Instead of using absolute addresses for both the old instrucions and
the alternative instructions, use offsets relative to the alt_entry
values. So this not only cuts the size of the alternative entry, but
also meets the prerequisite for patching alternatives in the vDSO,
since absolute alternative entries are subject to dynamic relocation,
which is incompatible with the vDSO building.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-10-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Generally, riscv ISA extensions are fixed for any specific hardware
platform, so a hart's features won't change after booting. This
chacteristic makes it straightforward to use a static branch to check
if a specific ISA extension is supported or not to optimize
performance.
However, some ISA extensions such as SVPBMT and ZICBOM are handled
via. the alternative sequences.
Basically, for ease of maintenance, we prefer to use static branches
in C code, but recently, Samuel found that the static branch usage in
cpu_relax() breaks building with CONFIG_CC_OPTIMIZE_FOR_SIZE[1]. As
Samuel pointed out, "Having a static branch in cpu_relax() is
problematic because that function is widely inlined, including in some
quite complex functions like in the VDSO. A quick measurement shows
this static branch is responsible by itself for around 40% of the jump
table."
Samuel's findings pointed out one of a few downsides of static branches
usage in C code to handle ISA extensions detected at boot time:
static branch's metadata in the __jump_table section, which is not
discarded after ISA extensions are finalized, wastes some space.
I want to try to solve the issue for all possible dynamic handling of
ISA extensions at boot time. Inspired by Mark[2], this patch introduces
riscv_has_extension_*() helpers, which work like static branches but
are patched using alternatives, thus the metadata can be freed after
patching.
Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ [1]
Link: https://lore.kernel.org/linux-arm-kernel/20220912162210.3626215-8-mark.rutland@arm.com/ [2]
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230128172856.3814-6-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This cleans up the ISA string handling to more closely match a version
of the ISA spec. This is visible in /proc/cpuinfo and the ordering
changes may break something in userspace, but these orderings have
changed before without issues so with any luck that's still the case.
This also adds documentation so userspace has a better idea of what is
intended when it comes to compatibility for /proc/cpuinfo, which should
help everyone as this will likely keep changing.
* b4-shazam-merge:
Documentation: riscv: add a section about ISA string ordering in /proc/cpuinfo
RISC-V: resort all extensions in consistent orders
RISC-V: clarify ISA string ordering rules in cpu.c
Link: https://lore.kernel.org/r/20221205144525.2148448-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
While the current list of rules may have been accurate when created
it now lacks some clarity in the face of isa-manual updates. Instead of
trying to continuously align this rule-set with the one in the
specifications, change the role of this comment.
This particular comment is important, as the array it "decorates"
defines the order in which the ISA string appears to userspace in
/proc/cpuinfo.
Re-jig and strengthen the wording to provide contributors with a set
order in which to add entries & note why this particular struct needs
more attention than others.
While in the area, add some whitespace and tweak some wording for
readability's sake.
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221205144525.2148448-2-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
When adding the ARCH_ symbol for the builtin K210 dtb, I erroneously
used the bool type for something that is quite obviously a string.
Unfortunately, there is no such thing as "def_string", but in this case
we can use "default" to propagate the value of
SOC_CANAAN_K210_DTB_SOURCE to ARCH_CANAAN_K210_DTB_SOURCE.
ARCH_CANAAN_K210_DTB_SOURCE is not user selectable, so using
olddefconfig etc will update ARCH_CANAAN_K210_DTB_SOURCE to reflect any
changes made to SOC_CANAAN_K210_DTB_SOURCE.
Fixes: fc43211939 ("RISC-V: kconfig.socs: convert usage of SOC_CANAAN to ARCH_CANAAN")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/all/20230111104848.2088516-1-conor.dooley@microchip.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Heiko Stuebner <heiko@sntech.de> says:
From: Heiko Stuebner <heiko.stuebner@vrull.eu>
This series is split out of my work on optimizing string functions
and provides the basics to:
- actually allowing calls in alternatives
Function calls use auipc + jalr to reach those 32bit relative
addresses but when they're compiled the offset will be wrong
as alternatives live in a different section. So when the patch
gets applied the address will point to the wrong location.
So similar to arm64 the target addresses need to be updated.
This is probably also helpful for other things needing more
complex code in alternatives.
For v2 I got into some sort of cleanup spree for the general instruction
parsing that already existed. A number of places do their own
instruction parsing and I tried consolidating some of them.
Noteable, the kvm parts still do, but I had to stop somewhere :-)
* b4-shazam-merge:
RISC-V: fix auipc-jalr addresses in patched alternatives
RISC-V: add helpers for handling immediates in U-type and I-type pairs
RISC-V: add rd reg parsing to insn.h header
RISC-V: add U-type imm parsing to insn.h header
RISC-V: kprobes: use central defined funct3 constants
RISC-V: rename parse_asm.h to insn.h
RISC-V: Move riscv_insn_is_* macros into a common header
RISC-V: add auipc elements to parse_asm header
RISC-V: add ebreak instructions to definitions
RISC-V: detach funct-values from their offset
RISC-V: add prefix to all constants/macros in parse_asm.h
RISC-V: fix funct4 definition for c.jalr in parse_asm.h
Link: https://lore.kernel.org/r/20221223221332.4127602-1-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
SOC_FOO to ARCH_FOO conversion for RISC-V
RISC-V is an outlier in using SOC_FOO rather than ARCH_FOO for
vendors/micro-archs. SOC_FOO may make more sense (I personally prefer
it), but the rest of the "world" uses ARCH_FOO. That'd be fine, with
with an increasing number of existing SoC vendors moving to RISC-V,
unifying our symbol names with the expectations of the rest of the world
makes sense.
Folks did not seem keen on changing the world (and they can't really be
blamed for that) so convert RISC-V over to match.
Add some ARCH_FOO stubs alongside the existing SOC_FOO ones, which will
be removed once all users of SOC_FOO have been converted*, and convert
the DT bits of RISC-V kbuild over to the new symbols.
* It may be best to wait until after the next LTS to remove the SOC_FOO
ones, for the sake of external users.
* tag 'soc2arch-immutable' of git://git.kernel.org/pub/scm/linux/kernel/git/conor/linux:
RISC-V: stop directly selecting drivers for SOC_CANAAN
RISC-V: stop selecting SiFive clock and serial drivers directly
RISC-V: stop selecting the PolarFire SoC clock driver
RISC-V: kbuild: convert all use of SOC_FOO to ARCH_FOO
RISC-V: kconfig.socs: convert usage of SOC_CANAAN to ARCH_CANAAN
RISC-V: introduce ARCH_FOO kconfig aliases for SOC_FOO symbols
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
While we cannot yet drop the SOC_ prefixed symbols, we can convert
uses of these symbols within Kconfig.socs to the ARCH_ variants.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
The serial and clock drivers will be enabled by default if the symbol
itself is enabled, so stop directly selecting the drivers in
Kconfigs.socs.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
To facilitate a transfer from SOC_FOO to ARCH_FOO, over a release cycle,
introduce some aliases so that drivers etc that use the SOC_FOO symbols
can be converted.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
To me, the most straight-forward conversion looks like so:
- this patch is applied in week 2 of the merge window, to avoid
any conflicts with the Renesas tree
- all users of the SOC_ variants can be converted over a release cycle
(or more) & no trees need to merge an immutable branch.
- we convert defconfig etc over after all users are converted
- doing it over at least one release cycle means that `make oldconfig`
will keep people's configs working as they upgrade
- any new SoC families added uses ARCH_FOO
The SiFive clock and serial drivers will now default to the value of
SOC_SIFIVE so there is no need to directly select their symbols
anymore.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
The driver is now enabled by default if SOC_MICROCHIP_POLARFIRE so
there is no longer a need to select it in Kconfig.socs
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Convert all non user visible use of SOC_FOO symbols to their ARCH_FOO
variants. The canaan DTs are an outlier in that they're gated at the
directory and the file level. Drop the directory level gating while we
are swapping the symbol names over.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown". After a timer is set to this state, then it can no
longer be re-armed.
The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed. It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.
This was created by using a coccinelle script and the following
commands:
$ cat timer.cocci
@@
expression ptr, slab;
identifier timer, rfield;
@@
(
- del_timer(&ptr->timer);
+ timer_shutdown(&ptr->timer);
|
- del_timer_sync(&ptr->timer);
+ timer_shutdown_sync(&ptr->timer);
)
... when strict
when != ptr->timer
(
kfree_rcu(ptr, rfield);
|
kmem_cache_free(slab, ptr);
|
kfree(ptr);
)
$ spatch timer.cocci . > /tmp/t.patch
$ patch -p1 < /tmp/t.patch
Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ]
Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ]
Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull spi fix from Mark Brown:
"One driver specific change here which handles the case where a SPI
device for some reason tries to change the bus speed during a message
on fsl_spi hardware, this should be very unusual"
* tag 'spi-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: fsl_spi: Don't change speed while chipselect is active
Pull regulator fixes from Mark Brown:
"Two core fixes here, one for a long standing race which some Qualcomm
systems have started triggering with their UFS driver and another
fixing a problem with supply lookup introduced by the fixes for devm
related use after free issues that were introduced in this merge
window"
* tag 'regulator-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: core: fix deadlock on regulator enable
regulator: core: Fix resolve supply lookup issue
Pull coccicheck update from Julia Lawall:
"Modernize use of grep in coccicheck:
Use 'grep -E' instead of 'egrep'"
* tag 'coccinelle-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux:
scripts: coccicheck: use "grep -E" instead of "egrep"
Pull kernel hardening fixes from Kees Cook:
- Fix CFI failure with KASAN (Sami Tolvanen)
- Fix LKDTM + CFI under GCC 7 and 8 (Kristina Martsenko)
- Limit CONFIG_ZERO_CALL_USED_REGS to Clang > 15.0.6 (Nathan
Chancellor)
- Ignore "contents" argument in LoadPin's LSM hook handling
- Fix paste-o in /sys/kernel/warn_count API docs
- Use READ_ONCE() consistently for oops/warn limit reading
* tag 'hardening-v6.2-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
cfi: Fix CFI failure with KASAN
exit: Use READ_ONCE() for all oops/warn limit reads
security: Restrict CONFIG_ZERO_CALL_USED_REGS to gcc or clang > 15.0.6
lkdtm: cfi: Make PAC test work with GCC 7 and 8
docs: Fix path paste-o for /sys/kernel/warn_count
LoadPin: Ignore the "contents" argument of the LSM hooks
Pull dma-mapping fixes from Christoph Hellwig:
"Fix up the sound code to not pass __GFP_COMP to the non-coherent DMA
allocator, as it copes with that just as badly as the coherent
allocator, and then add a check to make sure no one passes the flag
ever again"
* tag 'dma-mapping-2022-12-23' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: reject GFP_COMP for noncoherent allocations
ALSA: memalloc: don't use GFP_COMP for non-coherent dma allocations
Pull 9p updates from Dominique Martinet:
- improve p9_check_errors to check buffer size instead of msize when
possible (e.g. not zero-copy)
- some more syzbot and KCSAN fixes
- minor headers include cleanup
* tag '9p-for-6.2-rc1' of https://github.com/martinetd/linux:
9p/client: fix data race on req->status
net/9p: fix response size check in p9_check_errors()
net/9p: distinguish zero-copy requests
9p/xen: do not memcpy header into req->rc
9p: set req refcount to zero to avoid uninitialized usage
9p/net: Remove unneeded idr.h #include
9p/fs: Remove unneeded idr.h #include
