linux-stable.git/include/asm-generic/vmlinux.lds.h, branch v6.6.78

Rename .data.once to .data..once to fix resetting WARN*_ONCE

2024-12-09T09:32:59+00:00

[ Upstream commit dbefa1f31a91670c9e7dac9b559625336206466f ]

Commit b1fca27d384e ("kernel debug: support resetting WARN*_ONCE")
added support for clearing the state of once warnings. However,
it is not functional when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION or
CONFIG_LTO_CLANG is enabled, because .data.once matches the
.data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro.

Commit cb87481ee89d ("kbuild: linker script do not match C names unless
LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress
the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case,
providing a minimal fix for stable backporting. We were aware this did
not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The
plan was to apply correct fixes and then revert cb87481ee89d. [1]

Seven years have passed since then, yet the #ifdef workaround remains in
place. Meanwhile, commit b1fca27d384e introduced the .data.once section,
and commit dc5723b02e52 ("kbuild: add support for Clang LTO") extended
the #ifdef.

Using a ".." separator in the section name fixes the issue for
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG.

[1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/

Fixes: b1fca27d384e ("kernel debug: support resetting WARN*_ONCE")
Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

Rename .data.unlikely to .data..unlikely

2024-12-09T09:32:59+00:00

[ Upstream commit bb43a59944f45e89aa158740b8a16ba8f0b0fa2b ]

Commit 7ccaba5314ca ("consolidate WARN_...ONCE() static variables")
was intended to collect all .data.unlikely sections into one chunk.
However, this has not worked when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
or CONFIG_LTO_CLANG is enabled, because .data.unlikely matches the
.data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro.

Commit cb87481ee89d ("kbuild: linker script do not match C names unless
LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress
the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case,
providing a minimal fix for stable backporting. We were aware this did
not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The
plan was to apply correct fixes and then revert cb87481ee89d. [1]

Seven years have passed since then, yet the #ifdef workaround remains in
place.

Using a ".." separator in the section name fixes the issue for
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG.

[1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/

Fixes: cb87481ee89d ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured")
Signed-off-by: Masahiro Yamada 
Signed-off-by: Sasha Levin

init/modpost: conditionally check section mismatch to __meminit*

2024-12-09T09:32:59+00:00

[ Upstream commit 73db3abdca58c8a014ec4c88cf5ef925cbf63669 ]

This reverts commit eb8f689046b8 ("Use separate sections for __dev/
_cpu/__mem code/data").

Check section mismatch to __meminit* only when CONFIG_MEMORY_HOTPLUG=n.

With this change, the linker script and modpost become simpler, and we
can get rid of the __ref annotations from the memory hotplug code.

[sfr@canb.auug.org.au: remove MEM_KEEP from arch/powerpc/kernel/vmlinux.lds.S]
  Link: https://lkml.kernel.org/r/20240710093213.2aefb25f@canb.auug.org.au
Link: https://lkml.kernel.org/r/20240706160511.2331061-2-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada 
Signed-off-by: Stephen Rothwell 
Reviewed-by: Wei Yang 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Stable-dep-of: bb43a59944f4 ("Rename .data.unlikely to .data..unlikely")
Signed-off-by: Sasha Levin

vmlinux.lds.h: catch .bss..L* sections into BSS")

2024-08-03T06:53:35+00:00

[ Upstream commit 1a7b7326d587c9a5e8ff067e70d6aaf0333f4bb3 ]

Commit 9a427556fb8e ("vmlinux.lds.h: catch compound literals into
data and BSS") added catches for .data..L* and .rodata..L* but missed
.bss..L*

Since commit 5431fdd2c181 ("ptrace: Convert ptrace_attach() to use
lock guards") the following appears at build:

  LD      .tmp_vmlinux.kallsyms1
powerpc64-linux-ld: warning: orphan section `.bss..Lubsan_data33' from `kernel/ptrace.o' being placed in section `.bss..Lubsan_data33'
  NM      .tmp_vmlinux.kallsyms1.syms
  KSYMS   .tmp_vmlinux.kallsyms1.S
  AS      .tmp_vmlinux.kallsyms1.S
  LD      .tmp_vmlinux.kallsyms2
powerpc64-linux-ld: warning: orphan section `.bss..Lubsan_data33' from `kernel/ptrace.o' being placed in section `.bss..Lubsan_data33'
  NM      .tmp_vmlinux.kallsyms2.syms
  KSYMS   .tmp_vmlinux.kallsyms2.S
  AS      .tmp_vmlinux.kallsyms2.S
  LD      vmlinux
powerpc64-linux-ld: warning: orphan section `.bss..Lubsan_data33' from `kernel/ptrace.o' being placed in section `.bss..Lubsan_data33'

Lets add .bss..L* to BSS_MAIN macro to catch those sections into BSS.

Fixes: 9a427556fb8e ("vmlinux.lds.h: catch compound literals into data and BSS")
Signed-off-by: Christophe Leroy 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202404031349.nmKhyuUG-lkp@intel.com/
Signed-off-by: Arnd Bergmann 
Signed-off-by: Sasha Levin

linux/init: remove __memexit* annotations

2024-02-23T08:25:03+00:00

commit 6a4e59eeedc3018cb57722eecfcbb49431aeb05f upstream.

We have never used __memexit, __memexitdata, or __memexitconst.

These were unneeded.

Signed-off-by: Masahiro Yamada 
Acked-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

vmlinux.lds.h: remove unused CPU_KEEP and CPU_DISCARD macros

2023-10-01T05:55:23+00:00

Remove the left-over of commit e24f6628811e ("modpost: remove all
traces of cpuinit/cpuexit sections").

Signed-off-by: Masahiro Yamada 
Acked-by: Paul Gortmaker

vmlinux.lds.h: Remove a reference to no longer used sections .text..refcount

2023-07-11T21:29:43+00:00

Sections .text..refcount were previously used to hold an error path code
for fast refcount overflow protection on x86, see commit 7a46ec0e2f48
("locking/refcounts, x86/asm: Implement fast refcount overflow
protection") and commit 564c9cc84e2a ("locking/refcounts, x86/asm: Use
unique .text section for refcount exceptions").

The code was replaced and removed in commit fb041bb7c0a9
("locking/refcount: Consolidate implementations of refcount_t") and no
sections .text..refcount are present since then.

Remove then a relic referencing these sections from TEXT_TEXT to avoid
confusing people, like me. This is a non-functional change.

Signed-off-by: Petr Pavlu 
Link: https://lore.kernel.org/r/20230711125054.9000-1-petr.pavlu@suse.com
Signed-off-by: Kees Cook

Merge tag 'riscv-for-linus-6.5-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2023-07-07T17:07:19+00:00

Pull more RISC-V updates from Palmer Dabbelt:

 - A bunch of fixes/cleanups from the first part of the merge window,
   mostly related to ACPI and vector as those were large

 - Some documentation improvements, mostly related to the new code

 - The "riscv,isa" DT key is deprecated

 - Support for link-time dead code elimination

 - Support for minor fault registration in userfaultd

 - A handful of cleanups around CMO alternatives

* tag 'riscv-for-linus-6.5-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (23 commits)
  riscv: mm: mark noncoherent_supported as __ro_after_init
  riscv: mm: mark CBO relate initialization funcs as __init
  riscv: errata: thead: only set cbom size & noncoherent during boot
  riscv: Select HAVE_ARCH_USERFAULTFD_MINOR
  RISC-V: Document the ISA string parsing rules for ACPI
  risc-v: Fix order of IPI enablement vs RCU startup
  mm: riscv: fix an unsafe pte read in huge_pte_alloc()
  dt-bindings: riscv: deprecate riscv,isa
  RISC-V: drop error print from riscv_hartid_to_cpuid()
  riscv: Discard vector state on syscalls
  riscv: move memblock_allow_resize() after linear mapping is ready
  riscv: Enable ARCH_SUSPEND_POSSIBLE for s2idle
  riscv: vdso: include vdso/vsyscall.h for vdso_data
  selftests: Test RISC-V Vector's first-use handler
  riscv: vector: clear V-reg in the first-use trap
  riscv: vector: only enable interrupts in the first-use trap
  RISC-V: Fix up some vector state related build failures
  RISC-V: Document that V registers are clobbered on syscalls
  riscv: disable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for LLD
  riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION
  ...

Merge tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2023-07-01T16:24:31+00:00

Pull Kbuild updates from Masahiro Yamada:

 - Remove the deprecated rule to build *.dtbo from *.dts

 - Refactor section mismatch detection in modpost

 - Fix bogus ARM section mismatch detections

 - Fix error of 'make gtags' with O= option

 - Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error
   with the latest LLVM version

 - Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed

 - Ignore more compiler-generated symbols for kallsyms

 - Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles

 - Enable more kernel-doc warnings with W=2

 - Refactor  by generating KSYMTAB data by modpost

 - Deprecate  and 

 - Remove the EXPORT_DATA_SYMBOL macro

 - Move the check for static EXPORT_SYMBOL back to modpost, which makes
   the build faster

 - Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm

 - Warn missing MODULE_DESCRIPTION when building modules with W=1

 - Make 'make clean' robust against too long argument error

 - Exclude more objects from GCOV to fix CFI failures with GCOV

 - Allow 'make modules_install' to install modules.builtin and
   modules.builtin.modinfo even when CONFIG_MODULES is disabled

 - Include modules.builtin and modules.builtin.modinfo in the
   linux-image Debian package even when CONFIG_MODULES is disabled

 - Revive "Entering directory" logging for the latest Make version

* tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits)
  modpost: define more R_ARM_* for old distributions
  kbuild: revive "Entering directory" for Make >= 4.4.1
  kbuild: set correct abs_srctree and abs_objtree for package builds
  scripts/mksysmap: Ignore prefixed KCFI symbols
  kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb
  kbuild: builddeb: always make modules_install, to install modules.builtin*
  modpost: continue even with unknown relocation type
  modpost: factor out Elf_Sym pointer calculation to section_rel()
  modpost: factor out inst location calculation to section_rel()
  kbuild: Disable GCOV for *.mod.o
  kbuild: Fix CFI failures with GCOV
  kbuild: make clean rule robust against too long argument error
  script: modpost: emit a warning when the description is missing
  kbuild: make modules_install copy modules.builtin(.modinfo)
  linux/export.h: rename 'sec' argument to 'license'
  modpost: show offset from symbol for section mismatch warnings
  modpost: merge two similar section mismatch warnings
  kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion
  modpost: use null string instead of NULL pointer for default namespace
  modpost: squash sym_update_namespace() into sym_add_exported()
  ...

Merge patch series "riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION"

2023-07-01T14:38:19+00:00

Jisheng Zhang  says:

When trying to run linux with various opensource riscv core on
resource limited FPGA platforms, for example, those FPGAs with less
than 16MB SDRAM, I want to save mem as much as possible. One of the
major technologies is kernel size optimizations, I found that riscv
does not currently support HAVE_LD_DEAD_CODE_DATA_ELIMINATION, which
passes -fdata-sections, -ffunction-sections to CFLAGS and passes the
--gc-sections flag to the linker.

This not only benefits my case on FPGA but also benefits defconfigs.
Here are some notable improvements from enabling this with defconfigs:

nommu_k210_defconfig:
   text    data     bss     dec     hex
1112009  410288   59837 1582134  182436     before
 962838  376656   51285 1390779  1538bb     after

rv32_defconfig:
   text    data     bss     dec     hex
8804455 2816544  290577 11911576 b5c198     before
8692295 2779872  288977 11761144 b375f8     after

defconfig:
   text    data     bss     dec     hex
9438267 3391332  485333 13314932 cb2b74     before
9285914 3350052  483349 13119315 c82f53     after

patch1 and patch2 are clean ups.
patch3 fixes a typo.
patch4 finally enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for riscv.

* b4-shazam-merge:
  riscv: disable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for LLD
  riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION
  vmlinux.lds.h: use correct .init.data.* section name
  riscv: vmlinux-xip.lds.S: remove .alternative section
  riscv: move options to keep entries sorted
  riscv: Fix orphan section warnings caused by kernel/pi

Link: https://lore.kernel.org/r/20230523165502.2592-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt