linux/scripts
Helge Deller 333bdb72be modules: Ensure natural alignment for .altinstructions and __bug_table sections
[ Upstream commit 87c482bdfa ]

In the kernel image vmlinux.lds.S linker scripts the .altinstructions
and __bug_table sections are 4- or 8-byte aligned because they hold 32-
and/or 64-bit values.

Most architectures use altinstructions and BUG() or WARN() in modules as
well, but in the module linker script (module.lds.S) those sections are
currently missing. As consequence the linker will store their content
byte-aligned by default, which then can lead to unnecessary unaligned
memory accesses by the CPU when those tables are processed at runtime.

Usually unaligned memory accesses are unnoticed, because either the
hardware (as on x86 CPUs) or in-kernel exception handlers (e.g. on
parisc or sparc) emulate and fix them up at runtime. Nevertheless, such
unaligned accesses introduce a performance penalty and can even crash
the kernel if there is a bug in the unalignment exception handlers
(which happened once to me on the parisc architecture and which is why I
noticed that issue at all).

This patch fixes a non-critical issue and might be backported at any time.
It's trivial and shouldn't introduce any regression because it simply
tells the linker to use a different (8-byte alignment) for those
sections by default.

Signed-off-by: Helge Deller <deller@gmx.de>
Link: https://lore.kernel.org/all/Yr8%2Fgr8e8I7tVX4d@p100/
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:38:19 +02:00
..
atomic Merge branch 'kcsan' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into locking/core 2020-10-09 08:56:02 +02:00
basic kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
clang-tools gen_compile_commands: fix missing 'sys' package 2021-09-22 12:27:58 +02:00
coccinelle Merge branch 'for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux 2020-10-18 14:20:35 -07:00
dtc scripts/dtc: Call pkg-config POSIXly correct 2022-04-08 14:40:15 +02:00
dummy-tools kbuild: dummy-tools: avoid tmpdir leak in dummy gcc 2022-08-25 11:38:01 +02:00
gcc-plugins gcc-plugins: latent_entropy: use /dev/urandom 2022-04-20 09:23:26 +02:00
gdb scripts/gdb: change kernel config dumping method 2022-06-14 18:32:45 +02:00
genksyms genksyms: keywords: Use __restrict not _restrict 2020-08-18 20:16:46 +09:00
kconfig kconfig: fix failing to generate auto.conf 2022-02-23 12:01:07 +01:00
ksymoops
mod modpost: fix section mismatch check for exported init/exit sections 2022-06-29 08:59:54 +02:00
package builddeb: Fix rootless build in setuid/setgid directory 2020-11-02 11:31:00 +09:00
selinux scripts/selinux,selinux: update mdp to enable policy capabilities 2020-08-17 20:42:00 -04:00
tracing scripts/tracing: fix the bug that can't parse raw_trace_func 2021-08-12 13:22:12 +02:00
.gitignore kbuild: preprocess module linker script 2020-09-25 00:36:41 +09:00
adjust_autoksyms.sh kbuild: split adjust_autoksyms.sh in two parts 2020-03-03 20:49:21 +09:00
asn1_compiler.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
bin2c.c kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
bloat-o-meter scripts: switch explicitly to Python 3 2021-05-22 11:40:55 +02:00
bootgraph.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 391 2019-06-05 17:37:11 +02:00
bpf_helpers_doc.py bpf: Add struct bpf_redir_neigh forward declaration to BPF helper defs 2020-10-29 15:19:04 +01:00
cc-can-link.sh bpfilter: check compiler capability in Kconfig 2018-06-28 13:36:39 +09:00
check_extable.sh
check-sysctl-docs docs: add a script to check sysctl docs 2020-02-25 03:35:16 -07:00
checkincludes.pl
checkkconfigsymbols.py kconfig: remove '---help---' support 2020-08-14 13:30:03 +09:00
checkpatch.pl checkpatch: fix unescaped left brace 2020-12-30 11:53:56 +01:00
checkstack.pl scripts/checkstack.pl: fix arm sp regex 2020-05-26 00:03:16 +09:00
checksyscalls.sh checksyscalls: fix up mq_timedreceive and stat exceptions 2019-02-19 21:27:53 +01:00
checkversion.pl
clang-version.sh kbuild: update comment block of scripts/clang-version.sh 2019-03-04 22:34:54 +09:00
cleanfile
cleanpatch
coccicheck scripts: coccicheck: Change default condition for parallelism 2020-10-12 10:37:56 +02:00
config tweewide: Fix most Shebang lines 2021-05-22 11:40:55 +02:00
const_structs.checkpatch const_structs.checkpatch: add pinctrl_ops and pinmux_ops 2020-10-16 11:11:21 -07:00
decode_stacktrace.sh scripts/decode_stacktrace.sh: guess path to vmlinux by release name 2020-08-07 11:33:21 -07:00
decodecode scripts/decodecode: add the capability to supply the program counter 2020-10-13 18:38:26 -07:00
depmod.sh depmod: handle the case of /sbin/depmod without /sbin in PATH 2021-01-12 20:18:16 +01:00
dev-needs.sh scripts/dev-needs: Add script to list device dependencies 2020-09-04 18:19:37 +02:00
diffconfig scripts: switch explicitly to Python 3 2021-05-22 11:40:55 +02:00
documentation-file-ref-check scripts: documentation-file-ref-check: Add line break before exit 2020-04-15 15:13:13 -06:00
export_report.pl modpost: move the namespace field in Module.symvers last 2020-03-17 08:59:03 +09:00
extract_xc3028.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 339 2019-06-05 17:37:07 +02:00
extract-cert.c extract-cert: add static to local data 2020-08-18 20:16:46 +09:00
extract-ikconfig
extract-module-sig.pl
extract-sys-certs.pl
extract-vmlinux treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378 2019-06-05 17:37:10 +02:00
faddr2line scripts/faddr2line: Fix vmlinux detection on arm64 2022-08-21 15:16:12 +02:00
file-size.sh kbuild: Use ls(1) instead of stat(1) to obtain file size 2018-03-26 02:01:24 +09:00
find-unused-docs.sh scripts/find-unused-docs: Fix massive false positives 2020-01-27 14:25:06 -07:00
gcc-goto.sh jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
gcc-ld
gcc-version.sh kbuild: clean up scripts/gcc-version.sh 2019-03-04 22:35:04 +09:00
gcc-x86_32-has-stack-protector.sh stack-protector: test compiler capability in Kconfig and drop AUTO mode 2018-06-08 18:56:00 +09:00
gcc-x86_64-has-stack-protector.sh stack-protector: Fix test with 32-bit userland and CONFIG_64BIT=y 2018-06-25 23:21:13 +09:00
gen_autoksyms.sh kbuild: fix CONFIG_TRIM_UNUSED_KSYMS build for ppc64 2021-02-26 10:13:01 +01:00
gen_ksymdeps.sh kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y 2021-09-18 13:40:16 +02:00
get_abi.pl tweewide: Fix most Shebang lines 2021-05-22 11:40:55 +02:00
get_dvb_firmware treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 2019-05-24 17:36:45 +02:00
get_maintainer.pl get_maintainer: exclude MAINTAINERS file(s) from --git-fallback 2020-10-16 11:11:19 -07:00
gfp-translate treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 166 2019-05-30 11:26:39 -07:00
headerdep.pl
headers_check.pl
headers_install.sh Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
insert-sys-cert.c
jobserver-exec docs, parallelism: Rearrange how jobserver reservations are made 2019-11-22 10:35:18 -07:00
kallsyms.c kallsyms: fix nonconverging kallsyms table with lld 2021-02-17 11:02:24 +01:00
Kbuild.include kbuild: sink stdout from cmd for silent build 2021-07-25 14:36:12 +02:00
Kconfig.include kconfig: unify cc-option and as-option 2020-06-17 10:38:42 +09:00
kernel-doc scripts: kernel-doc: fix parsing function-like typedefs 2020-12-30 11:53:33 +01:00
ld-version.sh
leaking_addresses.pl leaking_addresses: Always print a trailing newline 2021-11-18 14:03:57 +01:00
Lindent
link-vmlinux.sh x86/retbleed: Add fine grained Kconfig knobs 2022-07-25 11:26:50 +02:00
lld-version.sh scripts/lld-version.sh: Rewrite based on upstream ld-version.sh 2021-11-21 13:46:37 +01:00
Makefile certs: Add ability to preload revocation certs 2021-06-30 08:47:30 -04:00
Makefile.asm-generic kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
Makefile.build x86/retbleed: Add fine grained Kconfig knobs 2022-07-25 11:26:50 +02:00
Makefile.clean kbuild: introduce hostprogs-always-y and userprogs-always-y 2020-08-10 01:32:59 +09:00
Makefile.dtbinst kbuild: refactor Makefile.dtbinst more 2020-03-25 10:19:43 +09:00
Makefile.extrawarn Makefile.extrawarn: Move -Wunaligned-access to W=1 2022-02-16 12:54:30 +01:00
Makefile.gcc-plugins gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file 2022-08-25 11:38:10 +02:00
Makefile.headersinst kbuild: move headers_check rule to usr/include/Makefile 2019-11-15 00:23:10 +09:00
Makefile.host kbuild: sort hostprogs before passing it to ifneq 2020-08-10 01:32:59 +09:00
Makefile.kasan kasan: fix hwasan build for gcc 2021-04-28 13:40:02 +02:00
Makefile.kcov kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled 2020-08-10 01:32:59 +09:00
Makefile.kcsan Kbuild updates for v5.10 2020-10-22 13:13:57 -07:00
Makefile.lib dt-bindings: Use json for processed-schema* 2020-08-19 14:31:57 -06:00
Makefile.modfinal kbuild: preprocess module linker script 2020-09-25 00:36:41 +09:00
Makefile.modinst kbuild: modinst: read modules.order instead of $(MODVERDIR)/*.mod 2019-07-17 22:39:27 +09:00
Makefile.modpost kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
Makefile.modsign kbuild: modsign: read modules.order instead of $(MODVERDIR)/*.mod 2019-07-17 22:39:27 +09:00
Makefile.package kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables 2020-06-11 20:14:41 +09:00
Makefile.ubsan ubsan: remove CONFIG_UBSAN_OBJECT_SIZE 2022-04-13 21:01:10 +02:00
Makefile.userprogs kbuild: add infrastructure to build userspace programs 2020-05-17 18:52:01 +09:00
makelst
markup_oops.pl treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 373 2019-06-05 17:37:10 +02:00
mkcompile_h kbuild: mkcompile_h: consider timestamp if KBUILD_BUILD_TIMESTAMP is set 2021-07-25 14:36:16 +02:00
mkmakefile kbuild: get rid of $(realpath ...) from scripts/mkmakefile 2019-08-29 23:54:29 +09:00
mksysmap mksysmap: Fix the mismatch of '.L' symbols in System.map 2020-06-06 23:39:20 +09:00
mkuboot.sh
module.lds.S modules: Ensure natural alignment for .altinstructions and __bug_table sections 2022-08-25 11:38:19 +02:00
modules-check.sh kbuild: make module name conflict fatal error 2020-05-26 00:03:16 +09:00
nsdeps scripts: add dummy report mode to add_namespace.cocci 2020-07-10 14:19:58 +02:00
objdiff treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 199 2019-05-30 11:29:23 -07:00
parse-maintainers.pl parse-maintainers: Do not sort section content by default 2020-03-26 15:08:27 -07:00
patch-kernel
profile2linkerlist.pl
prune-kernel
recordmcount.c ftrace: Have recordmcount use w8 to read relp->r_info in arm64_is_fake_mcount 2021-03-09 11:11:14 +01:00
recordmcount.h recordmcount: Correct st_shndx handling 2021-06-30 08:47:23 -04:00
recordmcount.pl recordmcount.pl: fix typo in s390 mcount regex 2022-01-05 12:40:29 +01:00
setlocalversion scripts/setlocalversion: make git describe output more reliable 2020-09-25 02:28:12 +09:00
show_delta tweewide: Fix most Shebang lines 2021-05-22 11:40:55 +02:00
sign-file.c
sorttable.c s390/kernel: expand exception table logic to allow new handling options 2020-07-20 10:55:50 +02:00
sorttable.h scripts/sorttable: Implement build-time ORC unwind table sorting 2019-12-13 10:47:58 +01:00
spdxcheck-test.sh scripts: add spdxcheck.py self test 2018-12-28 12:11:44 -08:00
spdxcheck.py scripts/spdxcheck.py: handle license identifiers in XML comments 2020-10-02 11:31:26 +02:00
spelling.txt Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2020-10-15 15:11:56 -07:00
sphinx-pre-install scripts: sphinx-pre-install: Fix ctex support on Debian 2022-01-27 10:54:36 +01:00
split-man.pl tweewide: Fix most Shebang lines 2021-05-22 11:40:55 +02:00
stackdelta
stackusage
subarch.include selftests: add headers_install to lib.mk 2018-09-05 08:12:09 -06:00
tags.sh Merge branch 'locking/urgent' into locking/core, to pick up fixes 2020-10-09 08:55:17 +02:00
tools-support-relr.sh Makefile: fix GDB warning with CONFIG_RELR 2021-07-14 16:55:53 +02:00
unifdef.c unifdef: use memcpy instead of strncpy 2018-11-30 14:45:01 -08:00
ver_linux ver_linux: Query ld cache for versions of libc/libcpp run-time 2020-02-10 13:35:15 -08:00
xen-hypercalls.sh
xz_wrap.sh kbuild: add variables for compression tools 2020-06-06 23:42:01 +09:00