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<title>pm24.git/arch/s390/lib, branch master</title>
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<updated>2024-11-29T18:40:52Z</updated>
<entry>
<title>Merge tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux</title>
<updated>2024-11-29T18:40:52Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-29T18:40:52Z</published>
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<id>urn:sha1:509f806f7f70db42cbb95856d32a9a0d6700b2e5</id>
<content type='text'>
Pull more s390 updates from Heiko Carstens:

 - Add swap entry for hugetlbfs support

 - Add PTE_MARKER support for hugetlbs mappings; this fixes a regression
   (possible page fault loop) which was introduced when support for
   UFFDIO_POISON for hugetlbfs was added

 - Add ARCH_HAS_PREEMPT_LAZY and PREEMPT_DYNAMIC support

 - Mark IRQ entries in entry code, so that stack tracers can filter out
   the non-IRQ parts of stack traces. This fixes stack depot capacity
   limit warnings, since without filtering the number of unique stack
   traces is huge

 - In PCI code fix leak of struct zpci_dev object, and fix potential
   double remove of hotplug slot

 - Fix pagefault_disable() / pagefault_enable() unbalance in
   arch_stack_user_walk_common()

 - A couple of inline assembly optimizations, more cmpxchg() to
   try_cmpxchg() conversions, and removal of usages of xchg() and
   cmpxchg() on one and two byte memory areas

 - Various other small improvements and cleanups

* tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (27 commits)
  Revert "s390/mm: Allow large pages for KASAN shadow mapping"
  s390/spinlock: Use flag output constraint for arch_cmpxchg_niai8()
  s390/spinlock: Use R constraint for arch_load_niai4()
  s390/spinlock: Generate shorter code for arch_spin_unlock()
  s390/spinlock: Remove condition code clobber from arch_spin_unlock()
  s390/spinlock: Use symbolic names in inline assemblies
  s390: Support PREEMPT_DYNAMIC
  s390/pci: Fix potential double remove of hotplug slot
  s390/pci: Fix leak of struct zpci_dev when zpci_add_device() fails
  s390/mm/hugetlbfs: Add missing includes
  s390/mm: Add PTE_MARKER support for hugetlbfs mappings
  s390/mm: Introduce region-third and segment table swap entries
  s390/mm: Introduce region-third and segment table entry present bits
  s390/mm: Rearrange region-third and segment table entry SW bits
  KVM: s390: Increase size of union sca_utility to four bytes
  KVM: s390: Remove one byte cmpxchg() usage
  KVM: s390: Use try_cmpxchg() instead of cmpxchg() loops
  s390/ap: Replace xchg() with WRITE_ONCE()
  s390/mm: Allow large pages for KASAN shadow mapping
  s390: Add ARCH_HAS_PREEMPT_LAZY support
  ...
</content>
</entry>
<entry>
<title>s390/spinlock: Use flag output constraint for arch_cmpxchg_niai8()</title>
<updated>2024-11-28T13:14:34Z</updated>
<author>
<name>Heiko Carstens</name>
<email>hca@linux.ibm.com</email>
</author>
<published>2024-11-26T13:28:27Z</published>
<link rel='alternate' type='text/html' href='https://git.kobert.dev/pm24.git/commit/?id=889221c4d78d754023bec8edec13d11a13b3fb51'/>
<id>urn:sha1:889221c4d78d754023bec8edec13d11a13b3fb51</id>
<content type='text'>
Add a new variant of arch_cmpxchg_niai8() which makes use of the flag
output constraint, which allows the compiler to generate slightly better
code. Also rename arch_cmpxchg_niai8() to arch_try_cmpxchg_niai8() which
reflects the purpose of the function and makes it consistent with other
"try" variants.

Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
</entry>
<entry>
<title>s390/spinlock: Use R constraint for arch_load_niai4()</title>
<updated>2024-11-28T13:12:05Z</updated>
<author>
<name>Heiko Carstens</name>
<email>hca@linux.ibm.com</email>
</author>
<published>2024-11-26T13:28:26Z</published>
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<id>urn:sha1:84ac96587b2a7a27d2aba250009c45dffb8ab4b6</id>
<content type='text'>
The load instruction used within arch_load_niai4() has a short displacement
and index register. Therefore use the R constraint to reflect this.
The used Q constraint does consider an index register.

Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
</entry>
<entry>
<title>s390/spinlock: Use symbolic names in inline assemblies</title>
<updated>2024-11-28T13:12:04Z</updated>
<author>
<name>Heiko Carstens</name>
<email>hca@linux.ibm.com</email>
</author>
<published>2024-11-26T13:28:23Z</published>
<link rel='alternate' type='text/html' href='https://git.kobert.dev/pm24.git/commit/?id=78486ed9e76b72d81e7bb142adb47194f95e188d'/>
<id>urn:sha1:78486ed9e76b72d81e7bb142adb47194f95e188d</id>
<content type='text'>
Improve readability and use symbolic names.

Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'ftrace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2024-11-20T19:34:10Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-20T19:34:10Z</published>
<link rel='alternate' type='text/html' href='https://git.kobert.dev/pm24.git/commit/?id=aad3a0d084513e811233ad48bf234fbfcfcd0a14'/>
<id>urn:sha1:aad3a0d084513e811233ad48bf234fbfcfcd0a14</id>
<content type='text'>
Pull ftrace updates from Steven Rostedt:

 - Restructure the function graph shadow stack to prepare it for use
   with kretprobes

   With the goal of merging the shadow stack logic of function graph and
   kretprobes, some more restructuring of the function shadow stack is
   required.

   Move out function graph specific fields from the fgraph
   infrastructure and store it on the new stack variables that can pass
   data from the entry callback to the exit callback.

   Hopefully, with this change, the merge of kretprobes to use fgraph
   shadow stacks will be ready by the next merge window.

 - Make shadow stack 4k instead of using PAGE_SIZE.

   Some architectures have very large PAGE_SIZE values which make its
   use for shadow stacks waste a lot of memory.

 - Give shadow stacks its own kmem cache.

   When function graph is started, every task on the system gets a
   shadow stack. In the future, shadow stacks may not be 4K in size.
   Have it have its own kmem cache so that whatever size it becomes will
   still be efficient in allocations.

 - Initialize profiler graph ops as it will be needed for new updates to
   fgraph

 - Convert to use guard(mutex) for several ftrace and fgraph functions

 - Add more comments and documentation

 - Show function return address in function graph tracer

   Add an option to show the caller of a function at each entry of the
   function graph tracer, similar to what the function tracer does.

 - Abstract out ftrace_regs from being used directly like pt_regs

   ftrace_regs was created to store a partial pt_regs. It holds only the
   registers and stack information to get to the function arguments and
   return values. On several archs, it is simply a wrapper around
   pt_regs. But some users would access ftrace_regs directly to get the
   pt_regs which will not work on all archs. Make ftrace_regs an
   abstract structure that requires all access to its fields be through
   accessor functions.

 - Show how long it takes to do function code modifications

   When code modification for function hooks happen, it always had the
   time recorded in how long it took to do the conversion. But this
   value was never exported. Recently the code was touched due to new
   ROX modification handling that caused a large slow down in doing the
   modifications and had a significant impact on boot times.

   Expose the timings in the dyn_ftrace_total_info file. This file was
   created a while ago to show information about memory usage and such
   to implement dynamic function tracing. It's also an appropriate file
   to store the timings of this modification as well. This will make it
   easier to see the impact of changes to code modification on boot up
   timings.

 - Other clean ups and small fixes

* tag 'ftrace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (22 commits)
  ftrace: Show timings of how long nop patching took
  ftrace: Use guard to take ftrace_lock in ftrace_graph_set_hash()
  ftrace: Use guard to take the ftrace_lock in release_probe()
  ftrace: Use guard to lock ftrace_lock in cache_mod()
  ftrace: Use guard for match_records()
  fgraph: Use guard(mutex)(&amp;ftrace_lock) for unregister_ftrace_graph()
  fgraph: Give ret_stack its own kmem cache
  fgraph: Separate size of ret_stack from PAGE_SIZE
  ftrace: Rename ftrace_regs_return_value to ftrace_regs_get_return_value
  selftests/ftrace: Fix check of return value in fgraph-retval.tc test
  ftrace: Use arch_ftrace_regs() for ftrace_regs_*() macros
  ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs
  ftrace: Make ftrace_regs abstract from direct use
  fgragh: No need to invoke the function call_filter_check_discard()
  fgraph: Simplify return address printing in function graph tracer
  function_graph: Remove unnecessary initialization in ftrace_graph_ret_addr()
  function_graph: Support recording and printing the function return address
  ftrace: Have calltime be saved in the fgraph storage
  ftrace: Use a running sleeptime instead of saving on shadow stack
  fgraph: Use fgraph data to store subtime for profiler
  ...
</content>
</entry>
<entry>
<title>s390/string: Convert to use flag output macros</title>
<updated>2024-11-13T13:31:33Z</updated>
<author>
<name>Heiko Carstens</name>
<email>hca@linux.ibm.com</email>
</author>
<published>2024-11-07T15:11:45Z</published>
<link rel='alternate' type='text/html' href='https://git.kobert.dev/pm24.git/commit/?id=0caf91f6d695dac811b7959c98625238390ad075'/>
<id>urn:sha1:0caf91f6d695dac811b7959c98625238390ad075</id>
<content type='text'>
Use flag output macros in inline asm to allow for better code generation if
the compiler has support for the flag output constraint.

Reviewed-by: Juergen Christ &lt;jchrist@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
</entry>
<entry>
<title>s390/locking: Use arch_try_cmpxchg() instead of __atomic_cmpxchg_bool()</title>
<updated>2024-11-12T13:01:29Z</updated>
<author>
<name>Heiko Carstens</name>
<email>hca@linux.ibm.com</email>
</author>
<published>2024-11-06T10:03:15Z</published>
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<id>urn:sha1:d5fd93629af76748751ff583d35039e5834eeb47</id>
<content type='text'>
Use arch_try_cmpxchg() instead of __atomic_cmpxchg_bool() everywhere.
This generates the same code like before, but uses the standard
cmpxchg() implementation instead of a custom __atomic_cmpxchg_bool().

Reviewed-by: Juergen Christ &lt;jchrist@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
</content>
</entry>
<entry>
<title>ftrace: Make ftrace_regs abstract from direct use</title>
<updated>2024-10-11T00:18:01Z</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2024-10-08T23:05:28Z</published>
<link rel='alternate' type='text/html' href='https://git.kobert.dev/pm24.git/commit/?id=7888af4166d4ab07ba51234be6ba332b7807e901'/>
<id>urn:sha1:7888af4166d4ab07ba51234be6ba332b7807e901</id>
<content type='text'>
ftrace_regs was created to hold registers that store information to save
function parameters, return value and stack. Since it is a subset of
pt_regs, it should only be used by its accessor functions. But because
pt_regs can easily be taken from ftrace_regs (on most archs), it is
tempting to use it directly. But when running on other architectures, it
may fail to build or worse, build but crash the kernel!

Instead, make struct ftrace_regs an empty structure and have the
architectures define __arch_ftrace_regs and all the accessor functions
will typecast to it to get to the actual fields. This will help avoid
usage of ftrace_regs directly.

Link: https://lore.kernel.org/all/20241007171027.629bdafd@gandalf.local.home/

Cc: "linux-arch@vger.kernel.org" &lt;linux-arch@vger.kernel.org&gt;
Cc: "x86@kernel.org" &lt;x86@kernel.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Huacai Chen &lt;chenhuacai@kernel.org&gt;
Cc: WANG Xuerui &lt;kernel@xen0n.name&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Cc: Naveen N Rao &lt;naveen@kernel.org&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Cc: Paul  Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas  Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Borislav  Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Link: https://lore.kernel.org/20241008230628.958778821@goodmis.org
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Acked-by: Heiko Carstens &lt;hca@linux.ibm.com&gt; # s390
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>s390/alternatives: Rework to allow for callbacks</title>
<updated>2024-07-23T14:02:31Z</updated>
<author>
<name>Heiko Carstens</name>
<email>hca@linux.ibm.com</email>
</author>
<published>2024-07-16T11:50:53Z</published>
<link rel='alternate' type='text/html' href='https://git.kobert.dev/pm24.git/commit/?id=b3e0c5f734f934dab1cfdef669e3baa165a0cbfe'/>
<id>urn:sha1:b3e0c5f734f934dab1cfdef669e3baa165a0cbfe</id>
<content type='text'>
Rework alternatives to allow for callbacks. With this every
alternative entry has additional data encoded:

- When (aka context) an alternative is supposed to be applied

- The type of an alternative, which allows for type specific handling
  and callbacks

- Extra type specific payload (patch information), which can be passed
  to callbacks in order to decide if an alternative should be applied
  or not

With this only the "late" context is implemented, which means there is
no change to the previous behaviour. All code is just converted to the
more generic new infrastructure.

Reviewed-by: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Tested-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
</content>
</entry>
<entry>
<title>s390/lib: Add missing MODULE_DESCRIPTION() macros</title>
<updated>2024-06-28T12:52:30Z</updated>
<author>
<name>Jeff Johnson</name>
<email>quic_jjohnson@quicinc.com</email>
</author>
<published>2024-06-16T00:47:26Z</published>
<link rel='alternate' type='text/html' href='https://git.kobert.dev/pm24.git/commit/?id=4657a8a1c0538abc9e841fa64692d2c59edac2c0'/>
<id>urn:sha1:4657a8a1c0538abc9e841fa64692d2c59edac2c0</id>
<content type='text'>
With ARCH=s390, make allmodconfig &amp;&amp; make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/s390/lib/test_kprobes_s390.o
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/s390/lib/test_unwind.o
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/s390/lib/test_modules.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.

Acked-by: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Signed-off-by: Jeff Johnson &lt;quic_jjohnson@quicinc.com&gt;
Link: https://lore.kernel.org/r/20240615-md-s390-arch-s390-lib-v1-1-d7424b943973@quicinc.com
Signed-off-by: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Signed-off-by: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
</content>
</entry>
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