linux-toradex.git/include/linux/init.h, branch v6.6-rc5

x86/mem_encrypt: Remove stale mem_encrypt_init() declaration

2023-06-28T19:47:30+00:00

The memory encryption initialization logic was moved from init/main.c
into arch_cpu_finalize_init() in commit 439e17576eb4 ("init, x86: Move
mem_encrypt_init() into arch_cpu_finalize_init()"), but a stale
declaration for the init function was left in .

And didn't cause any problems if you had X86_MEM_ENCRYPT enabled, which
apparently everybody involved did have.  See also commit 0a9567ac5e6a
("x86/mem_encrypt: Unbreak the AMD_MEM_ENCRYPT=n build") in this whole
sad saga of conflicting declarations for different situations.

Reported-by: Matthew Wilcox 
Fixes: 439e17576eb4 init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()
Cc: Thomas Gleixner 
Signed-off-by: Linus Torvalds

init: consolidate prototypes in linux/init.h

2023-06-10T00:44:16+00:00

The init/main.c file contains some extern declarations for functions
defined in architecture code, and it defines some other functions that are
called from architecture code with a custom prototype.  Both of those
result in warnings with 'make W=1':

init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
init/main.c:790:20: error: no previous prototype for 'mem_encrypt_init' [-Werror=missing-prototypes]
init/main.c:792:20: error: no previous prototype for 'poking_init' [-Werror=missing-prototypes]
arch/arm64/kernel/irq.c:122:13: error: no previous prototype for 'init_IRQ' [-Werror=missing-prototypes]
arch/arm64/kernel/time.c:55:13: error: no previous prototype for 'time_init' [-Werror=missing-prototypes]
arch/x86/kernel/process.c:935:13: error: no previous prototype for 'arch_post_acpi_subsys_init' [-Werror=missing-prototypes]
init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
kernel/fork.c:991:20: error: no previous prototype for 'arch_task_cache_init' [-Werror=missing-prototypes]

Add prototypes for all of these in include/linux/init.h or another
appropriate header, and remove the duplicate declarations from
architecture specific code.

[sfr@canb.auug.org.au: declare time_init_early()]
  Link: https://lkml.kernel.org/r/20230519124311.5167221c@canb.auug.org.au
Link: https://lkml.kernel.org/r/20230517131102.934196-12-arnd@kernel.org
Signed-off-by: Arnd Bergmann 
Signed-off-by: Stephen Rothwell 
Cc: Boqun Feng 
Cc: Catalin Marinas 
Cc: Christoph Lameter 
Cc: Dennis Zhou 
Cc: Eric Paris 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Moore 
Cc: Pavel Machek 
Cc: Peter Zijlstra 
Cc: Rafael J. Wysocki 
Cc: Russell King 
Cc: Tejun Heo 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Waiman Long 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

linux/init.h: include and

2022-12-01T00:13:18+00:00

With CONFIG_HAVE_ARCH_PREL32_RELOCATIONS=y, the following code fails to
build:

  ---------------->8----------------
  #include 

  int foo(void) { return 0; }
  core_initcall(foo);
  ---------------->8----------------

Include  for static_assert() and 
for __stringify().

Link: https://lkml.kernel.org/r/20221113110802.3760705-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada 
Cc: Jiangshan Yi 
Cc: Kees Cook 
Cc: Peter Zijlstra 
Cc: Randy Dunlap  # build-tested
Cc: Sami Tolvanen 
Signed-off-by: Andrew Morton

proc: give /proc/cmdline size

2022-11-18T21:55:07+00:00

Most /proc files don't have length (in fstat sense).  This leads to
inefficiencies when reading such files with APIs commonly found in modern
programming languages.  They open file, then fstat descriptor, get st_size
== 0 and either assume file is empty or start reading without knowing
target size.

cat(1) does OK because it uses large enough buffer by default.  But naive
programs copy-pasted from SO aren't:

	let mut f = std::fs::File::open("/proc/cmdline").unwrap();
	let mut buf: Vec = Vec::new();
	f.read_to_end(&mut buf).unwrap();

will result in

	openat(AT_FDCWD, "/proc/cmdline", O_RDONLY|O_CLOEXEC) = 3
	statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address)
	statx(3, "", AT_STATX_SYNC_AS_STAT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_BASIC_STATS|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0444, stx_size=0, ...}) = 0
	lseek(3, 0, SEEK_CUR)                   = 0
	read(3, "BOOT_IMAGE=(hd3,gpt2)/vmlinuz-5.", 32) = 32
	read(3, "19.6-100.fc35.x86_64 root=/dev/m", 32) = 32
	read(3, "apper/fedora_localhost--live-roo"..., 64) = 64
	read(3, "ocalhost--live-swap rd.lvm.lv=fe"..., 128) = 116
	read(3, "", 12)

open/stat is OK, lseek looks silly but there are 3 unnecessary reads
because Rust starts with 32 bytes per Vec and grows from there.

In case of /proc/cmdline, the length is known precisely.

Make variables readonly while I'm at it.

P.S.: I tried to scp /proc/cpuinfo today and got empty file
	but this is separate story.

Link: https://lkml.kernel.org/r/YxoywlbM73JJN3r+@localhost.localdomain
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-10-12T18:00:22+00:00

Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...

init.h: fix spelling typo in comment

2022-10-03T21:21:42+00:00

Fix spelling typo in comment.

Link: https://lkml.kernel.org/r/20220905021034.947701-1-13667453960@163.com
Signed-off-by: Jiangshan Yi 
Reported-by: k2ci 
Signed-off-by: Andrew Morton

treewide: Drop __cficanonical

2022-09-26T17:13:15+00:00

CONFIG_CFI_CLANG doesn't use a jump table anymore and therefore,
won't change function references to point elsewhere. Remove the
__cficanonical attribute and all uses of it.

Note that the Clang definition of the attribute was removed earlier,
just clean up the no-op definition and users.

Signed-off-by: Sami Tolvanen 
Reviewed-by: Kees Cook 
Tested-by: Kees Cook 
Tested-by: Nathan Chancellor 
Acked-by: Peter Zijlstra (Intel) 
Tested-by: Peter Zijlstra (Intel) 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20220908215504.3686827-16-samitolvanen@google.com

init: Drop nocfi from init

2022-09-26T17:13:14+00:00

It's no longer necessary to disable CFI checking for all __init
functions. Drop the __nocfi attribute from __init.

Signed-off-by: Sami Tolvanen 
Reviewed-by: Kees Cook 
Tested-by: Kees Cook 
Tested-by: Nathan Chancellor 
Acked-by: Peter Zijlstra (Intel) 
Tested-by: Peter Zijlstra (Intel) 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20220908215504.3686827-13-samitolvanen@google.com

init.h: improve __setup and early_param documentation

2022-03-24T02:00:34+00:00

Igor noted in [1] that there are quite a few __setup() handling
functions that return incorrect values.  Doing this can be harmless, but
it can also cause strings to be added to init's argument or environment
list, polluting them.

Since __setup() handling and return values are not documented, first add
documentation for that.  Also add more documentation for early_param()
handling and return values.

For __setup() functions, returning 0 (not handled) has questionable
value if it is just a malformed option value, as in

  rodata=junk

since returning 0 would just cause "rodata=junk" to be added to init's
environment unnecessarily:

  Run /sbin/init as init process
    with arguments:
      /sbin/init
    with environment:
      HOME=/
      TERM=linux
      splash=native
      rodata=junk

Also, there are no recommendations on whether to print a warning when an
unknown parameter value is seen.  I am not addressing that here.

[1] lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru

Link: https://lkml.kernel.org/r/20220221050852.1147-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap 
Reported-by: Igor Zhbanov 
Cc: Ingo Molnar 
Cc: Greg Kroah-Hartman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

init: verify that function is initcall_t at compile-time

2021-05-24T22:24:33+00:00

In the spirit of making it hard to misuse an interface, add a
compile-time assertion in the CONFIG_HAVE_ARCH_PREL32_RELOCATIONS case
to verify the initcall function matches initcall_t, because the inline
asm bypasses any type-checking the compiler would otherwise do. This
will help developers catch incorrect API use in all configurations.

A recent example of this is:
https://lkml.kernel.org/r/20210514140015.2944744-1-arnd@kernel.org

Signed-off-by: Marco Elver 
Reviewed-by: Miguel Ojeda 
Reviewed-by: Nathan Chancellor 
Tested-by: Nathan Chancellor 
Reviewed-by: Sami Tolvanen 
Tested-by: Paul E. McKenney 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20210521072610.2880286-1-elver@google.com