Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

- Support for the new "riscv,isa-extensions" and "riscv,is

Merge tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

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
...

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Merge patch series "riscv: KCFI support"

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 su

Merge patch series "riscv: KCFI support"

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.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

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riscv: Add CFI error handling

With CONFIG_CFI_CLANG, the compiler injects a type preamble immediately
before each function and a check to validate the target function type
before indirect calls:

riscv: Add CFI error handling

With CONFIG_CFI_CLANG, the compiler injects a type preamble immediately
before each function and a check to validate the target function type
before indirect calls:

; type preamble
.word <id>
function:
...
; indirect call check
lw t1, -4(a0)
lui t2, <hi20>
addiw t2, t2, <lo12>
beq t1, t2, .Ltmp0
ebreak
.Ltmp0:
jarl a0

Implement error handling code for the ebreak traps emitted for the
checks. This produces the following oops on a CFI failure (generated
using lkdtm):

[ 21.177245] CFI failure at lkdtm_indirect_call+0x22/0x32 [lkdtm]
(target: lkdtm_increment_int+0x0/0x18 [lkdtm]; expected type: 0x3ad55aca)
[ 21.178483] Kernel BUG [#1]
[ 21.178671] Modules linked in: lkdtm
[ 21.179037] CPU: 1 PID: 104 Comm: sh Not tainted
6.3.0-rc6-00037-g37d5ec6297ab #1
[ 21.179511] Hardware name: riscv-virtio,qemu (DT)
[ 21.179818] epc : lkdtm_indirect_call+0x22/0x32 [lkdtm]
[ 21.180106] ra : lkdtm_CFI_FORWARD_PROTO+0x48/0x7c [lkdtm]
[ 21.180426] epc : ffffffff01387092 ra : ffffffff01386f14 sp : ff20000000453cf0
[ 21.180792] gp : ffffffff81308c38 tp : ff6000000243f080 t0 : ff20000000453b78
[ 21.181157] t1 : 000000003ad55aca t2 : 000000007e0c52a5 s0 : ff20000000453d00
[ 21.181506] s1 : 0000000000000001 a0 : ffffffff0138d170 a1 : ffffffff013870bc
[ 21.181819] a2 : b5fea48dd89aa700 a3 : 0000000000000001 a4 : 0000000000000fff
[ 21.182169] a5 : 0000000000000004 a6 : 00000000000000b7 a7 : 0000000000000000
[ 21.182591] s2 : ff20000000453e78 s3 : ffffffffffffffea s4 : 0000000000000012
[ 21.183001] s5 : ff600000023c7000 s6 : 0000000000000006 s7 : ffffffff013882a0
[ 21.183653] s8 : 0000000000000008 s9 : 0000000000000002 s10: ffffffff0138d878
[ 21.184245] s11: ffffffff0138d878 t3 : 0000000000000003 t4 : 0000000000000000
[ 21.184591] t5 : ffffffff8133df08 t6 : ffffffff8133df07
[ 21.184858] status: 0000000000000120 badaddr: 0000000000000000
cause: 0000000000000003
[ 21.185415] [<ffffffff01387092>] lkdtm_indirect_call+0x22/0x32 [lkdtm]
[ 21.185772] [<ffffffff01386f14>] lkdtm_CFI_FORWARD_PROTO+0x48/0x7c [lkdtm]
[ 21.186093] [<ffffffff01383552>] lkdtm_do_action+0x22/0x34 [lkdtm]
[ 21.186445] [<ffffffff0138350c>] direct_entry+0x128/0x13a [lkdtm]
[ 21.186817] [<ffffffff8033ed8c>] full_proxy_write+0x58/0xb2
[ 21.187352] [<ffffffff801d4fe8>] vfs_write+0x14c/0x33a
[ 21.187644] [<ffffffff801d5328>] ksys_write+0x64/0xd4
[ 21.187832] [<ffffffff801d53a6>] sys_write+0xe/0x1a
[ 21.188171] [<ffffffff80003996>] ret_from_syscall+0x0/0x2
[ 21.188595] Code: 0513 0f65 a303 ffc5 53b7 7e0c 839b 2a53 0363 0073 (9002) 9582
[ 21.189178] ---[ end trace 0000000000000000 ]---
[ 21.189590] Kernel panic - not syncing: Fatal exception

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com> # ISA bits
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20230710183544.999540-12-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

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