Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up
objtool warnings), teach objtool about 'noreturn' Rust symbols and
mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we
should be objtool-warning-free, so enable it to run for all Rust
object files.
- KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.
- Support 'RUSTC_VERSION', including re-config and re-build on
change.
- Split helpers file into several files in a folder, to avoid
conflicts in it. Eventually those files will be moved to the right
places with the new build system. In addition, remove the need to
manually export the symbols defined there, reusing existing
machinery for that.
- Relax restriction on configurations with Rust + GCC plugins to just
the RANDSTRUCT plugin.
'kernel' crate:
- New 'list' module: doubly-linked linked list for use with reference
counted values, which is heavily used by the upcoming Rust Binder.
This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
unique for the given ID), 'AtomicTracker' (tracks whether a
'ListArc' exists using an atomic), 'ListLinks' (the prev/next
pointers for an item in a linked list), 'List' (the linked list
itself), 'Iter' (an iterator over a 'List'), 'Cursor' (a cursor
into a 'List' that allows to remove elements), 'ListArcField' (a
field exclusively owned by a 'ListArc'), as well as support for
heterogeneous lists.
- New 'rbtree' module: red-black tree abstractions used by the
upcoming Rust Binder.
This includes 'RBTree' (the red-black tree itself), 'RBTreeNode' (a
node), 'RBTreeNodeReservation' (a memory reservation for a node),
'Iter' and 'IterMut' (immutable and mutable iterators), 'Cursor'
(bidirectional cursor that allows to remove elements), as well as
an entry API similar to the Rust standard library one.
- 'init' module: add 'write_[pin_]init' methods and the
'InPlaceWrite' trait. Add the 'assert_pinned!' macro.
- 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
introducing an associated type in the trait.
- 'alloc' module: add 'drop_contents' method to 'BoxExt'.
- 'types' module: implement the 'ForeignOwnable' trait for
'Pin<Box<T>>' and improve the trait's documentation. In addition,
add the 'into_raw' method to the 'ARef' type.
- 'error' module: in preparation for the upcoming Rust support for
32-bit architectures, like arm, locally allow Clippy lint for
those.
Documentation:
- https://rust.docs.kernel.org has been announced, so link to it.
- Enable rustdoc's "jump to definition" feature, making its output a
bit closer to the experience in a cross-referencer.
- Debian Testing now also provides recent Rust releases (outside of
the freeze period), so add it to the list.
MAINTAINERS:
- Trevor is joining as reviewer of the "RUST" entry.
And a few other small bits"
* tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux: (54 commits)
kasan: rust: Add KASAN smoke test via UAF
kbuild: rust: Enable KASAN support
rust: kasan: Rust does not support KHWASAN
kbuild: rust: Define probing macros for rustc
kasan: simplify and clarify Makefile
rust: cfi: add support for CFI_CLANG with Rust
cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
rust: support for shadow call stack sanitizer
docs: rust: include other expressions in conditional compilation section
kbuild: rust: replace proc macros dependency on `core.o` with the version text
kbuild: rust: rebuild if the version text changes
kbuild: rust: re-run Kconfig if the version text changes
kbuild: rust: add `CONFIG_RUSTC_VERSION`
rust: avoid `box_uninit_write` feature
MAINTAINERS: add Trevor Gross as Rust reviewer
rust: rbtree: add `RBTree::entry`
rust: rbtree: add cursor
rust: rbtree: add mutable iterator
rust: rbtree: add iterator
rust: rbtree: add red-black tree implementation backed by the C version
...
Pull RISC-V updates from Palmer Dabbelt:
- Support using Zkr to seed KASLR
- Support IPI-triggered CPU backtracing
- Support for generic CPU vulnerabilities reporting to userspace
- A few cleanups for missing licenses
- The size limit on the XIP kernel has been removed
- Support for tracing userspace stacks
- Support for the Svvptc extension
- Various cleanups and fixes throughout the tree
* tag 'riscv-for-linus-6.12-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (47 commits)
crash: Fix riscv64 crash memory reserve dead loop
perf/riscv-sbi: Add platform specific firmware event handling
tools: Optimize ring buffer for riscv
tools: Add riscv barrier implementation
RISC-V: Don't have MAX_PHYSMEM_BITS exceed phys_addr_t
ACPI: NUMA: initialize all values of acpi_early_node_map to NUMA_NO_NODE
riscv: Enable bitops instrumentation
riscv: Omit optimized string routines when using KASAN
ACPI: RISCV: Make acpi_numa_get_nid() to be static
riscv: Randomize lower bits of stack address
selftests: riscv: Allow mmap test to compile on 32-bit
riscv: Make riscv_isa_vendor_ext_andes array static
riscv: Use LIST_HEAD() to simplify code
riscv: defconfig: Disable RZ/Five peripheral support
RISC-V: Implement kgdb_roundup_cpus() to enable future NMI Roundup
riscv: avoid Imbalance in RAS
riscv: cacheinfo: Add back init_cache_level() function
riscv: Remove unused _TIF_WORK_MASK
drivers/perf: riscv: Remove redundant macro check
riscv: define ILLEGAL_POINTER_VALUE for 64bit
...
Pull non-MM updates from Andrew Morton:
"Many singleton patches - please see the various changelogs for
details.
Quite a lot of nilfs2 work this time around.
Notable patch series in this pull request are:
- "mul_u64_u64_div_u64: new implementation" by Nicolas Pitre, with
assistance from Uwe Kleine-König. Reimplement mul_u64_u64_div_u64()
to provide (much) more accurate results. The current implementation
was causing Uwe some issues in the PWM drivers.
- "xz: Updates to license, filters, and compression options" from
Lasse Collin. Miscellaneous maintenance and kinor feature work to
the xz decompressor.
- "Fix some GDB command error and add some GDB commands" from
Kuan-Ying Lee. Fixes and enhancements to the gdb scripts.
- "treewide: add missing MODULE_DESCRIPTION() macros" from Jeff
Johnson. Adds lots of MODULE_DESCRIPTIONs, thus fixing lots of
warnings about this.
- "nilfs2: add support for some common ioctls" from Ryusuke Konishi.
Adds various commonly-available ioctls to nilfs2.
- "This series fixes a number of formatting issues in kernel doc
comments" from Ryusuke Konishi does that.
- "nilfs2: prevent unexpected ENOENT propagation" from Ryusuke
Konishi. Fix issues where -ENOENT was being unintentionally and
inappropriately returned to userspace.
- "nilfs2: assorted cleanups" from Huang Xiaojia.
- "nilfs2: fix potential issues with empty b-tree nodes" from Ryusuke
Konishi fixes some issues which can occur on corrupted nilfs2
filesystems.
- "scripts/decode_stacktrace.sh: improve error reporting and
usability" from Luca Ceresoli does those things"
* tag 'mm-nonmm-stable-2024-09-21-07-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (103 commits)
list: test: increase coverage of list_test_list_replace*()
list: test: fix tests for list_cut_position()
proc: use __auto_type more
treewide: correct the typo 'retun'
ocfs2: cleanup return value and mlog in ocfs2_global_read_info()
nilfs2: remove duplicate 'unlikely()' usage
nilfs2: fix potential oob read in nilfs_btree_check_delete()
nilfs2: determine empty node blocks as corrupted
nilfs2: fix potential null-ptr-deref in nilfs_btree_insert()
user_namespace: use kmemdup_array() instead of kmemdup() for multiple allocation
tools/mm: rm thp_swap_allocator_test when make clean
squashfs: fix percpu address space issues in decompressor_multi_percpu.c
lib: glob.c: added null check for character class
nilfs2: refactor nilfs_segctor_thread()
nilfs2: use kthread_create and kthread_stop for the log writer thread
nilfs2: remove sc_timer_task
nilfs2: do not repair reserved inode bitmap in nilfs_new_inode()
nilfs2: eliminate the shared counter and spinlock for i_generation
nilfs2: separate inode type information from i_state field
nilfs2: use the BITS_PER_LONG macro
...
Jisheng Zhang <jszhang@kernel.org> says:
commit 76329c6939 ("riscv: Use SYM_*() assembly macros instead
of deprecated ones"), most riscv has been to converted the new style
SYM_ assembler annotations. The remaining one is sifive's
errata_cip_453.S, so convert to new style SYM_ annotations as well.
After that select ARCH_USE_SYM_ANNOTATIONS.
* b4-shazam-merge:
riscv: select ARCH_USE_SYM_ANNOTATIONS
riscv: errata: sifive: Use SYM_*() assembly macros
Link: https://lore.kernel.org/r/20240709160536.3690-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Currently, userstacktrace is unsupported for riscv. So use the
perf_callchain_user() code as blueprint to implement the
arch_stack_walk_user() which add userstacktrace support on riscv.
Meanwhile, we can use arch_stack_walk_user() to simplify the implementation
of perf_callchain_user().
A ftrace test case is shown as below:
# cd /sys/kernel/debug/tracing
# echo 1 > options/userstacktrace
# echo 1 > options/sym-userobj
# echo 1 > events/sched/sched_process_fork/enable
# cat trace
......
bash-178 [000] ...1. 97.968395: sched_process_fork: comm=bash pid=178 child_comm=bash child_pid=231
bash-178 [000] ...1. 97.970075: <user stack trace>
=> /lib/libc.so.6[+0xb5090]
Also a simple perf test is ok as below:
# perf record -e cpu-clock --call-graph fp top
# perf report --call-graph
.....
[[31m 66.54%[[m 0.00% top [kernel.kallsyms] [k] ret_from_exception
|
---ret_from_exception
|
|--[[31m58.97%[[m--do_trap_ecall_u
| |
| |--[[31m17.34%[[m--__riscv_sys_read
| | ksys_read
| | |
| | --[[31m16.88%[[m--vfs_read
| | |
| | |--[[31m10.90%[[m--seq_read
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Tested-by: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20240708032847.2998158-3-ruanjinjie@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Add all of the flags that are needed to support the shadow call stack
(SCS) sanitizer with Rust, and updates Kconfig to allow only
configurations that work.
The -Zfixed-x18 flag is required to use SCS on arm64, and requires rustc
version 1.80.0 or greater. This restriction is reflected in Kconfig.
When CONFIG_DYNAMIC_SCS is enabled, the build will be configured to
include unwind tables in the build artifacts. Dynamic SCS uses the
unwind tables at boot to find all places that need to be patched. The
-Cforce-unwind-tables=y flag ensures that unwind tables are available
for Rust code.
In non-dynamic mode, the -Zsanitizer=shadow-call-stack flag is what
enables the SCS sanitizer. Using this flag requires rustc version 1.82.0
or greater on the targets used by Rust in the kernel. This restriction
is reflected in Kconfig.
It is possible to avoid the requirement of rustc 1.80.0 by using
-Ctarget-feature=+reserve-x18 instead of -Zfixed-x18. However, this flag
emits a warning during the build, so this patch does not add support for
using it and instead requires 1.80.0 or greater.
The dependency is placed on `select HAVE_RUST` to avoid a situation
where enabling Rust silently turns off the sanitizer. Instead, turning
on the sanitizer results in Rust being disabled. We generally do not
want changes to CONFIG_RUST to result in any mitigations being changed
or turned off.
At the time of writing, rustc 1.82.0 only exists via the nightly release
channel. There is a chance that the -Zsanitizer=shadow-call-stack flag
will end up needing 1.83.0 instead, but I think it is small.
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240829-shadow-call-stack-v7-1-2f62a4432abf@google.com
[ Fixed indentation using spaces. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Merge ACPI and irqchip updates related to external interrupt controller
support on RISC-V:
- Add ACPI device enumeration support for interrupt controller probing
including taking dependencies into account (Sunil V L).
- Implement ACPI-based interrupt controller probing on RISC-V (Sunil V L).
- Add ACPI support for AIA in riscv-intc and add ACPI support to
riscv-imsic, riscv-aplic, and sifive-plic (Sunil V L).
* acpi-riscv:
irqchip/sifive-plic: Add ACPI support
irqchip/riscv-aplic: Add ACPI support
irqchip/riscv-imsic: Add ACPI support
irqchip/riscv-imsic-state: Create separate function for DT
irqchip/riscv-intc: Add ACPI support for AIA
ACPI: RISC-V: Implement function to add implicit dependencies
ACPI: RISC-V: Initialize GSI mapping structures
ACPI: RISC-V: Implement function to reorder irqchip probe entries
ACPI: RISC-V: Implement PCI related functionality
ACPI: pci_link: Clear the dependencies after probe
ACPI: bus: Add RINTC IRQ model for RISC-V
ACPI: scan: Define weak function to populate dependencies
ACPI: scan: Add RISC-V interrupt controllers to honor list
ACPI: scan: Refactor dependency creation
ACPI: bus: Add acpi_riscv_init() function
ACPI: scan: Add a weak arch_sort_irqchip_probe() to order the IRQCHIP probe
arm64: PCI: Migrate ACPI related functions to pci-acpi.c
Currently x86, ARM and ARM64 support generic CPU vulnerabilites, but
RISC-V not, such as:
# cd /sys/devices/system/cpu/vulnerabilities/
x86:
# cat spec_store_bypass
Mitigation: Speculative Store Bypass disabled via prctl and seccomp
# cat meltdown
Not affected
ARM64:
# cat spec_store_bypass
Mitigation: Speculative Store Bypass disabled via prctl and seccomp
# cat meltdown
Mitigation: PTI
RISC-V:
# cat /sys/devices/system/cpu/vulnerabilities
# ... No such file or directory
As SiFive RISC-V Core IP offerings are not affected by Meltdown and
Spectre, it can use the default weak function as below:
# cat spec_store_bypass
Not affected
# cat meltdown
Not affected
Link: https://www.sifive.cn/blog/sifive-statement-on-meltdown-and-spectre
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/r/20240703022732.2068316-1-ruanjinjie@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Pull more RISC-V updates from Palmer Dabbelt:
- Support for NUMA (via SRAT and SLIT), console output (via SPCR), and
cache info (via PPTT) on ACPI-based systems.
- The trap entry/exit code no longer breaks the return address stack
predictor on many systems, which results in an improvement to trap
latency.
- Support for HAVE_ARCH_STACKLEAK.
- The sv39 linear map has been extended to support 128GiB mappings.
- The frequency of the mtime CSR is now visible via hwprobe.
* tag 'riscv-for-linus-6.11-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (21 commits)
RISC-V: Provide the frequency of time CSR via hwprobe
riscv: Extend sv39 linear mapping max size to 128G
riscv: enable HAVE_ARCH_STACKLEAK
riscv: signal: Remove unlikely() from WARN_ON() condition
riscv: Improve exception and system call latency
RISC-V: Select ACPI PPTT drivers
riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT
riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init()
RISC-V: ACPI: Enable SPCR table for console output on RISC-V
riscv: boot: remove duplicated targets line
trace: riscv: Remove deprecated kprobe on ftrace support
riscv: cpufeature: Extract common elements from extension checking
riscv: Introduce vendor variants of extension helpers
riscv: Add vendor extensions to /proc/cpuinfo
riscv: Extend cpufeature.c to detect vendor extensions
RISC-V: run savedefconfig for defconfig
RISC-V: hwprobe: sort EXT_KEY()s in hwprobe_isa_ext0() alphabetically
ACPI: NUMA: replace pr_info with pr_debug in arch_acpi_numa_init
ACPI: NUMA: change the ACPI_NUMA to a hidden option
ACPI: NUMA: Add handler for SRAT RINTC affinity structure
...
This series adds support for ACPI PPTT via cacheinfo.
* b4-shazam-merge:
RISC-V: Select ACPI PPTT drivers
riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT
riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init()
Link: https://lore.kernel.org/r/20240617131425.7526-1-cuiyunhui@bytedance.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Add support for the stackleak feature. Whenever the kernel returns to user
space the kernel stack is filled with a poison value.
At the same time, disables the plugin in EFI stub code because EFI stub
is out of scope for the protection.
Tested on qemu and milkv duo:
/ # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT
[ 38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING
[ 38.678448] lkdtm: stackleak stack usage:
[ 38.678448] high offset: 288 bytes
[ 38.678448] current: 496 bytes
[ 38.678448] lowest: 1328 bytes
[ 38.678448] tracked: 1328 bytes
[ 38.678448] untracked: 448 bytes
[ 38.678448] poisoned: 14312 bytes
[ 38.678448] low offset: 8 bytes
[ 38.689887] lkdtm: OK: the rest of the thread stack is properly erased
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240623235316.2010-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Since commit 7caa976546 ("ftrace: riscv: move from REGS to ARGS"),
kprobe on ftrace is not supported by riscv, because riscv's support for
FTRACE_WITH_REGS has been replaced with support for FTRACE_WITH_ARGS, and
KPROBES_ON_FTRACE will be supplanted by FPROBES. So remove the deprecated
kprobe on ftrace support, which is misunderstood.
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240613111347.1745379-1-ruanjinjie@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Pull Kbuild updates from Masahiro Yamada:
- Remove tristate choice support from Kconfig
- Stop using the PROVIDE() directive in the linker script
- Reduce the number of links for the combination of CONFIG_KALLSYMS and
CONFIG_DEBUG_INFO_BTF
- Enable the warning for symbol reference to .exit.* sections by
default
- Fix warnings in RPM package builds
- Improve scripts/make_fit.py to generate a FIT image with separate
base DTB and overlays
- Improve choice value calculation in Kconfig
- Fix conditional prompt behavior in choice in Kconfig
- Remove support for the uncommon EMAIL environment variable in Debian
package builds
- Remove support for the uncommon "name <email>" form for the DEBEMAIL
environment variable
- Raise the minimum supported GNU Make version to 4.0
- Remove stale code for the absolute kallsyms
- Move header files commonly used for host programs to scripts/include/
- Introduce the pacman-pkg target to generate a pacman package used in
Arch Linux
- Clean up Kconfig
* tag 'kbuild-v6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (65 commits)
kbuild: doc: gcc to CC change
kallsyms: change sym_entry::percpu_absolute to bool type
kallsyms: unify seq and start_pos fields of struct sym_entry
kallsyms: add more original symbol type/name in comment lines
kallsyms: use \t instead of a tab in printf()
kallsyms: avoid repeated calculation of array size for markers
kbuild: add script and target to generate pacman package
modpost: use generic macros for hash table implementation
kbuild: move some helper headers from scripts/kconfig/ to scripts/include/
Makefile: add comment to discourage tools/* addition for kernel builds
kbuild: clean up scripts/remove-stale-files
kconfig: recursive checks drop file/lineno
kbuild: rpm-pkg: introduce a simple changelog section for kernel.spec
kallsyms: get rid of code for absolute kallsyms
kbuild: Create INSTALL_PATH directory if it does not exist
kbuild: Abort make on install failures
kconfig: remove 'e1' and 'e2' macros from expression deduplication
kconfig: remove SYMBOL_CHOICEVAL flag
kconfig: add const qualifiers to several function arguments
kconfig: call expr_eliminate_yn() at least once in expr_eliminate_dups()
...
Charlie Jenkins <charlie@rivosinc.com> says:
All extensions, both standard and vendor, live in one struct
"riscv_isa_ext". There is currently one vendor extension, xandespmu, but
it is likely that more vendor extensions will be added to the kernel in
the future. As more vendor extensions (and standard extensions) are
added, riscv_isa_ext will become more bloated with a mix of vendor and
standard extensions.
This also allows each vendor to be conditionally enabled through
Kconfig.
* b4-shazam-merge:
riscv: cpufeature: Extract common elements from extension checking
riscv: Introduce vendor variants of extension helpers
riscv: Add vendor extensions to /proc/cpuinfo
riscv: Extend cpufeature.c to detect vendor extensions
Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-0-0af7587bbec0@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Instead of grouping all vendor extensions into the same riscv_isa_ext
that standard instructions use, create a struct
"riscv_isa_vendor_ext_data_list" that allows each vendor to maintain
their vendor extensions independently of the standard extensions.
xandespmu is currently the only vendor extension so that is the only
extension that is affected by this change.
An additional benefit of this is that the extensions of each vendor can
be conditionally enabled. A config RISCV_ISA_VENDOR_EXT_ANDES has been
added to allow for that.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
Tested-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-1-0af7587bbec0@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Pull RISC-V updates from Palmer Dabbelt:
- Support for various new ISA extensions:
* The Zve32[xf] and Zve64[xfd] sub-extensios of the vector
extension
* Zimop and Zcmop for may-be-operations
* The Zca, Zcf, Zcd and Zcb sub-extensions of the C extension
* Zawrs
- riscv,cpu-intc is now dtschema
- A handful of performance improvements and cleanups to text patching
- Support for memory hot{,un}plug
- The highest user-allocatable virtual address is now visible in
hwprobe
* tag 'riscv-for-linus-6.11-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (58 commits)
riscv: lib: relax assembly constraints in hweight
riscv: set trap vector earlier
KVM: riscv: selftests: Add Zawrs extension to get-reg-list test
KVM: riscv: Support guest wrs.nto
riscv: hwprobe: export Zawrs ISA extension
riscv: Add Zawrs support for spinlocks
dt-bindings: riscv: Add Zawrs ISA extension description
riscv: Provide a definition for 'pause'
riscv: hwprobe: export highest virtual userspace address
riscv: Improve sbi_ecall() code generation by reordering arguments
riscv: Add tracepoints for SBI calls and returns
riscv: Optimize crc32 with Zbc extension
riscv: Enable DAX VMEMMAP optimization
riscv: mm: Add support for ZONE_DEVICE
virtio-mem: Enable virtio-mem for RISC-V
riscv: Enable memory hotplugging for RISC-V
riscv: mm: Take memory hotplug read-lock during kernel page table dump
riscv: mm: Add memory hotplugging support
riscv: mm: Add pfn_to_kaddr() implementation
riscv: mm: Refactor create_linear_mapping_range() for memory hot add
...
While Documentation/kbuild/kconfig-language.rst provides a brief
explanation, there are recurring confusions regarding the usage of a
prompt followed by 'if <expr>'. This conditional controls _only_ the
prompt.
A typical usage is as follows:
menuconfig BLOCK
bool "Enable the block layer" if EXPERT
default y
When EXPERT=n, the prompt is hidden, but this config entry is still
active, and BLOCK is set to its default value 'y'. This is reasonable
because you are likely want to enable the block device support. When
EXPERT=y, the prompt is shown, allowing you to toggle BLOCK.
Please note that it is different from 'depends on EXPERT', which would
enable and disable the entire config entry.
However, this conditional prompt has never worked in a choice block.
The following two work in the same way: when EXPERT is disabled, the
choice block is entirely disabled.
[Test Code 1]
choice
prompt "choose" if EXPERT
config A
bool "A"
config B
bool "B"
endchoice
[Test Code 2]
choice
prompt "choose"
depends on EXPERT
config A
bool "A"
config B
bool "B"
endchoice
I believe the first case should hide only the prompt, producing the
default:
CONFIG_A=y
# CONFIG_B is not set
The next commit will change (fix) the behavior of the conditional prompt
in choice blocks.
I see several choice blocks wrongly using a conditional prompt, where
'depends on' makes more sense.
To preserve the current behavior, this commit converts such misuses.
I did not touch the following entry in arch/x86/Kconfig:
choice
prompt "Memory split" if EXPERT
default VMSPLIT_3G
This is truly the correct use of the conditional prompt; when EXPERT=n,
this choice block should silently select the reasonable VMSPLIT_3G,
although the resulting PAGE_OFFSET will not be affected anyway.
Presumably, the one in fs/jffs2/Kconfig is also correct, but I converted
it to 'depends on' to avoid any potential behavioral change.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Andrew Jones <ajones@ventanamicro.com> says:
Zawrs provides two instructions (wrs.nto and wrs.sto), where both are
meant to allow the hart to enter a low-power state while waiting on a
store to a memory location. The instructions also both wait an
implementation-defined "short" duration (unless the implementation
terminates the stall for another reason). The difference is that while
wrs.sto will terminate when the duration elapses, wrs.nto, depending on
configuration, will either just keep waiting or an ILL exception will be
raised. Linux will use wrs.nto, so if platforms have an implementation
which falls in the "just keep waiting" category (which is not expected),
then it should _not_ advertise Zawrs in the hardware description.
Like wfi (and with the same {m,h}status bits to configure it), when
wrs.nto is configured to raise exceptions it's expected that the higher
privilege level will see the instruction was a wait instruction, do
something, and then resume execution following the instruction. For
example, KVM does configure exceptions for wfi (hstatus.VTW=1) and
therefore also for wrs.nto. KVM does this for wfi since it's better to
allow other tasks to be scheduled while a VCPU waits for an interrupt.
For waits such as those where wrs.nto/sto would be used, which are
typically locks, it is also a good idea for KVM to be involved, as it
can attempt to schedule the lock holding VCPU.
This series starts with Christoph's addition of the riscv
smp_cond_load_relaxed function which applies wrs.sto when available.
That patch has been reworked to use wrs.nto and to use the same approach
as Arm for the wait loop, since we can't have arbitrary C code between
the load-reserved and the wrs. Then, hwprobe support is added (since the
instructions are also usable from usermode), and finally KVM is
taught about wrs.nto, allowing guests to see and use the Zawrs
extension.
We still don't have test results from hardware, and it's not possible to
prove that using Zawrs is a win when testing on QEMU, not even when
oversubscribing VCPUs to guests. However, it is possible to use KVM
selftests to force a scenario where we can prove Zawrs does its job and
does it well. [4] is a test which does this and, on my machine, without
Zawrs it takes 16 seconds to complete and with Zawrs it takes 0.25
seconds.
This series is also available here [1]. In order to use QEMU for testing
a build with [2] is needed. In order to enable guests to use Zawrs with
KVM using kvmtool, the branch at [3] may be used.
[1] https://github.com/jones-drew/linux/commits/riscv/zawrs-v3/
[2] https://lore.kernel.org/all/20240312152901.512001-2-ajones@ventanamicro.com/
[3] https://github.com/jones-drew/kvmtool/commits/riscv/zawrs/
[4] cb2beccebc
Link: https://lore.kernel.org/r/20240426100820.14762-8-ajones@ventanamicro.com
* b4-shazam-merge:
KVM: riscv: selftests: Add Zawrs extension to get-reg-list test
KVM: riscv: Support guest wrs.nto
riscv: hwprobe: export Zawrs ISA extension
riscv: Add Zawrs support for spinlocks
dt-bindings: riscv: Add Zawrs ISA extension description
riscv: Provide a definition for 'pause'
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
RISC-V code uses the generic ticket lock implementation, which calls
the macros smp_cond_load_relaxed() and smp_cond_load_acquire().
Introduce a RISC-V specific implementation of smp_cond_load_relaxed()
which applies WRS.NTO of the Zawrs extension in order to reduce power
consumption while waiting and allows hypervisors to enable guests to
trap while waiting. smp_cond_load_acquire() doesn't need a RISC-V
specific implementation as the generic implementation is based on
smp_cond_load_relaxed() and smp_acquire__after_ctrl_dep() sufficiently
provides the acquire semantics.
This implementation is heavily based on Arm's approach which is the
approach Andrea Parri also suggested.
The Zawrs specification can be found here:
https://github.com/riscv/riscv-zawrs/blob/main/zawrs.adoc
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Co-developed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240426100820.14762-11-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
If we're going to provide the encoding for 'pause' in cpu_relax()
anyway, then we can drop the toolchain checks and just always use
it. The advantage of doing this is that other code that need
pause don't need to also define it (yes, another use is coming).
Add the definition to insn-def.h since it's an instruction
definition and also because insn-def.h doesn't include much, so
it's safe to include from asm/vdso/processor.h without concern for
circular dependencies.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240426100820.14762-9-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
As suggested by the B-ext spec, the Zbc (carry-less multiplication)
instructions can be used to accelerate CRC calculations. Currently, the
crc32 is the most widely used crc function inside kernel, so this patch
focuses on the optimization of just the crc32 APIs.
Compared with the current table-lookup based optimization, Zbc based
optimization can also achieve large stride during CRC calculation loop,
meantime, it avoids the memory access latency of the table-lookup based
implementation and it reduces memory footprint.
If Zbc feature is not supported in a runtime environment, then the
table-lookup based implementation would serve as fallback via alternative
mechanism.
By inspecting the vmlinux built by gcc v12.2.0 with default optimization
level (-O2), we can see below instruction count change for each 8-byte
stride in the CRC32 loop:
rv64: crc32_be (54->31), crc32_le (54->13), __crc32c_le (54->13)
rv32: crc32_be (50->32), crc32_le (50->16), __crc32c_le (50->16)
The compile target CPU is little endian, extra effort is needed for byte
swapping for the crc32_be API, thus, the instruction count change is not
as significant as that in the *_le cases.
This patch is tested on QEMU VM with the kernel CRC32 selftest for both
rv64 and rv32. Running the CRC32 selftest on a real hardware (SpacemiT K1)
with Zbc extension shows 65% and 125% performance improvement respectively
on crc32_test() and crc32c_test().
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240621054707.1847548-1-xiao.w.wang@intel.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Björn Töpel <bjorn@kernel.org> says:
From: Björn Töpel <bjorn@rivosinc.com>
================================================================
Memory Hot(Un)Plug support (and ZONE_DEVICE) for the RISC-V port
================================================================
Introduction
============
To quote "Documentation/admin-guide/mm/memory-hotplug.rst": "Memory
hot(un)plug allows for increasing and decreasing the size of physical
memory available to a machine at runtime."
This series adds memory hot(un)plugging, and ZONE_DEVICE support for
the RISC-V Linux port.
MM configuration
================
RISC-V MM has the following configuration:
* Memory blocks are 128M, analogous to x86-64. It uses PMD
("hugepage") vmemmaps. From that follows that 2M (PMD) worth of
vmemmap spans 32768 pages á 4K which gets us 128M.
* The pageblock size is the minimum minimum virtio_mem size, and on
RISC-V it's 2M (2^9 * 4K).
Implementation
==============
The PGD table on RISC-V is shared/copied between for all processes. To
avoid doing page table synchronization, the first patch (patch 1)
pre-allocated the PGD entries for vmemmap/direct map. By doing that
the init_mm PGD will be fixed at kernel init, and synchronization can
be avoided all together.
The following two patches (patch 2-3) does some preparations, followed
by the actual MHP implementation (patch 4-5). Then, MHP and virtio-mem
are enabled (patch 6-7), and finally ZONE_DEVICE support is added
(patch 8).
MHP and locking
===============
TL;DR: The MHP does not step on any toes, except for ptdump.
Additional locking is required for ptdump.
Long version: For v2 I spent some time digging into init_mm
synchronization/update. Here are my findings, and I'd love them to be
corrected if incorrect.
It's been a gnarly path...
The `init_mm` structure is a special mm (perhaps not a "real" one).
It's a "lazy context" that tracks kernel page table resources, e.g.,
the kernel page table (swapper_pg_dir), a kernel page_table_lock (more
about the usage below), mmap_lock, and such.
`init_mm` does not track/contain any VMAs. Having the `init_mm` is
convenient, so that the regular kernel page table walk/modify
functions can be used.
Now, `init_mm` being special means that the locking for kernel page
tables are special as well.
On RISC-V the PGD (top-level page table structure), similar to x86, is
shared (copied) with user processes. If the kernel PGD is modified, it
has to be synched to user-mode processes PGDs. This is avoided by
pre-populating the PGD, so it'll be fixed from boot.
The in-kernel pgd regions are documented in
`Documentation/arch/riscv/vm-layout.rst`.
The distinct regions are:
* vmemmap
* vmalloc/ioremap space
* direct mapping of all physical memory
* kasan
* modules, BPF
* kernel
Memory hotplug is the process of adding/removing memory to/from the
kernel.
Adding is done in two phases:
1. Add the memory to the kernel
2. Online memory, making it available to the page allocator.
Step 1 is partially architecture dependent, and updates the init_mm
page table:
* Update the direct map page tables. The direct map is a linear map,
representing all physical memory: `virt = phys + PAGE_OFFSET`
* Add a `struct page` for each added page of memory. Update the
vmemmap (virtual mapping to the `struct page`, so we can easily
transform a kernel virtual address to a `struct page *` address.
From an MHP perspective, there are two regions of the PGD that are
updated:
* vmemmap
* direct mapping of all physical memory
The `struct mm_struct` has a couple of locks in play:
* `spinlock_t page_table_lock` protects the page table, and some
counters
* `struct rw_semaphore mmap_lock` protect an mm's VMAs
Note again that `init_mm` does not contain any VMAs, but still uses
the mmap_lock in some places.
The `page_table_lock` was originally used to to protect all pages
tables, but more recently a split page table lock has been introduced.
The split lock has a per-table lock for the PTE and PMD tables. If
split lock is disabled, all tables are guarded by
`mm->page_table_lock` (for user processes). Split page table locks are
not used for init_mm.
MHP operations is typically synchronized using
`DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock)`.
Actors
------
The following non-MHP actors in the kernel traverses (read), and/or
modifies the kernel PGD.
* `ptdump`
Walks the entire `init_mm`, via `ptdump_walk_pgd()` with the
`mmap_write_lock(init_mm)` taken.
Observation: ptdump can race with MHP, and needs additional locking
to avoid crashes/races.
* `set_direct_*` / `arch/riscv/mm/pageattr.c`
The `set_direct_*` functionality is used to "synchronize" the
direct map to other kernel mappings, e.g. modules/kernel text. The
direct map is using "as large huge table mappings as possible",
which means that the `set_direct_*` might need to split the direct
map.
The `set_direct_*` functions operates with the
`mmap_write_lock(init_mm)` taken.
Observation: `set_direct_*` uses the direct map, but will never
modify the same entry as MHP. If there is a mapping, that entry will
never race with MHP. Further, MHP acts when memory is offline.
* HVO / `mm/hugetlb_vmemmap`
HVO optimizes the backing `struct page` for hugetlb pages, which
means changing the "vmemmap" region. HVO can split (merge?) a
vmemmap pmd. However, it will never race with MHP, since HVO only
operates at online memory. HVO cannot touch memory being MHP added
or removed.
* `apply_to_page_range`
Walks a range, creates pages and applies a callback (setting
permissions) for the page.
When creating a table, it might use `int __pte_alloc_kernel(pmd_t
*pmd)` which takes the `init_mm.page_table_lock` to synchronize pmd
populate.
Used by: `mm/vmalloc.c` and `mm/kasan/shadow.c`. The KASAN callback
takes the `init_mm.page_table_lock` to synchronize pte creation.
Observations: `apply_to_page_range` applies to the "vmalloc/ioremap
space" region, and "kasan" region. *Not* affected by MHP.
* `apply_to_existing_page_range`
Walks a range, applies a callback (setting permissions) for the
page (no page creation).
Used by: `kernel/bpf/arena.c` and `mm/kasan/shadow.c`. The KASAN
callback takes the `init_mm.page_table_lock` to synchronize pte
creation. *Not* affected by MHP regions.
* `apply_to_existing_page_range` applies to the "vmalloc/ioremap
space" region, and "kasan" region. *Not* affected by MHP regions.
* `ioremap_page_range` and `vmap_page_range`
Uses the same internal function, and might create table entries at
the "vmalloc/ioremap space" region. Can call
`__pte_alloc_kernel()` which takes the `init_mm.page_table_lock`
synchronizing pmd populate in the region. *Not* affected by MHP
regions.
Summary:
* MHP add will never modify the same page table entries, as any of
the other actors.
* MHP remove is done when memory is offlined, and will not clash
with any of the actors.
* Functions that walk the entire kernel page table need
synchronization
* It's sufficient to add the MHP lock ptdump.
Testing
=======
This series adds basic DT supported hotplugging. There is a QEMU
series enabling MHP for the RISC-V "virt" machine here: [1]
ACPI/MSI support is still in the making for RISC-V, and prior proper
(ACPI) PCI MSI support lands [2] and NUMA SRAT support [3], it hard to
try it out.
I've prepared a QEMU branch with proper ACPI GED/PC-DIMM support [4],
and a this series with the required prerequisites [5] (AIA, ACPI AIA
MADT, ACPI NUMA SRAT).
To test with virtio-mem, e.g.:
| qemu-system-riscv64 \
| -machine virt,aia=aplic-imsic \
| -cpu rv64,v=true,vlen=256,elen=64,h=true,zbkb=on,zbkc=on,zbkx=on,zkr=on,zkt=on,svinval=on,svnapot=on,svpbmt=on \
| -nodefaults \
| -nographic -smp 8 -kernel rv64-u-boot.bin \
| -drive file=rootfs.img,format=raw,if=virtio \
| -device virtio-rng-pci \
| -m 16G,slots=3,maxmem=32G \
| -object memory-backend-ram,id=mem0,size=16G \
| -numa node,nodeid=0,memdev=mem0 \
| -serial chardev:char0 \
| -mon chardev=char0,mode=readline \
| -chardev stdio,mux=on,id=char0 \
| -device pci-serial,id=serial0,chardev=char0 \
| -object memory-backend-ram,id=vmem0,size=2G \
| -device virtio-mem-pci,id=vm0,memdev=vmem0,node=0
where "rv64-u-boot.bin" is U-boot with EFI/ACPI-support (use [6] if
you're lazy).
In the QEMU monitor:
| (qemu) info memory-devices
| (qemu) qom-set vm0 requested-size 1G
...to test DAX/KMEM, use the follow QEMU parameters:
| -object memory-backend-file,id=mem1,share=on,mem-path=virtio_pmem.img,size=4G \
| -device virtio-pmem-pci,memdev=mem1,id=nv1
and the regular ndctl/daxctl dance.
If you're brave to try the ACPI branch, add "acpi=on" to "-machine
virt", and test PC-DIMM MHP (in addition to virtio-{p},mem):
In the QEMU monitor:
| (qemu) object_add memory-backend-ram,id=mem1,size=1G
| (qemu) device_add pc-dimm,id=dimm1,memdev=mem1
You can also try hot-remove with some QEMU options, say:
| -object memory-backend-file,id=mem-1,size=256M,mem-path=/pagesize-2MB
| -device pc-dimm,id=mem1,memdev=mem-1
| -object memory-backend-file,id=mem-2,size=1G,mem-path=/pagesize-1GB
| -device pc-dimm,id=mem2,memdev=mem-2
| -object memory-backend-file,id=mem-3,size=256M,mem-path=/pagesize-2MB
| -device pc-dimm,id=mem3,memdev=mem-3
Remove "acpi=on" to run with DT.
Thanks to Alex, Andrew, David, and Oscar for all
comments/tests/fixups.
References
==========
[1] https://lore.kernel.org/qemu-devel/20240521105635.795211-1-bjorn@kernel.org/
[2] https://lore.kernel.org/linux-riscv/20240501121742.1215792-1-sunilvl@ventanamicro.com/
[3] https://lore.kernel.org/linux-riscv/cover.1713778236.git.haibo1.xu@intel.com/
[4] https://github.com/bjoto/qemu/commits/virtio-mem-pc-dimm-mhp-acpi-v2/
[5] https://github.com/bjoto/linux/commits/mhp-v4-acpi
[6] https://github.com/bjoto/riscv-rootfs-utils/tree/acpi
* b4-shazam-merge:
riscv: Enable DAX VMEMMAP optimization
riscv: mm: Add support for ZONE_DEVICE
virtio-mem: Enable virtio-mem for RISC-V
riscv: Enable memory hotplugging for RISC-V
riscv: mm: Take memory hotplug read-lock during kernel page table dump
riscv: mm: Add memory hotplugging support
riscv: mm: Add pfn_to_kaddr() implementation
riscv: mm: Refactor create_linear_mapping_range() for memory hot add
riscv: mm: Change attribute from __init to __meminit for page functions
riscv: mm: Pre-allocate vmemmap/direct map/kasan PGD entries
riscv: mm: Properly forward vmemmap_populate() altmap parameter
Link: https://lore.kernel.org/r/20240605114100.315918-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
drivers/net/ethernet/pensando/ionic/ionic_txrx.c
d9c0420999 ("ionic: Mark error paths in the data path as unlikely")
491aee894a ("ionic: fix kernel panic in XDP_TX action")
net/ipv6/ip6_fib.c
b4cb4a1391 ("net: use unrcu_pointer() helper")
b01e1c0307 ("ipv6: fix possible race in __fib6_drop_pcpu_from()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-05-28
We've added 23 non-merge commits during the last 11 day(s) which contain
a total of 45 files changed, 696 insertions(+), 277 deletions(-).
The main changes are:
1) Rename skb's mono_delivery_time to tstamp_type for extensibility
and add SKB_CLOCK_TAI type support to bpf_skb_set_tstamp(),
from Abhishek Chauhan.
2) Add netfilter CT zone ID and direction to bpf_ct_opts so that arbitrary
CT zones can be used from XDP/tc BPF netfilter CT helper functions,
from Brad Cowie.
3) Several tweaks to the instruction-set.rst IETF doc to address
the Last Call review comments, from Dave Thaler.
4) Small batch of riscv64 BPF JIT optimizations in order to emit more
compressed instructions to the JITed image for better icache efficiency,
from Xiao Wang.
5) Sort bpftool C dump output from BTF, aiming to simplify vmlinux.h
diffing and forcing more natural type definitions ordering,
from Mykyta Yatsenko.
6) Use DEV_STATS_INC() macro in BPF redirect helpers to silence
a syzbot/KCSAN race report for the tx_errors counter,
from Jiang Yunshui.
7) Un-constify bpf_func_info in bpftool to fix compilation with LLVM 17+
which started treating const structs as constants and thus breaking
full BTF program name resolution, from Ivan Babrou.
8) Fix up BPF program numbers in test_sockmap selftest in order to reduce
some of the test-internal array sizes, from Geliang Tang.
9) Small cleanup in Makefile.btf script to use test-ge check for v1.25-only
pahole, from Alan Maguire.
10) Fix bpftool's make dependencies for vmlinux.h in order to avoid needless
rebuilds in some corner cases, from Artem Savkov.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (23 commits)
bpf, net: Use DEV_STAT_INC()
bpf, docs: Fix instruction.rst indentation
bpf, docs: Clarify call local offset
bpf, docs: Add table captions
bpf, docs: clarify sign extension of 64-bit use of 32-bit imm
bpf, docs: Use RFC 2119 language for ISA requirements
bpf, docs: Move sentence about returning R0 to abi.rst
bpf: constify member bpf_sysctl_kern:: Table
riscv, bpf: Try RVC for reg move within BPF_CMPXCHG JIT
riscv, bpf: Use STACK_ALIGN macro for size rounding up
riscv, bpf: Optimize zextw insn with Zba extension
selftests/bpf: Handle forwarding of UDP CLOCK_TAI packets
net: Add additional bit to support clockid_t timestamp type
net: Rename mono_delivery_time to tstamp_type for scalabilty
selftests/bpf: Update tests for new ct zone opts for nf_conntrack kfuncs
net: netfilter: Make ct zone opts configurable for bpf ct helpers
selftests/bpf: Fix prog numbers in test_sockmap
bpf: Remove unused variable "prev_state"
bpftool: Un-const bpf_func_info to fix it for llvm 17 and newer
bpf: Fix order of args in call to bpf_map_kvcalloc
...
====================
Link: https://lore.kernel.org/r/20240528105924.30905-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull more RISC-V updates from Palmer Dabbelt:
- The compression format used for boot images is now configurable at
build time, and these formats are shown in `make help`
- access_ok() has been optimized
- A pair of performance bugs have been fixed in the uaccess handlers
- Various fixes and cleanups, including one for the IMSIC build failure
and one for the early-boot ftrace illegal NOPs bug
* tag 'riscv-for-linus-6.10-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Fix early ftrace nop patching
irqchip: riscv-imsic: Fixup riscv_ipi_set_virq_range() conflict
riscv: selftests: Add signal handling vector tests
riscv: mm: accelerate pagefault when badaccess
riscv: uaccess: Relax the threshold for fast path
riscv: uaccess: Allow the last potential unrolled copy
riscv: typo in comment for get_f64_reg
Use bool value in set_cpu_online()
riscv: selftests: Add hwprobe binaries to .gitignore
riscv: stacktrace: fixed walk_stackframe()
ftrace: riscv: move from REGS to ARGS
riscv: do not select MODULE_SECTIONS by default
riscv: show help string for riscv-specific targets
riscv: make image compression configurable
riscv: cpufeature: Fix extension subset checking
riscv: cpufeature: Fix thead vector hwcap removal
riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context
riscv: force PAGE_SIZE linear mapping if debug_pagealloc is enabled
riscv: Define TASK_SIZE_MAX for __access_ok()
riscv: Remove PGDIR_SIZE_L3 and TASK_SIZE_MIN
Pull more non-mm updates from Andrew Morton:
- A series ("kbuild: enable more warnings by default") from Arnd
Bergmann which enables a number of additional build-time warnings. We
fixed all the fallout which we could find, there may still be a few
stragglers.
- Samuel Holland has developed the series "Unified cross-architecture
kernel-mode FPU API". This does a lot of consolidation of
per-architecture kernel-mode FPU usage and enables the use of newer
AMD GPUs on RISC-V.
- Tao Su has fixed some selftests build warnings in the series
"Selftests: Fix compilation warnings due to missing _GNU_SOURCE
definition".
- This pull also includes a nilfs2 fixup from Ryusuke Konishi.
* tag 'mm-nonmm-stable-2024-05-22-17-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (23 commits)
nilfs2: make block erasure safe in nilfs_finish_roll_forward()
selftests/harness: use 1024 in place of LINE_MAX
Revert "selftests/harness: remove use of LINE_MAX"
selftests/fpu: allow building on other architectures
selftests/fpu: move FP code to a separate translation unit
drm/amd/display: use ARCH_HAS_KERNEL_FPU_SUPPORT
drm/amd/display: only use hard-float, not altivec on powerpc
riscv: add support for kernel-mode FPU
x86: implement ARCH_HAS_KERNEL_FPU_SUPPORT
powerpc: implement ARCH_HAS_KERNEL_FPU_SUPPORT
LoongArch: implement ARCH_HAS_KERNEL_FPU_SUPPORT
lib/raid6: use CC_FLAGS_FPU for NEON CFLAGS
arm64: crypto: use CC_FLAGS_FPU for NEON CFLAGS
arm64: implement ARCH_HAS_KERNEL_FPU_SUPPORT
ARM: crypto: use CC_FLAGS_FPU for NEON CFLAGS
ARM: implement ARCH_HAS_KERNEL_FPU_SUPPORT
arch: add ARCH_HAS_KERNEL_FPU_SUPPORT
x86/fpu: fix asm/fpu/types.h include guard
kbuild: enable -Wcast-function-type-strict unconditionally
kbuild: enable -Wformat-truncation on clang
...
This commit replaces riscv's support for FTRACE_WITH_REGS with support
for FTRACE_WITH_ARGS. This is required for the ongoing effort to stop
relying on stop_machine() for RISCV's implementation of ftrace.
The main relevant benefit that this change will bring for the above
use-case is that now we don't have separate ftrace_caller and
ftrace_regs_caller trampolines. This will allow the callsite to call
ftrace_caller by modifying a single instruction. Now the callsite can
do something similar to:
When not tracing: | When tracing:
func: func:
auipc t0, ftrace_caller_top auipc t0, ftrace_caller_top
nop <=========<Enable/Disable>=========> jalr t0, ftrace_caller_bottom
[...] [...]
The above assumes that we are dropping the support of calling a direct
trampoline from the callsite. We need to drop this as the callsite can't
change the target address to call, it can only enable/disable a call to
a preset target (ftrace_caller in the above diagram). We can later optimize
this by calling an intermediate dispatcher trampoline before ftrace_caller.
Currently, ftrace_regs_caller saves all CPU registers in the format of
struct pt_regs and allows the tracer to modify them. We don't need to
save all of the CPU registers because at function entry only a subset of
pt_regs is live:
|----------+----------+---------------------------------------------|
| Register | ABI Name | Description |
|----------+----------+---------------------------------------------|
| x1 | ra | Return address for traced function |
| x2 | sp | Stack pointer |
| x5 | t0 | Return address for ftrace_caller trampoline |
| x8 | s0/fp | Frame pointer |
| x10-11 | a0-1 | Function arguments/return values |
| x12-17 | a2-7 | Function arguments |
|----------+----------+---------------------------------------------|
See RISCV calling convention[1] for the above table.
Saving just the live registers decreases the amount of stack space
required from 288 Bytes to 112 Bytes.
Basic testing was done with this on the VisionFive 2 development board.
Note:
- Moving from REGS to ARGS will mean that RISCV will stop supporting
KPROBES_ON_FTRACE as it requires full pt_regs to be saved.
- KPROBES_ON_FTRACE will be supplanted by FPROBES see [2].
[1] https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf
[2] https://lore.kernel.org/all/170887410337.564249.6360118840946697039.stgit@devnote2/
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240405142453.4187-1-puranjay@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Since commit aad15bc85c ("riscv: Change code model of module to
medany to improve data accessing"), kernel modules have not been built
with -fPIC, so they wouldn't have R_RISCV_GOT_HI20 or R_RISCV_CALL_PLT
relocations, and handling of those relocations is unnecessary.
If RELOCATABLE=y, kernel modules will be built with -fPIE, which would
reintroduce said relocations, so only select MODULE_SECTIONS when
RELOCATABLE.
Signed-off-by: Qingfang Deng <qingfang.deng@siflower.com.cn>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240511015725.1162-1-dqfext@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Previously the build process would always set KBUILD_IMAGE to the
uncompressed Image file (unless XIP_KERNEL or EFI_ZBOOT was enabled) and
unconditionally compress it into Image.gz. However there are already
build targets for Image.bz2, Image.lz4, Image.lzma, Image.lzo and
Image.zstd, so let's make use of those, make the compression method
configurable and set KBUILD_IMAGE accordingly so that targets like
'make install' and 'make bindeb-pkg' will use the chosen image.
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240504193446.196886-2-emil.renner.berthing@canonical.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Pull RISC-V updates from Palmer Dabbelt:
- Add byte/half-word compare-and-exchange, emulated via LR/SC loops
- Support for Rust
- Support for Zihintpause in hwprobe
- Add PR_RISCV_SET_ICACHE_FLUSH_CTX prctl()
- Support lockless lockrefs
* tag 'riscv-for-linus-6.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
riscv: defconfig: Enable CONFIG_CLK_SOPHGO_CV1800
riscv: select ARCH_HAS_FAST_MULTIPLIER
riscv: mm: still create swiotlb buffer for kmalloc() bouncing if required
riscv: Annotate pgtable_l{4,5}_enabled with __ro_after_init
riscv: Remove redundant CONFIG_64BIT from pgtable_l{4,5}_enabled
riscv: mm: Always use an ASID to flush mm contexts
riscv: mm: Preserve global TLB entries when switching contexts
riscv: mm: Make asid_bits a local variable
riscv: mm: Use a fixed layout for the MM context ID
riscv: mm: Introduce cntx2asid/cntx2version helper macros
riscv: Avoid TLB flush loops when affected by SiFive CIP-1200
riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma
riscv: mm: Combine the SMP and UP TLB flush code
riscv: Only send remote fences when some other CPU is online
riscv: mm: Broadcast kernel TLB flushes only when needed
riscv: Use IPIs for remote cache/TLB flushes by default
riscv: Factor out page table TLB synchronization
riscv: Flush the instruction cache during SMP bringup
riscv: hwprobe: export Zihintpause ISA extension
riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code
...
Pull mm updates from Andrew Morton:
"The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.
Notable series include:
- Lucas Stach has provided some page-mapping cleanup/consolidation/
maintainability work in the series "mm/treewide: Remove pXd_huge()
API".
- In the series "Allow migrate on protnone reference with
MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
one test.
- In their series "Memory allocation profiling" Kent Overstreet and
Suren Baghdasaryan have contributed a means of determining (via
/proc/allocinfo) whereabouts in the kernel memory is being
allocated: number of calls and amount of memory.
- Matthew Wilcox has provided the series "Various significant MM
patches" which does a number of rather unrelated things, but in
largely similar code sites.
- In his series "mm: page_alloc: freelist migratetype hygiene"
Johannes Weiner has fixed the page allocator's handling of
migratetype requests, with resulting improvements in compaction
efficiency.
- In the series "make the hugetlb migration strategy consistent"
Baolin Wang has fixed a hugetlb migration issue, which should
improve hugetlb allocation reliability.
- Liu Shixin has hit an I/O meltdown caused by readahead in a
memory-tight memcg. Addressed in the series "Fix I/O high when
memory almost met memcg limit".
- In the series "mm/filemap: optimize folio adding and splitting"
Kairui Song has optimized pagecache insertion, yielding ~10%
performance improvement in one test.
- Baoquan He has cleaned up and consolidated the early zone
initialization code in the series "mm/mm_init.c: refactor
free_area_init_core()".
- Baoquan has also redone some MM initializatio code in the series
"mm/init: minor clean up and improvement".
- MM helper cleanups from Christoph Hellwig in his series "remove
follow_pfn".
- More cleanups from Matthew Wilcox in the series "Various
page->flags cleanups".
- Vlastimil Babka has contributed maintainability improvements in the
series "memcg_kmem hooks refactoring".
- More folio conversions and cleanups in Matthew Wilcox's series:
"Convert huge_zero_page to huge_zero_folio"
"khugepaged folio conversions"
"Remove page_idle and page_young wrappers"
"Use folio APIs in procfs"
"Clean up __folio_put()"
"Some cleanups for memory-failure"
"Remove page_mapping()"
"More folio compat code removal"
- David Hildenbrand chipped in with "fs/proc/task_mmu: convert
hugetlb functions to work on folis".
- Code consolidation and cleanup work related to GUP's handling of
hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
- Rick Edgecombe has developed some fixes to stack guard gaps in the
series "Cover a guard gap corner case".
- Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
series "mm/ksm: fix ksm exec support for prctl".
- Baolin Wang has implemented NUMA balancing for multi-size THPs.
This is a simple first-cut implementation for now. The series is
"support multi-size THP numa balancing".
- Cleanups to vma handling helper functions from Matthew Wilcox in
the series "Unify vma_address and vma_pgoff_address".
- Some selftests maintenance work from Dev Jain in the series
"selftests/mm: mremap_test: Optimizations and style fixes".
- Improvements to the swapping of multi-size THPs from Ryan Roberts
in the series "Swap-out mTHP without splitting".
- Kefeng Wang has significantly optimized the handling of arm64's
permission page faults in the series
"arch/mm/fault: accelerate pagefault when badaccess"
"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
- GUP cleanups from David Hildenbrand in "mm/gup: consistently call
it GUP-fast".
- hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
path to use struct vm_fault".
- selftests build fixes from John Hubbard in the series "Fix
selftests/mm build without requiring "make headers"".
- Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
series "Improved Memory Tier Creation for CPUless NUMA Nodes".
Fixes the initialization code so that migration between different
memory types works as intended.
- David Hildenbrand has improved follow_pte() and fixed an errant
driver in the series "mm: follow_pte() improvements and acrn
follow_pte() fixes".
- David also did some cleanup work on large folio mapcounts in his
series "mm: mapcount for large folios + page_mapcount() cleanups".
- Folio conversions in KSM in Alex Shi's series "transfer page to
folio in KSM".
- Barry Song has added some sysfs stats for monitoring multi-size
THP's in the series "mm: add per-order mTHP alloc and swpout
counters".
- Some zswap cleanups from Yosry Ahmed in the series "zswap
same-filled and limit checking cleanups".
- Matthew Wilcox has been looking at buffer_head code and found the
documentation to be lacking. The series is "Improve buffer head
documentation".
- Multi-size THPs get more work, this time from Lance Yang. His
series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
optimizes the freeing of these things.
- Kemeng Shi has added more userspace-visible writeback
instrumentation in the series "Improve visibility of writeback".
- Kemeng Shi then sent some maintenance work on top in the series
"Fix and cleanups to page-writeback".
- Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
the series "Improve anon_vma scalability for anon VMAs". Intel's
test bot reported an improbable 3x improvement in one test.
- SeongJae Park adds some DAMON feature work in the series
"mm/damon: add a DAMOS filter type for page granularity access recheck"
"selftests/damon: add DAMOS quota goal test"
- Also some maintenance work in the series
"mm/damon/paddr: simplify page level access re-check for pageout"
"mm/damon: misc fixes and improvements"
- David Hildenbrand has disabled some known-to-fail selftests ni the
series "selftests: mm: cow: flag vmsplice() hugetlb tests as
XFAIL".
- memcg metadata storage optimizations from Shakeel Butt in "memcg:
reduce memory consumption by memcg stats".
- DAX fixes and maintenance work from Vishal Verma in the series
"dax/bus.c: Fixups for dax-bus locking""
* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
selftests: cgroup: add tests to verify the zswap writeback path
mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
mm/damon/core: fix return value from damos_wmark_metric_value
mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
selftests: cgroup: remove redundant enabling of memory controller
Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
Docs/mm/damon/design: use a list for supported filters
Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
selftests/damon: classify tests for functionalities and regressions
selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
selftests/damon: add a test for DAMOS quota goal
...
Samuel Holland <samuel.holland@sifive.com> says:
This series converts uniprocessor kernel builds to use the same TLB
flushing code as SMP builds, to take advantage of batching and existing
range- and ASID-based TLB flush optimizations. It optimizes out IPIs and
SBI calls based on the online CPU count, which also covers the scenario
where SMP was enabled at build time but only one CPU is present/online.
A final optimization is to use single-ASID flushes wherever possible, to
avoid unnecessary TLB misses for kernel mappings.
This series has a semantic conflict with the AIA patches that are in
linux-next due to the removal of the third parameter of
riscv_ipi_set_virq_range(), which is called from imsic_ipi_domain_init()
in drivers/irqchip/irq-riscv-imsic-early.c. The resolution is to remove
the extra argument from the call site.
Here are some numbers from D1 which show the performance impact:
v6.9-rc1:
System Benchmarks Partial Index BASELINE RESULT INDEX
Execl Throughput 43.0 198.5 46.2
File Copy 1024 bufsize 2000 maxblocks 3960.0 73934.4 186.7
File Copy 256 bufsize 500 maxblocks 1655.0 20242.6 122.3
File Copy 4096 bufsize 8000 maxblocks 5800.0 197706.4 340.9
Pipe Throughput 12440.0 176974.2 142.3
Pipe-based Context Switching 4000.0 23626.8 59.1
Process Creation 126.0 449.9 35.7
Shell Scripts (1 concurrent) 42.4 544.4 128.4
Shell Scripts (16 concurrent) --- 35.3 ---
Shell Scripts (8 concurrent) 6.0 71.6 119.3
System Call Overhead 15000.0 248072.6 165.4
========
System Benchmarks Index Score (Partial Only) 110.6
v6.9-rc1 + this patch series:
System Benchmarks Partial Index BASELINE RESULT INDEX
Execl Throughput 43.0 196.8 45.8
File Copy 1024 bufsize 2000 maxblocks 3960.0 71782.2 181.3
File Copy 256 bufsize 500 maxblocks 1655.0 21269.4 128.5
File Copy 4096 bufsize 8000 maxblocks 5800.0 199424.0 343.8
Pipe Throughput 12440.0 196468.6 157.9
Pipe-based Context Switching 4000.0 24261.8 60.7
Process Creation 126.0 459.0 36.4
Shell Scripts (1 concurrent) 42.4 543.8 128.2
Shell Scripts (16 concurrent) --- 35.5 ---
Shell Scripts (8 concurrent) 6.0 71.7 119.6
System Call Overhead 15000.0 259415.2 172.9
========
System Benchmarks Index Score (Partial Only) 113.0
* b4-shazam-lts:
riscv: mm: Always use an ASID to flush mm contexts
riscv: mm: Preserve global TLB entries when switching contexts
riscv: mm: Make asid_bits a local variable
riscv: mm: Use a fixed layout for the MM context ID
riscv: mm: Introduce cntx2asid/cntx2version helper macros
riscv: Avoid TLB flush loops when affected by SiFive CIP-1200
riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma
riscv: mm: Combine the SMP and UP TLB flush code
riscv: Only send remote fences when some other CPU is online
riscv: mm: Broadcast kernel TLB flushes only when needed
riscv: Use IPIs for remote cache/TLB flushes by default
riscv: Factor out page table TLB synchronization
riscv: Flush the instruction cache during SMP bringup
Link: https://lore.kernel.org/r/20240327045035.368512-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
