<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/arch/arm64/Kconfig, branch v6.4</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.4</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.4'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2023-06-02T12:00:52+00:00</updated>
<entry>
<title>arm64: Remove the ARCH_FORCE_MAX_ORDER config input prompt</title>
<updated>2023-06-02T12:00:52+00:00</updated>
<author>
<name>Catalin Marinas</name>
<email>catalin.marinas@arm.com</email>
</author>
<published>2023-05-19T17:14:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=f3c3762178fad5cf5dc108fb061ba010818323b4'/>
<id>urn:sha1:f3c3762178fad5cf5dc108fb061ba010818323b4</id>
<content type='text'>
Commit 34affcd7577a ("arm64: drop ranges in definition of
ARCH_FORCE_MAX_ORDER") dropped the ranges from the config entry and
introduced an EXPERT condition on the input prompt instead.

However, starting with defconfig (ARCH_FORCE_MAX_ORDER of 10) and
setting ARM64_64K_PAGES together with EXPERT leaves MAX_ORDER 10 which
fails to build in this configuration.

Drop the input prompt for ARCH_FORCE_MAX_ORDER completely so that it's
no longer configurable. People requiring a higher MAX_ORDER should send
a patch changing the default, together with proper justification.

Fixes: 34affcd7577a ("arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER")
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Reported-by: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Justin M. Forbes &lt;jforbes@fedoraproject.org&gt;
Reviewed-by: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Acked-by: Marc Zyngier &lt;maz@kernel.org&gt;
Acked-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Link: https://lore.kernel.org/r/20230519171440.1941213-1-catalin.marinas@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2023-04-28T02:42:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-28T02:42:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7fa8a8ee9400fe8ec188426e40e481717bc5e924'/>
<id>urn:sha1:7fa8a8ee9400fe8ec188426e40e481717bc5e924</id>
<content type='text'>
Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in -&gt;map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...
</content>
</entry>
<entry>
<title>Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux</title>
<updated>2023-04-25T19:39:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-25T19:39:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=df45da57cbd35715d590a36a12968a94508ccd1f'/>
<id>urn:sha1:df45da57cbd35715d590a36a12968a94508ccd1f</id>
<content type='text'>
Pull arm64 updates from Will Deacon:
 "ACPI:

   - Improve error reporting when failing to manage SDEI on AGDI device
     removal

  Assembly routines:

   - Improve register constraints so that the compiler can make use of
     the zero register instead of moving an immediate #0 into a GPR

   - Allow the compiler to allocate the registers used for CAS
     instructions

  CPU features and system registers:

   - Cleanups to the way in which CPU features are identified from the
     ID register fields

   - Extend system register definition generation to handle Enum types
     when defining shared register fields

   - Generate definitions for new _EL2 registers and add new fields for
     ID_AA64PFR1_EL1

   - Allow SVE to be disabled separately from SME on the kernel
     command-line

  Tracing:

   - Support for "direct calls" in ftrace, which enables BPF tracing for
     arm64

  Kdump:

   - Don't bother unmapping the crashkernel from the linear mapping,
     which then allows us to use huge (block) mappings and reduce TLB
     pressure when a crashkernel is loaded.

  Memory management:

   - Try again to remove data cache invalidation from the coherent DMA
     allocation path

   - Simplify the fixmap code by mapping at page granularity

   - Allow the kfence pool to be allocated early, preventing the rest of
     the linear mapping from being forced to page granularity

  Perf and PMU:

   - Move CPU PMU code out to drivers/perf/ where it can be reused by
     the 32-bit ARM architecture when running on ARMv8 CPUs

   - Fix race between CPU PMU probing and pKVM host de-privilege

   - Add support for Apple M2 CPU PMU

   - Adjust the generic PERF_COUNT_HW_BRANCH_INSTRUCTIONS event
     dynamically, depending on what the CPU actually supports

   - Minor fixes and cleanups to system PMU drivers

  Stack tracing:

   - Use the XPACLRI instruction to strip PAC from pointers, rather than
     rolling our own function in C

   - Remove redundant PAC removal for toolchains that handle this in
     their builtins

   - Make backtracing more resilient in the face of instrumentation

  Miscellaneous:

   - Fix single-step with KGDB

   - Remove harmless warning when 'nokaslr' is passed on the kernel
     command-line

   - Minor fixes and cleanups across the board"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (72 commits)
  KVM: arm64: Ensure CPU PMU probes before pKVM host de-privilege
  arm64: kexec: include reboot.h
  arm64: delete dead code in this_cpu_set_vectors()
  arm64/cpufeature: Use helper macro to specify ID register for capabilites
  drivers/perf: hisi: add NULL check for name
  drivers/perf: hisi: Remove redundant initialized of pmu-&gt;name
  arm64/cpufeature: Consistently use symbolic constants for min_field_value
  arm64/cpufeature: Pull out helper for CPUID register definitions
  arm64/sysreg: Convert HFGITR_EL2 to automatic generation
  ACPI: AGDI: Improve error reporting for problems during .remove()
  arm64: kernel: Fix kernel warning when nokaslr is passed to commandline
  perf/arm-cmn: Fix port detection for CMN-700
  arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step
  arm64: move PAC masks to &lt;asm/pointer_auth.h&gt;
  arm64: use XPACLRI to strip PAC
  arm64: avoid redundant PAC stripping in __builtin_return_address()
  arm64/sme: Fix some comments of ARM SME
  arm64/signal: Alloc tpidr2 sigframe after checking system_supports_tpidr2()
  arm64/signal: Use system_supports_tpidr2() to check TPIDR2
  arm64/idreg: Don't disable SME when disabling SVE
  ...
</content>
</entry>
<entry>
<title>Merge tag 'asm-generic-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic</title>
<updated>2023-04-25T19:22:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-25T19:22:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=53b5e72b9d89853b7e622239676163ede52acffe'/>
<id>urn:sha1:53b5e72b9d89853b7e622239676163ede52acffe</id>
<content type='text'>
Pull asm-generic updates from Arnd Bergmann:
 "These are various cleanups, fixing a number of uapi header files to no
  longer reference CONFIG_* symbols, and one patch that introduces the
  new CONFIG_HAS_IOPORT symbol for architectures that provide working
  inb()/outb() macros, as a preparation for adding driver dependencies
  on those in the following release"

* tag 'asm-generic-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  Kconfig: introduce HAS_IOPORT option and select it as necessary
  scripts: Update the CONFIG_* ignore list in headers_install.sh
  pktcdvd: Remove CONFIG_CDROM_PKTCDVD_WCACHE from uapi header
  Move bp_type_idx to include/linux/hw_breakpoint.h
  Move ep_take_care_of_epollwakeup() to fs/eventpoll.c
  Move COMPAT_ATM_ADDPARTY to net/atm/svc.c
</content>
</entry>
<entry>
<title>Merge branch 'for-next/stacktrace' into for-next/core</title>
<updated>2023-04-20T17:03:02+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will@kernel.org</email>
</author>
<published>2023-04-20T17:03:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9772b7f07499b71482276cb5a8e4aa23bfca6b27'/>
<id>urn:sha1:9772b7f07499b71482276cb5a8e4aa23bfca6b27</id>
<content type='text'>
* for-next/stacktrace:
  arm64: move PAC masks to &lt;asm/pointer_auth.h&gt;
  arm64: use XPACLRI to strip PAC
  arm64: avoid redundant PAC stripping in __builtin_return_address()
  arm64: stacktrace: always inline core stacktrace functions
  arm64: stacktrace: move dump functions to end of file
  arm64: stacktrace: recover return address for first entry
</content>
</entry>
<entry>
<title>arm64: reword ARCH_FORCE_MAX_ORDER prompt and help text</title>
<updated>2023-04-18T23:29:44+00:00</updated>
<author>
<name>Mike Rapoport (IBM)</name>
<email>rppt@kernel.org</email>
</author>
<published>2023-03-24T05:22:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4632cb22ac26e9e6e4ad651fb53f25f0b78c2889'/>
<id>urn:sha1:4632cb22ac26e9e6e4ad651fb53f25f0b78c2889</id>
<content type='text'>
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.

Update both to actually describe what this option does.

[rppt@kernel.org: change ARCH_FORCE_MAX_ORDER dependencies]
  Link: https://lkml.kernel.org/r/20230325060828.2662773-4-rppt@kernel.org
Link: https://lkml.kernel.org/r/20230324052233.2654090-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Reviewed-by: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Dinh Nguyen &lt;dinguyen@kernel.org&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Guo Ren &lt;guoren@kernel.org&gt;
Cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: "Russell King (Oracle)" &lt;linux@armlinux.org.uk&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER</title>
<updated>2023-04-18T23:29:44+00:00</updated>
<author>
<name>Mike Rapoport (IBM)</name>
<email>rppt@kernel.org</email>
</author>
<published>2023-03-24T05:22:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=34affcd7577a232803f729d1870ba475f294e4ea'/>
<id>urn:sha1:34affcd7577a232803f729d1870ba475f294e4ea</id>
<content type='text'>
It is not a good idea to change fundamental parameters of core memory
management.  Having predefined ranges suggests that the values within
those ranges are sensible, but one has to *really* understand implications
of changing MAX_ORDER before actually amending it and ranges don't help
here.

Drop ranges in definition of ARCH_FORCE_MAX_ORDER and make its prompt
visible only if EXPERT=y

Link: https://lkml.kernel.org/r/20230324052233.2654090-3-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Reviewed-by: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Dinh Nguyen &lt;dinguyen@kernel.org&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Guo Ren &lt;guoren@kernel.org&gt;
Cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
Cc: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Max Filippov &lt;jcmvbkbc@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: "Russell King (Oracle)" &lt;linux@armlinux.org.uk&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>irqchip/gic-v3: Add Rockchip 3588001 erratum workaround</title>
<updated>2023-04-18T16:31:17+00:00</updated>
<author>
<name>Sebastian Reichel</name>
<email>sebastian.reichel@collabora.com</email>
</author>
<published>2023-04-18T14:21:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a8707f5538846611c90116c14f72539ad5fb37da'/>
<id>urn:sha1:a8707f5538846611c90116c14f72539ad5fb37da</id>
<content type='text'>
Rockchip RK3588/RK3588s GIC600 integration does not support the
sharability feature. Rockchip assigned Erratum ID #3588001 for this
issue.

Note, that the 0x0201743b ID is not Rockchip specific and thus
there is an extra of_machine_is_compatible() check.

The flags are named FORCE_NON_SHAREABLE to be vendor agnostic,
since apparently similar integration design errors exist in other
platforms and they can reuse the same flag.

Co-developed-by: XiaoDong Huang &lt;derrick.huang@rock-chips.com&gt;
Signed-off-by: XiaoDong Huang &lt;derrick.huang@rock-chips.com&gt;
Co-developed-by: Kever Yang &lt;kever.yang@rock-chips.com&gt;
Signed-off-by: Kever Yang &lt;kever.yang@rock-chips.com&gt;
Co-developed-by: Lucas Tanure &lt;lucas.tanure@collabora.com&gt;
Signed-off-by: Lucas Tanure &lt;lucas.tanure@collabora.com&gt;
Reviewed-by: AngeloGioacchino Del Regno &lt;angelogioacchino.delregno@collabora.com&gt;
Signed-off-by: Sebastian Reichel &lt;sebastian.reichel@collabora.com&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20230418142109.49762-2-sebastian.reichel@collabora.com
</content>
</entry>
<entry>
<title>arm64: avoid redundant PAC stripping in __builtin_return_address()</title>
<updated>2023-04-13T11:27:11+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2023-04-12T16:01:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9df3f5082ff94c55e84523a28c040445220b2f64'/>
<id>urn:sha1:9df3f5082ff94c55e84523a28c040445220b2f64</id>
<content type='text'>
In old versions of GCC and Clang, __builtin_return_address() did not
strip the PAC. This was not the behaviour we desired, and so we wrapped
this with code to strip the PAC in commit:

  689eae42afd7a916 ("arm64: mask PAC bits of __builtin_return_address")

Since then, both GCC and Clang decided that __builtin_return_address()
*should* strip the PAC, and the existing behaviour was a bug.

GCC was fixed in 11.1.0, with those fixes backported to 10.2.0, 9.4.0,
8.5.0, but not earlier:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891

Clang was fixed in 12.0.0, though this was not backported:

  https://reviews.llvm.org/D75044

When using a compiler whose __builtin_return_address() strips the PAC,
our wrapper to strip the PAC is redundant. Similarly, when pointer
authentication is not in use within the kernel pointers will not have a
PAC, and so there's no point stripping those pointers.

To avoid this redundant work, this patch updates the
__builtin_return_address() wrapper to only be used when in-kernel
pointer authentication is configured and the compiler's
__builtin_return_address() does not strip the PAC.

This is a cleanup/optimization, and not a fix that requires backporting.
Stripping a PAC should be an idempotent operation, and so redundantly
stripping the PAC is not harmful.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Amit Daniel Kachhap &lt;amit.kachhap@arm.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Kristina Martsenko &lt;kristina.martsenko@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20230412160134.306148-2-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
</entry>
<entry>
<title>arm64: ftrace: Add direct call support</title>
<updated>2023-04-11T17:06:39+00:00</updated>
<author>
<name>Florent Revest</name>
<email>revest@chromium.org</email>
</author>
<published>2023-04-05T18:02:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=2aa6ac03516d078cf0c35aaa273b5cd11ea9734c'/>
<id>urn:sha1:2aa6ac03516d078cf0c35aaa273b5cd11ea9734c</id>
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This builds up on the CALL_OPS work which extends the ftrace patchsite
on arm64 with an ops pointer usable by the ftrace trampoline.

This ops pointer is valid at all time. Indeed, it is either pointing to
ftrace_list_ops or to the single ops which should be called from that
patchsite.

There are a few cases to distinguish:
- If a direct call ops is the only one tracing a function:
  - If the direct called trampoline is within the reach of a BL
    instruction
     -&gt; the ftrace patchsite jumps to the trampoline
  - Else
     -&gt; the ftrace patchsite jumps to the ftrace_caller trampoline which
        reads the ops pointer in the patchsite and jumps to the direct
        call address stored in the ops
- Else
  -&gt; the ftrace patchsite jumps to the ftrace_caller trampoline and its
     ops literal points to ftrace_list_ops so it iterates over all
     registered ftrace ops, including the direct call ops and calls its
     call_direct_funcs handler which stores the direct called
     trampoline's address in the ftrace_regs and the ftrace_caller
     trampoline will return to that address instead of returning to the
     traced function

Signed-off-by: Florent Revest &lt;revest@chromium.org&gt;
Co-developed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Link: https://lore.kernel.org/r/20230405180250.2046566-2-revest@chromium.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
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