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Linus Torvalds aad3a0d084 ftrace updates for v6.13:
- Merged tag ftrace-v6.12-rc4
 
   There was a fix to locking in register_ftrace_graph() for shadow stacks
   that was sent upstream. But this code was also being rewritten, and the
   locking fix was needed. Merging this fix was required to continue the
   work.
 
 - 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
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Merge tag 'ftrace-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

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)(&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
  ...
2024-11-20 11:34:10 -08:00
arch ftrace updates for v6.13: 2024-11-20 11:34:10 -08:00
block for-6.13/block-20241118 2024-11-18 16:50:08 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto Random number generator updates for Linux 6.13-rc1. 2024-11-19 10:43:44 -08:00
Documentation sched_ext: Change for v6.13 2024-11-20 10:08:00 -08:00
drivers printk changes for 6.13 2024-11-20 09:21:11 -08:00
fs A rather large update for timekeeping and timers: 2024-11-19 16:35:06 -08:00
include ftrace updates for v6.13: 2024-11-20 11:34:10 -08:00
init printk changes for 6.13 2024-11-20 09:21:11 -08:00
io_uring A rather large update for timekeeping and timers: 2024-11-19 16:35:06 -08:00
ipc fdget(), more trivial conversions 2024-11-03 01:28:06 -05:00
kernel ftrace updates for v6.13: 2024-11-20 11:34:10 -08:00
lib A rather large update for timekeeping and timers: 2024-11-19 16:35:06 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm A rather large update for timekeeping and timers: 2024-11-19 16:35:06 -08:00
net A rather large update for timekeeping and timers: 2024-11-19 16:35:06 -08:00
rust Locking changes for v6.13 are: 2024-11-19 12:43:11 -08:00
samples - Log and handle twp new AMD-specific MCA registers: SYND1 and SYND2 and 2024-11-19 12:04:51 -08:00
scripts Another moderately busy cycle in docsland: 2024-11-20 09:16:45 -08:00
security This update includes the following changes: 2024-11-19 10:28:41 -08:00
sound A rather large update for timekeeping and timers: 2024-11-19 16:35:06 -08:00
tools ftrace updates for v6.13: 2024-11-20 11:34:10 -08:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt the bulk of struct fd memory safety stuff 2024-11-18 12:24:06 -08:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap Another moderately busy cycle in docsland: 2024-11-20 09:16:45 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS cgroup: Changes for v6.13 2024-11-20 09:54:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS cgroup: Changes for v6.13 2024-11-20 09:54:49 -08:00
Makefile Linux 6.12 2024-11-17 14:15:08 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.