Charlie Jenkins <charlie@rivosinc.com> says:
On riscv, mmap currently returns an address from the largest address
space that can fit entirely inside of the hint address. This makes it
such that the hint address is almost never returned. This patch raises
the mappable area up to and including the hint address. This allows mmap
to often return the hint address, which allows a performance improvement
over searching for a valid address as well as making the behavior more
similar to other architectures.
Note that a previous patch introduced stronger semantics compared to
other architectures for riscv mmap. On riscv, mmap will not use bits in
the upper bits of the virtual address depending on the hint address. On
other architectures, a random address is returned in the address space
requested. On all architectures the hint address will be returned if it
is available. This allows riscv applications to configure how many bits
in the virtual address should be left empty. This has the two benefits
of being able to request address spaces that are smaller than the
default and doesn't require the application to know the page table
layout of riscv.
* b4-shazam-merge:
docs: riscv: Define behavior of mmap
selftests: riscv: Generalize mm selftests
riscv: mm: Use hint address in mmap if available
Link: https://lore.kernel.org/r/20240130-use_mmap_hint_address-v3-0-8a655cfa8bcb@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Christoph Muellner <christoph.muellner@vrull.eu> says:
From: Christoph Müllner <christoph.muellner@vrull.eu>
When building the RISC-V selftests with a riscv32 compiler I ran into
a couple of compiler warnings. While riscv32 support for these tests is
questionable, the fixes are so trivial that it is probably best to simply
apply them.
Note that the missing-include patch and some format string warnings
are also relevant for riscv64.
* b4-shazam-merge:
tools: selftests: riscv: Fix compile warnings in mm tests
tools: selftests: riscv: Fix compile warnings in vector tests
tools: selftests: riscv: Add missing include for vector test
tools: selftests: riscv: Fix compile warnings in cbo
tools: selftests: riscv: Fix compile warnings in hwprobe
Link: https://lore.kernel.org/r/20231123185821.2272504-1-christoph.muellner@vrull.eu
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The "count" parameter associated with the 'cpus' parameter of the
hwprobe syscall is the size in bytes of 'cpus'. Naming it 'cpu_count'
may mislead users (it did me) to think it's the number of CPUs that
are or can be represented by 'cpus' instead. This is particularly
easy (IMO) to get wrong since 'cpus' is documented to be defined by
CPU_SET(3) and CPU_SET(3) also documents a CPU_COUNT() (the number
of CPUs in set) macro. CPU_SET(3) refers to the size of cpu sets
with 'setsize'. Adopt 'cpusetsize' for the hwprobe parameter and
specifically state it is in bytes in Documentation/riscv/hwprobe.rst
to clarify.
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231122164700.127954-7-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Pull RISC-V updates from Palmer Dabbelt:
- Support for cbo.zero in userspace
- Support for CBOs on ACPI-based systems
- A handful of improvements for the T-Head cache flushing ops
- Support for software shadow call stacks
- Various cleanups and fixes
* tag 'riscv-for-linus-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (31 commits)
RISC-V: hwprobe: Fix vDSO SIGSEGV
riscv: configs: defconfig: Enable configs required for RZ/Five SoC
riscv: errata: prefix T-Head mnemonics with th.
riscv: put interrupt entries into .irqentry.text
riscv: mm: Update the comment of CONFIG_PAGE_OFFSET
riscv: Using TOOLCHAIN_HAS_ZIHINTPAUSE marco replace zihintpause
riscv/mm: Fix the comment for swap pte format
RISC-V: clarify the QEMU workaround in ISA parser
riscv: correct pt_level name via pgtable_l5/4_enabled
RISC-V: Provide pgtable_l5_enabled on rv32
clocksource: timer-riscv: Increase rating of clock_event_device for Sstc
clocksource: timer-riscv: Don't enable/disable timer interrupt
lkdtm: Fix CFI_BACKWARD on RISC-V
riscv: Use separate IRQ shadow call stacks
riscv: Implement Shadow Call Stack
riscv: Move global pointer loading to a macro
riscv: Deduplicate IRQ stack switching
riscv: VMAP_STACK overflow detection thread-safe
RISC-V: cacheflush: Initialize CBO variables on ACPI systems
RISC-V: ACPI: RHCT: Add function to get CBO block sizes
...
Add hwprobe test for Zicboz and its block size. Also, when Zicboz is
present, test that cbo.zero may be issued and works. Additionally
provide a command line option that enables testing that the Zicbom
instructions cause SIGILL and also that cbo.zero causes SIGILL when
Zicboz it's not present. The SIGILL tests require "opt-in" with a
command line option because the RISC-V ISA does not require
unimplemented standard opcodes to issue illegal-instruction
exceptions (but hopefully most platforms do).
Pinning the test to a subset of cpus with taskset will also restrict
the hwprobe calls to that set.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Xiao Wang <xiao.w.wang@intel.com>
Link: https://lore.kernel.org/r/20230918131518.56803-14-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Returning (exiting with) negative exit codes isn't user friendly,
because the user must output the exit code with the shell, convert it
from its unsigned 8-bit value back to the negative value, and then
look up where that comes from in the code (which may be multiple
places). Use the kselftests TAP interface, instead.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230918131518.56803-13-ajones@ventanamicro.com
Signed-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
...
Add tests that enforce mmap hint address behavior. mmap should default
to sv48. mmap will provide an address at the highest address space that
can fit into the hint address, unless the hint address is less than sv39
and not 0, then it will return a sv39 address.
These tests are split into two files: mmap_default.c and mmap_bottomup.c
because a new process must be exec'd in order to change the mmap layout.
The run_mmap.sh script sets the stack to be unlimited for the
mmap_bottomup.c test which triggers a bottomup layout.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20230809232218.849726-3-charlie@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The following error happens:
In file included from vstate_exec_nolibc.c:2:
/usr/include/riscv64-linux-gnu/sys/prctl.h:42:12: error: conflicting types for ‘prctl’; h
ave ‘int(int, ...)’
42 | extern int prctl (int __option, ...) __THROW;
| ^~~~~
In file included from ./../../../../include/nolibc/nolibc.h:99,
from <command-line>:
./../../../../include/nolibc/sys.h:892:5: note: previous definition of ‘prctl’ with type
‘int(int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)
’
892 | int prctl(int option, unsigned long arg2, unsigned long arg3,
| ^~~~~
Fix this by not including <sys/prctl.h>, which is not needed here since
prctl syscall is directly called using its number.
Fixes: 7cf6198ce2 ("selftests: Test RISC-V Vector prctl interface")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230713115829.110421-1-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The riscv selftests (which were modeled after the arm64 selftests) are
improperly declaring the "emit_tests" target to depend upon the "all"
target. This approach, when combined with commit 9fc96c7c19
("selftests: error out if kernel header files are not yet built"), has
caused build failures [1] on arm64, and is likely to cause similar
failures for riscv.
To fix this, simply remove the unnecessary "all" dependency from the
emit_tests target. The dependency is still effectively honored, because
again, invocation is via "install", which also depends upon "all".
An alternative approach would be to harden the emit_tests target so that
it can depend upon "all", but that's a lot more complicated and hard to
get right, and doesn't seem worth it, especially given that emit_tests
should probably not be overridden at all.
[1] https://lore.kernel.org/20230710-kselftest-fix-arm64-v1-1-48e872844f25@kernel.org
Fixes: 9fc96c7c19 ("selftests: error out if kernel header files are not yet built")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230712193514.740033-1-jhubbard@nvidia.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This add a test to check if the kernel zero-initializes all V registers
after the first-use trap handler returns.
If V registers are not zero-initialized, then the test should fail one
out of several runs:
```
root@sifive-fpga:~# ./v_initval_nolibc
# vl = 256
not ok 1 detect stale values on v-regesters
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 4c 41 4e 47 3d 43 0 50 41 54 48 3d 2f 75 73
72 2f 6c 6f 63 61 6c 2f 73 62 69 6e 3a 2f 75 73
72 2f 6c 6f 63 61 6c 2f 62 69 6e 3a 2f 75 73 72
ff ff 81 0 0 0 0 0 0 0 0 0 0 0 0 0
```
Otherwise, the test passes without errors each run.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230627015556.12329-3-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
