[ Upstream commit d262a192d38e527faa5984629aabda2e0d1c4f54 ]
Erhard reported the following KASAN hit while booting his PowerMac G4
with a KASAN-enabled kernel 6.13-rc6:
BUG: KASAN: vmalloc-out-of-bounds in copy_to_kernel_nofault+0xd8/0x1c8
Write of size 8 at addr f1000000 by task chronyd/1293
CPU: 0 UID: 123 PID: 1293 Comm: chronyd Tainted: G W 6.13.0-rc6-PMacG4 #2
Tainted: [W]=WARN
Hardware name: PowerMac3,6 7455 0x80010303 PowerMac
Call Trace:
[c2437590] [c1631a84] dump_stack_lvl+0x70/0x8c (unreliable)
[c24375b0] [c0504998] print_report+0xdc/0x504
[c2437610] [c050475c] kasan_report+0xf8/0x108
[c2437690] [c0505a3c] kasan_check_range+0x24/0x18c
[c24376a0] [c03fb5e4] copy_to_kernel_nofault+0xd8/0x1c8
[c24376c0] [c004c014] patch_instructions+0x15c/0x16c
[c2437710] [c00731a8] bpf_arch_text_copy+0x60/0x7c
[c2437730] [c0281168] bpf_jit_binary_pack_finalize+0x50/0xac
[c2437750] [c0073cf4] bpf_int_jit_compile+0xb30/0xdec
[c2437880] [c0280394] bpf_prog_select_runtime+0x15c/0x478
[c24378d0] [c1263428] bpf_prepare_filter+0xbf8/0xc14
[c2437990] [c12677ec] bpf_prog_create_from_user+0x258/0x2b4
[c24379d0] [c027111c] do_seccomp+0x3dc/0x1890
[c2437ac0] [c001d8e0] system_call_exception+0x2dc/0x420
[c2437f30] [c00281ac] ret_from_syscall+0x0/0x2c
--- interrupt: c00 at 0x5a1274
NIP: 005a1274 LR: 006a3b3c CTR: 005296c8
REGS: c2437f40 TRAP: 0c00 Tainted: G W (6.13.0-rc6-PMacG4)
MSR: 0200f932 <VEC,EE,PR,FP,ME,IR,DR,RI> CR: 24004422 XER: 00000000
GPR00: 00000166 af8f3fa0 a7ee3540 00000001 00000000 013b6500 005a5858 0200f932
GPR08: 00000000 00001fe9 013d5fc8 005296c8 2822244c 00b2fcd8 00000000 af8f4b57
GPR16: 00000000 00000001 00000000 00000000 00000000 00000001 00000000 00000002
GPR24: 00afdbb0 00000000 00000000 00000000 006e0004 013ce060 006e7c1c 00000001
NIP [005a1274] 0x5a1274
LR [006a3b3c] 0x6a3b3c
--- interrupt: c00
The buggy address belongs to the virtual mapping at
[f1000000, f1002000) created by:
text_area_cpu_up+0x20/0x190
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x76e30
flags: 0x80000000(zone=2)
raw: 80000000 00000000 00000122 00000000 00000000 00000000 ffffffff 00000001
raw: 00000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
f0ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>f1000000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
^
f1000080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
f1000100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================
f8 corresponds to KASAN_VMALLOC_INVALID which means the area is not
initialised hence not supposed to be used yet.
Powerpc text patching infrastructure allocates a virtual memory area
using get_vm_area() and flags it as VM_ALLOC. But that flag is meant
to be used for vmalloc() and vmalloc() allocated memory is not
supposed to be used before a call to __vmalloc_node_range() which is
never called for that area.
That went undetected until commit e4137f08816b ("mm, kasan, kmsan:
instrument copy_from/to_kernel_nofault")
The area allocated by text_area_cpu_up() is not vmalloc memory, it is
mapped directly on demand when needed by map_kernel_page(). There is
no VM flag corresponding to such usage, so just pass no flag. That way
the area will be unpoisonned and usable immediately.
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Closes: https://lore.kernel.org/all/20250112135832.57c92322@yea/
Fixes: 37bc3e5fd764 ("powerpc/lib/code-patching: Use alternate map for patch_instruction()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/06621423da339b374f48c0886e3a5db18e896be8.1739342693.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dc9c5166c3cb044f8a001e397195242fd6796eee ]
Erhard reports the following KASAN hit on Talos II (power9) with kernel 6.13:
[ 12.028126] ==================================================================
[ 12.028198] BUG: KASAN: user-memory-access in copy_to_kernel_nofault+0x8c/0x1a0
[ 12.028260] Write of size 8 at addr 0000187e458f2000 by task systemd/1
[ 12.028346] CPU: 87 UID: 0 PID: 1 Comm: systemd Tainted: G T 6.13.0-P9-dirty #3
[ 12.028408] Tainted: [T]=RANDSTRUCT
[ 12.028446] Hardware name: T2P9D01 REV 1.01 POWER9 0x4e1202 opal:skiboot-bc106a0 PowerNV
[ 12.028500] Call Trace:
[ 12.028536] [c000000008dbf3b0] [c000000001656a48] dump_stack_lvl+0xbc/0x110 (unreliable)
[ 12.028609] [c000000008dbf3f0] [c0000000006e2fc8] print_report+0x6b0/0x708
[ 12.028666] [c000000008dbf4e0] [c0000000006e2454] kasan_report+0x164/0x300
[ 12.028725] [c000000008dbf600] [c0000000006e54d4] kasan_check_range+0x314/0x370
[ 12.028784] [c000000008dbf640] [c0000000006e6310] __kasan_check_write+0x20/0x40
[ 12.028842] [c000000008dbf660] [c000000000578e8c] copy_to_kernel_nofault+0x8c/0x1a0
[ 12.028902] [c000000008dbf6a0] [c0000000000acfe4] __patch_instructions+0x194/0x210
[ 12.028965] [c000000008dbf6e0] [c0000000000ade80] patch_instructions+0x150/0x590
[ 12.029026] [c000000008dbf7c0] [c0000000001159bc] bpf_arch_text_copy+0x6c/0xe0
[ 12.029085] [c000000008dbf800] [c000000000424250] bpf_jit_binary_pack_finalize+0x40/0xc0
[ 12.029147] [c000000008dbf830] [c000000000115dec] bpf_int_jit_compile+0x3bc/0x930
[ 12.029206] [c000000008dbf990] [c000000000423720] bpf_prog_select_runtime+0x1f0/0x280
[ 12.029266] [c000000008dbfa00] [c000000000434b18] bpf_prog_load+0xbb8/0x1370
[ 12.029324] [c000000008dbfb70] [c000000000436ebc] __sys_bpf+0x5ac/0x2e00
[ 12.029379] [c000000008dbfd00] [c00000000043a228] sys_bpf+0x28/0x40
[ 12.029435] [c000000008dbfd20] [c000000000038eb4] system_call_exception+0x334/0x610
[ 12.029497] [c000000008dbfe50] [c00000000000c270] system_call_vectored_common+0xf0/0x280
[ 12.029561] --- interrupt: 3000 at 0x3fff82f5cfa8
[ 12.029608] NIP: 00003fff82f5cfa8 LR: 00003fff82f5cfa8 CTR: 0000000000000000
[ 12.029660] REGS: c000000008dbfe80 TRAP: 3000 Tainted: G T (6.13.0-P9-dirty)
[ 12.029735] MSR: 900000000280f032 <SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI> CR: 42004848 XER: 00000000
[ 12.029855] IRQMASK: 0
GPR00: 0000000000000169 00003fffdcf789a0 00003fff83067100 0000000000000005
GPR04: 00003fffdcf78a98 0000000000000090 0000000000000000 0000000000000008
GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000000000 00003fff836ff7e0 c000000000010678 0000000000000000
GPR16: 0000000000000000 0000000000000000 00003fffdcf78f28 00003fffdcf78f90
GPR20: 0000000000000000 0000000000000000 0000000000000000 00003fffdcf78f80
GPR24: 00003fffdcf78f70 00003fffdcf78d10 00003fff835c7239 00003fffdcf78bd8
GPR28: 00003fffdcf78a98 0000000000000000 0000000000000000 000000011f547580
[ 12.030316] NIP [00003fff82f5cfa8] 0x3fff82f5cfa8
[ 12.030361] LR [00003fff82f5cfa8] 0x3fff82f5cfa8
[ 12.030405] --- interrupt: 3000
[ 12.030444] ==================================================================
Commit c28c15b6d28a ("powerpc/code-patching: Use temporary mm for
Radix MMU") is inspired from x86 but unlike x86 is doesn't disable
KASAN reports during patching. This wasn't a problem at the begining
because __patch_mem() is not instrumented.
Commit 465cabc97b42 ("powerpc/code-patching: introduce
patch_instructions()") use copy_to_kernel_nofault() to copy several
instructions at once. But when using temporary mm the destination is
not regular kernel memory but a kind of kernel-like memory located
in user address space. Because it is not in kernel address space it is
not covered by KASAN shadow memory. Since commit e4137f08816b ("mm,
kasan, kmsan: instrument copy_from/to_kernel_nofault") KASAN reports
bad accesses from copy_to_kernel_nofault(). Here a bad access to user
memory is reported because KASAN detects the lack of shadow memory and
the address is below TASK_SIZE.
Do like x86 in commit b3fd8e83ada0 ("x86/alternatives: Use temporary
mm for text poking") and disable KASAN reports during patching when
using temporary mm.
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Close: https://lore.kernel.org/all/20250201151435.48400261@yea/
Fixes: 465cabc97b42 ("powerpc/code-patching: introduce patch_instructions()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/1c05b2a1b02ad75b981cfc45927e0b4a90441046.1738577687.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
Pull powerpc updates from Michael Ellerman: - Rework kfence support for the HPT MMU to work on systems with >= 16TB of RAM. - Remove the powerpc "maple" platform, used by the "Yellow Dog Powerstation". - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS, DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines. - Add support for running KVM nested guests on Power11. - Other small features, cleanups and fixes. Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard, Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek, Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao, Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash, Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum, Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao. * tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits) EDAC/powerpc: Remove PPC_MAPLE drivers powerpc/perf: Add per-task/process monitoring to vpa_pmu driver powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu powerpc/perf: Add perf interface to expose vpa counters MAINTAINERS: powerpc: Mark Maddy as "M" powerpc/Makefile: Allow overriding CPP powerpc-km82xx.c: replace of_node_put() with __free ps3: Correct some typos in comments powerpc/kexec: Fix return of uninitialized variable macintosh: Use common error handling code in via_pmu_led_init() powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type() powerpc: remove dead config options for MPC85xx platform support powerpc/xive: Use cpumask_intersects() selftests/powerpc: Remove the path after initialization. powerpc/xmon: symbol lookup length fixed powerpc/ep8248e: Use %pa to format resource_size_t powerpc/ps3: Reorganize kerneldoc parameter names KVM: PPC: Book3S HV: Fix kmv -> kvm typo powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static ...
These functions are not used outside of sstep.c
Fixes: 350779a29f11 ("powerpc: Handle most loads and stores in instruction emulation code")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241001130356.14664-1-msuchanek@suse.de
Several architectures support text patching, but they name the header files that declare patching functions differently. Make all such headers consistently named text-patching.h and add an empty header in asm-generic for architectures that do not support text patching. Link: https://lkml.kernel.org/r/20241023162711.2579610-4-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Tested-by: kdevops <kdevops@lists.linux.dev> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Song Liu <song@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
crtsavres.S content is encloded by a #ifndef CONFIG_PPC64
To be used on VDSO32 on PPC64 it's content must available on PPC64 as
well.
Replace #ifndef CONFIG_PPC64 by #ifndef __powerpc64__ as __powerpc64__
is not set when building VDSO32 on PPC64.
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Closes: https://lore.kernel.org/linuxppc-dev/047b7503-af0c-4bb0-b12a-2f6b1e461752@csgroup.eu/T/
Fixes: b163596a5b6f ("powerpc/vdso32: Add crtsavres")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/aded2b257018fe654db759fdfa4ab1a0b5426b1b.1726772140.git.christophe.leroy@csgroup.eu
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 ...
If an interrupt occurs in queued_spin_lock_slowpath() after we increment
qnodesp->count and before node->lock is initialized, another CPU might
see stale lock values in get_tail_qnode(). If the stale lock value happens
to match the lock on that CPU, then we write to the "next" pointer of
the wrong qnode. This causes a deadlock as the former CPU, once it becomes
the head of the MCS queue, will spin indefinitely until it's "next" pointer
is set by its successor in the queue.
Running stress-ng on a 16 core (16EC/16VP) shared LPAR, results in
occasional lockups similar to the following:
$ stress-ng --all 128 --vm-bytes 80% --aggressive \
--maximize --oomable --verify --syslog \
--metrics --times --timeout 5m
watchdog: CPU 15 Hard LOCKUP
......
NIP [c0000000000b78f4] queued_spin_lock_slowpath+0x1184/0x1490
LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90
Call Trace:
0xc000002cfffa3bf0 (unreliable)
_raw_spin_lock+0x6c/0x90
raw_spin_rq_lock_nested.part.135+0x4c/0xd0
sched_ttwu_pending+0x60/0x1f0
__flush_smp_call_function_queue+0x1dc/0x670
smp_ipi_demux_relaxed+0xa4/0x100
xive_muxed_ipi_action+0x20/0x40
__handle_irq_event_percpu+0x80/0x240
handle_irq_event_percpu+0x2c/0x80
handle_percpu_irq+0x84/0xd0
generic_handle_irq+0x54/0x80
__do_irq+0xac/0x210
__do_IRQ+0x74/0xd0
0x0
do_IRQ+0x8c/0x170
hardware_interrupt_common_virt+0x29c/0x2a0
--- interrupt: 500 at queued_spin_lock_slowpath+0x4b8/0x1490
......
NIP [c0000000000b6c28] queued_spin_lock_slowpath+0x4b8/0x1490
LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90
--- interrupt: 500
0xc0000029c1a41d00 (unreliable)
_raw_spin_lock+0x6c/0x90
futex_wake+0x100/0x260
do_futex+0x21c/0x2a0
sys_futex+0x98/0x270
system_call_exception+0x14c/0x2f0
system_call_vectored_common+0x15c/0x2ec
The following code flow illustrates how the deadlock occurs.
For the sake of brevity, assume that both locks (A and B) are
contended and we call the queued_spin_lock_slowpath() function.
CPU0 CPU1
---- ----
spin_lock_irqsave(A) |
spin_unlock_irqrestore(A) |
spin_lock(B) |
| |
▼ |
id = qnodesp->count++; |
(Note that nodes[0].lock == A) |
| |
▼ |
Interrupt |
(happens before "nodes[0].lock = B") |
| |
▼ |
spin_lock_irqsave(A) |
| |
▼ |
id = qnodesp->count++ |
nodes[1].lock = A |
| |
▼ |
Tail of MCS queue |
| spin_lock_irqsave(A)
▼ |
Head of MCS queue ▼
| CPU0 is previous tail
▼ |
Spin indefinitely ▼
(until "nodes[1].next != NULL") prev = get_tail_qnode(A, CPU0)
|
▼
prev == &qnodes[CPU0].nodes[0]
(as qnodes[CPU0].nodes[0].lock == A)
|
▼
WRITE_ONCE(prev->next, node)
|
▼
Spin indefinitely
(until nodes[0].locked == 1)
Thanks to Saket Kumar Bhaskar for help with recreating the issue
Fixes: 84990b169557 ("powerpc/qspinlock: add mcs queueing for contended waiters")
Cc: stable@vger.kernel.org # v6.2+
Reported-by: Geetika Moolchandani <geetika@linux.ibm.com>
Reported-by: Vaishnavi Bhat <vaish123@in.ibm.com>
Reported-by: Jijo Varghese <vargjijo@in.ibm.com>
Signed-off-by: Nysal Jan K.A. <nysal@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240829022830.1164355-1-nysal@linux.ibm.com
Extend the code patching selftests with some basic coverage of the new data patching variants too. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240515024445.236364-6-bgray@linux.ibm.com
The new data patching still needs to be aligned within a cacheline too for the flushes to work correctly. To simplify this requirement, we just say data patches must be aligned. Detect when data patching is not aligned, returning an invalid argument error. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> Acked-by: Naveen N Rao <naveen@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240515024445.236364-3-bgray@linux.ibm.com