
complaints the filesystem code can be removed probably in a couple of
years.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:22 +02:00
Heiko Carstens
b7857acc1b s390/hypfs: remove open-coded PTR_ALIGN()
Get rid of page_align_ptr() and use PTR_ALIGN() instead.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:22 +02:00
Heiko Carstens
83f9567194 s390/hypfs: simplify memory allocation
Simplify memory allocation for diagnose 204 memory buffer:

- allocate with __vmalloc_node() to enure page alignment
- allocate real / physical memory area also within vmalloc area and handle
  vmalloc to real / physical address translation within diag204().

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:22 +02:00
Harald Freudenberger
5ac8c72462 s390/zcrypt: remove CEX2 and CEX3 device drivers
Remove the legacy device driver code for CEX2 and CEX3 cards.

The last machines which are able to handle CEX2 crypto cards
are z10 EC first available 2008 and z10 BC first available 2009.
The last machines able to handle a CEX3 crypto card are
z196 first available 2010 and z114 first available 2011.

Please note that this does not imply to drop CEX2 and CEX3
support in general. With older kernels on hardware up to the
aforementioned machine models these crypto cards will get
support by IBM.

The removal of the CEX2 and CEX3 device drivers code opens up
some simplifications, for example support for crypto cards
without rng support can be removed also.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:22 +02:00
Heiko Carstens
86e74965bb s390/sthyi: enforce 4k alignment of vmalloc'ed area
vmalloc() does not guarantee any alignment, unless it is explicitly
requested with e.g. __vmalloc_node(). Using diag204() with subcode 7
requires a 4k aligned virtual buffer. Therefore switch to __vmalloc_node().

Note: with the current vmalloc() implementation callers would still get a
4k aligned area, even though this is quite non-obvious looking at the
code. So changing this in sthyi doesn't fix a real bug. It is just to make
sure the code will not suffer from some obscure options, like it happened
in the past with kmalloc() where debug options changed the assumed
alignment of allocated memory areas.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:21 +02:00
Heiko Carstens
c83cd4fe31 s390/diag: handle diag 204 subcode 4 address correctly
Diagnose 204 subcode 4 requires a real (physical) address, but a
virtual address is passed to the inline assembly.

Convert the address to a physical address for only this specific case.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:21 +02:00
Anastasia Eskova
8cf57d7217 s390: add support for user-defined certificates
Enable receiving the user-defined certificates from the s390x
hypervisor via new diagnose 0x320 calls, and make them available to the
Linux root user as 'cert_store_key' type keys in a so-called
'cert_store' keyring.

New user-space interfaces:

  /sys/firmware/cert_store/refresh

    Writing to this attribute re-fetches certificates via DIAG 0x320

  /sys/firmware/cert_store/cs_status

    Reading from this attribute returns either of:

	  "uninitialized"
	    If no certificate has been retrieved yet
	  "ok"
	    If certificates have been successfully retrieved
	  "failed (<number>)"
	    If certificate retrieval failed with reason code <number>

New debug trace areas:

  /sys/kernel/debug/s390dbf/cert_store_msg

  /sys/kernel/debug/s390dbf/cert_store_hexdump

Usage example:

To initiate request for certificates available to the system as root:

  $ echo 1 > /sys/firmware/cert_store/refresh

Upon success the '/sys/firmware/cert_store/cs_status' contains
the value 'ok'.

  $ cat /sys/firmware/cert_store/cs_status
  ok

Get the ID of the keyring 'cert_store':

  $ keyctl search @us keyring cert_store
OR
  $ keyctl link @us @s; keyctl request keyring cert_store

Obtain list of IDs of certificates:

  $ keyctl rlist <cert_store keyring ID>

Display certificate content as hex-dump:

  $ keyctl read <certificate ID>

Read certificate contents as binary data:

  $ keyctl pipe <certificate ID> >cert_data

Display certificate description:

  $ keyctl describe <certificate ID>

The certificate description has the following format:

  <64 bytes certificate name in EBCDIC> ':'
  <certificate index as obtained from hypervisor> ':'
  <certificate store token obtained from hypervisor>

The certificate description in /proc/keys has certificate name
represented in ASCII.

Users can read but cannot update the content of the certificate.

Signed-off-by: Anastasia Eskova <anastasia.eskova@ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:21 +02:00
Linus Torvalds
6eaae19807 Linux 6.5-rc3 v6.5-rc3 2023-07-23 15:24:10 -07:00
Linus Torvalds
3b4e48b800 Merge tag 'trace-v6.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
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()
2023-07-23 15:19:14 -07:00
Linus Torvalds
12a5336ca3 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
2023-07-23 14:55:41 -07:00
Miguel Ojeda
df01b7cfce kbuild: rust: avoid creating temporary files
`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/1015
Reported-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: 295d8398c6 ("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>
2023-07-24 03:15:31 +09:00
Linus Torvalds
269f4a4b85 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
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
2023-07-23 10:44:38 -07:00
Linus Torvalds
15b593ba68 Merge tag 'ext4_for_linus-6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
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
2023-07-23 10:21:49 -07:00
Linus Torvalds
8266f53b39 Merge tag '6.5-rc2-smb3-client-fixes-ver2' of git://git.samba.org/sfrench/cifs-2.6
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
2023-07-23 10:16:44 -07:00
Paolo Bonzini
0c189708bf 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
2023-07-23 12:50:30 -04:00
Paolo Bonzini
675a15f4db 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.
2023-07-23 12:50:14 -04:00
Mohamed Khalfella
4b8b390516 tracing/histograms: Return an error if we fail to add histogram to hist_vars list
Commit 6018b585e8 ("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: 6018b585e8 ("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>
2023-07-23 11:18:52 -04:00
Chen Lin
8a96c0288d ring-buffer: Do not swap cpu_buffer during resize process
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-g20edcec23f92 #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-g20edcec23f92 #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.cn

Signed-off-by: Chen Lin <chen.lin5@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-07-23 11:09:25 -04:00
YueHaibing
1faf7e4a0b tracing: Remove unused extern declaration tracing_map_set_field_descr()
Since commit 08d43a5fa0 ("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>
2023-07-23 11:08:14 -04:00
Alexey Dobriyan
0817d2599c kbuild: flatten KBUILD_CFLAGS
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>
2023-07-23 22:36:07 +09:00
Benjamin Gray
1c67921444 gen_compile_commands: add assembly files to compilation database
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>
2023-07-23 22:36:07 +09:00
Ojaswin Mujoo
9d3de7ee19 ext4: fix rbtree traversal bug in ext4_mb_use_preallocated
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: 3872778664 ("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.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-23 08:21:14 -04:00
Ojaswin Mujoo
5d5460fa79 ext4: fix off by one issue in ext4_mb_choose_next_group_best_avail()
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.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-23 08:21:14 -04:00
Eric Whitney
6909cf5c41 ext4: correct inline offset when handling xattrs in inode body
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.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-23 08:21:05 -04:00
Linus Torvalds
c278253139 Merge tag 'powerpc-6.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
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
2023-07-22 19:32:00 -07:00
Steve French
ba61a03af2 cifs: update internal module version number for cifs.ko
From 2.43 to 2.44

Signed-off-by: Steve French <stfrench@microsoft.com>
2023-07-22 14:43:13 -05:00
Shyam Prasad N
b3edef6b9c cifs: allow dumping keys for directories too
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>
2023-07-22 14:42:54 -05:00
Linus Torvalds
295e1388de Merge tag 's390-6.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
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
2023-07-22 11:24:03 -07:00
Linus Torvalds
f036d67c02 Merge tag 'block-6.5-2023-07-21' of git://git.kernel.dk/linux
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
2023-07-22 11:05:15 -07:00
Linus Torvalds
bdd1d82e7d Merge tag 'io_uring-6.5-2023-07-21' of git://git.kernel.dk/linux
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()
2023-07-22 10:46:30 -07:00
Linus Torvalds
725d444db6 Merge tag 'devicetree-fixes-for-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
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
2023-07-22 10:28:22 -07:00
Linus Torvalds
39b1428639 Merge tag 'regmap-fix-v6.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
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
2023-07-22 10:20:56 -07:00
Linus Torvalds
c0842db5e5 Merge tag 'gpio-fixes-for-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
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
2023-07-22 10:14:04 -07:00
Rob Herring
ffc59c6414 dt-bindings: serial: Remove obsolete nxp,lpc1850-uart.txt
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.org
Signed-off-by: Rob Herring <robh@kernel.org>
2023-07-21 13:39:12 -06:00
Rob Herring
5921181cf9 dt-bindings: serial: Remove obsolete cavium-uart.txt
cavium-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/20230707221602.1063972-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
2023-07-21 13:39:12 -06:00
Mauricio Faria de Oliveira
bb5faa99f0 loop: do not enforce max_loop hard limit by (new) default
Problem:

The max_loop parameter is used for 2 different purposes:

1) initial number of loop devices to pre-create on init
2) maximum number of loop devices to add on access/open()

Historically, its default value (zero) caused 1) to create non-zero
number of devices (CONFIG_BLK_DEV_LOOP_MIN_COUNT), and no hard limit on
2) to add devices with autoloading.

However, the default value changed in commit 85c5019771 ("loop: Fix
the max_loop commandline argument treatment when it is set to 0") to
CONFIG_BLK_DEV_LOOP_MIN_COUNT, for max_loop=0 not to pre-create devices.

That does improve 1), but unfortunately it breaks 2), as the default
behavior changed from no-limit to hard-limit.

Example:

For example, this userspace code broke for N >= CONFIG, if the user
relied on the default value 0 for max_loop:

    mknod("/dev/loopN");
    open("/dev/loopN");  // now fails with ENXIO

Though affected users may "fix" it with (loop.)max_loop=0, this means to
require a kernel parameter change on stable kernel update (that commit
Fixes: an old commit in stable).

Solution:

The original semantics for the default value in 2) can be applied if the
parameter is not set (ie, default behavior).

This still keeps the intended function in 1) and 2) if set, and that
commit's intended improvement in 1) if max_loop=0.

Before 85c5019771:
  - default:     1) CONFIG devices   2) no limit
  - max_loop=0:  1) CONFIG devices   2) no limit
  - max_loop=X:  1) X devices        2) X limit

After 85c5019771:
  - default:     1) CONFIG devices   2) CONFIG limit (*)
  - max_loop=0:  1) 0 devices (*)    2) no limit
  - max_loop=X:  1) X devices        2) X limit

This commit:
  - default:     1) CONFIG devices   2) no limit (*)
  - max_loop=0:  1) 0 devices        2) no limit
  - max_loop=X:  1) X devices        2) X limit

Future:

The issue/regression from that commit only affects code under the
CONFIG_BLOCK_LEGACY_AUTOLOAD deprecation guard, thus the fix too is
contained under it.

Once that deprecated functionality/code is removed, the purpose 2) of
max_loop (hard limit) is no longer in use, so the module parameter
description can be changed then.

Tests:

Linux 6.4-rc7
CONFIG_BLK_DEV_LOOP_MIN_COUNT=8
CONFIG_BLOCK_LEGACY_AUTOLOAD=y

- default (original)

	# ls -1 /dev/loop*
	/dev/loop-control
	/dev/loop0
	...
	/dev/loop7

	# ./test-loop
	open: /dev/loop8: No such device or address

- default (patched)

	# ls -1 /dev/loop*
	/dev/loop-control
	/dev/loop0
	...
	/dev/loop7

	# ./test-loop
	#

- max_loop=0 (original & patched):

	# ls -1 /dev/loop*
	/dev/loop-control

	# ./test-loop
	#

- max_loop=8 (original & patched):

	# ls -1 /dev/loop*
	/dev/loop-control
	/dev/loop0
	...
	/dev/loop7

	# ./test-loop
	open: /dev/loop8: No such device or address

- max_loop=0 (patched; CONFIG_BLOCK_LEGACY_AUTOLOAD is not set)

	# ls -1 /dev/loop*
	/dev/loop-control

	# ./test-loop
	open: /dev/loop8: No such device or address

Fixes: 85c5019771 ("loop: Fix the max_loop commandline argument treatment when it is set to 0")
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230720143033.841001-3-mfo@canonical.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-21 13:20:57 -06:00