This resurrects the vector ptrace() support that was removed for 6.5 due
to some bugs cropping up as part of the GDB review process.

* b4-shazam-merge:
  RISC-V: Add ptrace support for vectors

Link: https://lore.kernel.org/r/20230825050248.32681-1-andy.chiu@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Prabhakar <prabhakar.csengg@gmail.com> says:

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

non-coherent DMA support for AX45MP
====================================

On the Andes AX45MP core, cache coherency is a specification option so it
may not be supported. In this case DMA will fail. To get around with this
issue this patch series does the below:

1] Andes alternative ports is implemented as errata which checks if the
IOCP is missing and only then applies to CMO errata. One vendor specific
SBI EXT (ANDES_SBI_EXT_IOCP_SW_WORKAROUND) is implemented as part of
errata.

Below are the configs which Andes port provides (and are selected by
RZ/Five):
      - ERRATA_ANDES
      - ERRATA_ANDES_CMO

OpenSBI patch supporting ANDES_SBI_EXT_IOCP_SW_WORKAROUND SBI is now
part v1.3 release.

2] Andes AX45MP core has a Programmable Physical Memory Attributes (PMA)
block that allows dynamic adjustment of memory attributes in the runtime.
It contains a configurable amount of PMA entries implemented as CSR
registers to control the attributes of memory locations in interest.
OpenSBI configures the PMA regions as required and creates a reserve memory
node and propagates it to the higher boot stack.

Currently OpenSBI (upstream) configures the required PMA region and passes
this a shared DMA pool to Linux.

    reserved-memory {
        #address-cells = <2>;
        #size-cells = <2>;
        ranges;

        pma_resv0@58000000 {
            compatible = "shared-dma-pool";
            reg = <0x0 0x58000000 0x0 0x08000000>;
            no-map;
            linux,dma-default;
        };
    };

The above shared DMA pool gets appended to Linux DTB so the DMA memory
requests go through this region.

3] We provide callbacks to synchronize specific content between memory and
cache.

4] RZ/Five SoC selects the below configs
        - AX45MP_L2_CACHE
        - DMA_GLOBAL_POOL
        - ERRATA_ANDES
        - ERRATA_ANDES_CMO

----------x---------------------x--------------------x---------------x----

* b4-shazam-merge:
  soc: renesas: Kconfig: Select the required configs for RZ/Five SoC
  cache: Add L2 cache management for Andes AX45MP RISC-V core
  dt-bindings: cache: andestech,ax45mp-cache: Add DT binding documentation for L2 cache controller
  riscv: mm: dma-noncoherent: nonstandard cache operations support
  riscv: errata: Add Andes alternative ports
  riscv: asm: vendorid_list: Add Andes Technology to the vendors list

Link: https://lore.kernel.org/r/20230818135723.80612-1-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Prabhakar <prabhakar.csengg@gmail.com> says:

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

This patch series is a subset from Arnd's original series [0]. Ive just
picked up the bits required for RISC-V unification of cache flushing.
Remaining patches from the series [0] will be taken care by Arnd soon.

* b4-shazam-merge:
  riscv: dma-mapping: switch over to generic implementation
  riscv: dma-mapping: skip invalidation before bidirectional DMA
  riscv: dma-mapping: only invalidate after DMA, not flush

Link: https://lore.kernel.org/r/20230816232336.164413-1-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Evan Green <evan@rivosinc.com> says:

The current setting for the hwprobe bit indicating misaligned access
speed is controlled by a vendor-specific feature probe function. This is
essentially a per-SoC table we have to maintain on behalf of each vendor
going forward. Let's convert that instead to something we detect at
runtime.

We have two assembly routines at the heart of our probe: one that
does a bunch of word-sized accesses (without aligning its input buffer),
and the other that does byte accesses. If we can move a larger number of
bytes using misaligned word accesses than we can with the same amount of
time doing byte accesses, then we can declare misaligned accesses as
"fast".

The tradeoff of reducing this maintenance burden is boot time. We spend
4-6 jiffies per core doing this measurement (0-2 on jiffie edge
alignment, and 4 on measurement). The timing loop was based on
raid6_choose_gen(), which uses (16+1)*N jiffies (where N is the number
of algorithms). By taking only the fastest iteration out of all
attempts for use in the comparison, variance between runs is very low.
On my THead C906, it looks like this:

[    0.047563] cpu0: Ratio of byte access time to unaligned word access is 4.34, unaligned accesses are fast

Several others have chimed in with results on slow machines with the
older algorithm, which took all runs into account, including noise like
interrupts. Even with this variation, results indicate that in all cases
(fast, slow, and emulated) the measured numbers are nowhere near each
other (always multiple factors away).

* b4-shazam-merge:
  RISC-V: alternative: Remove feature_probe_func
  RISC-V: Probe for unaligned access speed

Link: https://lore.kernel.org/r/20230818194136.4084400-1-evan@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This patch add back the ptrace support with the following fix:
 - Define NT_RISCV_CSR and re-number NT_RISCV_VECTOR to prevent
   conflicting with gdb's NT_RISCV_CSR.
 - Use struct __riscv_v_regset_state to handle ptrace requests

Since gdb does not directly include the note description header in
Linux and has already defined NT_RISCV_CSR as 0x900, we decide to
sync with gdb and renumber NT_RISCV_VECTOR to solve and prevent future
conflicts.

Fixes: 0c59922c ("riscv: Add ptrace vector support")
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20230825050248.32681-1-andy.chiu@sifive.com
[Palmer: Drop the unused "size" variable in riscv_vr_set().]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Explicitly select the required Cache management and Errata configs
required for the RZ/Five SoC.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Conor Dooley <conor.dooley@microchip.com> # tyre-kicking on a d1
Link: https://lore.kernel.org/r/20230818135723.80612-7-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

I/O Coherence Port (IOCP) provides an AXI interface for connecting
external non-caching masters, such as DMA controllers. The accesses
from IOCP are coherent with D-Caches and L2 Cache.

IOCP is a specification option and is disabled on the Renesas RZ/Five
SoC due to this reason IP blocks using DMA will fail.

The Andes AX45MP core has a Programmable Physical Memory Attributes (PMA)
block that allows dynamic adjustment of memory attributes in the runtime.
It contains a configurable amount of PMA entries implemented as CSR
registers to control the attributes of memory locations in interest.
Below are the memory attributes supported:
* Device, Non-bufferable
* Device, bufferable
* Memory, Non-cacheable, Non-bufferable
* Memory, Non-cacheable, Bufferable
* Memory, Write-back, No-allocate
* Memory, Write-back, Read-allocate
* Memory, Write-back, Write-allocate
* Memory, Write-back, Read and Write-allocate

More info about PMA (section 10.3):
Link: http://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.0-Datasheet.pdf

As a workaround for SoCs with IOCP disabled CMO needs to be handled by
software. Firstly OpenSBI configures the memory region as
"Memory, Non-cacheable, Bufferable" and passes this region as a global
shared dma pool as a DT node. With DMA_GLOBAL_POOL enabled all DMA
allocations happen from this region and synchronization callbacks are
implemented to synchronize when doing DMA transactions.

Example PMA region passes as a DT node from OpenSBI:
    reserved-memory {
        #address-cells = <2>;
        #size-cells = <2>;
        ranges;

        pma_resv0@58000000 {
            compatible = "shared-dma-pool";
            reg = <0x0 0x58000000 0x0 0x08000000>;
            no-map;
            linux,dma-default;
        };
    };
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com> # tyre-kicking on a d1
Link: https://lore.kernel.org/r/20230818135723.80612-6-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Add DT binding documentation for L2 cache controller found on RZ/Five SoC.

The Renesas RZ/Five microprocessor includes a RISC-V CPU Core (AX45MP
Single) from Andes. The AX45MP core has an L2 cache controller, this patch
describes the L2 cache block.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com> # tyre-kicking on a d1
Link: https://lore.kernel.org/r/20230818135723.80612-5-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Introduce support for nonstandard noncoherent systems in the RISC-V
architecture. It enables function pointer support to handle cache
management in such systems.

This patch adds a new configuration option called
"RISCV_NONSTANDARD_CACHE_OPS." This option is a boolean flag that
depends on "RISCV_DMA_NONCOHERENT" and enables the function pointer
support for cache management in nonstandard noncoherent systems.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com> # tyre-kicking on a d1
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> #
Link: https://lore.kernel.org/r/20230818135723.80612-4-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Add required ports of the Alternative scheme for Andes CPU cores.

I/O Coherence Port (IOCP) provides an AXI interface for connecting external
non-caching masters, such as DMA controllers. IOCP is a specification
option and is disabled on the Renesas RZ/Five SoC due to this reason cache
management needs a software workaround.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com> # tyre-kicking on a d1
Link: https://lore.kernel.org/r/20230818135723.80612-3-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Add Andes Technology to the vendors list.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Conor Dooley <conor.dooley@microchip.com> # tyre-kicking on a d1
Link: https://lore.kernel.org/r/20230818135723.80612-2-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Add helper functions for cache wback/inval/clean and use them
arch_sync_dma_for_device()/arch_sync_dma_for_cpu() functions. The proposed
changes are in preparation for switching over to generic implementation.

Reorganization of the code is based on the patch (Link[0]) from Arnd.
For now I have dropped CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU check as this
will be enabled by default upon selection of RISCV_DMA_NONCOHERENT
and also dropped arch_dma_mark_dcache_clean().

Link[0]: https://lore.kernel.org/all/20230327121317.4081816-22-arnd@kernel.org/Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20230816232336.164413-4-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

For a DMA_BIDIRECTIONAL transfer, the caches have to be cleaned
first to let the device see data written by the CPU, and invalidated
after the transfer to let the CPU see data written by the device.

riscv also invalidates the caches before the transfer, which does
not appear to serve any purpose.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20230816232336.164413-3-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

No other architecture intentionally writes back dirty cache lines into
a buffer that a device has just finished writing into. If the cache is
clean, this has no effect at all, but if a cacheline in the buffer has
actually been written by the CPU,  there is a driver bug that is likely
made worse by overwriting that buffer.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20230816232336.164413-2-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Now that we're testing unaligned memory copy and making that
determination generically, there are no more users of the vendor
feature_probe_func(). While I think it's probably going to need to come
back, there are no users right now, so let's remove it until it's
needed.
Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230818194136.4084400-3-evan@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Rather than deferring unaligned access speed determinations to a vendor
function, let's probe them and find out how fast they are. If we
determine that an unaligned word access is faster than N byte accesses,
mark the hardware's unaligned access as "fast". Otherwise, we mark
accesses as slow.

The algorithm itself runs for a fixed amount of jiffies. Within each
iteration it attempts to time a single loop, and then keeps only the best
(fastest) loop it saw. This algorithm was found to have lower variance from
run to run than my first attempt, which counted the total number of
iterations that could be done in that fixed amount of jiffies. By taking
only the best iteration in the loop, assuming at least one loop wasn't
perturbed by an interrupt, we eliminate the effects of interrupts and
other "warm up" factors like branch prediction. The only downside is it
depends on having an rdtime granular and accurate enough to measure a
single copy. If we ever manage to complete a loop in 0 rdtime ticks, we
leave the unaligned setting at UNKNOWN.

There is a slight change in user-visible behavior here. Previously, all
boards except the THead C906 reported misaligned access speed of
UNKNOWN. C906 reported FAST. With this change, since we're now measuring
misaligned access speed on each hart, all RISC-V systems will have this
key set as either FAST or SLOW.

Currently, we don't have a way to confidently measure the difference between
SLOW and EMULATED, so we label anything not fast as SLOW. This will
mislabel some systems that are actually EMULATED as SLOW. When we get
support for delegating misaligned access traps to the kernel (as opposed
to the firmware quietly handling it), we can explicitly test in Linux to
see if unaligned accesses trap. Those systems will start to report
EMULATED, though older (today's) systems without that new SBI mechanism
will continue to report SLOW.

I've updated the documentation for those hwprobe values to reflect
this, specifically: SLOW may or may not be emulated by software, and FAST
represents means being faster than equivalent byte accesses. The change
in documentation is accurate with respect to both the former and current
behavior.
Signed-off-by: Evan Green <evan@rivosinc.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230818194136.4084400-2-evan@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Pull RISC-V updates from Palmer Dabbelt:

 - Support for the new "riscv,isa-extensions" and "riscv,isa-base"
   device tree interfaces for probing extensions

 - Support for userspace access to the performance counters

 - Support for more instructions in kprobes

 - Crash kernels can be allocated above 4GiB

 - Support for KCFI

 - Support for ELFs in !MMU configurations

 - ARCH_KMALLOC_MINALIGN has been reduced to 8

 - mmap() defaults to sv48-sized addresses, with longer addresses hidden
   behind a hint (similar to Arm and Intel)

 - Also various fixes and cleanups

* tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits)
  lib/Kconfig.debug: Restrict DEBUG_INFO_SPLIT for RISC-V
  riscv: support PREEMPT_DYNAMIC with static keys
  riscv: Move create_tmp_mapping() to init sections
  riscv: Mark KASAN tmp* page tables variables as static
  riscv: mm: use bitmap_zero() API
  riscv: enable DEBUG_FORCE_FUNCTION_ALIGN_64B
  riscv: remove redundant mv instructions
  RISC-V: mm: Document mmap changes
  RISC-V: mm: Update pgtable comment documentation
  RISC-V: mm: Add tests for RISC-V mm
  RISC-V: mm: Restrict address space for sv39,sv48,sv57
  riscv: enable DMA_BOUNCE_UNALIGNED_KMALLOC for !dma_coherent
  riscv: allow kmalloc() caches aligned to the smallest value
  riscv: support the elf-fdpic binfmt loader
  binfmt_elf_fdpic: support 64-bit systems
  riscv: Allow CONFIG_CFI_CLANG to be selected
  riscv/purgatory: Disable CFI
  riscv: Add CFI error handling
  riscv: Add ftrace_stub_graph
  riscv: Add types to indirectly called assembly functions
  ...

Pull arch/csky fix from Guo Ren:

 - Fix compile error by missing header file

* tag 'csky-for-linus-6.6-2' of https://github.com/c-sky/csky-linux:
  csky: Fixup compile error

Pull NFS client updates from Anna Schumaker:
 "New Features:
   - Enable the NFS v4.2 READ_PLUS operation by default

  Stable Fixes:
   - NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info
   - NFS: Fix a potential data corruption

  Bugfixes:
   - Fix various READ_PLUS issues including:
      - smatch warnings
      - xdr size calculations
      - scratch buffer handling
      - 32bit / highmem xdr page handling
   - Fix checkpatch errors in file.c
   - Fix redundant readdir request after an EOF
   - Fix handling of COPY ERR_OFFLOAD_NO_REQ
   - Fix assignment of xprtdata.cred

  Cleanups:
   - Remove unused xprtrdma function declarations
   - Clean up an integer overflow check to avoid a warning
   - Clean up #includes in dns_resolve.c
   - Clean up nfs4_get_device_info so we don't pass a NULL pointer
     to __free_page()
   - Clean up sunrpc TCP socket timeout configuration
   - Guard against READDIR loops when entry names are too long
   - Use EXCHID4_FLAG_USE_PNFS_DS for DS servers"

* tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (22 commits)
  pNFS: Fix assignment of xprtdata.cred
  NFSv4.2: fix handling of COPY ERR_OFFLOAD_NO_REQ
  NFS: Guard against READDIR loop when entry names exceed MAXNAMELEN
  NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server
  NFS/pNFS: Set the connect timeout for the pNFS flexfiles driver
  SUNRPC: Don't override connect timeouts in rpc_clnt_add_xprt()
  SUNRPC: Allow specification of TCP client connect timeout at setup
  SUNRPC: Refactor and simplify connect timeout
  SUNRPC: Set the TCP_SYNCNT to match the socket timeout
  NFS: Fix a potential data corruption
  nfs: fix redundant readdir request after get eof
  nfs/blocklayout: Use the passed in gfp flags
  filemap: Fix errors in file.c
  NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info
  NFS: Move common includes outside ifdef
  SUNRPC: clean up integer overflow check
  xprtrdma: Remove unused function declaration rpcrdma_bc_post_recv()
  NFS: Enable the READ_PLUS operation by default
  SUNRPC: kmap() the xdr pages during decode
  NFSv4.2: Rework scratch handling for READ_PLUS (again)
  ...

Pull nfsd updates from Chuck Lever:
 "I'm thrilled to announce that the Linux in-kernel NFS server now
  offers NFSv4 write delegations. A write delegation enables a client to
  cache data and metadata for a single file more aggressively, reducing
  network round trips and server workload. Many thanks to Dai Ngo for
  contributing this facility, and to Jeff Layton and Neil Brown for
  reviewing and testing it.

  This release also sees the removal of all support for DES- and
  triple-DES-based Kerberos encryption types in the kernel's SunRPC
  implementation. These encryption types have been deprecated by the
  Internet community for years and are considered insecure. This change
  affects both the in-kernel NFS client and server.

  The server's UDP and TCP socket transports have now fully adopted
  David Howells' new bio_vec iterator so that no more than one sendmsg()
  call is needed to transmit each RPC message. In particular, this helps
  kTLS optimize record boundaries when sending RPC-with-TLS replies, and
  it takes the server a baby step closer to handling file I/O via
  folios.

  We've begun work on overhauling the SunRPC thread scheduler to remove
  a costly linked-list walk when looking for an idle RPC service thread
  to wake. The pre-requisites are included in this release. Thanks to
  Neil Brown for his ongoing work on this improvement"

* tag 'nfsd-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (56 commits)
  Documentation: Add missing documentation for EXPORT_OP flags
  SUNRPC: Remove unused declaration rpc_modcount()
  SUNRPC: Remove unused declarations
  NFSD: da_addr_body field missing in some GETDEVICEINFO replies
  SUNRPC: Remove return value of svc_pool_wake_idle_thread()
  SUNRPC: make rqst_should_sleep() idempotent()
  SUNRPC: Clean up svc_set_num_threads
  SUNRPC: Count ingress RPC messages per svc_pool
  SUNRPC: Deduplicate thread wake-up code
  SUNRPC: Move trace_svc_xprt_enqueue
  SUNRPC: Add enum svc_auth_status
  SUNRPC: change svc_xprt::xpt_flags bits to enum
  SUNRPC: change svc_rqst::rq_flags bits to enum
  SUNRPC: change svc_pool::sp_flags bits to enum
  SUNRPC: change cache_head.flags bits to enum
  SUNRPC: remove timeout arg from svc_recv()
  SUNRPC: change svc_recv() to return void.
  SUNRPC: call svc_process() from svc_recv().
  nfsd: separate nfsd_last_thread() from nfsd_put()
  nfsd: Simplify code around svc_exit_thread() call in nfsd()
  ...

Pull smb server updates from Steve French:

 - fix potential overflows in decoding create and in session setup
   requests

 - cleanup fixes

 - compounding fixes, including one for MacOS compounded read requests

 - session setup error handling fix

 - fix mode bit bug when applying force_directory_mode and
   force_create_mode

 - RDMA (smbdirect) write fix

* tag '6.6-rc-ksmbd-fixes-part1' of git://git.samba.org/ksmbd:
  ksmbd: add missing calling smb2_set_err_rsp() on error
  ksmbd: replace one-element array with flex-array member in struct smb2_ea_info
  ksmbd: fix slub overflow in ksmbd_decode_ntlmssp_auth_blob()
  ksmbd: fix wrong DataOffset validation of create context
  ksmbd: Fix one kernel-doc comment
  ksmbd: reduce descriptor size if remaining bytes is less than request size
  ksmbd: fix `force create mode' and `force directory mode'
  ksmbd: fix wrong interim response on compound
  ksmbd: add support for read compound
  ksmbd: switch to use kmemdup_nul() helper

Pull jfs updates from Dave Kleikamp:
 "A few small fixes"

* tag 'jfs-6.6' of github.com:kleikamp/linux-shaggy:
  jfs: validate max amount of blocks before allocation.
  jfs: remove redundant initialization to pointer ip
  jfs: fix invalid free of JFS_IP(ipimap)->i_imap in diUnmount
  FS: JFS: (trivial) Fix grammatical error in extAlloc
  fs/jfs: prevent double-free in dbUnmount() after failed jfs_remount()

Pull ext4 updates from Ted Ts'o:
 "Many ext4 and jbd2 cleanups and bug fixes:

   - Cleanups in the ext4 remount code when going to and from read-only

   - Cleanups in ext4's multiblock allocator

   - Cleanups in the jbd2 setup/mounting code paths

   - Performance improvements when appending to a delayed allocation file

   - Miscellaneous syzbot and other bug fixes"

* tag 'ext4_for_linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (60 commits)
  ext4: fix slab-use-after-free in ext4_es_insert_extent()
  libfs: remove redundant checks of s_encoding
  ext4: remove redundant checks of s_encoding
  ext4: reject casefold inode flag without casefold feature
  ext4: use LIST_HEAD() to initialize the list_head in mballoc.c
  ext4: do not mark inode dirty every time when appending using delalloc
  ext4: rename s_error_work to s_sb_upd_work
  ext4: add periodic superblock update check
  ext4: drop dio overwrite only flag and associated warning
  ext4: add correct group descriptors and reserved GDT blocks to system zone
  ext4: remove unused function declaration
  ext4: mballoc: avoid garbage value from err
  ext4: use sbi instead of EXT4_SB(sb) in ext4_mb_new_blocks_simple()
  ext4: change the type of blocksize in ext4_mb_init_cache()
  ext4: fix unttached inode after power cut with orphan file feature enabled
  jbd2: correct the end of the journal recovery scan range
  ext4: ext4_get_{dev}_journal return proper error value
  ext4: cleanup ext4_get_dev_journal() and ext4_get_journal()
  jbd2: jbd2_journal_init_{dev,inode} return proper error return value
  jbd2: drop useless error tag in jbd2_journal_wipe()
  ...

Pull dlm updates from David Teigland:

 - Allow blocking posix lock requests to be interrupted while waiting.
   This requires a cancel request to be sent to the userspace daemon
   where posix lock requests are processed across the cluster.

 - Fix a posix lock patch from the previous cycle in which lock requests
   from different file systems could be mixed up.

 - Fix some long standing problems with nfs posix lock cancelation.

 - Add a new debugfs file for printing queued callbacks.

 - Stop modifying buffers that have been used to receive a message.

 - Misc cleanups and some refactoring.

* tag 'dlm-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm:
  dlm: fix plock lookup when using multiple lockspaces
  fs: dlm: don't use RCOM_NAMES for version detection
  fs: dlm: create midcomms nodes when configure
  fs: dlm: constify receive buffer
  fs: dlm: drop rxbuf manipulation in dlm_recover_master_copy
  fs: dlm: drop rxbuf manipulation in dlm_copy_master_names
  fs: dlm: get recovery sequence number as parameter
  fs: dlm: cleanup lock order
  fs: dlm: remove clear_members_cb
  fs: dlm: add plock dev tracepoints
  fs: dlm: check on plock ops when exit dlm
  fs: dlm: debugfs for queued callbacks
  fs: dlm: remove unused processed_nodes
  fs: dlm: add missing spin_unlock
  fs: dlm: fix F_CANCELLK to cancel pending request
  fs: dlm: allow to F_SETLKW getting interrupted
  fs: dlm: remove twice newline

Pull more superblock follow-on fixes from Christian Brauner:
 "This contains two more small follow-up fixes for the super work this
  cycle. I went through all filesystems once more and detected two minor
  issues that still needed fixing:

   - Some filesystems support mtd devices (e.g., mount -t jffs2 mtd2
     /mnt). The mtd infrastructure uses the sb->s_mtd pointer to find an
     existing superblock. When the mtd device is put and sb->s_mtd
     cleared the superblock can still be found fs_supers and so this
     risks a use-after-free.

     Add a small patch that aligns mtd with what we did for regular
     block devices and switch keying to rely on sb->s_dev.

     (This was tested with mtd devices and jffs2 as xfstests doesn't
     support mtd devices.)

   - Switch nfs back to rely on kill_anon_super() so the superblock is
     removed from the list of active supers before sb->s_fs_info is
     freed"

* tag 'v6.6-vfs.super.fixes.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  NFS: switch back to using kill_anon_super
  mtd: key superblock by device number
  fs: export sget_dev()

Fix up missed semantic mis-merge between commits

  161e393c ("mm: Make pte_mkwrite() take a VMA")
  27af67f3 ("powerpc/book3s64/mm: enable transparent pud hugepage")

where the newly introduced powerpc use of 'pte_mkwrite()' needs to use
the 'novma()' versions as per commit 2f0584f3 ("mm: Rename arch
pte_mkwrite()'s to pte_mkwrite_novma()").

Fixes: df57721f ("Merge tag 'x86_shstk_for_6.6-rc1' of [...]")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM updates from Russell King:

 - Refactor VFP code and convert to C code (Ard Biesheuvel)

 - Fix hardware breakpoint single-stepping using bpf_overflow_handler

 - Make SMP stop calls asynchronous allowing panic from irq context to
   work

 - Fix for kernel-doc warnings for locomo

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  Revert part of ae1f8d79 ("ARM: 9304/1: add prototype for function called only from asm")
  ARM: 9318/1: locomo: move kernel-doc to prevent warnings
  ARM: 9317/1: kexec: Make smp stop calls asynchronous
  ARM: 9316/1: hw_breakpoint: fix single-stepping when using bpf_overflow_handler
  ARM: entry: Make asm coproc dispatch code NWFPE only
  ARM: iwmmxt: Use undef hook to enable coprocessor for task
  ARM: entry: Disregard Thumb undef exception in coproc dispatch
  ARM: vfp: Use undef hook for handling VFP exceptions
  ARM: kernel: Get rid of thread_info::used_cp[] array
  ARM: vfp: Reimplement VFP exception entry in C code
  ARM: vfp: Remove workaround for Feroceon CPUs
  ARM: vfp: Record VFP bounces as perf emulation faults

Pull powerpc updates from Michael Ellerman:

 - Add HOTPLUG_SMT support (/sys/devices/system/cpu/smt) and honour the
   configured SMT state when hotplugging CPUs into the system

 - Combine final TLB flush and lazy TLB mm shootdown IPIs when using the
   Radix MMU to avoid a broadcast TLBIE flush on exit

 - Drop the exclusion between ptrace/perf watchpoints, and drop the now
   unused associated arch hooks

 - Add support for the "nohlt" command line option to disable CPU idle

 - Add support for -fpatchable-function-entry for ftrace, with GCC >=
   13.1

 - Rework memory block size determination, and support 256MB size on
   systems with GPUs that have hotpluggable memory

 - Various other small features and fixes

Thanks to Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Athira
Rajeev, Benjamin Gray, Christophe Leroy, Frederic Barrat, Gautam
Menghani, Geoff Levand, Hari Bathini, Immad Mir, Jialin Zhang, Joel
Stanley, Jordan Niethe, Justin Stitt, Kajol Jain, Kees Cook, Krzysztof
Kozlowski, Laurent Dufour, Liang He, Linus Walleij, Mahesh Salgaonkar,
Masahiro Yamada, Michal Suchanek, Nageswara R Sastry, Nathan Chancellor,
Nathan Lynch, Naveen N Rao, Nicholas Piggin, Nick Desaulniers, Omar
Sandoval, Randy Dunlap, Reza Arbab, Rob Herring, Russell Currey, Sourabh
Jain, Thomas Gleixner, Trevor Woerner, Uwe Kleine-König, Vaibhav Jain,
Xiongfeng Wang, Yuan Tan, Zhang Rui, and Zheng Zengkai.

* tag 'powerpc-6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (135 commits)
  macintosh/ams: linux/platform_device.h is needed
  powerpc/xmon: Reapply "Relax frame size for clang"
  powerpc/mm/book3s64: Use 256M as the upper limit with coherent device memory attached
  powerpc/mm/book3s64: Fix build error with SPARSEMEM disabled
  powerpc/iommu: Fix notifiers being shared by PCI and VIO buses
  powerpc/mpc5xxx: Add missing fwnode_handle_put()
  powerpc/config: Disable SLAB_DEBUG_ON in skiroot
  powerpc/pseries: Remove unused hcall tracing instruction
  powerpc/pseries: Fix hcall tracepoints with JUMP_LABEL=n
  powerpc: dts: add missing space before {
  powerpc/eeh: Use pci_dev_id() to simplify the code
  powerpc/64s: Move CPU -mtune options into Kconfig
  powerpc/powermac: Fix unused function warning
  powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT
  powerpc: Don't include lppaca.h in paca.h
  powerpc/pseries: Move hcall_vphn() prototype into vphn.h
  powerpc/pseries: Move VPHN constants into vphn.h
  cxl: Drop unused detach_spa()
  powerpc: Drop zalloc_maybe_bootmem()
  powerpc/powernv: Use struct opal_prd_msg in more places
  ...

Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...

ams.h uses struct platform_device, so the header should be used
to prevent build errors:

drivers/macintosh/ams/ams-input.c: In function 'ams_input_enable':
drivers/macintosh/ams/ams-input.c:68:45: error: invalid use of undefined type 'struct platform_device'
   68 |         input->dev.parent = &ams_info.of_dev->dev;
drivers/macintosh/ams/ams-input.c: In function 'ams_input_init':
drivers/macintosh/ams/ams-input.c:146:51: error: invalid use of undefined type 'struct platform_device'
  146 |         return device_create_file(&ams_info.of_dev->dev, &dev_attr_joystick);
drivers/macintosh/ams/ams-input.c: In function 'ams_input_exit':
drivers/macintosh/ams/ams-input.c:151:44: error: invalid use of undefined type 'struct platform_device'
  151 |         device_remove_file(&ams_info.of_dev->dev, &dev_attr_joystick);
drivers/macintosh/ams/ams-input.c: In function 'ams_input_init':
drivers/macintosh/ams/ams-input.c:147:1: error: control reaches end of non-void function [-Werror=return-type]
  147 | }

Fixes: 233d687d ("macintosh: Explicitly include correct DT includes")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230829225837.15520-1-rdunlap@infradead.org

NFS switch to open coding kill_anon_super in 7b14a213
("nfs: don't call bdi_unregister") to avoid the extra bdi_unregister
call.  At that point bdi_destroy was called in nfs_free_server and
thus it required a later freeing of the anon dev_t.  But since
0db10944 ("nfs: Convert to separately allocated bdi") the bdi has
been free implicitly by the sb destruction, so this isn't needed
anymore.

By not open coding kill_anon_super, nfs now inherits the fix in
dc3216b1 ("super: ensure valid info"), and we remove the only
open coded version of kill_anon_super.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230831052940.256193-1-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

The mtd driver has similar problems than the one that was fixed in
commit dc3216b1 ("super: ensure valid info").

The kill_mtd_super() helper calls shuts the superblock down but leaves
the superblock on fs_supers as the devices are still in use but puts the
mtd device and cleans out the superblock's s_mtd field.

This means another mounter can find the superblock on the list accessing
its s_mtd field while it is curently in the process of being freed or
already freed.

Prevent that from happening by keying superblock by dev_t just as we do
in the generic code.

Link: https://lore.kernel.org/linux-fsdevel/20230829-weitab-lauwarm-49c40fc85863@braunerAcked-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230829-vfs-super-mtd-v1-2-fecb572e5df3@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

They will be used for mtd devices as well.
Acked-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230829-vfs-super-mtd-v1-1-fecb572e5df3@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

When building for ARCH=riscv using LLVM < 14, there is an error with
CONFIG_DEBUG_INFO_SPLIT=y:

  error: A dwo section may not contain relocations

This was worked around in LLVM 15 by disallowing '-gsplit-dwarf' with
'-mrelax' (the default), so CONFIG_DEBUG_INFO_SPLIT is not selectable
with newer versions of LLVM:

  $ clang --target=riscv64-linux-gnu -gsplit-dwarf -c -o /dev/null -x c /dev/null
  clang: error: -gsplit-dwarf is unsupported with RISC-V linker relaxation (-mrelax)

GCC silently had a similar issue that was resolved with GCC 12.x.
Restrict CONFIG_DEBUG_INFO_SPLIT for RISC-V when using LLVM or GCC <
12.x to avoid these known issues.

Link: https://github.com/ClangBuiltLinux/linux/issues/1914
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/all/202308090204.9yZffBWo-lkp@intel.com/Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230816-riscv-debug_info_split-v1-1-d1019d6ccc11@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Charlie Jenkins <charlie@rivosinc.com> says:

Make sv48 the default address space for mmap as some applications
currently depend on this assumption. Users can now select a
desired address space using a non-zero hint address to mmap. Previously,
requesting the default address space from mmap by passing zero as the hint
address would result in using the largest address space possible. Some
applications depend on empty bits in the virtual address space, like Go and
Java, so this patch provides more flexibility for application developers.

* b4-shazam-merge:
  RISC-V: mm: Document mmap changes
  RISC-V: mm: Update pgtable comment documentation
  RISC-V: mm: Add tests for RISC-V mm
  RISC-V: mm: Restrict address space for sv39,sv48,sv57

Link: https://lore.kernel.org/r/20230809232218.849726-1-charlie@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Jisheng Zhang <jszhang@kernel.org> says:

Currently, riscv defines ARCH_DMA_MINALIGN as L1_CACHE_BYTES, I.E
64Bytes, if CONFIG_RISCV_DMA_NONCOHERENT=y. To support unified kernel
Image, usually we have to enable CONFIG_RISCV_DMA_NONCOHERENT, thus
it brings some bad effects to coherent platforms:

Firstly, it wastes memory, kmalloc-96, kmalloc-32, kmalloc-16 and
kmalloc-8 slab caches don't exist any more, they are replaced with
either kmalloc-128 or kmalloc-64.

Secondly, larger than necessary kmalloc aligned allocations results
in unnecessary cache/TLB pressure.

This issue also exists on arm64 platforms. From last year, Catalin
tried to solve this issue by decoupling ARCH_KMALLOC_MINALIGN from
ARCH_DMA_MINALIGN, limiting kmalloc() minimum alignment to
dma_get_cache_alignment() and replacing ARCH_KMALLOC_MINALIGN usage
in various drivers with ARCH_DMA_MINALIGN etc.[1]

One fact we can make use of for riscv: if the CPU doesn't support
ZICBOM or T-HEAD CMO, we know the platform is coherent. Based on
Catalin's work and above fact, we can easily solve the kmalloc align
issue for riscv: we can override dma_get_cache_alignment(), then let
it return ARCH_DMA_MINALIGN at the beginning and return 1 once we know
the underlying HW neither supports ZICBOM nor supports T-HEAD CMO.

So what about if the CPU supports ZICBOM or T-HEAD CMO, but all the
devices are dma coherent? Well, we use ARCH_DMA_MINALIGN as the
kmalloc minimum alignment, nothing changed in this case. This case
can be improved in the future once we see such platforms in mainline.

After this patch, a simple test of booting to a small buildroot rootfs
on qemu shows:

kmalloc-96           5041    5041     96  ...
kmalloc-64           9606    9606     64  ...
kmalloc-32           5128    5128     32  ...
kmalloc-16           7682    7682     16  ...
kmalloc-8           10246   10246      8  ...

So we save about 1268KB memory. The saving will be much larger in normal
OS env on real HW platforms.

patch1 allows kmalloc() caches aligned to the smallest value.
patch2 enables DMA_BOUNCE_UNALIGNED_KMALLOC.

After this series:

As for coherent platforms, kmalloc-{8,16,32,96} caches come back on
coherent both RV32 and RV64 platforms, I.E !ZICBOM and !THEAD_CMO.

As for noncoherent RV32 platforms, nothing changed.

As for noncoherent RV64 platforms, I.E either ZICBOM or THEAD_CMO, the
above kmalloc caches also come back if > 4GB memory or users pass
"swiotlb=mmnn,force" to force swiotlb creation if <= 4GB memory. How
much mmnn should be depends on the specific platform, it needs to be
tried and tested all possible usage case on the specific hardware. For
example, I can use the minimal I/O TLB slabs on Sipeed M1S Dock.

* b4-shazam-merge:
  riscv: enable DMA_BOUNCE_UNALIGNED_KMALLOC for !dma_coherent
  riscv: allow kmalloc() caches aligned to the smallest value

Link: https://lore.kernel.org/linux-arm-kernel/20230524171904.3967031-1-catalin.marinas@arm.com/ [1]
Link: https://lore.kernel.org/r/20230718152214.2907-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Currently, each architecture can support PREEMPT_DYNAMIC through
either static calls or static keys. To support PREEMPT_DYNAMIC on
riscv, we face three choices:

1. only add static calls support to riscv
As Mark pointed out in commit 99cf983c ("sched/preempt: Add
PREEMPT_DYNAMIC using static keys"), static keys "...should have
slightly lower overhead than non-inline static calls, as this
effectively inlines each trampoline into the start of its callee. This
may avoid redundant work, and may integrate better with CFI schemes."
So even we add static calls(without inline static calls) to riscv,
static keys is still a better choice.

2. add static calls and inline static calls to riscv
Per my understanding, inline static calls requires objtool support
which is not easy.

3. use static keys

While riscv doesn't have static calls support, it supports static keys
perfectly. So this patch selects HAVE_PREEMPT_DYNAMIC_KEY to enable
support for PREEMPT_DYNAMIC on riscv, so that the preemption model can
be chosen at boot time. It also patches asm-generic/preempt.h, mainly
to add __preempt_schedule() and __preempt_schedule_notrace() macros
for PREEMPT_DYNAMIC case. Other architectures which use generic
preempt.h can also benefit from this patch by simply selecting
HAVE_PREEMPT_DYNAMIC_KEY to enable PREEMPT_DYNAMIC if they supports
static keys.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230716164925.1858-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Greg Ungerer <gerg@kernel.org> says:

The following changes add the ability to run ELF format binaries when
running RISC-V in nommu mode. That support is actually part of the
ELF-FDPIC loader, so these changes are all about making that work on
RISC-V.

The first issue to deal with is making the ELF-FDPIC loader capable of
handling 64-bit ELF files. As coded right now it only supports 32-bit
ELF files.

Secondly some changes are required to enable and compile the ELF-FDPIC
loader on RISC-V and to pass the ELF-FDPIC mapping addresses through to
user space when execing the new program.

These changes have not been used to run actual ELF-FDPIC binaries.
It is used to load and run normal ELF - compiled -pie format. Though the
underlying changes are expected to work with full ELF-FDPIC binaries if
or when that is supported on RISC-V in gcc.

To avoid needing changes to the C-library (tested with uClibc-ng
currently) there is a simple runtime dynamic loader (interpreter)
available to do the final relocations, https://github.com/gregungerer/uldso.
The nice thing about doing it this way is that the same program
binary can also be loaded with the usual ELF loader in MMU linux.

The motivation here is to provide an easy to use alternative to the
flat format binaries normally used for RISC-V nommu based systems.

* b4-shazam-merge:
  riscv: support the elf-fdpic binfmt loader
  binfmt_elf_fdpic: support 64-bit systems

Link: https://lore.kernel.org/r/20230711130754.481209-1-gerg@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Sami Tolvanen <samitolvanen@google.com> says:

This series adds KCFI support for RISC-V. KCFI is a fine-grained
forward-edge control-flow integrity scheme supported in Clang >=16,
which ensures indirect calls in instrumented code can only branch to
functions whose type matches the function pointer type, thus making
code reuse attacks more difficult.

Patch 1 implements a pt_regs based syscall wrapper to address
function pointer type mismatches in syscall handling. Patches 2 and 3
annotate indirectly called assembly functions with CFI types. Patch 4
implements error handling for indirect call checks. Patch 5 disables
CFI for arch/riscv/purgatory. Patch 6 finally allows CONFIG_CFI_CLANG
to be enabled for RISC-V.

Note that Clang 16 has a generic architecture-agnostic KCFI
implementation, which does work with the kernel, but doesn't produce
a stable code sequence for indirect call checks, which means
potential failures just trap and won't result in informative error
messages. Clang 17 includes a RISC-V specific back-end implementation
for KCFI, which emits a predictable code sequence for the checks and a
.kcfi_traps section with locations of the traps, which patch 5 uses to
produce more useful errors.

The type mismatch fixes and annotations in the first three patches
also become necessary in future if the kernel decides to support
fine-grained CFI implemented using the hardware landing pad
feature proposed in the in-progress Zicfisslp extension. Once the
specification is ratified and hardware support emerges, implementing
runtime patching support that replaces KCFI instrumentation with
Zicfisslp landing pads might also be feasible (similarly to KCFI to
FineIBT patching on x86_64), allowing distributions to ship a unified
kernel binary for all devices.

* b4-shazam-merge:
  riscv: Allow CONFIG_CFI_CLANG to be selected
  riscv/purgatory: Disable CFI
  riscv: Add CFI error handling
  riscv: Add ftrace_stub_graph
  riscv: Add types to indirectly called assembly functions
  riscv: Implement syscall wrappers

Link: https://lore.kernel.org/r/20230710183544.999540-8-samitolvanen@google.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This function is only used at boot time so mark it as __init.

Fixes: 96f9d4da ("riscv: Rework kasan population functions")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230704074357.233982-2-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>