linux/samples
Linus Torvalds daa22f5a78 Modules changes for v6.6-rc1
Summary of the changes worth highlighting from most interesting to boring below:
 
   * Christoph Hellwig's symbol_get() fix to Nvidia's efforts to circumvent the
     protection he put in place in year 2020 to prevent proprietary modules from
     using GPL only symbols, and also ensuring proprietary modules which export
     symbols grandfather their taint. That was done through year 2020 commit
     262e6ae708 ("modules: inherit TAINT_PROPRIETARY_MODULE"). Christoph's new
     fix is done by clarifing __symbol_get() was only ever intended to prevent
     module reference loops by Linux kernel modules and so making it only find
     symbols exported via EXPORT_SYMBOL_GPL(). The circumvention tactic used
     by Nvidia was to use symbol_get() to purposely swift through proprietary
     module symbols and completley bypass our traditional EXPORT_SYMBOL*()
     annotations and community agreed upon restrictions.
 
     A small set of preamble patches fix up a few symbols which just needed
     adjusting for this on two modules, the rtc ds1685 and the networking enetc
     module. Two other modules just needed some build fixing and removal of use
     of __symbol_get() as they can't ever be modular, as was done by Arnd on
     the ARM pxa module and Christoph did on the mmc au1xmmc driver.
 
     This is a good reminder to us that symbol_get() is just a hack to address
     things which should be fixed through Kconfig at build time as was done in
     the later patches, and so ultimately it should just go.
 
   * Extremely late minor fix for old module layout 055f23b74b ("module: check
     for exit sections in layout_sections() instead of module_init_section()") by
     James Morse for arm64. Note that this layout thing is old, it is *not*
     Song Liu's commit ac3b432839 ("module: replace module_layout with
     module_memory"). The issue however is very odd to run into and so there was
     no hurry to get this in fast.
 
   * Although the fix did not go through the modules tree I'd like to highlight
     the fix by Peter Zijlstra in commit 5409730962 ("x86/static_call: Fix
     __static_call_fixup()") now merged in your tree which came out of what
     was originally suspected to be a fallout of the the newer module layout
     changes by Song Liu commit ac3b432839 ("module: replace module_layout
     with module_memory") instead of module_init_section()"). Thanks to the report
     by Christian Bricart and the debugging by Song Liu & Peter that turned to
     be noted as a kernel regression in place since v5.19 through commit
     ee88d363d1 ("x86,static_call: Use alternative RET encoding").
 
     I highlight this to reflect and clarify that we haven't seen more fallout
     from ac3b432839 ("module: replace module_layout with module_memory").
 
   * RISC-V toolchain got mapping symbol support which prefix symbols with "$"
     to help with alignment considerations for disassembly. This is used to
     differentiate between incompatible instruction encodings when disassembling.
     RISC-V just matches what ARM/AARCH64 did for alignment considerations and
     Palmer Dabbelt extended is_mapping_symbol() to accept these symbols for
     RISC-V. We already had support for this for all architectures but it also
     checked for the second character, the RISC-V check Dabbelt added was just
     for the "$". After a bit of testing and fallout on linux-next and based on
     feedback from Masahiro Yamada it was decided to simplify the check and treat
     the first char "$" as unique for all architectures, and so we no make
     is_mapping_symbol() for all archs if the symbol starts with "$".
 
     The most relevant commit for this for RISC-V on binutils was:
 
     https://sourceware.org/pipermail/binutils/2021-July/117350.html
 
   * A late fix by Andrea Righi (today) to make module zstd decompression use
     vmalloc() instead of kmalloc() to account for large compressed modules. I
     suspect we'll see similar things for other decompression algorithms soon.
 
   * samples/hw_breakpoint minor fixes by Rong Tao, Arnd Bergmann and Chen Jiahao
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Merge tag 'modules-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull modules updates from Luis Chamberlain:
 "Summary of the changes worth highlighting from most interesting to
  boring below:

   - Christoph Hellwig's symbol_get() fix to Nvidia's efforts to
     circumvent the protection he put in place in year 2020 to prevent
     proprietary modules from using GPL only symbols, and also ensuring
     proprietary modules which export symbols grandfather their taint.

     That was done through year 2020 commit 262e6ae708 ("modules:
     inherit TAINT_PROPRIETARY_MODULE"). Christoph's new fix is done by
     clarifing __symbol_get() was only ever intended to prevent module
     reference loops by Linux kernel modules and so making it only find
     symbols exported via EXPORT_SYMBOL_GPL(). The circumvention tactic
     used by Nvidia was to use symbol_get() to purposely swift through
     proprietary module symbols and completely bypass our traditional
     EXPORT_SYMBOL*() annotations and community agreed upon
     restrictions.

     A small set of preamble patches fix up a few symbols which just
     needed adjusting for this on two modules, the rtc ds1685 and the
     networking enetc module. Two other modules just needed some build
     fixing and removal of use of __symbol_get() as they can't ever be
     modular, as was done by Arnd on the ARM pxa module and Christoph
     did on the mmc au1xmmc driver.

     This is a good reminder to us that symbol_get() is just a hack to
     address things which should be fixed through Kconfig at build time
     as was done in the later patches, and so ultimately it should just
     go.

   - Extremely late minor fix for old module layout 055f23b74b
     ("module: check for exit sections in layout_sections() instead of
     module_init_section()") by James Morse for arm64. Note that this
     layout thing is old, it is *not* Song Liu's commit ac3b432839
     ("module: replace module_layout with module_memory"). The issue
     however is very odd to run into and so there was no hurry to get
     this in fast.

   - Although the fix did not go through the modules tree I'd like to
     highlight the fix by Peter Zijlstra in commit 5409730962
     ("x86/static_call: Fix __static_call_fixup()") now merged in your
     tree which came out of what was originally suspected to be a
     fallout of the the newer module layout changes by Song Liu commit
     ac3b432839 ("module: replace module_layout with module_memory")
     instead of module_init_section()"). Thanks to the report by
     Christian Bricart and the debugging by Song Liu & Peter that turned
     to be noted as a kernel regression in place since v5.19 through
     commit ee88d363d1 ("x86,static_call: Use alternative RET
     encoding").

     I highlight this to reflect and clarify that we haven't seen more
     fallout from ac3b432839 ("module: replace module_layout with
     module_memory").

   - RISC-V toolchain got mapping symbol support which prefix symbols
     with "$" to help with alignment considerations for disassembly.

     This is used to differentiate between incompatible instruction
     encodings when disassembling. RISC-V just matches what ARM/AARCH64
     did for alignment considerations and Palmer Dabbelt extended
     is_mapping_symbol() to accept these symbols for RISC-V. We already
     had support for this for all architectures but it also checked for
     the second character, the RISC-V check Dabbelt added was just for
     the "$". After a bit of testing and fallout on linux-next and based
     on feedback from Masahiro Yamada it was decided to simplify the
     check and treat the first char "$" as unique for all architectures,
     and so we no make is_mapping_symbol() for all archs if the symbol
     starts with "$".

     The most relevant commit for this for RISC-V on binutils was:

       https://sourceware.org/pipermail/binutils/2021-July/117350.html

   - A late fix by Andrea Righi (today) to make module zstd
     decompression use vmalloc() instead of kmalloc() to account for
     large compressed modules. I suspect we'll see similar things for
     other decompression algorithms soon.

   - samples/hw_breakpoint minor fixes by Rong Tao, Arnd Bergmann and
     Chen Jiahao"

* tag 'modules-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  module/decompress: use vmalloc() for zstd decompression workspace
  kallsyms: Add more debug output for selftest
  ARM: module: Use module_init_layout_section() to spot init sections
  arm64: module: Use module_init_layout_section() to spot init sections
  module: Expose module_init_layout_section()
  modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules
  rtc: ds1685: use EXPORT_SYMBOL_GPL for ds1685_rtc_poweroff
  net: enetc: use EXPORT_SYMBOL_GPL for enetc_phc_index
  mmc: au1xmmc: force non-modular build and remove symbol_get usage
  ARM: pxa: remove use of symbol_get()
  samples/hw_breakpoint: mark sample_hbp as static
  samples/hw_breakpoint: fix building without module unloading
  samples/hw_breakpoint: Fix kernel BUG 'invalid opcode: 0000'
  modpost, kallsyms: Treat add '$'-prefixed symbols as mapping symbols
  kernel: params: Remove unnecessary ‘0’ values from err
  module: Ignore RISC-V mapping symbols too
2023-08-29 17:32:32 -07:00
..
acrn virt: acrn: Replace obsolete memalign() with posix_memalign() 2023-04-20 14:20:51 +02:00
auxdisplay
binderfs
bpf samples/bpf: Add note to README about the XDP utilities moved to xdp-tools 2023-08-24 08:43:50 -07:00
configfs treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
connector
coresight coresight: syscfg: Example CoreSight configuration loadable module 2021-11-26 11:34:07 -07:00
fanotify Add gitignore file for samples/fanotify/ subdirectory 2021-11-07 11:19:24 -08:00
fprobe fprobe: Pass return address to the handlers 2023-06-06 21:39:55 +09:00
ftrace samples: ftrace: Replace bti assembly with hint for older compiler 2023-08-21 22:03:58 -04:00
hid bpf: Replace deprecated -target with --target= for Clang 2023-06-29 15:46:17 +02:00
hidraw
hw_breakpoint samples/hw_breakpoint: mark sample_hbp as static 2023-07-26 11:17:19 -07:00
kdb kdb: Rename members of struct kdbtab_t 2021-07-27 17:05:06 +01:00
kfifo samples/kfifo: Rename read_lock/write_lock 2021-10-13 14:36:48 +02:00
kmemleak kmemleak-test: drop __init to get better backtrace 2023-06-09 16:25:40 -07:00
kobject samples/kobject: make kobj_type structure constant 2023-02-08 13:34:41 +01:00
kprobes samples/kprobes: Add LoongArch support 2023-02-25 22:12:17 +08:00
landlock samples/landlock: Document best-effort approach for LANDLOCK_ACCESS_FS_REFER 2022-11-07 20:49:50 +01:00
livepatch livepatch: Reorder to use before freeing a pointer 2022-03-23 13:51:11 +01:00
mei samples: mei: don't wait on read completion upon write. 2021-08-01 09:54:22 +02:00
nitro_enclaves nitro_enclaves: Add fixes for checkpatch blank line reports 2021-09-14 11:11:20 +02:00
pfsm samples: Add userspace example for TI TPS6594 PFSM 2023-06-15 13:41:53 +02:00
pidfd
pktgen samples: pktgen: fix append mode failed issue 2023-07-03 09:15:26 +01:00
qmi soc: qcom: qmi: use const for struct qmi_elem_info 2022-08-29 17:33:01 -05:00
rpmsg
rust samples: rust: print: Add sample code for Arc printing 2023-04-10 05:05:43 +02:00
seccomp samples/seccomp: Adjust sample to also provide kill option 2022-02-10 19:09:12 -08:00
timers
trace_events tracing: Fix cpumask() example typo 2022-12-14 11:17:55 -05:00
trace_printk
uhid
user_events tracing/user_events: Use write ABI in example 2023-03-29 06:52:09 -04:00
v4l treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_168.RULE (part 2) 2022-06-10 14:51:36 +02:00
vfio-mdev Driver core changes for 6.4-rc1 2023-04-27 11:53:57 -07:00
vfs
watch_queue
watchdog
Kconfig samples: pfsm: add CC_CAN_LINK dependency 2023-06-19 17:13:24 +02:00
Makefile samples: Add userspace example for TI TPS6594 PFSM 2023-06-15 13:41:53 +02:00