Pull powerpc updates from Michael Ellerman:
- Reduce alignment constraints on STRICT_KERNEL_RWX and speed-up TLB
misses on 8xx and 603
- Replace kretprobe code with rethook and enable fprobe
- Remove the "fast endian switch" syscall
- Handle DLPAR device tree updates in kernel, allowing the deprecation
of the binary /proc/powerpc/ofdt interface
Thanks to Abhishek Dubey, Alex Shi, Benjamin Gray, Christophe Leroy,
Gaosheng Cui, Gautam Menghani, Geert Uytterhoeven, Haren Myneni, Hari
Bathini, Huang Xiaojia, Jinjie Ruan, Madhavan Srinivasan, Miguel Ojeda,
Mina Almasry, Narayana Murty N, Naveen Rao, Rob Herring (Arm), Scott
Cheloha, Segher Boessenkool, Stephen Rothwell, Thomas Zimmermann, Uwe
Kleine-König, Vaibhav Jain, and Zhang Zekun.
* tag 'powerpc-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (59 commits)
powerpc/atomic: Use YZ constraints for DS-form instructions
MAINTAINERS: powerpc: Add Maddy
powerpc: Switch back to struct platform_driver::remove()
powerpc/pseries/eeh: Fix pseries_eeh_err_inject
selftests/powerpc: Allow building without static libc
macintosh/via-pmu: register_pmu_pm_ops() can be __init
powerpc: Stop using no_llseek
powerpc/64s: Remove the "fast endian switch" syscall
powerpc/mm/64s: Restrict THP to Radix or HPT w/64K pages
powerpc/mm/64s: Move THP reqs into a separate symbol
powerpc/64s: Make mmu_hash_ops __ro_after_init
powerpc: Replace kretprobe code with rethook on powerpc
powerpc: pseries: Constify struct kobj_type
powerpc: powernv: Constify struct kobj_type
powerpc: Constify struct kobj_type
powerpc/pseries/dlpar: Add device tree nodes for DLPAR IO add
powerpc/pseries/dlpar: Remove device tree node for DLPAR IO remove
powerpc/pseries: Use correct data types from pseries_hp_errorlog struct
powerpc/vdso: Inconditionally use CFUNC macro
powerpc/32: Implement validation of emergency stack
...
Pull random number generator updates from Jason Donenfeld:
"Originally I'd planned on sending each of the vDSO getrandom()
architecture ports to their respective arch trees. But as we started
to work on this, we found lots of interesting issues in the shared
code and infrastructure, the fixes for which the various archs needed
to base their work.
So in the end, this turned into a nice collaborative effort fixing up
issues and porting to 5 new architectures -- arm64, powerpc64,
powerpc32, s390x, and loongarch64 -- with everybody pitching in and
commenting on each other's code. It was a fun development cycle.
This contains:
- Numerous fixups to the vDSO selftest infrastructure, getting it
running successfully on more platforms, and fixing bugs in it.
- Additions to the vDSO getrandom & chacha selftests. Basically every
time manual review unearthed a bug in a revision of an arch patch,
or an ambiguity, the tests were augmented.
By the time the last arch was submitted for review, s390x, v1 of
the series was essentially fine right out of the gate.
- Fixes to the the generic C implementation of vDSO getrandom, to
build and run successfully on all archs, decoupling it from
assumptions we had (unintentionally) made on x86_64 that didn't
carry through to the other architectures.
- Port of vDSO getrandom to LoongArch64, from Xi Ruoyao and acked by
Huacai Chen.
- Port of vDSO getrandom to ARM64, from Adhemerval Zanella and acked
by Will Deacon.
- Port of vDSO getrandom to PowerPC, in both 32-bit and 64-bit
varieties, from Christophe Leroy and acked by Michael Ellerman.
- Port of vDSO getrandom to S390X from Heiko Carstens, the arch
maintainer.
While it'd be natural for there to be things to fix up over the course
of the development cycle, these patches got a decent amount of review
from a fairly diverse crew of folks on the mailing lists, and, for the
most part, they've been cooking in linux-next, which has been helpful
for ironing out build issues.
In terms of architectures, I think that mostly takes care of the
important 64-bit archs with hardware still being produced and running
production loads in settings where vDSO getrandom is likely to help.
Arguably there's still RISC-V left, and we'll see for 6.13 whether
they find it useful and submit a port"
* tag 'random-6.12-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (47 commits)
selftests: vDSO: check cpu caps before running chacha test
s390/vdso: Wire up getrandom() vdso implementation
s390/vdso: Move vdso symbol handling to separate header file
s390/vdso: Allow alternatives in vdso code
s390/module: Provide find_section() helper
s390/facility: Let test_facility() generate static branch if possible
s390/alternatives: Remove ALT_FACILITY_EARLY
s390/facility: Disable compile time optimization for decompressor code
selftests: vDSO: fix vdso_config for s390
selftests: vDSO: fix ELF hash table entry size for s390x
powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64
powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32
powerpc/vdso: Refactor CFLAGS for CVDSO build
powerpc/vdso32: Add crtsavres
mm: Define VM_DROPPABLE for powerpc/32
powerpc/vdso: Fix VDSO data access when running in a non-root time namespace
selftests: vDSO: don't include generated headers for chacha test
arm64: vDSO: Wire up getrandom() vDSO implementation
arm64: alternative: make alternative_has_cap_likely() VDSO compatible
selftests: vDSO: also test counter in vdso_test_chacha
...
Pull RCU updates from Neeraj Upadhyay:
"Context tracking:
- rename context tracking state related symbols and remove references
to "dynticks" in various context tracking state variables and
related helpers
- force context_tracking_enabled_this_cpu() to be inlined to avoid
leaving a noinstr section
CSD lock:
- enhance CSD-lock diagnostic reports
- add an API to provide an indication of ongoing CSD-lock stall
nocb:
- update and simplify RCU nocb code to handle (de-)offloading of
callbacks only for offline CPUs
- fix RT throttling hrtimer being armed from offline CPU
rcutorture:
- remove redundant rcu_torture_ops get_gp_completed fields
- add SRCU ->same_gp_state and ->get_comp_state functions
- add generic test for NUM_ACTIVE_*RCU_POLL* for testing RCU and SRCU
polled grace periods
- add CFcommon.arch for arch-specific Kconfig options
- print number of update types in rcu_torture_write_types()
- add rcutree.nohz_full_patience_delay testing to the TREE07 scenario
- add a stall_cpu_repeat module parameter to test repeated CPU stalls
- add argument to limit number of CPUs a guest OS can use in
torture.sh
rcustall:
- abbreviate RCU CPU stall warnings during CSD-lock stalls
- Allow dump_cpu_task() to be called without disabling preemption
- defer printing stall-warning backtrace when holding rcu_node lock
srcu:
- make SRCU gp seq wrap-around faster
- add KCSAN checks for concurrent updates to ->srcu_n_exp_nodelay and
->reschedule_count which are used in heuristics governing
auto-expediting of normal SRCU grace periods and
grace-period-state-machine delays
- mark idle SRCU-barrier callbacks to help identify stuck
SRCU-barrier callback
rcu tasks:
- remove RCU Tasks Rude asynchronous APIs as they are no longer used
- stop testing RCU Tasks Rude asynchronous APIs
- fix access to non-existent percpu regions
- check processor-ID assumptions during chosen CPU calculation for
callback enqueuing
- update description of rtp->tasks_gp_seq grace-period sequence
number
- add rcu_barrier_cb_is_done() to identify whether a given
rcu_barrier callback is stuck
- mark idle Tasks-RCU-barrier callbacks
- add *torture_stats_print() functions to print detailed diagnostics
for Tasks-RCU variants
- capture start time of rcu_barrier_tasks*() operation to help
distinguish a hung barrier operation from a long series of barrier
operations
refscale:
- add a TINY scenario to support tests of Tiny RCU and Tiny
SRCU
- optimize process_durations() operation
rcuscale:
- dump stacks of stalled rcu_scale_writer() instances and
grace-period statistics when rcu_scale_writer() stalls
- mark idle RCU-barrier callbacks to identify stuck RCU-barrier
callbacks
- print detailed grace-period and barrier diagnostics on
rcu_scale_writer() hangs for Tasks-RCU variants
- warn if async module parameter is specified for RCU implementations
that do not have async primitives such as RCU Tasks Rude
- make all writer tasks report upon hang
- tolerate repeated GFP_KERNEL failure in rcu_scale_writer()
- use special allocator for rcu_scale_writer()
- NULL out top-level pointers to heap memory to avoid double-free
bugs on modprobe failures
- maintain per-task instead of per-CPU callbacks count to avoid any
issues with migration of either tasks or callbacks
- constify struct ref_scale_ops
Fixes:
- use system_unbound_wq for kfree_rcu work to avoid disturbing
isolated CPUs
Misc:
- warn on unexpected rcu_state.srs_done_tail state
- better define "atomic" for list_replace_rcu() and
hlist_replace_rcu() routines
- annotate struct kvfree_rcu_bulk_data with __counted_by()"
* tag 'rcu.release.v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (90 commits)
rcu: Defer printing stall-warning backtrace when holding rcu_node lock
rcu/nocb: Remove superfluous memory barrier after bypass enqueue
rcu/nocb: Conditionally wake up rcuo if not already waiting on GP
rcu/nocb: Fix RT throttling hrtimer armed from offline CPU
rcu/nocb: Simplify (de-)offloading state machine
context_tracking: Tag context_tracking_enabled_this_cpu() __always_inline
context_tracking, rcu: Rename rcu_dyntick trace event into rcu_watching
rcu: Update stray documentation references to rcu_dynticks_eqs_{enter, exit}()
rcu: Rename rcu_momentary_dyntick_idle() into rcu_momentary_eqs()
rcu: Rename rcu_implicit_dynticks_qs() into rcu_watching_snap_recheck()
rcu: Rename dyntick_save_progress_counter() into rcu_watching_snap_save()
rcu: Rename struct rcu_data .exp_dynticks_snap into .exp_watching_snap
rcu: Rename struct rcu_data .dynticks_snap into .watching_snap
rcu: Rename rcu_dynticks_zero_in_eqs() into rcu_watching_zero_in_eqs()
rcu: Rename rcu_dynticks_in_eqs_since() into rcu_watching_snap_stopped_since()
rcu: Rename rcu_dynticks_in_eqs() into rcu_watching_snap_in_eqs()
rcu: Rename rcu_dynticks_eqs_online() into rcu_watching_online()
context_tracking, rcu: Rename rcu_dynticks_curr_cpu_in_eqs() into rcu_is_watching_curr_cpu()
context_tracking, rcu: Rename rcu_dynticks_task*() into rcu_task*()
refscale: Constify struct ref_scale_ops
...
The 'ld' and 'std' instructions require a 4-byte aligned displacement
because they are DS-form instructions. But the "m" asm constraint
doesn't enforce that.
That can lead to build errors if the compiler chooses a non-aligned
displacement, as seen with GCC 14:
/tmp/ccuSzwiR.s: Assembler messages:
/tmp/ccuSzwiR.s:2579: Error: operand out of domain (39 is not a multiple of 4)
make[5]: *** [scripts/Makefile.build:229: net/core/page_pool.o] Error 1
Dumping the generated assembler shows:
ld 8,39(8) # MEM[(const struct atomic64_t *)_29].counter, t
Use the YZ constraints to tell the compiler either to generate a DS-form
displacement, or use an X-form instruction, either of which prevents the
build error.
See commit 2d43cc701b ("powerpc/uaccess: Fix build errors seen with
GCC 13/14") for more details on the constraint letters.
Fixes: 9f0cbea0d8 ("[POWERPC] Implement atomic{, 64}_{read, write}() without volatile")
Cc: stable@vger.kernel.org # v2.6.24+
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20240913125302.0a06b4c7@canb.auug.org.au
Tested-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240916120510.2017749-1-mpe@ellerman.id.au
Pull CPU hotplug updates from Thomas Gleixner:
- Prepare the core for supporting parallel hotplug on loongarch
- A small set of cleanups and enhancements
* tag 'smp-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
smp: Mark smp_prepare_boot_cpu() __init
cpu: Fix W=1 build kernel-doc warning
cpu/hotplug: Provide weak fallback for arch_cpuhp_init_parallel_bringup()
cpu/hotplug: Make HOTPLUG_PARALLEL independent of HOTPLUG_SMT
Pull arm64 updates from Will Deacon:
"The highlights are support for Arm's "Permission Overlay Extension"
using memory protection keys, support for running as a protected guest
on Android as well as perf support for a bunch of new interconnect
PMUs.
Summary:
ACPI:
- Enable PMCG erratum workaround for HiSilicon HIP10 and 11
platforms.
- Ensure arm64-specific IORT header is covered by MAINTAINERS.
CPU Errata:
- Enable workaround for hardware access/dirty issue on Ampere-1A
cores.
Memory management:
- Define PHYSMEM_END to fix a crash in the amdgpu driver.
- Avoid tripping over invalid kernel mappings on the kexec() path.
- Userspace support for the Permission Overlay Extension (POE) using
protection keys.
Perf and PMUs:
- Add support for the "fixed instruction counter" extension in the
CPU PMU architecture.
- Extend and fix the event encodings for Apple's M1 CPU PMU.
- Allow LSM hooks to decide on SPE permissions for physical
profiling.
- Add support for the CMN S3 and NI-700 PMUs.
Confidential Computing:
- Add support for booting an arm64 kernel as a protected guest under
Android's "Protected KVM" (pKVM) hypervisor.
Selftests:
- Fix vector length issues in the SVE/SME sigreturn tests
- Fix build warning in the ptrace tests.
Timers:
- Add support for PR_{G,S}ET_TSC so that 'rr' can deal with
non-determinism arising from the architected counter.
Miscellaneous:
- Rework our IPI-based CPU stopping code to try NMIs if regular IPIs
don't succeed.
- Minor fixes and cleanups"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits)
perf: arm-ni: Fix an NULL vs IS_ERR() bug
arm64: hibernate: Fix warning for cast from restricted gfp_t
arm64: esr: Define ESR_ELx_EC_* constants as UL
arm64: pkeys: remove redundant WARN
perf: arm_pmuv3: Use BR_RETIRED for HW branch event if enabled
MAINTAINERS: List Arm interconnect PMUs as supported
perf: Add driver for Arm NI-700 interconnect PMU
dt-bindings/perf: Add Arm NI-700 PMU
perf/arm-cmn: Improve format attr printing
perf/arm-cmn: Clean up unnecessary NUMA_NO_NODE check
arm64/mm: use lm_alias() with addresses passed to memblock_free()
mm: arm64: document why pte is not advanced in contpte_ptep_set_access_flags()
arm64: Expose the end of the linear map in PHYSMEM_END
arm64: trans_pgd: mark PTEs entries as valid to avoid dead kexec()
arm64/mm: Delete __init region from memblock.reserved
perf/arm-cmn: Support CMN S3
dt-bindings: perf: arm-cmn: Add CMN S3
perf/arm-cmn: Refactor DTC PMU register access
perf/arm-cmn: Make cycle counts less surprising
perf/arm-cmn: Improve build-time assertion
...
Extend getrandom() vDSO implementation to VDSO64.
Tested on QEMU on both ppc64_defconfig and ppc64le_defconfig.
Results from a Power9 (PowerNV):
~ # ./vdso_test_getrandom bench-single
vdso: 25000000 times in 0.787943615 seconds
libc: 25000000 times in 14.101887252 seconds
syscall: 25000000 times in 14.047475082 seconds
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
To be consistent with other VDSO functions, the function is called
__kernel_getrandom()
__arch_chacha20_blocks_nostack() fonction is implemented basically
with 32 bits operations. It performs 4 QUARTERROUND operations in
parallele. There are enough registers to avoid using the stack:
On input:
r3: output bytes
r4: 32-byte key input
r5: 8-byte counter input/output
r6: number of 64-byte blocks to write to output
During operation:
stack: pointer to counter (r5) and non-volatile registers (r14-131)
r0: counter of blocks (initialised with r6)
r4: Value '4' after key has been read, used for indexing
r5-r12: key
r14-r15: block counter
r16-r31: chacha state
At the end:
r0, r6-r12: Zeroised
r5, r14-r31: Restored
Performance on powerpc 885 (using kernel selftest):
~# ./vdso_test_getrandom bench-single
vdso: 25000000 times in 62.938002291 seconds
libc: 25000000 times in 535.581916866 seconds
syscall: 25000000 times in 531.525042806 seconds
Performance on powerpc 8321 (using kernel selftest):
~# ./vdso_test_getrandom bench-single
vdso: 25000000 times in 16.899318858 seconds
libc: 25000000 times in 131.050596522 seconds
syscall: 25000000 times in 129.794790389 seconds
This first patch adds support for VDSO32. As selftests cannot easily
be generated only for VDSO32, and because the following patch brings
support for VDSO64 anyway, this patch opts out all code in
__arch_chacha20_blocks_nostack() so that vdso_test_chacha will not
fail to compile and will not crash on PPC64/PPC64LE, allthough the
selftest itself will fail.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
In order to avoid two much duplication when we add new VDSO
functionnalities in C like getrandom, refactor common CFLAGS.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Commit 08c18b63d9 ("powerpc/vdso32: Add missing _restgpr_31_x to fix
build failure") added _restgpr_31_x to the vdso for gettimeofday, but
the work on getrandom shows that we will need more of those functions.
Remove _restgpr_31_x and link in crtsavres.o so that we get all
save/restore functions when optimising the kernel for size.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
When running in a non-root time namespace, the global VDSO data page
is replaced by a dedicated namespace data page and the global data
page is mapped next to it. Detailed explanations can be found at
commit 660fd04f93 ("lib/vdso: Prepare for time namespace support").
When it happens, __kernel_get_syscall_map and __kernel_get_tbfreq
and __kernel_sync_dicache don't work anymore because they read 0
instead of the data they need.
To address that, clock_mode has to be read. When it is set to
VDSO_CLOCKMODE_TIMENS, it means it is a dedicated namespace data page
and the global data is located on the following page.
Add a macro called get_realdatapage which reads clock_mode and add
PAGE_SIZE to the pointer provided by get_datapage macro when
clock_mode is equal to VDSO_CLOCKMODE_TIMENS. Use this new macro
instead of get_datapage macro except for time functions as they handle
it internally.
Fixes: 74205b3fc2 ("powerpc/vdso: Add support for time namespaces")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Closes: https://lore.kernel.org/all/ZtnYqZI-nrsNslwy@zx2c4.com/
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
After commit 0edb555a65 ("platform: Make platform_driver::remove()
return void") .remove() is (again) the right callback to implement for
platform drivers.
Convert all pwm drivers to use .remove(), with the eventual goal to drop
struct platform_driver::remove_new(). As .remove() and .remove_new() have
the same prototypes, conversion is done by just changing the structure
member name in the driver initializer.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240909130902.851274-2-u.kleine-koenig@baylibre.com
VFIO_EEH_PE_INJECT_ERR ioctl is currently failing on pseries
due to missing implementation of err_inject eeh_ops for pseries.
This patch implements pseries_eeh_err_inject in eeh_ops/pseries
eeh_ops. Implements support for injecting MMIO load/store error
for testing from user space.
The check on PCI error type (bus type) code is moved to platform
code, since the eeh_pe_inject_err can be allowed to more error
types depending on platform requirement. Removal of the check for
'type' in eeh_pe_inject_err() doesn't impact PowerNV as
pnv_eeh_err_inject() already has an equivalent check in place.
Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240909140220.529333-1-nnmlinux@linux.ibm.com
Since commit 868941b144 ("fs: remove no_llseek"), no_llseek() is
simply defined to be NULL, and a NULL llseek means seeking is
unsupported.
So for statically defined file_operations, such as all these, there's no
need or benefit to set llseek = no_llseek.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240903111951.141376-1-mpe@ellerman.id.au
The non-standard "fast endian switch" syscall was added in 2008[1],
but was never widely used. It was disabled by default in 2017[2], and
there's no evidence it's ever been used since.
Remove it entirely.
A normal endian switch syscall was added in 2015[3].
[1]: 745a14cc26 ("[POWERPC] Add fast little-endian switch system call")
[2]: 529d235a0e ("powerpc: Add a proper syscall for switching endianness")
[3]: 727f13616c ("powerpc: Disable the fast-endian switch syscall by default")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240823070830.1269033-1-mpe@ellerman.id.au
Transparent hugepages (THP) are not supported when using the Hash Page
Table (HPT) MMU with 4K pages.
Currently a HPT-only 4K kernel still allows THP to be enabled, which
is misleading.
Add restrictions to the PPC_THP symbol so that if the kernel is
configured with 4K pages and only the HPT MMU (no Radix), then THP is
disabled.
Note that it's still possible to build a combined Radix/HPT kernel with 4K
pages, which does allow THP to be enabled at build time. As such the HPT
code still needs to provide some THP related symbols, to allow the build
to succeed, but those code paths are never run. See the stubs in
arch/powerpc/include/asm/book3s/64/hash-4k.h.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240823032911.1238471-2-mpe@ellerman.id.au
Move the Kconfig symbols related to transparent hugepages (THP) under a
separate config symbol, separate from CONFIG_PPC_BOOK3S_64.
The new symbol is automatically enabled if CONFIG_PPC_BOOK3S_64 is
enabled, so there is no behaviour change, except for the existence of
the new PPC_THP symbol.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240823032911.1238471-1-mpe@ellerman.id.au
This is an adaptation of commit f3a112c0c4 ("x86,rethook,kprobes:
Replace kretprobe with rethook on x86") to powerpc.
Rethook follows the existing kretprobe implementation, but separates
it from kprobes so that it can be used by fprobe (ftrace-based
function entry/exit probes). As such, this patch also enables fprobe
to work on powerpc. The only other change compared to the existing
kretprobe implementation is doing the return address fixup in
arch_rethook_fixup_return().
Reference to other archs:
commit b57c2f1240 ("riscv: add riscv rethook implementation")
commit 7b0a096436 ("LoongArch: Replace kretprobe with rethook")
Note:
=====
In future, rethook will be only for kretprobe, and kretprobe
will be replaced by fprobe.
https://lore.kernel.org/all/172000134410.63468.13742222887213469474.stgit@devnote2/
We will adapt the above implementation for powerpc once its upstream.
Until then, we can have this implementation of rethook to serve
current kretprobe usecases.
Reviewed-by: Naveen Rao <naveen@kernel.org>
Signed-off-by: Abhishek Dubey <adubey@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240830113131.7597-1-adubey@linux.ibm.com
'struct kobj_type' is not modified. It is only used in kobject_init()
which takes a 'const struct kobj_type *ktype' parameter.
Constifying this structure moves some data to a read-only section,
so increase over all security.
On a x86_64, compiled with ppc64 defconfig:
Before:
======
text data bss dec hex filename
1885 368 16 2269 8dd arch/powerpc/platforms/pseries/vas-sysfs.o
After:
======
text data bss dec hex filename
1981 272 16 2269 8dd arch/powerpc/platforms/pseries/vas-sysfs.o
Signed-off-by: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240826150957.3500237-3-huangxiaojia2@huawei.com
'struct kobj_type' is not modified. It is only used in kobject_init()
which takes a 'const struct kobj_type *ktype' parameter.
Constifying this structure moves some data to a read-only section,
so increase over all security.
On a x86_64, compiled with ppc64 defconfig:
Before:
======
text data bss dec hex filename
3775 256 8 4039 fc7 arch/powerpc/platforms/powernv/opal-dump.o
2679 260 8 2947 b83 arch/powerpc/platforms/powernv/opal-elog.o
After:
======
text data bss dec hex filename
3823 208 8 4039 fc7 arch/powerpc/platforms/powernv/opal-dump.o
2727 212 8 2947 b83 arch/powerpc/platforms/powernv/opal-elog.o
Signed-off-by: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240826150957.3500237-2-huangxiaojia2@huawei.com
'struct kobj_type' is not modified. It is only used in
kobject_init_and_add()/kobject_init() which takes
a 'const struct kobj_type *ktype' parameter.
Constifying this structure moves some data to a read-only section,
so increase over all security.
On a x86_64, compiled with ppc64 defconfig:
Before:
======
text data bss dec hex filename
7145 606 0 7751 1e47 arch/powerpc/kernel/cacheinfo.o
3663 384 16 4063 fdf arch/powerpc/kernel/secvar-sysfs.o
After:
======
text data bss dec hex filename
7193 558 0 7751 1e47 arch/powerpc/kernel/cacheinfo.o
3663 384 16 4063 fdf arch/powerpc/kernel/secvar-sysfs.o
Signed-off-by: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240826150957.3500237-1-huangxiaojia2@huawei.com
In the powerpc-pseries specific implementation, the IO hotplug
event is handled in the user space (drmgr tool). For the DLPAR
IO ADD, the corresponding device tree nodes and properties will
be added to the device tree after the device enable. The user
space (drmgr tool) uses configure_connector RTAS call with the
DRC index to retrieve the device nodes and updates the device
tree by writing to /proc/ppc64/ofdt. Under system lockdown,
/dev/mem access to allocate buffers for configure_connector RTAS
call is restricted which means the user space can not issue this
RTAS call and also can not access to /proc/ppc64/ofdt. The
pseries implementation need user interaction to power-on and add
device to the slot during the ADD event handling. So adds
complexity if the complete hotplug ADD event handling moved to
the kernel.
To overcome /dev/mem access restriction, this patch extends the
/sys/kernel/dlpar interface and provides ‘dt add index <drc_index>’
to the user space. The drmgr tool uses this interface to update
the device tree whenever the device is added. This interface
retrieves device tree nodes for the corresponding DRC index using
the configure_connector RTAS call and adds new device nodes /
properties to the device tree.
Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240822025028.938332-3-haren@linux.ibm.com
In the powerpc-pseries specific implementation, the IO hotplug
event is handled in the user space (drmgr tool). But update the
device tree and /dev/mem access to allocate buffers for some
RTAS calls are restricted when the kernel lockdown feature is
enabled. For the DLPAR IO REMOVE, the corresponding device tree
nodes and properties have to be removed from the device tree
after the device disable. The user space removes the device tree
nodes by updating /proc/ppc64/ofdt which is not allowed under
system lockdown is enabled. This restriction can be resolved
by moving the complete IO hotplug handling in the kernel. But
the pseries implementation need user interaction to power off
and to remove device from the slot during hotplug event handling.
To overcome the /proc/ppc64/ofdt restriction, this patch extends
the /sys/kernel/dlpar interface and provides
‘dt remove index <drc_index>’ to the user space so that drmgr
tool can remove the corresponding device tree nodes based on DRC
index from the device tree.
Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240822025028.938332-2-haren@linux.ibm.com
_be32 type is defined for some elements in pseries_hp_errorlog
struct but also used them u32 after be32_to_cpu() conversion.
Example: In handle_dlpar_errorlog()
hp_elog->_drc_u.drc_index = be32_to_cpu(hp_elog->_drc_u.drc_index);
And later assigned to u32 type
dlpar_cpu() - u32 drc_index = hp_elog->_drc_u.drc_index;
This incorrect usage is giving the following warnings and the
patch resolve these warnings with the correct assignment.
arch/powerpc/platforms/pseries/dlpar.c:398:53: sparse: sparse:
incorrect type in argument 1 (different base types) @@
expected unsigned int [usertype] drc_index @@
got restricted __be32 [usertype] drc_index @@
...
arch/powerpc/platforms/pseries/dlpar.c:418:43: sparse: sparse:
incorrect type in assignment (different base types) @@
expected restricted __be32 [usertype] drc_count @@
got unsigned int [usertype] @@
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202408182142.wuIKqYae-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202408182302.o7QRO45S-lkp@intel.com/
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
v3:
- Fix warnings from using incorrect data types in pseries_hp_errorlog
struct
v2:
- Remove pr_info() and TODO comments
- Update more information in the commit logs
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240822025028.938332-1-haren@linux.ibm.com
At the time being, DATA TLB miss handlers use task PGDIR for user
addresses and swapper_pg_dir for kernel addresses.
Now that kernel part of swapper_pg_dir is copied into task PGDIR
at PGD allocation, it is possible to avoid the above logic and
always use task PGDIR.
But new kernel PGD entries can still be created after init, in
which case those PGD entries may miss in task PGDIR. This can be
handled in DATA TLB error handler.
However, it needs to be done in real mode because the missing
entry might be related to the stack.
So implement copy of missing PGD entry in DATA TLB miss handler
just after detection of invalid PGD entry.
Also replace comparison by same calculation as in previous patch
to know if an address belongs to a kernel or user segment.
Note that as mentioned in platforms/Kconfig.cputype, SMP is not
supported on 603 processors so there is no risk of the PGD entry
be populated during the fault.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/a2ba8eeb1c845eeb9e46b6fe3a5e9f841df9a033.1724173828.git.christophe.leroy@csgroup.eu
Now that modules exec page tables are preallocated, the instruction
TLBmiss handler can use task PGDIR inconditionally.
Also revise the identification of user vs kernel user space by doing
a calculation instead of a comparison: Get the segment number and
subtract the number of the first kernel segment. The result is
positive for kernel addresses and negative for user addresses,
which means that upper 2 bits are 0 for kernel and 3 for user.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/9a3242162ad2faab8019c698e501b326a126ee9e.1724173828.git.christophe.leroy@csgroup.eu
In preparation of next patch that will perform some additional
calculations to replace comparison, switch the use of r0 and r3
as r0 has some limitations in some instructions like 'addi/subi'.
Also remove outdated comments about the meaning of each register.
The registers are used for many things and it would be difficult
to accurately describe all things done with a given register. The
function is now small enough to get a global view without much
description.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/566af5e87685b1a85d3182549c0d520ce2d8877a.1724173828.git.christophe.leroy@csgroup.eu
At the time being, DATA TLB miss handlers use task PGDIR for user
addresses and swapper_pg_dir for kernel addresses.
Now that kernel part of swapper_pg_dir is copied into task PGDIR
at PGD allocation, it is possible to avoid the above logic and
always use task PGDIR.
But new kernel PGD entries can still be created after init, in
which case those PGD entries may miss in task PGDIR. This can be
handled in DATA TLB error handler.
However, it needs to be done in real mode because the missing
entry might be related to the stack.
So implement copy of missing PGD entry in the prolog of DATA TLB
ERROR handler just after the fixup of DAR.
Note that this is feasible because 8xx doesn't implement vmap or
ioremap with 8Mbytes pages but only 512kbytes pages which are at
PTE level.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/7a76a923d2a111f1d843d8b20b4df0c65d2f4a7b.1724173828.git.christophe.leroy@csgroup.eu
8xx boards don't have much memory, the two I know have respectively
32Mbytes and 128Mbytes, so there is no point in having 256 Mbytes of
memory for module text.
Reduce it to 32Mbytes for 8xx, that's more than enough.
Nevertheless, make it a configurable value so that it can be customised
if needed.
Also add a build verification for overlap of module execmem space
with user PMD.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/8db23b61e33a0d1913d814f94bfe71ba7ac78b0f.1724173828.git.christophe.leroy@csgroup.eu
This reverts commit bccc58986a.
When STRICT_KERNEL_RWX is selected, EXEC memory must stop where
RW memory start. When pinning iTLBs it means an 8M alignment for
RW data start. That may be acceptable on boards with a lot of
memory but one of my supported boards only has 32 Mbytes and this
forced alignment leads to a waste of almost 4 Mbytes with is more
than 10% of the total memory.
So revert commit bccc58986a ("powerpc/8xx: Always pin kernel text
TLB") but don't restore previous behaviour in ITLB miss handler
as now kernel PGD entries are copied into each process PGDIR.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/01b6780b860c8043b51a1ba9d83acfc6f2dde910.1724173828.git.christophe.leroy@csgroup.eu
Since commit 9132a2e82a ("powerpc/8xx: Define a MODULE area below
kernel text"), module exec space is below PAGE_OFFSET so not only
space above PAGE_OFFSET, but space above TASK_SIZE need to be seen
as kernel space.
Until now the problem went undetected because by default TASK_SIZE
is 0x8000000 which means address space is determined by just
checking upper address bit. But when TASK_SIZE is over 0x80000000,
PAGE_OFFSET is used for comparison, leading to thinking module
addresses are part of user space.
Fix it by using TASK_SIZE instead of PAGE_OFFSET for address
comparison.
Fixes: 9132a2e82a ("powerpc/8xx: Define a MODULE area below kernel text")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/3f574c9845ff0a023b46cb4f38d2c45aecd769bd.1724173828.git.christophe.leroy@csgroup.eu
Commit cf209951fa ("powerpc/8xx: Map linear memory with huge pages")
introduced an initial mapping of kernel TEXT using PAGE_KERNEL_TEXT,
but the pages that contain kernel TEXT may also contain kernel RODATA,
and depending on selected debug options PAGE_KERNEL_TEXT may be either
RWX or ROX. RODATA must be writable during init because it also
contains ro_after_init data.
So use PAGE_KERNEL_X instead to be sure it is RWX.
Fixes: cf209951fa ("powerpc/8xx: Map linear memory with huge pages")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/dac7a828d8497c4548c91840575a706657baa4f1.1724173828.git.christophe.leroy@csgroup.eu
