| Age | Commit message (Collapse) | Author |
|---|
|
# Conflicts:
# drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
# net/ceph/osd_client.c
|
|
# Conflicts:
# arch/arm64/include/asm/ptrace.h
# arch/arm64/include/asm/sysreg.h
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
# Conflicts:
# Documentation/scheduler/index.rst
# arch/arm64/configs/defconfig
|
|
# Conflicts:
# fs/coredump.c
# fs/f2fs/f2fs.h
# fs/fuse/dax.c
# fs/xfs/libxfs/xfs_btree.c
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git
|
|
Most architectures' asm/vdso/vsyscall.h do not define any symbols.
Add an empty asm-generic variant and replace the pointless
architecture-specific copies.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260909-vdso-asm-generic-vsyscall-h-v1-14-63ae856cc659@linutronix.de
|
|
Recent refactoring have made the header empty.
Remove it and its mentions.
Also that header was never a real asm-generic header anyways.
It had no reason to be in the asm-generic directory.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260909-vdso-asm-generic-vsyscall-h-v1-5-63ae856cc659@linutronix.de
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 fixes for 7.3, round #2
- Take a reference on the last IRQ loaded into an LR to prevent it
from being freed while running the guest (Marc Zyngier)
- Ensure that the ITS MOVALL command only affects LPIs that were
previously affined to the source redistributor (Marc Zyngier)
- Fix + test for honoring the host's trap configuration when running
non-protected VMs while KVM is in protected mode (Fuad Tabba)
- Use the host stage-1 mapping granularity for VM_PFNMAP mappings at
stage-2 (Mostafa Saleh)
|
|
Defining KVM_MMIO is not flexible enough for multi-KVM systems where one
KVM implements MMIO but others do not. Therefore, remove KVM_MMIO from the
config space and use the macro __KVM_NO_MMIO instead. Define __KVM_NO_MMIO
for KVM/s390 and for HV-only 64-bit Book3s (aka pSeries/sPAPR) configurations.
In particular, for PowerPC configurations:
* KVM_BOOK3S_32 got KVM_MMIO via KVM_BOOK3S_32_HANDLER and KVM_BOOK3S_PR_POSSIBLE
* KVM_BOOK3S_64 got KVM_MMIO via KVM_BOOK3S_PR_POSSIBLE if !KVM_BOOK3S_HV_POSSIBLE
* KVM_BOOK3S_64 + KVM_BOOK3S_64_PR got KVM_MMIO via KVM_BOOK3S_PR_POSSIBLE
* likewise for KVM_BOOK3S_64 + KVM_BOOK3S_64_PR + KVM_BOOK3S_64_HV
* KVM_E500V2 and KVM_E500MC directly selected KVM_MMIO
but KVM_BOOK3S_64 + KVM_BOOK3S_64_HV didn't and therefore needs __KVM_NO_MMIO.
coalesced_mmio.c is now always compiled and linked. However, for
architectures/configurations defining __KVM_NO_MMIO this effectively
collapses to an empty object with no mmio code.
No functional changes.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Link: https://patch.msgid.link/20260930173441.66762-4-seiden@linux.ibm.com
[Simplify powerpc condition, add underscores. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
With s390 hosting multiple independent KVM implementations within the
same kernel build (native s390 KVM and arm64 on s390), global Kconfig
selections force both implementations to inherit options that only apply
to one of them.
Replace global Kconfig options which only apply to one KVM
implementation with architecture-specific opt-in defines in the
respective <asm/kvm_host.h>. Only remove Kconfig symbols that would be
different on both s390 KVM implementations
- __KVM_HAVE_INVALID_WAKEUPS (formerly HAVE_KVM_INVALID_WAKEUPS)
- __KVM_HAVE_MSI (formerly HAVE_KVM_MSI)
- __KVM_HAVE_NO_POLL (formerly HAVE_KVM_NO_POLL)
- __KVM_HAVE_READONLY_MEM (formerly HAVE_KVM_READONLY_MEM)
- __KVM_HAVE_VCPU_RUN_PID_CHANGE (formerly HAVE_KVM_VCPU_RUN_PID_CHANGE)
This allows each architecture and guest implementation to configure its
supported capabilities independently in its kvm_host header and eliminates
adding unnecessary fallback stubs across different KVM targets.
Acked-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Link: https://patch.msgid.link/20261013121343.1997112-1-seiden@linux.ibm.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Make cpu_to_coregroup_id() available outside PPC_SPLPAR so it can be
used by platforms that do not rely on the SPLPAR-specific VPHN path.
Keep the existing fallback behavior by returning the core ID when
coregroup information is unavailable.
Signed-off-by: Srikar Dronamraju <srikar@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260902123458.340456-7-srikar@linux.ibm.com
|
|
commit bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature") introduced
a bug that, when CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX is not
set, expand to two consecutive ELFv2 global entry points for the
same function body:
_GLOBAL_TOC_KASAN(memcpy) expands to:
_GLOBAL_TOC(memcpy);
_GLOBAL_TOC(__memcpy)
On powerpc64le this produces:
memcpy:
addis r2,r12,(.TOC.-0b)@ha <- global entry, sets up r2
addi r2,r2,(.TOC.-0b)@l
.localentry memcpy,.-memcpy <- local entry at memcpy+8
__memcpy:
addis r2,r12,(.TOC.-0b)@ha <- memcpy+8: __memcpy global entry
addi r2,r2,(.TOC.-0b)@l
.localentry __memcpy,.-__memcpy
The assembler sets memcpy's st_other field so its local entry offset is
8 bytes past the global entry point. The linker resolves same-TOC
calls to the local entry, so every same-TOC caller of memcpy() lands
at memcpy+8 — which is the beginning of the __memcpy global-entry TOC
prologue. That prologue uses r12 as the base to recompute r2, but r12
holds whatever the caller left in it (not the address of memcpy+8).
The result is r2 pointing at garbage on return. Same-TOC callers do
not reload r2 after the call, so the first TOC-relative access after
returning from memcpy() or memmove() crashes or silently corrupts data.
With GENERIC_ENTRY selected, mm/kasan/shadow.c no longer provides its
own memcpy()/memmove()/memset() wrappers, so on a toolchain without
-mllvm -asan-kernel-mem-intrinsic-prefix=1 (e.g. GCC 9) every
instrumented file resolves mem*() directly to the assembly symbols and
hits this corrupt-r2 path. This manifests as an early boot hang unique
to powerpc with GCC 9 and CONFIG_KASAN=y.
Fix this by removing the dual-entry macros entirely. The assembly
files in mem_64.S, memcpy_64.S and copy_32.S now use plain
_GLOBAL()/_GLOBAL_TOC() for memset/memcpy/memmove, emitting a single
correct ELFv2 entry point. The __mem* aliases required by mm/kasan
(used in mm/kasan/shadow.c and mm/kasan/generic.c as raw backends to
bypass KASAN checking) are provided entirely through the #define
redirections in asm/string.h, which already handles both the
CC_HAS_KASAN_MEMINTRINSIC_PREFIX and non-prefix cases in C.
As a consequence the _GLOBAL_KASAN(), _GLOBAL_TOC_KASAN() and
EXPORT_SYMBOL_KASAN() macros have no remaining users and are removed
from asm/kasan.h. The has_renamed_memintrinsics() branch in
prom_init_check.sh, which conditionally whitelisted __memcpy/__memset
when CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX was absent, is dead code
after this change and is removed; the whitelist now unconditionally
lists memcpy and memset.
Fixes: bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/96dae110-f79b-4e54-8a9b-514369019b5d@linux.ibm.com
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
[Maddy: Fixed commit message to avoid checkpatch error]
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20261003094006.3404731-1-mkchauras@gmail.com
|
|
When running with CONFIG_PPC_IRQ_SOFT_MASK_DEBUG=y and LOCKDEP=y, an
Oops is triggered during NMI exit:
[ 202.258332] Oops: Exception in kernel mode, sig: 4 [#1]
NIP [000000000003e178] 0x3e178
LR [c00000000003e174] arch_local_irq_restore+0x2a4/0x328
TRAP: 0700 MSR: 0000000000081000 <ME>
The faulting instruction at NIP is a 'trap' (0fe00000) inside the
rfi_flush_fallback trampoline at a userspace-looking low address, reached
after a bad rfid caused by an incorrect SRR0 value.
Root cause:
DEFINE_INTERRUPT_HANDLER_NMI used to call arch_interrupt_nmi_exit_prepare()
*before* irqentry_nmi_exit(), giving this sequence:
arch_interrupt_nmi_enter_prepare() // saves irq_soft_mask, irq_happened
irqentry_nmi_enter() // __nmi_enter() -> nmi_count++, in_nmi()=true
____func(regs) // NMI handler body
arch_interrupt_nmi_exit_prepare() // RESTORES irq_soft_mask=0 (IRQS_ENABLED)
// RESTORES irq_happened with pending bits
irqentry_nmi_exit() // instrumentation block runs here...
trace_hardirqs_on_prepare() // ...with in_nmi()==true still
lockdep_hardirqs_on_prepare() // ...and irq_soft_mask already restored to 0
-> arch_local_irq_restore(0) // mask=0 -> enable path entered
WARN_ON_ONCE(in_nmi()) // FIRES: __nmi_exit() hasn't run yet
__nmi_exit() // nmi_count-- (too late)
arch_interrupt_nmi_exit_prepare() restores irq_soft_mask to whatever
the interrupted thread had (IRQS_ENABLED / 0) and restores irq_happened
with any pending deferred-interrupt bits that were present when the NMI
fired. This is correct and necessary before rfid back to the interrupted
context, but it must not happen until irqentry_nmi_exit() has fully
completed.
With irq_soft_mask=0 and pending bits in irq_happened, the
trace_hardirqs_on_prepare() call inside irqentry_nmi_exit()'s
instrumentation block reaches lockdep_hardirqs_on_prepare() which
calls __trace_hardirqs_on_caller(), which eventually calls
arch_local_irq_restore(0) (the IRQS_ENABLED / enable path).
arch_local_irq_restore() with mask=0 hits the CONFIG_PPC_IRQ_SOFT_MASK_DEBUG
guards at irq_64.c:217:
WARN_ON_ONCE(in_nmi()); // TRUE: __nmi_exit() not yet called
The WARN_ON_ONCE fires a 'trap' instruction (tw 31,0,0 / 0fe00000) in
kernel mode with MSR_PR=0, MSR_IR=0 (real-mode). The program check
handler (TRAP 0700) takes the sig:4 (SIGILL) path via do_program_check()
and calls die(), producing the Oops.
The RESTART_TABLE mechanism in arch_local_irq_restore then causes the
bad rfid that lands at the userspace-looking address visible in the NIP.
The bug is invisible with LOCKDEP=n because trace_hardirqs_on_prepare()
is a no-op when CONFIG_TRACE_IRQFLAGS is not set (TRACE_IRQFLAGS is
selected by PROVE_LOCKING which selects LOCKDEP).
Fix:
Move arch_interrupt_nmi_exit_prepare() to after the irqentry_nmi_exit()
block, so that:
irqentry_nmi_exit() // __nmi_exit() -> nmi_count--, in_nmi()=false
arch_interrupt_nmi_exit_prepare() // now safe to restore soft mask state
The instrumentation inside irqentry_nmi_exit() now executes while
in_nmi() is still true (nmi_count not yet decremented), but
irq_soft_mask is still IRQS_ALL_DISABLED (NMI-entry value), so
arch_local_irq_restore() is never called with mask=0 from that path.
After __nmi_exit() returns, arch_interrupt_nmi_exit_prepare() restores
the pre-NMI soft mask and irq_happened, which is the correct state for
the rfid back to the interrupted context.
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/d4cccba9-ce5c-424b-864c-2248fb0d99e6@linux.ibm.com/
Fixes: bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20261003094509.3408190-1-mkchauras@gmail.com
|
|
There are no more users left for any pxd_ERROR() either in generic MM or
in the platform MM. Hence all these platform macros along with their
generic fallback could be dropped across the tree.
Link: https://lore.kernel.org/20260831054331.625505-9-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: James Bottomley <james.bottomley@HansenPartnership.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
|
|
A task that dumps open spufs context adds a bunch of extra elf notes
describing the SPU state. It is the only reason do_coredump() unshares
the file descriptor table. We could make this conditional on spufs but
eh.
Nothing can consume those notes anymore. gdb dropped Cell Broadband
Engine debugging in 9.1 and binutils removed it in 2.34. That's about 6
years ago. So no program can actually read an SPU note out of a core
file and probably never did in recent history.
Note that the IBM Cell blades that shipped the Cell processor were
removed in commit 05bf59fbeef3 ("powerpc/cell: Remove support for IBM
Cell Blades"). The PlayStation 3 is the only platform left and nothing
there produces or reads these notes.
So remove it.
Link: https://patch.msgid.link/20260826-work-spufs-coredump-v1-1-579e72a7ab66@kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
radix_enabled() uses a jump label which is only valid after
setup_feature_keys() is called. Before that point, on a pSeries
hash guest, early_check_vec5() clears MMU_FTR_TYPE_RADIX in
cur_cpu_spec->mmu_features, but the jump label has not yet been patched,
so radix_enabled() incorrectly returns true.
The dangerous usage window where it goes wrong in early_setup():
early_setup:
configure_exceptions();
<exceptions can happen now, and handler enter/exit can be invoked>
<those could use radix_enabled(), which returns stale true>
setup_feature_keys();
<jump labels set up; post this it is safe to use radix_enabled()>
If an NMI occurs in this window, !radix_enabled() evaluates to false in
DEFINE_INTERRUPT_HANDLER_NMI. The handler fails to skip NMI entry in real
mode and attempts to access memory outside the Real Mode Area (RMA),
hanging the boot.
Since common interrupt wrappers do not have the context of early or late,
using early_radix_enabled() is the safer option. It does a plain bitmask
check against cur_cpu_spec->mmu_features and is correct at all times.
Console logs from a pSeries HASH guest showing values across boot stages:
[ 0.000000] DEBUG: after early_init_devtree: early_radix_enabled=0 radix_enabled=1 (mismatch means NMI real-mode check is unsafe!)
[ 0.000000] DEBUG: after configure_exceptions (DANGEROUS WINDOW): early_radix_enabled=0 radix_enabled=1
[ 0.000000] DEBUG: after setup_feature_keys (jump labels initialized): early_radix_enabled=0 radix_enabled=0 (should now match!)
[ 0.057124] DEBUG: post secondary CPU bringup: early_radix_enabled=0 radix_enabled=0 (should match!)
Console logs from a RADIX guest showing values across boot stages:
[ 0.000000] DEBUG: after early_init_devtree: early_radix_enabled=1 radix_enabled=1 (mismatch means NMI real-mode check is unsafe!)
[ 0.000000] DEBUG: after configure_exceptions (DANGEROUS WINDOW): early_radix_enabled=1 radix_enabled=1
[ 0.000000] DEBUG: after setup_feature_keys (jump labels initialized): early_radix_enabled=1 radix_enabled=1 (should now match!)
[ 0.057016] DEBUG: post secondary CPU bringup: early_radix_enabled=1 radix_enabled=1 (should match!)
Add the missing #include <asm/mmu.h> in alphabetical order since
early_radix_enabled() is declared there.
Fixes: 8d0e21012743 ("powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash")
Signed-off-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Mukesh Kumar Chaurasiya <mkchauras@gmail.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260909123240.58786-1-venkat88@linux.ibm.com
|
|
Some interrupts are always zero and that is expected since they occur
very rarely and are mostly error indications. Don't print them by
default.
"MCE" - "Machine check exceptions"
"NMI" - "System Reset interrupts"
Print them if they occur once. Maintain a bitmap to know which
interrupts are to be printed.
Time taken to read /proc/interrupts 1000 times.
Base and v6 details can be found in cover-letter.
Base : 103us
v6 : 63us
v6+patch 1+2 : 57us
v6+patch 1+2+3 : 54us
Patch 3 shows an additional 5% gain compared to patch 1+2. So it does
make sense to print them only if they are ever set.
Note: Since /proc/interrupts depend on kconfig and arch dependent,
userspace tools don't make explicit assumptions.
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260921090153.54745-4-sshegde@linux.ibm.com
|
|
Current irq_cpustat_t has separate member for handling each arch
specific interrupt type. The same can be achieved with array instead
indexed by corresponding irq counter type.
This helps to,
- Make it easy to integrate into genirq improvements by calling
genirq provided irq_proc_emit_counts. That speeds up quite a bit
by printing all 0's once as much as possible.
- Adding a new vector or software counter only requires to update the table
and everything just works
- Remove ifdef usage a bit.
- Instead of going through each member, it simply becomes an array
traversal.
Time taken to read /proc/interrupts 1000 times.
Base and v6 details can be found in cover-letter.
Base : 103us
v6 : 63us
v6+this_patch : 57us
A Decent 10% reduction can be seen in a system 240 CPUs. As the system
size increases the gain would be more as emitting 0 would reduce more
and more.
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260921090153.54745-3-sshegde@linux.ibm.com
|
|
__softirq_pending isn't part of arch specific irq_stats. It is used
by softirq core for various decision making such as whether to kick off
ksoftirqd.
Move it out of irq_cpustat_t. This makes it simple to make irq_cpustat_t
array based approach.
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260921090153.54745-2-sshegde@linux.ibm.com
|
|
Since the switch to generic entry, an interrupt from user mode
accounts user time twice: once in arch_interrupt_enter_prepare()
and again in arch_enter_from_user_mode(), which irqentry_enter()
invokes for the same interrupt:
arch_interrupt_enter_prepare()
account_cpu_user_entry() /* first */
irqentry_enter()
arch_enter_from_user_mode()
account_cpu_user_entry() /* second */
The second call charges the same interval again, because
account_cpu_user_entry() accumulates the time spent in user mode
since the last return to user space.
The two calls come from the GENERIC_ENTRY preparation series,
where each step was a no-op on its own. Commit 09a9d3a8499d
("powerpc: introduce arch_enter_from_user_mode") added the hook
with the user-time accounting in it, but nothing called it yet.
Commit 893082ac769b ("powerpc: Prepare for IRQ entry exit")
copied interrupt_enter_prepare() verbatim into entry-common.h as
arch_interrupt_enter_prepare(); that copy was equally unused, as
handlers still called interrupt_enter_prepare().
Commit bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
made both live. On the syscall side it did the full conversion:
system_call_exception() now accounts once through the hook via
syscall_enter_from_user_mode(), rather than calling
account_cpu_user_entry() directly. On the interrupt side it
switched the handler macros to arch_interrupt_enter_prepare()
followed by irqentry_enter(), which also runs the hook, but the
accounting in arch_interrupt_enter_prepare() was not removed to
match. The double accounting starts with that commit.
With CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y this roughly doubles the
reported user time of any workload that takes interrupts. The
other accounting modes compile account_cpu_user_entry() to an
empty stub, so they are not affected.
Remove the accounting from arch_interrupt_enter_prepare() and rely
on arch_enter_from_user_mode(), which already runs for both
syscalls and interrupts. The duplicate account_stolen_time() call
is removed the same way.
On a pseries LPAR a busy loop reports 6s user time in 3s elapsed
(~210% CPU) before the fix, and 3s (~105% CPU) after it:
$ python3 -c 'while True: pass' &
$ sleep 3; ps -p $! -o etime,time,pcpu
ELAPSED TIME %CPU
Before 00:03 00:00:06 210
After 00:03 00:00:03 105
A 50% load reports ~70% usr / 30% idle before the fix, and
~49% usr / 51% idle after it:
$ taskset -c 6 stress-ng --cpu 1 --cpu-load 50 &
$ mpstat -P 6 1
CPU %usr %idle
Before 6 69.74 30.26
After 6 48.51 50.50
Fixes: bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260904025831.3439809-1-aboorvad@linux.ibm.com
|
|
When __replay_soft_interrupts() replays a pending interrupt (e.g.
PACA_IRQ_DEC -> timer_interrupt), it calls the handler directly with a
synthetic pt_regs. The DEFINE_INTERRUPT_HANDLER_ASYNC wrapper around
each handler calls arch_interrupt_async_exit_prepare() on the way out,
which calls arch_interrupt_exit_prepare() -> local_irq_disable() ->
arch_local_irq_disable(), which does:
irq_soft_mask_set(IRQS_DISABLED) /* 0x1 */
This unconditionally overwrites irq_soft_mask with IRQS_DISABLED (0x1),
stripping the IRQS_PMI_DISABLED (0x2) bit. The result is that
irq_soft_mask is 0x1 instead of IRQS_ALL_DISABLED (0x3) when the
handler returns to __replay_soft_interrupts().
For a normally-taken interrupt this is harmless: the next interrupt
always enters through arch_interrupt_enter_prepare() which
unconditionally sets irq_soft_mask to IRQS_ALL_DISABLED. But during
replay, next_interrupt() is called directly between replayed handlers
without going back through arch_interrupt_enter_prepare(), so the
stripped bit is never restored. next_interrupt() then fires a WARNING:
WARNING: arch/powerpc/kernel/irq_64.c:75
WARN_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED)
The warning was observed early in boot on a POWER10 pseries guest
during kmem_cache_init_late(), where a spinlock release triggers
interrupt replay that processes a pending timer interrupt.
Debugger state confirming the bug:
Before timer_interrupt(®s):
irq_soft_mask = 0x3 (IRQS_ALL_DISABLED) correct
irq_happened = 0x41 (HARD_DIS|REPLAYING) correct
After timer_interrupt(®s) returns:
irq_soft_mask = 0x1 (IRQS_DISABLED) WRONG - PMI bit stripped
irq_happened = 0x41 unchanged
The fix is to replace local_irq_disable() with hard_irq_disable().
hard_irq_disable() is the right primitive here for two reasons:
1. On PPC64 (hw_irq.h:301) it calls irq_soft_mask_set_return(IRQS_ALL_DISABLED),
setting the soft mask to 0x3 (both IRQS_DISABLED and IRQS_PMI_DISABLED),
which preserves the PMI bit and fixes the WARNING. The additional
work it does (__hard_irq_disable(), PACA_IRQ_HARD_DIS |=) is
redundant but safe since both are already set at this point in the
exit path; the trace_hardirqs_off() inside is guarded by
if (!arch_irqs_disabled_flags(flags)) so it will not double-fire.
2. On PPC32 (hw_irq.h:467) hard_irq_disable() maps to
arch_local_irq_disable() -> __hard_irq_disable(), which clears
MSR[EE] in hardware. This is exactly correct: PPC32 has no soft-mask
PACA mechanism, so the hardware disable is the right way to satisfy
irqentry_exit()'s requirement. This also fixes a build error on PPC32
where irq_soft_mask_set() is only defined under CONFIG_PPC64:
arch/powerpc/include/asm/entry-common.h:273: error: implicit
declaration of function 'irq_soft_mask_set'
Using hard_irq_disable() requires no #ifdef and is consistent with
how the rest of the entry code (e.g. entry-common.h:463) handles the
same PPC32/PPC64 split.
Fixes: 334f3f6d7a16 ("powerpc/entry: Disable interrupts before irqentry_exit")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/6f9bfb0f-b14c-468e-bb9f-c157d120d0dc@linux.ibm.com/
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260904090858.128563-1-mkchauras@gmail.com
|
|
KUAP means kernel cannot touch user memory unless it explicitly is
enabled. In the kernel it should stay AMR_KUAP_BLOCKED. While returning
to userspace just before RFI, kernel should restore the user AMR value
back.
Looks like GENERIC_ENTRY might be treating arch_exit_to_user_mode_prepare()
as the last architecture step before returning to userspace.
commit bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
therefore called kuap_user_restore() from that hook. But on PowerPC that
is too early. After irqentry_exit() / syscall_exit_to_user_mode() we
still run platform specific exit routines.
e.g. code snippets showing both exception handling and system call
handling as the callers of function arch_exit_to_user_mode_prepare()
which does kuap_user_restore(). The below path shows that calling
kuap_user_restore() is too early when called from
arch_exit_to_user_mode_prepare().
Exception handling in exceptions-64s.S
=======================================
bl CFUNC(do_page_fault)
..DEFINE_INTERRUPT_HANDLER_ASYNC(do_page_fault)
arch_interrupt_async_enter_prepare(regs);
state = irqentry_enter(regs);
instrumentation_begin();
irq_enter_rcu();
handler(regs);
nap_adjust_return(regs);
irq_exit_rcu();
instrumentation_end();
arch_interrupt_async_exit_prepare(regs);
irqentry_exit(regs, state); <<< too early
irqentry_exit_to_user_mode()
__exit_to_user_mode_prepare(regs, EXIT_TO_USER_MODE_WORK_IRQ);
arch_exit_to_user_mode_prepare(regs, ti_work); <<< too early
b interrupt_return_srr
.. bl CFUNC(interrupt_exit_user_prepare) <<< already calls kuap_user_restore
prep_irq_for_enabled_exit() retry can run kernel code with IRQs on. So
only when that routine is fully finished is when the user KUAP should be
fully restored which interrupt_exit_user_prepare() already takes care of
before returning.
Similarly for system call handling in interrupt_64.S
======================================================
bl CFUNC(system_call_exception)
.Lsyscall_exit:
addi r4,r1,STACK_INT_FRAME_REGS
li r5,0 /* !scv */
bl CFUNC(syscall_exit_prepare)
.. kuap_assert_locked();
syscall_exit_to_user_mode(regs); <<< too early
syscall_exit_to_user_mode_prepare(regs); <<< too early
kuap_user_restore(regs); <<< already calls
syscall_exit_prepare(), which can enable IRQs, replay a pending
interrupt, and only then rfi. Those functions already restore KUAP
immediately before rfi.
Note that if we restore the user AMR too early like in the current code
as shown from the code snippets above, then we get the following warning
when CONFIG_PPC_KUAP_DEBUG is enabled:
WARNING: arch/powerpc/include/asm/book3s/64/kup.h:293 at interrupt_exit_user_prepare+0x1a0/0x1c0
Hardware name: IBM pSeries (emulated by qemu) POWER10 (architected)
TRAP: 0700
LR: c00000000000d8d4 CTR: c0000000021fe500
MSR: <SF,EE,ME,IR,DR,RI,LE> CR: 44000804 XER: 20040000
interrupt_exit_user_prepare+0x1a0/0x1c0
interrupt_return_srr_user+0x8/0x12c
Fixes: bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
Fixes: 02565a782c1ee ("powerpc: Introduce syscall exit arch functions")
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/52fee44fd23acf8e1c024ace668728e626a783a8.1788101609.git.ritesh.list@gmail.com
|
|
There's no reason to include pagemap.h in any arch include file; these
should all be too low-level to include pagemap.h. Some git archaelogy
indicates that at one point, swap.h needed declarations from pagemap.h but
couldn't include pagemap.h itself. That reason seems to have disappeared
since swap.h now includes pagemap.h.
Some of these files turn into just including the asm-generic version,
so in those cases, modify Kbuild to just use the asm-generic version
directly.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm: drop "sub" prefix from various places" (Dev Jain)
page->folio conversion and a naming cleanup
- "mm/kasan: remove redundant initialization for kasan_flag_write_only"
(Igor Putko)
KASAN cleanup work
- "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)
Small speedup in the pagecaache read code
- "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)
Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
allocations when the caller asked for GFP_NOFS or GFP_NOIO
- "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
Leitao)
Avoid a soft lockup watchdog trigger from the kmemleak scanning code
in extreme situations
- "mm/page_owner: misc cleanups" (Ye Liu)
Cleanups to the page_owner code. For some reason lots of people have
been working on the page_owner code this cycle.
- "mm: convert to walk_page_range_vma() to eliminate find_vma()"
(Kefeng Wang)
Simplify and accelerate the page walking library function
- "mm/migrate: preparatory cleanups for batch copy and offload"
(Shivank Garg)
Cleanups in the migration code
- "mm/page_owner: add per-fd filter infrastructure for print_mode and
NUMA filtering" (Zhen Ni)
Per-fd filtering to page_owner in order to reduce the sometimes vast
amount of output it can produce
- "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)
Fixes and preparatory cleanups around bootmem HugeTLB handling,
sparse initialization ordering, and related vmemmap setup
- "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)
Reduce lock contention in zs_free(), which dominates the unmap path
under memory pressure on Android (LMK kills) and on x86 servers
running zswap-heavy workloads.
Up to 1.83x improvement in microbenchmarking.
- "move alloc_tag.c file under mm/" (Suren Baghdasaryan)
- "samples/damon: handle damon_{start,stop}() failures" (SJ Park)
Fix improper handling of damon_start(), damon_stop(), and
damon_call() failures across DAMON sample modules to prevent
potential memory leaks, operation disruptions and use-after-free
bugs
- "mm/damon/sysfs: kobject_del() directories that users can
create/remove" (SJ Park)
Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
causeing creation failures due to duplicate directory names by adding
missing kobject_del() calls before creating new directories
- "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)
Clean up the core pte handling code
- "selftests/damon: misc fixes for test bugs" (Kunwu Chan)
Fix several bugs in the DAMON selftests
- "selftests/damon: fix memcg_path staging handling" (Cheng Nie)
Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
add a test case for it in sysfs.py.
- "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)
Selftest coverage for DAMON's refresh_ms sysfs feature by updating
the test control module and verifying that scheme stats update
automatically without manual intervention
- "mm/damon: five misc fixups" (Akinobu Mita)
Miscellaneous DAMON fixups.
- "mm/damon/core: detect internal variation above max_nr_regions/2"
(Jiayuan Chen)
Fix DAMON's region splitting behavior when region counts exceed half
the maximum budget by dynamically scaling down the split fraction as
the limit approaches, preventing large regions from staying un-split,
and add corresponding KUnit test coverage
- "mm: preparatory patches for PMD level swap entries" (Usama Arif)
Refactor and clean up PMD softleaf helpers, call sites, and
architecture flags to lay the groundwork for a follow-up series that
introduces PMD page table swap entries
- "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
Park)
Update DAMON design and ABI documentation, expands unit and selftest
coverage, optimize damon_commit_target_regions(), and clean up
recently added sysfs interface code for better readability
- "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
(Usama Arif)
Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
userspace event notifications and refactor v1-only eventfd handling
into mm/memcontrol-v1.c to reduce memory overhead and code complexity
- "selftests/mm: refactor pkey helpers and fix mmap error handling"
(Hongfu Li)
Refactor pkeys shared tracing and assertion helpers into a common
file, unify protection key selftests to use consistent diagnostic
logging and assertions, and enforce standardized MAP_FAILED return
checks for mmap() calls across the tests
- "mm/damon: optimize out nr_accesses_bp" (SJ Park)
Replace the error-prone, continuously updated nr_accesses_bp field in
damon_region with an on-demand moving sum function, reducing
structure memory overhead and avoiding state corruption bugs
- "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)
Decouple HugeTLB folio allocation from VMA dependencies by
introducing hugetlb_alloc_folio(), enabling subsystems like
guest_memfd to allocate HugeTLB folios without standard VMA
reservations or pseudo-VMAs
- "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)
Integrate DAMON's probe_hits attribute counter into the pseudo moving
sum infrastructure, enabling real-time, online monitoring without
waiting for full aggregation intervals
- "mm: Some cleanups for page allocator APIs" (Brendan Jackman)
Simplify and refactor the page allocator entry points and flags by
unifying allocation paths, adding internal alloc_flags arguments, and
eliminating redundant __ prefixed alloc_pages variants.
- "Fix incorrect access of hugetlb pte entries" (Dev Jain)
Enforce the consistent use of huge_ptep_get() instead of ptep_get()
for HugeTLB entries and fixes an unaligned address issue in arm64's
huge_ptep_get() implementation
- "mm/damon: validate all parameters in the core" (SJ Park)
Consolidate parameter validation into the DAMON core specifically
within damon_start() and damon_commit_ctx() to centralize error
checking, eliminate caller-side redundant checks and to improve
maintenance efficiency
- "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
Chen)
Rename is_need() to filter_record() for clearer return semantics, fix
per-record allocation memory leaks and bound output copies in
search_pattern() to address an existing buffer issue
- "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)
Mitigate a system-wide stall which occurs when a cgroup is removed
while one of its memory control files is doing synchronous reclaim
- "mm/memory-failure: add panic option for unrecoverable pages" (Breno
Leitao)
Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
that immediately panics the kernel on unrecoverable memory errors in
kernel-owned pages to preserve error context and prevent delayed,
silent data corruption
- "mm/damon: refactor damon_{start,stop,commit}() for simple error
handling" (SJ Park)
Refactor the DAMON core API functions to guarantee that all contexts
are fully stopped when damon_start(), damon_stop(), or damon_commit()
fail, eliminating the need for complex and error-prone caller-side
cleanup code
- "Keep tail page private zero at free and folio split" (Zi Yan)
Add checks to ensure tail_page->private is zero when freeing compound
or high-order pages and when promoting tail pages during large folio
splits. By validating these fields at free and split time, it allows
the removal of redundant private field clearing inside
prep_compound_tail()
- "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
Song)
Eliminate redundant lru_add_drain() calls in
wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
contention and system overhead
By validating folio refcounts against the LRU cache before draining
and removing unnecessary drains in the swap path, it achieves up to a
30.5% reduction in drain calls during heavy swap workloads
- "mm: clean up folio LRU and swap declarations" (Jianyue Wu)
Reorganize folio LRU and swap code by relocating page-cluster state
to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
MM-internal reclaim declarations into mm/internal.h.
- "userfaultfd: working set tracking for VM guest memory" (Kiryl
Shutsemau)
Add userfaultfd support for tracking the working set of VM guest
memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
Hildenbrand)
Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
performing some smaller cleanups around freeing of reserved vmemmap
pages on the way.
- "mm/damon: update probe hits for runtime parameter commits" (SJ Park)
Ensure that DAMON's probe_hits attribute counter is properly updated
when monitoring intervals are changed at runtime, matching the
behavior of nr_accesses. To achieve this, it refactors and renames
existing helper functions for shared use, applies the updates to
probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
maintain measurement accuracy.
- "KSM: performance optimizations for rmap_walk_ksm" (xu xin)
Resolve a severe KSM reverse-mapping performance bottleneck where
thousands of split VMAs sharing a single anon_vma cause extended lock
contention.
By adding an interval-filtering check during the rmap walk, it
reduces worst-case anon_vma lock hold times from over 500ms down to
under 2ms, preventing application freezes and latency spikes under
memory pressure.
- "mm: split a couple of headers from internal.h" (Mike Rapoport)
Split declarations related to mm_init, memblock, vmalloc and sparse
into new headers
- "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)
Apply the interval tree optimization from rmap_walk_ksm() to
collect_procs_ksm() to avoid iterating over non-matching VMAs during
KSM memory error handling.
It hoists loop-invariant address initialization and restricts the
anon_vma_interval_tree_foreach walk to a targeted page offset range,
reducing redundant checks and improving lookup efficiency.
- "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
Patil)
Fix issues in the hugetlb and KSM MM selftest categories that can
report failures when the prerequisites for the tests are not
satisfied
- "mm/damon: introduce data attributes only monitoring" (SJ Park)
Introduce attribute-weighted region management in DAMON, allowing
users to prioritize specific data attributes (such as page sizes or
cgroups) over or instead of access monitoring.
By assigning weights to attribute probes, DAMON can completely
disable access tracking and adjust monitoring regions based on
weighted probe-hit counters to optimize monitoring quality for
attribute-focused workloads.
- "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
(Stanislav Kinsburskii)
Extend hmm_range_fault() to support userfaultfd-backed regions by
allowing the mmap lock to be dropped during fault handling via a new
hmm_range_fault_locked() helper.
By accepting a locked pointer and signaling retry status when lock
release occurs, it enables page fault resolution in userfaultfd
regions while preserving backward compatibility for existing callers.
- "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)
Clean up and standardize how vma->vm_pgoff is accessed and
manipulated across file-backed and anonymous mappings in the kernel
It introduces dedicated helper functions such as vma_start_pgoff(),
vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
renaming rmap interval tree helpers to better reflect their
functionality.
These changes establish a cleaner foundation for future work that
will unify virtual page offset indexing for all anonymous and CoW'd
folios.
- "mm: handle device-private PMDs in walk callbacks" (Usama Arif)
Address kernel panics and state corruption caused by MM walk
callbacks reaching non-present device-private PMD swap entries
created during HMM migrations
It ensures that functions which acquire pmd_trans_huge_lock()
properly recognize device-private PMDs instead of assuming a present
THP or a standard migration entry.
- "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)
Refactor try_to_unmap_one by modularizing Hugetlb,
anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
functions, laying the structural groundwork for batched anonymous
large folio unmapping.
- "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)
Fix typos and fills in missing entries in the DAMON sysfs ABI
document
- "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)
Introduce an atomic sysfs state attribute and supporting DAX/MM
infrastructure to prevent userland races when offlining and removing
entire memory regions
By adding an unplugged state alongside standard online modes, it
enables whole-device atomic hotplug control while preserving backward
compatibility.
- "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)
Continue transitioning the kernel from the deprecated vm_flags_t type
to vma_flags_t across core memory management infrastructure.
It replaces legacy type usage in core functions such as do_mmap(),
unmapped area allocation, mm->def_vma_flags, and VMA operations like
mlock, mprotect, and mremap.
- "Two small patches to clean up mm/mm_slot.h" (xu xin)
Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
slot deletion sequences in khugepaged and KSM. It also adds code
documentation explaining why mm_slot_lookup and mm_slot_insert must
remain as preprocessor macros rather than static inline functions.
- "mm/damon/core: hide core-private struct fields" (SJ Park)
Clean up DAMON core structures by consistently marking internal-only
fields with private: comment tags to prevent improper direct access
from outer layers.
It enforces encapsulation across core structures including
damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
interact through approved access APIs instead of exposing raw struct
members.
- "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
(SJ Park)
Address potential infinite loops, NULL dereferences, and race
conditions identified in DAMON
It fixes an infinite loop triggered by extreme user configurations, a
NULL pointer dereference within unit tests and minor monitoring
accuracy degradation caused by subtle runtime races.
- "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
Jackman)
Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
via non-PCP or isolated migration paths.
It also resolves potential kernel crashes and privilege escalation
risks triggered when BPF tracing runs in NMI context alongside memory
hotplug or large allocation frees.
- "mm/page_alloc: couple of followups for recent cleanups" (Brendan
Jackman)
Clean up and update page allocator nomenclature, documentation, and
debug assertions.
It aligns internal FPI_ flags with the public "nolock" naming
convention, removes outdated internal implementation details from
high-level page allocator comments, and eliminates obsolete
VM_BUG_ON() assertions in allocation paths.
- "mm/mseal: further cleanups" (Lorenzo Stoakes)
Refactor and simplify the mseal implementation by clarifying API
boundaries and removing unnecessary code complexity.
It replaces generic do_mseal() usage outside the syscall with a
dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
eliminates mm_struct parameters to enforce that sealing applies only
to current->mm, and streamlines overall logic and comments with no
functional changes intended.
- "mm/vmscan: fix swappiness=max and clean up per-node proactive
reclaim" (Ridong Chen)
Resolve reclaim behavior bugs and clean up function parameters across
memory reclaim paths
It fixes swappiness=max in both standard reclaim and MGLRU so
unswappable anonymous memory no longer falls back to evicting page
cache, ensures reclaim_store() returns accurate error codes instead
of collapsing all failures into -EAGAIN, and removes the obsolete
gfp_mask parameter from __node_reclaim().
- "mm: mincore: misc cleanups" (Kefeng Wang)
Clean up and simplifies the mincore code. Most importantly, it
removes the historical special behavior that always reports VM_PFNMAP
pages as non-resident.
- "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)
Two trivial cleanups in the folio split API
- "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
bugs" (SJ Park)
Resolve minor operational and testing bugs in DAMON identified by
Sashiko. It initializes the damos->last_applied field to prevent
occasional efficiency degradation and fixes invalid memory accesses
in DAMON KUnit tests during test failure handling.
- "cleanup for stable_page_flags()" (Jinjiang Tu)
Clean up and refactor stable_page_flags() used by /proc/kpageflags
without altering functionality.
It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
bits, converts folio-specific flag checks to standard folio_test_*()
helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
- "Batch unmap of uffd-wp file folios" (Dev Jain)
Extend batched folio unmapping support to file folios within
userfaultfd write-protect (uffd-wp) VMAs by adding batching
capabilities to pte_install_uffd_wp_if_needed().
This removes special-case restrictions on uffd-wp VMAs in
try_to_unmap_one(), significantly simplifying the function's control
flow and complexity.
- "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
(Sang-Heon Jeon)
Clarify and clean up the architecture-specific usage of
__late_set_fixmap() and __late_clear_fixmap() after
early_ioremap_reset()
It adds explicit documentation regarding when early_ioremap_reset()
must be called and removes redundant macro definitions and reset
calls in the RISC-V and ARM64 architectures.
- "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)
Address severe performance regressions, swap storms, and spurious
OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
production
It updates the page allocator slowpath so non-movable allocation
requests actively trigger direct reclaim and direct compaction at
pageblock_order scale, allowing them to claim whole pageblocks rather
than spinning unproductively.
- "zram: lockmap tweaks" (Sebastian Siewior)
Optimize and fix lockdep tracking for zram devices by consolidating
per-entry lockmaps and isolate lock classes across multiple instances
This reduces memory overhead by replacing per-entry lockdep_map
instances with a single map per struct zram, and assigns a dynamic
lock_class_key to each instance to prevent false deadlock reports
when different zram devices are backed by distinct filesystems.
* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
selftests/mm: unpoison pages in memory-failure teardown
mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
mm/zsmalloc: fix release order of locks in zs_page_migrate()
Documentation: zram: remove sections numbering
ksm: stop iterating VMAs when ksm_test_exit returns true
mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
zram: use a custom key for each zram object
zram: move lockmap to be per-zram instead per table
selftests/mm: fix gup_longterm EINVAL error message
mm: page_alloc: fix non-movable reclaim storm in defrag_mode
mm: page_alloc: move capture_control to the page allocator
mm: compaction: support non-movable compaction for pageblock requests
mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
hugetlb: evaluate subpool free state while locked
mm/damon: remove trailing semicolons after function definitions
mm/damon/ops-common: prevent migration fallback to non-target nodes
mm/damon: update outdated comment about DAMOS filter handling
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull treewide timer related cleanups from Thomas Gleixner:
- Remove the leftover CLOCK_TICK_RATE which has been scheduled for
removal more than a decade ago along with some now empty asm/timex.h
files.
- Consolidate delay timer calibration
The construct of having a define in a header requires that
architectures provided asm/timex.h for no reason. Also the function
name for reading the delay timer is confusing at best.
Use a config switch to enable that functionality and rename the
function to delay_read_timer() to make the purpose clear.
This removes some more now empty asm/timex.h files as well.
* tag 'timers-cleanups-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
calibrate: Rework delay timer calibration
treewide: Remove CLOCK_TICK_RATE
x86: Use PIT_TICK_RATE instead of CLOCK_TICK_RATE
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull generic entry code updates from Thomas Gleixner:
- Make syscall user dispatching configurable
Not all architectures can makes use of syscall user dispatching.
Allow them to disable the feature completely.
- Consolidate stack randomization for the generic entry code and the
architectures using it.
Stack randomization on syscall entry was sprinkled throughout the
architecture specific low level entry code and in some cases at the
wrong points, e.g. before establishing state, which violates the
non-instrumentable constraints of that code.
Clean this up by integrating stack randomization into the generic
entry code helpers so that it is invoked at the earliest possible
point right after establishing state and converting all generic entry
code using architecture over.
- Clean up the syscall number handling in the generic entry code. It
works correctly for architectures which have a separate return value
storage in pt_regs, but fails to distinguish the case where user
space handed in -1 as syscall number from the case where the entry
code rejects it by returning -1 to the callers. Aside of that the
return value functionality of those interfaces is not really
intuitive.
Fix this by separating the decision to reject a syscall (user
dispatch, ptrace, seccomp ...) from the potential modification of the
syscall number through these mechanisms.
This solves most of the problems for architectures which do not have
a separate return value storage in pt_regs except for the case where
a tracepoint has a BPF script or a probe attached which overwrite
both the syscall number and the return value. But that's a problem
which cannot be solved in the generic code, that only can be
addressed by separating the storage model in the affected
architectures.
* tag 'core-entry-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
entry, treewide: Make syscall_enter_from_user_mode[_work]() indicate syscall execution
entry: Make return type of syscall_trace_enter() bool
entry: Rework trace_syscall_enter()
entry: Rework syscall_audit_enter()
syscall_user_dispatch: Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCH
entry: Fix seccomp bypass after ptrace with TSYNC
x86/entry: Simplify the syscall number logic
x86/entry: Get rid of the sys_ni_syscall() indirection
x86/entry: Make syscall functions static
ptrace, treewide: Rename ptrace_report_syscall_entry() to ptrace_report_syscall_permit_entry()
seccomp, treewide: Rename and convert __secure_computing() to return boolean
entry: Use syscall number instead of rereading it
entry: Remove syscall_enter_from_user_mode()
x86/syscall: Use [syscall_]enter_from_user_mode_randomize_stack()
s390/syscall: Use enter_from_user_mode_randomize_stack()
riscv/syscall: Use syscall_enter_from_user_mode_randomize_stack()
powerpc/syscall: Use syscall_enter_from_user_mode_randomize_stack()
loongarch/syscall: Use syscall_enter_from_user_mode_randomize_stack()
entry: Provide [syscall_]enter_from_user_mode_randomize_stack()
randomize_kstack: Provide add_random_kstack_offset_irqsoff()
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Madhavan Srinivasan:
- Enable Rust for ppc64le
- ppc4xx gpio driver updates
- Add power12 base enablement support
- Validate arch_compat against host compatibility mode
- Simplify bootx_scan_dt_build_struct() in powermac platform
- Implement get_direction() in cpm2
- Use cpu_relax() in ps3_create_spu()
- Add NULL guard for cause_ipi in smp_muxed_ipi_message_pass
- Fixes to handle pseries watchdogs in kdump path
- Fix missing r2 clobber in PCREL inline assembly
- Set GPIO chip parent on ppc44x
- KVM: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl
- KVM: Use generic xfer to guest work function
- Enable to run posix cpu timers in task context
- Misc fixes and cleanups
Thanks to Aditya Gupta, Alice Ryhl, Amit Machhiwal, Andrew Morton,
Anushree Mathur, Athira Rajeev, Bartosz Golaszewski, Cédric Le Goater,
Christian König, Christophe Leroy (CS GROUP), Gary Guo, Gaurav Batra,
Gautam Menghani, Gou Hao, Hari Bathini, Harsh Prateek Bora, jiazhenyuan,
Jinjie Ruan, Link Mauve, Linus Walleij, Mahesh Kumar G Mahesh
Salgaonkar, Michael Walle, Michal Suchánek, Mukesh Kumar Chaurasiya
(IBM), Nicholas Piggin, Nikhil Kumar Singh, Praveen K Pandey, Ritesh
Harjani (IBM), Rosen Penev, Saket Kumar Bhaskar, Shrikanth Hegde,
Sourabh Jain, Thorsten Blum, Vaibhav Jain, Venkat Rao Bagalkote, Vishal
Chourasia, Wentao Guan, and Yanfei Xu.
* tag 'powerpc-7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (62 commits)
powerpc/pseries/iommu: switch to Default DMA window during kdump
powerpc/configs: enable CONFIG_RAS to fix EDAC support
KVM: PPC: Document KVM_PPC_GET_COMPAT_CAPS ioctl
KVM: PPC: Book3S HV: Add support for compat CPU capabilities for KVM on PowerNV
KVM: PPC: Book3S HV: Implement compat CPU capability retrieval for KVM on PowerVM
KVM: PPC: Introduce KVM_CAP_PPC_COMPAT_CAPS and wire up ioctl
gpio: ppc44x: use dev_name() for chip label
gpio: ppc44x: fix undefined behavior in GPIO_MASK2 macro
gpio: ppc44x: drop PPC-specific IO helpers
gpio: ppc44x: Convert GPIO to generic MMIO
gpio: ppc44x: Use platform resource helper for GPIO MMIO
gpio: ppc44x: Use module platform driver helper for GPIO
gpio: ppc44x: update all 4xx to 44x
gpio: move ppc4xx gpio driver from arch/powerpc to drivers/gpio
KVM: PPC: Use min() in kvm_vm_ioctl_check_extension()
KVM: PPC: booke: Use min() in watchdog_next_timeout()
powerpc/perf: Add power12 Base Performance Monitoring support
powerpc: Add Power12 architected mode
powerpc: Add Power12 raw mode
powerpc/pseries: Limit PVR list to 16 entries for CAS negotiation
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux
Pull kexec updates from Mike Rapoport:
- Deduplicate crash memory allocation and the exclusion of reserved
crash kernel regions from architecture specific code into a generic
crash_prepare_headers() and enable crashkernel CMA reservation on
arm64 and riscv reservation on arm64 and riscv.
- Skip purgatory checksum verification when the kexec segments cannot
be corrupted by DMA, which saves about 250ms on kexec.
- Replace __ASSEMBLY__ with the compiler provided __ASSEMBLER__ in
include/linux/kexec.h.
- Fix a keyring refcount imbalance in the kdump kernel's dm-crypt key
restore path, which over-dropped the user keyring reference when
more than one key was restored.
* tag 'kexec-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux:
crash_dump: release keyring reference at the correct time
kexec: Replace __ASSEMBLY__ with __ASSEMBLER__ in header file
kexec_file: skip checksum verification when safe
riscv: kexec_file: Add support for crashkernel CMA reservation
arm64: kexec_file: Add support for crashkernel CMA reservation
powerpc/kexec_file: Use crash_exclude_core_ranges() helper
LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
x86/crash: Use crash_prepare_headers() helper to simplify code
arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
crash: Add crash_prepare_headers() to exclude crash kernel memory
powerpc/crash: sort crash memory ranges before preparing elfcorehdr
riscv: kexec_file: Fix crashk_low_res not exclude bug
|
|
PowerVM
On POWER systems, the host CPU may run in a compatibility mode (e.g., a
Power11 processor operating in Power10 compatibility mode). In such
cases, the effective CPU level exposed to guests differs from the
physical processor generation.
When running nested KVM guests, QEMU derives the host CPU type using
mfpvr(), which reflects the physical processor version. This can result
in a mismatch between the CPU model selected by QEMU and the
compatibility mode enforced by the host, leading to guest boot failures.
For example, booting a nested guest on a Power11 LPAR configured in
Power10 compatibility mode fails with:
KVM-NESTEDv2: couldn't set guest wide elements
[..KVM reg dump..]
This occurs because QEMU selects a CPU model corresponding to the
physical processor (via mfpvr()), while the host operates in a lower
compatibility mode. As a result, KVM rejects the requested compatibility
level during guest initialization.
On pseries nestedv2 systems, add support for retrieving host CPU
compatibility capabilities for nested guests on PowerVM. The capability
bitmap reflects the processor modes negotiated between the Power
hypervisor (L0) and the host partition (L1) via the
H_GUEST_GET_CAPABILITIES hcall, but is retrieved from the cached
nested_capabilities value populated during module initialization,
avoiding repeated hypervisor calls. A WARN_ON_ONCE() flags the
unexpected case where nested_capabilities is zero on a nestedv2 system.
The implementation defines KVM-specific capability constants
(KVM_PPC_COMPAT_CAP_POWER9/10/11), masks unsupported bits, and exposes
the result through the KVM_PPC_GET_COMPAT_CAPS ioctl.
Hook the implementation into the Book3S HV kvmppc_ops so that it can be
invoked by the generic KVM ioctl handling code.
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-3-amachhiw@linux.ibm.com
|
|
Introduce a new capability and ioctl to expose CPU compatibility modes
supported by the host processor for nested guests.
On IBM POWER systems, newer processor generations (N) can operate in
compatibility modes corresponding to earlier generations, like (N-1) and
(N-2). This is particularly relevant for nested virtualization, where
nested KVM guests may need to run with a specific processor compatibility
level.
Introduce KVM_CAP_PPC_COMPAT_CAPS capability and the corresponding
KVM_PPC_GET_COMPAT_CAPS vm ioctl. The ioctl returns a bitmap describing
the compatibility modes supported by the host in respective bit numbers,
allowing userspace (e.g., QEMU) to select an appropriate compatibility
level when configuring nested KVM guests.
The ioctl handling is added in kvm_arch_vm_ioctl() and retrieves host
CPU compatibility capabilities via a PowerPC-specific backend
implementation when available.
The struct kvm_ppc_compat_caps places the 'size' field first so it can
be read alone via get_user() before copy_struct_from_user() is called,
avoiding pointer arithmetic to locate the size field.
The ioctl is defined using _IO so the ioctl number remains stable even if
the struct grows in future versions. It uses copy_struct_from_user() and
copy_struct_to_user() to provide forward- and backward-compatible
extensibility: older userspace passing a smaller struct to a newer kernel
gets zero-padded trailing fields. Newer userspace passing a larger struct to
an older kernel (usize > ksize) succeeds if trailing bytes are zero (the
kernel reports back min(usize, ksize) as the filled size); if trailing bytes
are non-zero, the kernel writes back ksize into host_caps.size and returns
-E2BIG so userspace can retry with the correct size.
KVM_PPC_COMPAT_CAPS_SIZE_VER0 is defined as a frozen integer constant
(24) marking the size of the initial struct version, used as the
minimum floor for size field validation, similar to other versioned
struct interfaces in the kernel.
The 'flags' field is reserved for future use. The kernel rejects any
call where flags is non-zero with -EINVAL, preventing garbage values
from being baked into ABI permanently.
The ioctl returns appropriate error codes: E2BIG if usize exceeds
PAGE_SIZE, or if new userspace provides a larger struct with non-zero
trailing bytes (with ksize written back into host_caps.size for the
retry); EINVAL for an invalid size or non-zero reserved fields; EFAULT
for failed copy operations; and ENOTTY if the backend doesn't implement
get_compat_caps.
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Reviewed-by: Gautam Menghani <gautam@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260808161148.66673-2-amachhiw@linux.ibm.com
|
|
PVR value of 0x0f000008 means we are arch v3.2 compliant (i.e.
Power12). This is used by phyp and kvm when booting as a pseries guest
to detect the presence of new Power12 features and to enable the
appropriate hwcap and facility bits.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Tested-by: Praveen K Pandey <praveen@linux.ibm.com>
Reviewed-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260806051120.3703698-4-mahesh@linux.ibm.com
|
|
Add CPU table entries for raw mode.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Tested-by: Praveen K Pandey <praveen@linux.ibm.com>
Reviewed-by: Nikhil Kumar Singh <nikhilks@linux.ibm.com>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260806051120.3703698-3-mahesh@linux.ibm.com
|
|
Patch series "userfaultfd: working set tracking for VM guest memory", v10.
This series adds userfaultfd support for tracking the working set of VM
guest memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage.
This patch (of 15):
pte_protnone() and pmd_protnone() detect present-but-inaccessible page
table entries. This capability is useful beyond NUMA balancing -- for
example, userfaultfd working set tracking uses protnone PTEs to track page
access without unmapping pages.
Introduce CONFIG_ARCH_HAS_PTE_PROTNONE to decouple the protnone PTE
infrastructure from CONFIG_NUMA_BALANCING. The six architectures that
support protnone PTEs (x86_64, arm64, powerpc, s390, riscv, loongarch) now
select this option, and CONFIG_NUMA_BALANCING depends on it.
No functional change -- the same set of architectures continues to have
working protnone support, but the infrastructure is now available
independently of NUMA balancing.
Link: https://lore.kernel.org/20260708111417.173443-1-kirill@shutemov.name
Link: https://lore.kernel.org/20260708111417.173443-2-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Assisted-by: Claude:claude-opus-4-6
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: James Houghton <jthoughton@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
After enabling GENERIC_ENTRY on PowerPC, syscall_enter_from_user_mode()
returns -1 as a sentinel to signal that seccomp or ptrace has intercepted
the syscall and already set a return value via syscall_set_return_value().
system_call_exception() was not handling this sentinel, and since -1UL
is >= NR_syscalls, the code fell into the out-of-range path and returned
-ENOSYS, overwriting the errno already placed in regs->gpr[3].
The naive fix of checking r0 == -1L before the NR_syscalls bounds check
is ambiguous: a user legitimately calling syscall(-1) also produces r0 ==
-1L, and a tracer intercepting such a call would have its injected return
value silently discarded.
Fix this by introducing a thread flag that is set whenever
syscall_set_return_value() explicitly updates the return value. In
system_call_exception(), check and clear this flag before dispatching
the syscall, and return the preset value directly when it is present.
This ensures that an explicitly supplied return value always suppresses
syscall execution, regardless of the syscall number.
This handles all seccomp actions correctly:
- SECCOMP_RET_ERRNO, SECCOMP_RET_TRACE (no tracer), SECCOMP_RET_USER_NOTIF:
all call syscall_set_return_value(), flag is set, injected value returned.
- SECCOMP_RET_TRAP, SECCOMP_RET_KILL: call syscall_rollback() and deliver
a signal; flag is not set, but the process is dying so the return value
is irrelevant.
The fix covers both ppc32 and ppc64 with no #ifdefs.
Fixes: bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
Reported-by: Michal Suchánek <msuchanek@suse.de>
Closes: https://lore.kernel.org/all/ajpp-_XnbF3UTM_E@kunlun.suse.cz/
Tested-by: Michal Suchánek <msuchanek@suse.de>
Reviewed-by: Michal Suchánek <msuchanek@suse.de>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260731081521.1852133-1-mkchauras@gmail.com
|
|
On pseries LPAR systems, watchdog timers configured from userspace can
remain active after a kernel panic. When a panic triggers kdump, the
crashing kernel jumps directly to the kdump kernel without stopping
active watchdogs. As a result, the watchdogs remain active after the
kdump kernel starts.
If dump capture takes longer than the watchdog timeout, PHYP resets the
LPAR before the dump is fully captured, causing dump capture to fail.
Fix this by issuing the `H_WATCHDOG` hcall during the crash shutdown
sequence to stop all active watchdogs before booting the kdump kernel.
Cc: stable@vger.kernel.org
Fixes: 69472ffa6575 ("watchdog/pseries-wdt: initial support for H_WATCHDOG-based watchdog timers")
Reported-by: Mahesh Kumar G <mahe657@linux.ibm.com>
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727053416.276317-4-sourabhjain@linux.ibm.com
|
|
The H_WATCHDOG input and output definitions are currently local to the
pseries watchdog driver. The next patch in this series also needs these
definitions to issue H_WATCHDOG hypercalls outside the watchdog driver.
Move the H_WATCHDOG definitions to a new common header,
asm/papr-watchdog.h, so they can be shared without duplicating the
PAPR watchdog definitions.
No functional changes.
Cc: stable@vger.kernel.org
Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727053416.276317-2-sourabhjain@linux.ibm.com
|
|
On IBM POWER systems, newer processor generations can operate in
compatibility modes corresponding to earlier generations. This becomes
relevant for nested virtualization, where nested KVM guests may need to
run with a specific processor compatibility level.
Currently, when running a nested KVM guest (L2) inside a Power11 pSeries
logical partition (L1) booted in Power10 compatibility mode, the guest
fails to boot while setting 'arch_compat'. This happens because the CPU
class is derived from the hardware PVR (via mfspr()), which reflects the
physical processor generation (Power11), rather than the effective
compatibility mode (Power10).
As a result, userspace may request a Power11 arch_compat for the L2
guest. However, the L1 partition, running in Power10 compatibility, has
only negotiated support up to Power10 with the Power Hypervisor (L0).
When H_GUEST_SET_STATE is invoked with a Power11 Logical PVR, the
hypervisor rejects the request, leading to a late guest boot failure:
KVM-NESTEDv2: couldn't set guest wide elements
[..KVM reg dump..]
This situation should be detected earlier and rejected by KVM. Without
proper validation, if userspace ignores the error, the guest may continue
to boot in Power11 raw mode on a Power10 compatibility host, which should
not be allowed.
Introduce a validation mechanism that detects unsupported arch_compat
values early in the guest initialization path. When an unsupported
arch_compat is requested (e.g., Power11 on a Power10 compatibility mode
host), kvmppc_set_arch_compat() uses cpu_has_feature(CPU_FTR_P11_PVR) to
detect the mismatch and sets arch_compat to PVR_ARCH_INVALID (0xffffffff).
This sentinel value is architecturally safe: PAPR specifies that valid
logical PVR values must have 0x0f as the first byte, ensuring 0xffffffff
lies permanently outside the specification-defined range. Setting this
value triggers kvmppc_sanity_check() to mark the vCPU as invalid by
setting vcpu->arch.sane to false. On the next vCPU run, kvmppc_vcpu_run_hv()
checks this flag and returns -EINVAL, preventing the guest from running
with an invalid processor compatibility configuration.
With this, when a Power11 arch_compat is requested on a Power10
compatibility mode host, the guest fails early during boot with:
error: kvm run failed Invalid argument
This provides a much clearer failure mode compared to the previous
behavior where the guest could boot in Power11 raw mode (if userspace
ignored the error) or fail late during H_GUEST_SET_STATE.
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Acked-by: Gautam Menghani <gautam@linux.ibm.com>
Cc: stable@vger.kernel.org # v6.13+
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260714175432.86388-1-amachhiw@linux.ibm.com
|
|
xive_smp_probe() calls xive_init_ipis() which can fail, but its
return value is currently ignored. Change xive_smp_probe() to
return int so that errors can be propagated to callers.
This is a preparatory patch for the next one.
No functional change yet; the return value is always 0 at this point.
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Reviewed-by: Wentao Guan <guanwentao@uniontech.com>
Reviewed-by: jiazhenyuan <jiazhenyuan@uniontech.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260727104215.184786-3-gouhao@uniontech.com
|
|
Include asm-generic/serial.h and use the generic BASE_BAUD definition
instead of redefining it.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260729223807.570178-3-thorsten.blum@linux.dev
|
|
Added support for a new macro ARCH_STATIC_BRANCH_ASM in powerpc
to avoid duplication of inline asm between C and Rust. This is
inline with 'commit aecaf181651c ("jump_label: adjust inline asm to be consistent")'
Co-developed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://github.com/Rust-for-Linux/linux/issues/105
Link: https://github.com/linuxppc/issues/issues/451
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260708082454.1254320-4-mkchauras@gmail.com
|
|
CONFIG_ARCH_ENABLE_THP_MIGRATION gates PMD-level migration entries.
PMD-level device-private entries use the same migration mechanism and
therefore require the same architecture support.
Upcoming PMD-level swap entries can use the same PMD softleaf helpers
without depending on page migration, so rename the architecture gate to
CONFIG_ARCH_HAS_PMD_SOFTLEAVES. This describes the PMD entry capability
rather than one current user of it.
This is a pure rename: the set of selecting architectures (x86, arm64,
s390, riscv, loongarch, and powerpc on PPC_BOOK3S_64) and the gating
semantics are unchanged.
No functional change intended.
Link: https://lore.kernel.org/20260706114320.1643046-7-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Replace _PPC64_SERIAL_H with _ASM_POWERPC_SERIAL_H to match the actual
macro name. Remove an empty comment while at it.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260623153825.403819-2-thorsten.blum@linux.dev
|
|
Commit d7a6797e0bc1 ("powerpc: add exit_flags field in pt_regs") added
the exit_flags field to struct pt_regs to pass internal exit control
flags (e.g. _TIF_RESTOREALL) from syscall_exit_prepare() to the
low-level assembly exit path.
However, the field was placed in a way that was visible to userspace
tools such as strace via PTRACE_GETREGS, or caused a struct layout or
size regression observable through ptrace. The field is purely
kernel-internal and must not be exposed beyond the user_pt_regs
boundary.
Move exit_flags into struct thread_info where it is only accessible to
the kernel, and keep it out of the ptrace-visible register window
entirely.
Fixes: d7a6797e0bc1 ("powerpc: add exit_flags field in pt_regs")
Reported-by: Dmitry V. Levin <ldv@strace.io>
Closes: https://lore.kernel.org/all/20260722070155.GA11808@strace.io/
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260723194809.4046600-1-mkchauras@gmail.com
|
|
On PowerMac G5 (PPC970, CONFIG_PPC_970_NAP) the system panics shortly
after boot with symptoms including instruction fetch faults, kernel data
access faults, and stack corruption, predominantly on SMP and always
somewhere inside softirq processing.
The PPC970 idle path works by setting _TLF_NAPPING in the current
thread's local flags before entering the MSR_POW nap loop. When any
async interrupt wakes the CPU, nap_adjust_return() is expected to detect
_TLF_NAPPING, clear it, and rewrite regs->NIP to power4_idle_nap_return
so that the interrupt returns cleanly to the caller of power4_idle_nap()
rather than back into the nap spin loop.
DEFINE_INTERRUPT_HANDLER_ASYNC generates the following sequence:
irq_enter_rcu();
____func(regs); /* timer_interrupt / do_IRQ body */
irq_exit_rcu(); /* softirqs run here, irqs re-enabled */
arch_interrupt_async_exit_prepare(regs); /* nap_adjust_return was here */
irqentry_exit(regs, state);
irq_exit_rcu() calls invoke_softirq() -> do_softirq_own_stack(), which
runs softirqs with hardware interrupts re-enabled. A nested async
interrupt can therefore arrive while _TLF_NAPPING is still set. That
nested interrupt reaches nap_adjust_return() in its own
arch_interrupt_async_exit_prepare() call, finds _TLF_NAPPING set, and
redirects *its own* regs->NIP to power4_idle_nap_return. Returning via
that blr with an unrelated LR on the softirq stack jumps to a garbage
address, causing the observed crashes.
The comment that previously lived in arch_interrupt_async_exit_prepare()
even described this exact hazard ("must come before irq_exit()"), but
nap_adjust_return() was placed after irq_exit_rcu() in the macro, so
the protection was never effective.
Fix this by calling nap_adjust_return() inside DEFINE_INTERRUPT_HANDLER_ASYNC
immediately before irq_exit_rcu(), ensuring _TLF_NAPPING is cleared and
regs->NIP is adjusted before any code that can re-enable interrupts or
invoke softirqs runs. Move the explanatory comment into
nap_adjust_return() itself and remove it from arch_interrupt_async_exit_prepare().
Fixes: bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY feature")
Closes: https://lore.kernel.org/all/87wlvazrdy.fsf@igel.home/
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Tested-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260707172430.790040-1-mkchauras@gmail.com
|
|
This has been scheduled for removal more than a decade ago and the comments
related to it have been dutifully ignored. The last dependencies are gone.
Remove it along with various now empty asm/timex.h files.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Link: https://patch.msgid.link/20260410120317.910770161@kernel.org
|
|
Since commit 7dadeaa6e851 ("sched: Further restrict the preemption
modes"), powerpc always has CONFIG_PREEMPTION because only
CONFIG_PREEMPT and CONFIG_PREEMPT_LAZY are possible, even in
dynamic preemption mode (see sched_dynamic_mode).
As a consequence, need_irq_preemption() is always true and can be
removed.
And because commit bee25f97ad24 ("powerpc: Enable GENERIC_ENTRY
feature") includes linux/irq-entry-common.h which already declares
sk_dynamic_irqentry_exit_cond_resched static key, asm/preempt.h
becauses useless and can be removed.
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/2bf10a0afffefb6aca44bf2f864cc17471a80e31.1781870889.git.chleroy@kernel.org
|
|
mask_user_address() incorrectly checks for CONFIG_E500 instead of
CONFIG_PPC_E500, causing mask_user_address_isel() to not be used on
E500 hardware. Fix the check to use the correct name.
Fixes: 861574d51bbd ("powerpc/uaccess: Implement masked user access")
Cc: stable@vger.kernel.org # 7.0+
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Fixes: 861574d51bbd ("powerpc/uaccess: Implement masked user access")
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260615233729.29386-1-enelsonmoore@gmail.com
|
|
Currently, only x86 genuinely implements and supports Syscall User Dispatch
(SUD).
Multiple architectures provide a stub arch_syscall_is_vdso_sigreturn()
returning 'false' simply to satisfy GENERIC_ENTRY compilation, which
creates a false impression of feature support.
Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCH to decouple this mechanism
from GENERIC_ENTRY. Select it exclusively on x86 and remove the redundant
stub functions from other architectures.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/20260713035422.582771-1-ruanjinjie@huawei.com
|
|
The crash memory exclude of crashk_res and crashk_cma memory on powerpc
are almost identical to the generic crash_exclude_core_ranges().
By introducing the architecture-specific arch_crash_exclude_mem_range()
function with a default implementation of crash_exclude_mem_range(),
and using crash_exclude_mem_range_guarded as powerpc's separate
implementation, the generic crash_exclude_core_ranges() helper function
can be reused.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Acked-by: Breno leitao <leitao@debian.org>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20260629094746.191843-9-ruanjinjie@huawei.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
|
|
During a memory hot-remove event, the elfcorehdr is rebuilt to exclude
the removed memory. While updating the crash memory ranges for this
operation, the crash memory ranges array can become unsorted. This
happens because remove_mem_range() may split a memory range into two
parts and append the higher-address part as a separate range at the end
of the array.
So far, no issues have been observed due to the unsorted crash memory
ranges. However, this could lead to problems once crash memory range
removal is handled by generic code, as introduced in the upcoming
patches in this series.
Currently, powerpc uses a platform-specific function,
remove_mem_range(), to exclude hot-removed memory from the crash memory
ranges. This function performs the same task as the generic
crash_exclude_mem_range() in crash_core.c. The generic helper also
ensures that the crash memory ranges remain sorted. So remove the
redundant powerpc-specific implementation and instead call
crash_exclude_mem_range_guarded() (which internally calls
crash_exclude_mem_range()) to exclude the hot-removed memory ranges.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baoquan he <bhe@redhat.com>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Cc: linux-kernel@vger.kernel.org
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patch.msgid.link/20260629094746.191843-3-ruanjinjie@huawei.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
|
