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Josh Poimboeuf 05026ea01e objtool, lkdtm: Obfuscate the do_nothing() pointer
If execute_location()'s memcpy of do_nothing() gets inlined and unrolled
by the compiler, it copies one word at a time:

    mov    0x0(%rip),%rax    R_X86_64_PC32    .text+0x1374
    mov    %rax,0x38(%rbx)
    mov    0x0(%rip),%rax    R_X86_64_PC32    .text+0x136c
    mov    %rax,0x30(%rbx)
    ...

Those .text references point to the middle of the function, causing
objtool to complain about their lack of ENDBR.

Prevent that by resolving the function pointer at runtime rather than
build time.  This fixes the following warning:

  drivers/misc/lkdtm/lkdtm.o: warning: objtool: execute_location+0x23: relocation to !ENDBR: .text+0x1378

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/30b9abffbddeb43c4f6320b1270fa9b4d74c54ed.1742852847.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/202503191453.uFfxQy5R-lkp@intel.com/
2025-03-28 14:38:09 +01:00
arch objtool: Fix X86_FEATURE_SMAP alternative handling 2025-03-25 09:20:26 +01:00
block cgroup: Changes for v6.15 2025-03-24 16:49:40 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
Documentation x86/build updates for v6.15: 2025-03-24 22:23:23 -07:00
drivers objtool, lkdtm: Obfuscate the do_nothing() pointer 2025-03-28 14:38:09 +01:00
fs Scheduler updates for v6.15: 2025-03-24 21:28:12 -07:00
include objtool: Fix up some outdated references to ENTRY/ENDPROC 2025-03-25 09:20:27 +01:00
init [ Merge note: this pull request depends on you having merged 2025-03-24 22:06:11 -07:00
io_uring io_uring-6.14-20250322 2025-03-22 10:45:44 -07:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel objtool, panic: Disable SMAP in __stack_chk_fail() 2025-03-25 23:00:15 +01:00
lib [ Merge note: this pull request depends on you having merged 2025-03-24 22:06:11 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm [ Merge note: this pull request depends on you having merged 2025-03-24 22:06:11 -07:00
net vfs-6.15-rc1.afs 2025-03-24 13:15:16 -07:00
rust Locking changes for v6.15: 2025-03-24 20:55:03 -07:00
samples hardening updates for v6.15-rc1 2025-03-24 15:18:08 -07:00
scripts objtool: Remove --no-unreachable for noinstr-only vmlinux.o runs 2025-03-25 09:20:27 +01:00
security hardening updates for v6.15-rc1 2025-03-24 15:18:08 -07:00
sound objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler() 2025-03-25 23:00:16 +01:00
tools objtool, panic: Disable SMAP in __stack_chk_fail() 2025-03-25 23:00:15 +01:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt vfs-6.15-rc1.misc 2025-03-24 09:13:50 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.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 rust: use host dylib naming convention to support macOS 2025-01-10 01:01:24 +01:00
.mailmap platform-drivers-x86 for v6.14-5 2025-03-14 10:57:28 -10:00
.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 MAINTAINERS: Move Pavel to kernel.org address 2025-02-07 09:12:33 -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 bitmap changes for 6.15 2025-03-24 19:11:58 -07:00
Makefile [ Merge note: this pull request depends on you having merged 2025-03-24 22:06:11 -07:00
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.