<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/arch/arm64/include/asm/exception.h, branch linux-6.7.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-6.7.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-6.7.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2023-06-23T17:32:20Z</updated>
<entry>
<title>Merge branches 'for-next/kpti', 'for-next/missing-proto-warn', 'for-next/iss2-decode', 'for-next/kselftest', 'for-next/misc', 'for-next/feat_mops', 'for-next/module-alloc', 'for-next/sysreg', 'for-next/cpucap', 'for-next/acpi', 'for-next/kdump', 'for-next/acpi-doc', 'for-next/doc' and 'for-next/tpidr2-fix', remote-tracking branch 'arm64/for-next/perf' into for-next/core</title>
<updated>2023-06-23T17:32:20Z</updated>
<author>
<name>Catalin Marinas</name>
</author>
<published>2023-06-23T17:32:20Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=f42039d10b0f1d0075568df1d64df31f5cc90e92'/>
<id>urn:sha1:f42039d10b0f1d0075568df1d64df31f5cc90e92</id>
<content type='text'>
* arm64/for-next/perf:
  docs: perf: Fix warning from 'make htmldocs' in hisi-pmu.rst
  docs: perf: Add new description for HiSilicon UC PMU
  drivers/perf: hisi: Add support for HiSilicon UC PMU driver
  drivers/perf: hisi: Add support for HiSilicon H60PA and PAv3 PMU driver
  perf: arm_cspmu: Add missing MODULE_DEVICE_TABLE
  perf/arm-cmn: Add sysfs identifier
  perf/arm-cmn: Revamp model detection
  perf/arm_dmc620: Add cpumask
  dt-bindings: perf: fsl-imx-ddr: Add i.MX93 compatible
  drivers/perf: imx_ddr: Add support for NXP i.MX9 SoC DDRC PMU driver
  perf/arm_cspmu: Decouple APMT dependency
  perf/arm_cspmu: Clean up ACPI dependency
  ACPI/APMT: Don't register invalid resource
  perf/arm_cspmu: Fix event attribute type
  perf: arm_cspmu: Set irq affinitiy only if overflow interrupt is used
  drivers/perf: hisi: Don't migrate perf to the CPU going to teardown
  drivers/perf: apple_m1: Force 63bit counters for M2 CPUs
  perf/arm-cmn: Fix DTC reset
  perf: qcom_l2_pmu: Make l2_cache_pmu_probe_cluster() more robust
  perf/arm-cci: Slightly optimize cci_pmu_sync_counters()

* for-next/kpti:
  : Simplify KPTI trampoline exit code
  arm64: entry: Simplify tramp_alias macro and tramp_exit routine
  arm64: entry: Preserve/restore X29 even for compat tasks

* for-next/missing-proto-warn:
  : Address -Wmissing-prototype warnings
  arm64: add alt_cb_patch_nops prototype
  arm64: move early_brk64 prototype to header
  arm64: signal: include asm/exception.h
  arm64: kaslr: add kaslr_early_init() declaration
  arm64: flush: include linux/libnvdimm.h
  arm64: module-plts: inline linux/moduleloader.h
  arm64: hide unused is_valid_bugaddr()
  arm64: efi: add efi_handle_corrupted_x18 prototype
  arm64: cpuidle: fix #ifdef for acpi functions
  arm64: kvm: add prototypes for functions called in asm
  arm64: spectre: provide prototypes for internal functions
  arm64: move cpu_suspend_set_dbg_restorer() prototype to header
  arm64: avoid prototype warnings for syscalls
  arm64: add scs_patch_vmlinux prototype
  arm64: xor-neon: mark xor_arm64_neon_*() static

* for-next/iss2-decode:
  : Add decode of ISS2 to data abort reports
  arm64/esr: Add decode of ISS2 to data abort reporting
  arm64/esr: Use GENMASK() for the ISS mask

* for-next/kselftest:
  : Various arm64 kselftest improvements
  kselftest/arm64: Log signal code and address for unexpected signals
  kselftest/arm64: Add a smoke test for ptracing hardware break/watch points

* for-next/misc:
  : Miscellaneous patches
  arm64: alternatives: make clean_dcache_range_nopatch() noinstr-safe
  arm64: hibernate: remove WARN_ON in save_processor_state
  arm64/fpsimd: Exit streaming mode when flushing tasks
  arm64: mm: fix VA-range sanity check
  arm64/mm: remove now-superfluous ISBs from TTBR writes
  arm64: consolidate rox page protection logic
  arm64: set __exception_irq_entry with __irq_entry as a default
  arm64: syscall: unmask DAIF for tracing status
  arm64: lockdep: enable checks for held locks when returning to userspace
  arm64/cpucaps: increase string width to properly format cpucaps.h
  arm64/cpufeature: Use helper for ECV CNTPOFF cpufeature

* for-next/feat_mops:
  : Support for ARMv8.8 memcpy instructions in userspace
  kselftest/arm64: add MOPS to hwcap test
  arm64: mops: allow disabling MOPS from the kernel command line
  arm64: mops: detect and enable FEAT_MOPS
  arm64: mops: handle single stepping after MOPS exception
  arm64: mops: handle MOPS exceptions
  KVM: arm64: hide MOPS from guests
  arm64: mops: don't disable host MOPS instructions from EL2
  arm64: mops: document boot requirements for MOPS
  KVM: arm64: switch HCRX_EL2 between host and guest
  arm64: cpufeature: detect FEAT_HCX
  KVM: arm64: initialize HCRX_EL2

* for-next/module-alloc:
  : Make the arm64 module allocation code more robust (clean-up, VA range expansion)
  arm64: module: rework module VA range selection
  arm64: module: mandate MODULE_PLTS
  arm64: module: move module randomization to module.c
  arm64: kaslr: split kaslr/module initialization
  arm64: kasan: remove !KASAN_VMALLOC remnants
  arm64: module: remove old !KASAN_VMALLOC logic

* for-next/sysreg: (21 commits)
  : More sysreg conversions to automatic generation
  arm64/sysreg: Convert TRBIDR_EL1 register to automatic generation
  arm64/sysreg: Convert TRBTRG_EL1 register to automatic generation
  arm64/sysreg: Convert TRBMAR_EL1 register to automatic generation
  arm64/sysreg: Convert TRBSR_EL1 register to automatic generation
  arm64/sysreg: Convert TRBBASER_EL1 register to automatic generation
  arm64/sysreg: Convert TRBPTR_EL1 register to automatic generation
  arm64/sysreg: Convert TRBLIMITR_EL1 register to automatic generation
  arm64/sysreg: Rename TRBIDR_EL1 fields per auto-gen tools format
  arm64/sysreg: Rename TRBTRG_EL1 fields per auto-gen tools format
  arm64/sysreg: Rename TRBMAR_EL1 fields per auto-gen tools format
  arm64/sysreg: Rename TRBSR_EL1 fields per auto-gen tools format
  arm64/sysreg: Rename TRBBASER_EL1 fields per auto-gen tools format
  arm64/sysreg: Rename TRBPTR_EL1 fields per auto-gen tools format
  arm64/sysreg: Rename TRBLIMITR_EL1 fields per auto-gen tools format
  arm64/sysreg: Convert OSECCR_EL1 to automatic generation
  arm64/sysreg: Convert OSDTRTX_EL1 to automatic generation
  arm64/sysreg: Convert OSDTRRX_EL1 to automatic generation
  arm64/sysreg: Convert OSLAR_EL1 to automatic generation
  arm64/sysreg: Standardise naming of bitfield constants in OSL[AS]R_EL1
  arm64/sysreg: Convert MDSCR_EL1 to automatic register generation
  ...

* for-next/cpucap:
  : arm64 cpucap clean-up
  arm64: cpufeature: fold cpus_set_cap() into update_cpu_capabilities()
  arm64: cpufeature: use cpucap naming
  arm64: alternatives: use cpucap naming
  arm64: standardise cpucap bitmap names

* for-next/acpi:
  : Various arm64-related ACPI patches
  ACPI: bus: Consolidate all arm specific initialisation into acpi_arm_init()

* for-next/kdump:
  : Simplify the crashkernel reservation behaviour of crashkernel=X,high on arm64
  arm64: add kdump.rst into index.rst
  Documentation: add kdump.rst to present crashkernel reservation on arm64
  arm64: kdump: simplify the reservation behaviour of crashkernel=,high

* for-next/acpi-doc:
  : Update ACPI documentation for Arm systems
  Documentation/arm64: Update ACPI tables from BBR
  Documentation/arm64: Update references in arm-acpi
  Documentation/arm64: Update ARM and arch reference

* for-next/doc:
  : arm64 documentation updates
  Documentation/arm64: Add ptdump documentation

* for-next/tpidr2-fix:
  : Fix the TPIDR2_EL0 register restoring on sigreturn
  kselftest/arm64: Add a test case for TPIDR2 restore
  arm64/signal: Restore TPIDR2 register rather than memory state
</content>
</entry>
<entry>
<title>arm64: set __exception_irq_entry with __irq_entry as a default</title>
<updated>2023-06-08T17:27:14Z</updated>
<author>
<name>Youngmin Nam</name>
</author>
<published>2023-04-24T01:04:36Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=f6794950f0e5ba37e3bbedda4d6ab0aad7395dd3'/>
<id>urn:sha1:f6794950f0e5ba37e3bbedda4d6ab0aad7395dd3</id>
<content type='text'>
filter_irq_stacks() is supposed to cut entries which are related irq entries
from its call stack.
And in_irqentry_text() which is called by filter_irq_stacks()
uses __irqentry_text_start/end symbol to find irq entries in callstack.

But it doesn't work correctly as without "CONFIG_FUNCTION_GRAPH_TRACER",
arm64 kernel doesn't include gic_handle_irq which is entry point of arm64 irq
between __irqentry_text_start and __irqentry_text_end as we discussed in below link.
https://lore.kernel.org/all/CACT4Y+aReMGLYua2rCLHgFpS9io5cZC04Q8GLs-uNmrn1ezxYQ@mail.gmail.com/#t

This problem can makes unintentional deep call stack entries especially
in KASAN enabled situation as below.

[ 2479.383395]I[0:launcher-loader: 1719] Stack depot reached limit capacity
[ 2479.383538]I[0:launcher-loader: 1719] WARNING: CPU: 0 PID: 1719 at lib/stackdepot.c:129 __stack_depot_save+0x464/0x46c
[ 2479.385693]I[0:launcher-loader: 1719] pstate: 624000c5 (nZCv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
[ 2479.385724]I[0:launcher-loader: 1719] pc : __stack_depot_save+0x464/0x46c
[ 2479.385751]I[0:launcher-loader: 1719] lr : __stack_depot_save+0x460/0x46c
[ 2479.385774]I[0:launcher-loader: 1719] sp : ffffffc0080073c0
[ 2479.385793]I[0:launcher-loader: 1719] x29: ffffffc0080073e0 x28: ffffffd00b78a000 x27: 0000000000000000
[ 2479.385839]I[0:launcher-loader: 1719] x26: 000000000004d1dd x25: ffffff891474f000 x24: 00000000ca64d1dd
[ 2479.385882]I[0:launcher-loader: 1719] x23: 0000000000000200 x22: 0000000000000220 x21: 0000000000000040
[ 2479.385925]I[0:launcher-loader: 1719] x20: ffffffc008007440 x19: 0000000000000000 x18: 0000000000000000
[ 2479.385969]I[0:launcher-loader: 1719] x17: 2065726568207475 x16: 000000000000005e x15: 2d2d2d2d2d2d2d20
[ 2479.386013]I[0:launcher-loader: 1719] x14: 5d39313731203a72 x13: 00000000002f6b30 x12: 00000000002f6af8
[ 2479.386057]I[0:launcher-loader: 1719] x11: 00000000ffffffff x10: ffffffb90aacf000 x9 : e8a74a6c16008800
[ 2479.386101]I[0:launcher-loader: 1719] x8 : e8a74a6c16008800 x7 : 00000000002f6b30 x6 : 00000000002f6af8
[ 2479.386145]I[0:launcher-loader: 1719] x5 : ffffffc0080070c8 x4 : ffffffd00b192380 x3 : ffffffd0092b313c
[ 2479.386189]I[0:launcher-loader: 1719] x2 : 0000000000000001 x1 : 0000000000000004 x0 : 0000000000000022
[ 2479.386231]I[0:launcher-loader: 1719] Call trace:
[ 2479.386248]I[0:launcher-loader: 1719]  __stack_depot_save+0x464/0x46c
[ 2479.386273]I[0:launcher-loader: 1719]  kasan_save_stack+0x58/0x70
[ 2479.386303]I[0:launcher-loader: 1719]  save_stack_info+0x34/0x138
[ 2479.386331]I[0:launcher-loader: 1719]  kasan_save_free_info+0x18/0x24
[ 2479.386358]I[0:launcher-loader: 1719]  ____kasan_slab_free+0x16c/0x170
[ 2479.386385]I[0:launcher-loader: 1719]  __kasan_slab_free+0x10/0x20
[ 2479.386410]I[0:launcher-loader: 1719]  kmem_cache_free+0x238/0x53c
[ 2479.386435]I[0:launcher-loader: 1719]  mempool_free_slab+0x1c/0x28
[ 2479.386460]I[0:launcher-loader: 1719]  mempool_free+0x7c/0x1a0
[ 2479.386484]I[0:launcher-loader: 1719]  bvec_free+0x34/0x80
[ 2479.386514]I[0:launcher-loader: 1719]  bio_free+0x60/0x98
[ 2479.386540]I[0:launcher-loader: 1719]  bio_put+0x50/0x21c
[ 2479.386567]I[0:launcher-loader: 1719]  f2fs_write_end_io+0x4ac/0x4d0
[ 2479.386594]I[0:launcher-loader: 1719]  bio_endio+0x2dc/0x300
[ 2479.386622]I[0:launcher-loader: 1719]  __dm_io_complete+0x324/0x37c
[ 2479.386650]I[0:launcher-loader: 1719]  dm_io_dec_pending+0x60/0xa4
[ 2479.386676]I[0:launcher-loader: 1719]  clone_endio+0xf8/0x2f0
[ 2479.386700]I[0:launcher-loader: 1719]  bio_endio+0x2dc/0x300
[ 2479.386727]I[0:launcher-loader: 1719]  blk_update_request+0x258/0x63c
[ 2479.386754]I[0:launcher-loader: 1719]  scsi_end_request+0x50/0x304
[ 2479.386782]I[0:launcher-loader: 1719]  scsi_io_completion+0x88/0x160
[ 2479.386808]I[0:launcher-loader: 1719]  scsi_finish_command+0x17c/0x194
[ 2479.386833]I[0:launcher-loader: 1719]  scsi_complete+0xcc/0x158
[ 2479.386859]I[0:launcher-loader: 1719]  blk_mq_complete_request+0x4c/0x5c
[ 2479.386885]I[0:launcher-loader: 1719]  scsi_done_internal+0xf4/0x1e0
[ 2479.386910]I[0:launcher-loader: 1719]  scsi_done+0x14/0x20
[ 2479.386935]I[0:launcher-loader: 1719]  ufshcd_compl_one_cqe+0x578/0x71c
[ 2479.386963]I[0:launcher-loader: 1719]  ufshcd_mcq_poll_cqe_nolock+0xc8/0x150
[ 2479.386991]I[0:launcher-loader: 1719]  ufshcd_intr+0x868/0xc0c
[ 2479.387017]I[0:launcher-loader: 1719]  __handle_irq_event_percpu+0xd0/0x348
[ 2479.387044]I[0:launcher-loader: 1719]  handle_irq_event_percpu+0x24/0x74
[ 2479.387068]I[0:launcher-loader: 1719]  handle_irq_event+0x74/0xe0
[ 2479.387091]I[0:launcher-loader: 1719]  handle_fasteoi_irq+0x174/0x240
[ 2479.387118]I[0:launcher-loader: 1719]  handle_irq_desc+0x7c/0x2c0
[ 2479.387147]I[0:launcher-loader: 1719]  generic_handle_domain_irq+0x1c/0x28
[ 2479.387174]I[0:launcher-loader: 1719]  gic_handle_irq+0x64/0x158
[ 2479.387204]I[0:launcher-loader: 1719]  call_on_irq_stack+0x2c/0x54
[ 2479.387231]I[0:launcher-loader: 1719]  do_interrupt_handler+0x70/0xa0
[ 2479.387258]I[0:launcher-loader: 1719]  el1_interrupt+0x34/0x68
[ 2479.387283]I[0:launcher-loader: 1719]  el1h_64_irq_handler+0x18/0x24
[ 2479.387308]I[0:launcher-loader: 1719]  el1h_64_irq+0x68/0x6c
[ 2479.387332]I[0:launcher-loader: 1719]  blk_attempt_bio_merge+0x8/0x170
[ 2479.387356]I[0:launcher-loader: 1719]  blk_mq_attempt_bio_merge+0x78/0x98
[ 2479.387383]I[0:launcher-loader: 1719]  blk_mq_submit_bio+0x324/0xa40
[ 2479.387409]I[0:launcher-loader: 1719]  __submit_bio+0x104/0x138
[ 2479.387436]I[0:launcher-loader: 1719]  submit_bio_noacct_nocheck+0x1d0/0x4a0
[ 2479.387462]I[0:launcher-loader: 1719]  submit_bio_noacct+0x618/0x804
[ 2479.387487]I[0:launcher-loader: 1719]  submit_bio+0x164/0x180
[ 2479.387511]I[0:launcher-loader: 1719]  f2fs_submit_read_bio+0xe4/0x1c4
[ 2479.387537]I[0:launcher-loader: 1719]  f2fs_mpage_readpages+0x888/0xa4c
[ 2479.387563]I[0:launcher-loader: 1719]  f2fs_readahead+0xd4/0x19c
[ 2479.387587]I[0:launcher-loader: 1719]  read_pages+0xb0/0x4ac
[ 2479.387614]I[0:launcher-loader: 1719]  page_cache_ra_unbounded+0x238/0x288
[ 2479.387642]I[0:launcher-loader: 1719]  do_page_cache_ra+0x60/0x6c
[ 2479.387669]I[0:launcher-loader: 1719]  page_cache_ra_order+0x318/0x364
[ 2479.387695]I[0:launcher-loader: 1719]  ondemand_readahead+0x30c/0x3d8
[ 2479.387722]I[0:launcher-loader: 1719]  page_cache_sync_ra+0xb4/0xc8
[ 2479.387749]I[0:launcher-loader: 1719]  filemap_read+0x268/0xd24
[ 2479.387777]I[0:launcher-loader: 1719]  f2fs_file_read_iter+0x1a0/0x62c
[ 2479.387806]I[0:launcher-loader: 1719]  vfs_read+0x258/0x34c
[ 2479.387831]I[0:launcher-loader: 1719]  ksys_pread64+0x8c/0xd0
[ 2479.387857]I[0:launcher-loader: 1719]  __arm64_sys_pread64+0x48/0x54
[ 2479.387881]I[0:launcher-loader: 1719]  invoke_syscall+0x58/0x158
[ 2479.387909]I[0:launcher-loader: 1719]  el0_svc_common+0xf0/0x134
[ 2479.387935]I[0:launcher-loader: 1719]  do_el0_svc+0x44/0x114
[ 2479.387961]I[0:launcher-loader: 1719]  el0_svc+0x2c/0x80
[ 2479.387985]I[0:launcher-loader: 1719]  el0t_64_sync_handler+0x48/0x114
[ 2479.388010]I[0:launcher-loader: 1719]  el0t_64_sync+0x190/0x194
[ 2479.388038]I[0:launcher-loader: 1719] Kernel panic - not syncing: kernel: panic_on_warn set ...

So let's set __exception_irq_entry with __irq_entry as a default.
Applying this patch, we can see gic_hande_irq is included in Systemp.map as below.

* Before
ffffffc008010000 T __do_softirq
ffffffc008010000 T __irqentry_text_end
ffffffc008010000 T __irqentry_text_start
ffffffc008010000 T __softirqentry_text_start
ffffffc008010000 T _stext
ffffffc00801066c T __softirqentry_text_end
ffffffc008010670 T __entry_text_start

* After
ffffffc008010000 T __irqentry_text_start
ffffffc008010000 T _stext
ffffffc008010000 t gic_handle_irq
ffffffc00801013c t gic_handle_irq
ffffffc008010294 T __irqentry_text_end
ffffffc008010298 T __do_softirq
ffffffc008010298 T __softirqentry_text_start
ffffffc008010904 T __softirqentry_text_end
ffffffc008010908 T __entry_text_start

Signed-off-by: Youngmin Nam &lt;youngmin.nam@samsung.com&gt;
Signed-off-by: SEO HOYOUNG &lt;hy50.seo@samsung.com&gt;
Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Link: https://lore.kernel.org/r/20230424010436.779733-1-youngmin.nam@samsung.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
<entry>
<title>arm64: mops: handle MOPS exceptions</title>
<updated>2023-06-05T16:05:41Z</updated>
<author>
<name>Kristina Martsenko</name>
</author>
<published>2023-05-09T14:22:31Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=8536ceaa747174ded7983f13906b225e0c33ac51'/>
<id>urn:sha1:8536ceaa747174ded7983f13906b225e0c33ac51</id>
<content type='text'>
The memory copy/set instructions added as part of FEAT_MOPS can take an
exception (e.g. page fault) part-way through their execution and resume
execution afterwards.

If however the task is re-scheduled and execution resumes on a different
CPU, then the CPU may take a new type of exception to indicate this.
This is because the architecture allows two options (Option A and Option
B) to implement the instructions and a heterogeneous system can have
different implementations between CPUs.

In this case the OS has to reset the registers and restart execution
from the prologue instruction. The algorithm for doing this is provided
as part of the Arm ARM.

Add an exception handler for the new exception and wire it up for
userspace tasks.

Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Kristina Martsenko &lt;kristina.martsenko@arm.com&gt;
Link: https://lore.kernel.org/r/20230509142235.3284028-8-kristina.martsenko@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
<entry>
<title>arm64/cpu: Mark cpu_park_loop() and friends __noreturn</title>
<updated>2023-04-14T15:31:24Z</updated>
<author>
<name>Josh Poimboeuf</name>
</author>
<published>2023-04-12T23:49:34Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=5ab6876c7843db5fe8bef691c5fdb92518b12070'/>
<id>urn:sha1:5ab6876c7843db5fe8bef691c5fdb92518b12070</id>
<content type='text'>
In preparation for marking panic_smp_self_stop() __noreturn across the
kernel, first mark the arm64 implementation of cpu_park_loop() and
related functions __noreturn.

Signed-off-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/55787d3193ea3e295ccbb097abfab0a10ae49d45.1681342859.git.jpoimboe@kernel.org
</content>
</entry>
<entry>
<title>arm64: split EL0/EL1 UNDEF handlers</title>
<updated>2022-11-15T13:46:17Z</updated>
<author>
<name>Mark Rutland</name>
</author>
<published>2022-10-19T14:41:16Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=61d64a376ea80f9097e7ea599bcd68671b836dc6'/>
<id>urn:sha1:61d64a376ea80f9097e7ea599bcd68671b836dc6</id>
<content type='text'>
In general, exceptions taken from EL1 need to be handled separately from
exceptions taken from EL0, as the logic to handle the two cases can be
significantly divergent, and exceptions taken from EL1 typically have
more stringent requirements on locking and instrumentation.

Subsequent patches will rework the way EL1 UNDEFs are handled in order
to address longstanding soundness issues with instrumentation and RCU.
In preparation for that rework, this patch splits the existing
do_undefinstr() handler into separate do_el0_undef() and do_el1_undef()
handlers.

Prior to this patch, do_undefinstr() was marked with NOKPROBE_SYMBOL(),
preventing instrumentation via kprobes. However, do_undefinstr() invokes
other code which can be instrumented, and:

* For UNDEFINED exceptions taken from EL0, there is no risk of recursion
  within kprobes. Therefore it is safe for do_el0_undef to be
  instrumented with kprobes, and it does not need to be marked with
  NOKPROBE_SYMBOL().

* For UNDEFINED exceptions taken from EL1, either:

  (a) The exception is has been taken when manipulating SSBS; these cases
      are limited and do not occur within code that can be invoked
      recursively via kprobes. Hence, in these cases instrumentation
      with kprobes is benign.

  (b) The exception has been taken for an unknown reason, as other than
      manipulating SSBS we do not expect to take UNDEFINED exceptions
      from EL1. Any handling of these exception is best-effort.

  ... and in either case, marking do_el1_undef() with NOKPROBE_SYMBOL()
  isn't sufficient to prevent recursion via kprobes as functions it
  calls (including die()) are instrumentable via kprobes.

  Hence, it's not worthwhile to mark do_el1_undef() with
  NOKPROBE_SYMBOL(). The same applies to do_el1_bti() and do_el1_fpac(),
  so their NOKPROBE_SYMBOL() annotations are also removed.

Aside from the new instrumentability, there should be no functional
change as a result of this patch.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Joey Gouly &lt;joey.gouly@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20221019144123.612388-3-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
</entry>
<entry>
<title>arm64: allow kprobes on EL0 handlers</title>
<updated>2022-11-15T13:46:17Z</updated>
<author>
<name>Mark Rutland</name>
</author>
<published>2022-10-19T14:41:15Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=b3a0c010e900a9f89dcd99f10bd8f7538d21b0a9'/>
<id>urn:sha1:b3a0c010e900a9f89dcd99f10bd8f7538d21b0a9</id>
<content type='text'>
Currently do_sysinstr() and do_cp15instr() are marked with
NOKPROBE_SYMBOL(). However, these are only called for exceptions taken
from EL0, and there is no risk of recursion in kprobes, so this is not
necessary.

Remove the NOKPROBE_SYMBOL() annotation, and rename the two functions to
more clearly indicate that these are solely for exceptions taken from
EL0, better matching the names used by the lower level entry points in
entry-common.c.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Joey Gouly &lt;joey.gouly@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20221019144123.612388-2-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge branch 'for-next/misc' into for-next/core</title>
<updated>2022-09-30T08:18:26Z</updated>
<author>
<name>Catalin Marinas</name>
</author>
<published>2022-09-30T08:18:26Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=53630a1f6186e9df5fb75e9b55328e22b64de150'/>
<id>urn:sha1:53630a1f6186e9df5fb75e9b55328e22b64de150</id>
<content type='text'>
* for-next/misc:
  : Miscellaneous patches
  arm64/kprobe: Optimize the performance of patching single-step slot
  ARM64: reloc_test: add __init/__exit annotations to module init/exit funcs
  arm64/mm: fold check for KFENCE into can_set_direct_map()
  arm64: uaccess: simplify uaccess_mask_ptr()
  arm64: mte: move register initialization to C
  arm64: mm: handle ARM64_KERNEL_USES_PMD_MAPS in vmemmap_populate()
  arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()
  arm64: support huge vmalloc mappings
  arm64: spectre: increase parameters that can be used to turn off bhb mitigation individually
  arm64: run softirqs on the per-CPU IRQ stack
  arm64: compat: Implement misalignment fixups for multiword loads
</content>
</entry>
<entry>
<title>arm64: rework BTI exception handling</title>
<updated>2022-09-16T11:17:03Z</updated>
<author>
<name>Mark Rutland</name>
</author>
<published>2022-09-13T10:17:32Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=830a2a4d853f2c4a1e4606aa03341b7f273b0e9b'/>
<id>urn:sha1:830a2a4d853f2c4a1e4606aa03341b7f273b0e9b</id>
<content type='text'>
If a BTI exception is taken from EL1, the entry code will treat this as
an unhandled exception and will panic() the kernel. This is inconsistent
with the way we handle FPAC exceptions, which have a dedicated handler
and only necessarily kill the thread from which the exception was taken
from, and we don't log all the information that could be relevant to
debug the issue.

The code in do_bti() has:

	BUG_ON(!user_mode(regs));

... and it seems like the intent was to call this for EL1 BTI
exceptions, as with FPAC, but this was omitted due to an oversight.

This patch adds separate EL0 and EL1 BTI exception handlers, with the
latter calling die() directly to report the original context the BTI
exception was taken from. This matches our handling of FPAC exceptions.

Prior to this patch, a BTI failure is reported as:

| Unhandled 64-bit el1h sync exception on CPU0, ESR 0x0000000034000002 -- BTI
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00131-g7d937ff0221d-dirty #9
| Hardware name: linux,dummy-virt (DT)
| pstate: 20400809 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=-c)
| pc : test_bti_callee+0x4/0x10
| lr : test_bti_caller+0x1c/0x28
| sp : ffff80000800bdf0
| x29: ffff80000800bdf0 x28: 0000000000000000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffff80000a2b8000 x22: 0000000000000000 x21: 0000000000000000
| x20: ffff8000099fa5b0 x19: ffff800009ff7000 x18: fffffbfffda37000
| x17: 3120676e696d7573 x16: 7361202c6e6f6974 x15: 0000000041a90000
| x14: 0040000000000041 x13: 0040000000000001 x12: ffff000001a90000
| x11: fffffbfffda37480 x10: 0068000000000703 x9 : 0001000040000000
| x8 : 0000000000090000 x7 : 0068000000000f03 x6 : 0060000000000f83
| x5 : ffff80000a2b6000 x4 : ffff0000028d0000 x3 : ffff800009f78378
| x2 : 0000000000000000 x1 : 0000000040210000 x0 : ffff8000080257e4
| Kernel panic - not syncing: Unhandled exception
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00131-g7d937ff0221d-dirty #9
| Hardware name: linux,dummy-virt (DT)
| Call trace:
|  dump_backtrace.part.0+0xcc/0xe0
|  show_stack+0x18/0x5c
|  dump_stack_lvl+0x64/0x80
|  dump_stack+0x18/0x34
|  panic+0x170/0x360
|  arm64_exit_nmi.isra.0+0x0/0x80
|  el1h_64_sync_handler+0x64/0xd0
|  el1h_64_sync+0x64/0x68
|  test_bti_callee+0x4/0x10
|  smp_cpus_done+0xb0/0xbc
|  smp_init+0x7c/0x8c
|  kernel_init_freeable+0x128/0x28c
|  kernel_init+0x28/0x13c
|  ret_from_fork+0x10/0x20

With this patch applied, a BTI failure is reported as:

| Internal error: Oops - BTI: 0000000034000002 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00132-g0ad98265d582-dirty #8
| Hardware name: linux,dummy-virt (DT)
| pstate: 20400809 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=-c)
| pc : test_bti_callee+0x4/0x10
| lr : test_bti_caller+0x1c/0x28
| sp : ffff80000800bdf0
| x29: ffff80000800bdf0 x28: 0000000000000000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffff80000a2b8000 x22: 0000000000000000 x21: 0000000000000000
| x20: ffff8000099fa5b0 x19: ffff800009ff7000 x18: fffffbfffda37000
| x17: 3120676e696d7573 x16: 7361202c6e6f6974 x15: 0000000041a90000
| x14: 0040000000000041 x13: 0040000000000001 x12: ffff000001a90000
| x11: fffffbfffda37480 x10: 0068000000000703 x9 : 0001000040000000
| x8 : 0000000000090000 x7 : 0068000000000f03 x6 : 0060000000000f83
| x5 : ffff80000a2b6000 x4 : ffff0000028d0000 x3 : ffff800009f78378
| x2 : 0000000000000000 x1 : 0000000040210000 x0 : ffff800008025804
| Call trace:
|  test_bti_callee+0x4/0x10
|  smp_cpus_done+0xb0/0xbc
|  smp_init+0x7c/0x8c
|  kernel_init_freeable+0x128/0x28c
|  kernel_init+0x28/0x13c
|  ret_from_fork+0x10/0x20
| Code: d50323bf d53cd040 d65f03c0 d503233f (d50323bf)

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Reviewed-by: Mark Brown &lt;broonie@kernel.org&gt;
Reviewed-by: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Cc: Alexandru Elisei &lt;alexandru.elisei@arm.com&gt;
Cc: Amit Daniel Kachhap &lt;amit.kachhap@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20220913101732.3925290-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
<entry>
<title>arm64: rework FPAC exception handling</title>
<updated>2022-09-16T11:17:03Z</updated>
<author>
<name>Mark Rutland</name>
</author>
<published>2022-09-13T10:17:31Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=a1fafa3b24a70461bbf3e5c0770893feb0a49292'/>
<id>urn:sha1:a1fafa3b24a70461bbf3e5c0770893feb0a49292</id>
<content type='text'>
If an FPAC exception is taken from EL1, the entry code will call
do_ptrauth_fault(), where due to:

	BUG_ON(!user_mode(regs))

... the kernel will report a problem within do_ptrauth_fault() rather
than reporting the original context the FPAC exception was taken from.
The pt_regs and ESR value reported will be from within
do_ptrauth_fault() and the code dump will be for the BRK in BUG_ON(),
which isn't sufficient to debug the cause of the original exception.

This patch makes the reporting better by having separate EL0 and EL1
FPAC exception handlers, with the latter calling die() directly to
report the original context the FPAC exception was taken from.

Note that we only need to prevent kprobes of the EL1 FPAC handler, since
the EL0 FPAC handler cannot be called recursively.

For consistency with do_el0_svc*(), I've named the split functions
do_el{0,1}_fpac() rather than do_el{0,1}_ptrauth_fault(). I've also
clarified the comment to not imply there are casues other than FPAC
exceptions.

Prior to this patch FPAC exceptions are reported as:

| kernel BUG at arch/arm64/kernel/traps.c:517!
| Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00130-g9c8a180a1cdf-dirty #12
| Hardware name: FVP Base RevC (DT)
| pstate: 00400009 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : do_ptrauth_fault+0x3c/0x40
| lr : el1_fpac+0x34/0x54
| sp : ffff80000a3bbc80
| x29: ffff80000a3bbc80 x28: ffff0008001d8000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: 0000000020400009 x22: ffff800008f70fa4 x21: ffff80000a3bbe00
| x20: 0000000072000000 x19: ffff80000a3bbcb0 x18: fffffbfffda37000
| x17: 3120676e696d7573 x16: 7361202c6e6f6974 x15: 0000000081a90000
| x14: 0040000000000041 x13: 0040000000000001 x12: ffff000001a90000
| x11: fffffbfffda37480 x10: 0068000000000703 x9 : 0001000080000000
| x8 : 0000000000090000 x7 : 0068000000000f03 x6 : 0060000000000783
| x5 : ffff80000a3bbcb0 x4 : ffff0008001d8000 x3 : 0000000072000000
| x2 : 0000000000000000 x1 : 0000000020400009 x0 : ffff80000a3bbcb0
| Call trace:
|  do_ptrauth_fault+0x3c/0x40
|  el1h_64_sync_handler+0xc4/0xd0
|  el1h_64_sync+0x64/0x68
|  test_pac+0x8/0x10
|  smp_init+0x7c/0x8c
|  kernel_init_freeable+0x128/0x28c
|  kernel_init+0x28/0x13c
|  ret_from_fork+0x10/0x20
| Code: 97fffe5e a8c17bfd d50323bf d65f03c0 (d4210000)

With this patch applied FPAC exceptions are reported as:

| Internal error: Oops - FPAC: 0000000072000000 [#1] PREEMPT SMP
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc3-00132-g78846e1c4757-dirty #11
| Hardware name: FVP Base RevC (DT)
| pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : test_pac+0x8/0x10
| lr : 0x0
| sp : ffff80000a3bbe00
| x29: ffff80000a3bbe00 x28: 0000000000000000 x27: 0000000000000000
| x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffff80000a2c8000 x22: 0000000000000000 x21: 0000000000000000
| x20: ffff8000099fa5b0 x19: ffff80000a007000 x18: fffffbfffda37000
| x17: 3120676e696d7573 x16: 7361202c6e6f6974 x15: 0000000081a90000
| x14: 0040000000000041 x13: 0040000000000001 x12: ffff000001a90000
| x11: fffffbfffda37480 x10: 0068000000000703 x9 : 0001000080000000
| x8 : 0000000000090000 x7 : 0068000000000f03 x6 : 0060000000000783
| x5 : ffff80000a2c6000 x4 : ffff0008001d8000 x3 : ffff800009f88378
| x2 : 0000000000000000 x1 : 0000000080210000 x0 : ffff000001a90000
| Call trace:
|  test_pac+0x8/0x10
|  smp_init+0x7c/0x8c
|  kernel_init_freeable+0x128/0x28c
|  kernel_init+0x28/0x13c
|  ret_from_fork+0x10/0x20
| Code: d50323bf d65f03c0 d503233f aa1f03fe (d50323bf)

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Reviewed-by: Mark Brown &lt;broonie@kernel.org&gt;
Reviewed-by: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Cc: Alexandru Elisei &lt;alexandru.elisei@arm.com&gt;
Cc: Amit Daniel Kachhap &lt;amit.kachhap@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20220913101732.3925290-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
<entry>
<title>arm64: consistently pass ESR_ELx to die()</title>
<updated>2022-09-16T11:17:03Z</updated>
<author>
<name>Mark Rutland</name>
</author>
<published>2022-09-13T10:17:30Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=0f2cb928a1547ae8f89e80a4b8df2c6c02ae5f96'/>
<id>urn:sha1:0f2cb928a1547ae8f89e80a4b8df2c6c02ae5f96</id>
<content type='text'>
Currently, bug_handler() and kasan_handler() call die() with '0' as the
'err' value, whereas die_kernel_fault() passes the ESR_ELx value.

For consistency, this patch ensures we always pass the ESR_ELx value to
die(). As this is only called for exceptions taken from kernel mode,
there should be no user-visible change as a result of this patch.

For UNDEFINED exceptions, I've had to modify do_undefinstr() and its
callers to pass the ESR_ELx value. In all cases the ESR_ELx value had
already been read and was available.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Cc: Alexandru Elisei &lt;alexandru.elisei@arm.com&gt;
Cc: Amit Daniel Kachhap &lt;amit.kachhap@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Reviewed-by: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Reviewed-by: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lore.kernel.org/r/20220913101732.3925290-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
</feed>
