95 Commits
Author SHA1 Message Date
Alexandre ChartreandPeter Zijlstra aff95e0d4e objtool: Add wide output for disassembly
Add the --wide option to provide a wide output when disassembling.
With this option, the disassembly of alternatives is displayed
side-by-side instead of one above the other.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-30-alexandre.chartre@oracle.com
2025-11-24 20:40:48 +01:00
Alexandre ChartreandPeter Zijlstra 5f326c8897 objtool: Add the --disas=<function-pattern> action
Add the --disas=<function-pattern> actions to disassemble the specified
functions. The function pattern can be a single function name (e.g.
--disas foo to disassemble the function with the name "foo"), or a shell
wildcard pattern (e.g. --disas foo* to disassemble all functions with a
name starting with "foo").

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-18-alexandre.chartre@oracle.com
2025-11-21 15:30:12 +01:00
Alexandre ChartreandPeter Zijlstra 70589843b3 objtool: Add option to trace function validation
Add an option to trace and have information during the validation
of specified functions. Functions are specified with the --trace
option which can be a single function name (e.g. --trace foo to
trace the function with the name "foo"), or a shell wildcard
pattern (e.g. --trace foo* to trace all functions with a name
starting with "foo").

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-11-alexandre.chartre@oracle.com
2025-11-21 15:30:09 +01:00
Josh PoimboeufandPeter Zijlstra ee0b48faba objtool: Set minimum xxhash version to 0.8
XXH3 is only supported starting with xxhash 0.8.  Enforce that.

Fixes: 0d83da43b1 ("objtool/klp: Add --checksum option to generate per-function checksums")
Closes: https://lore.kernel.org/SN6PR02MB41579B83CD295C9FEE40EED6D4FCA@SN6PR02MB4157.namprd02.prod.outlook.com
Reported-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Link: https://patch.msgid.link/7227c94692a3a51840278744c7af31b4797c6b96.1762990139.git.jpoimboe@kernel.org
2025-11-18 09:59:25 +01:00
Borislav Petkov (AMD) da247eff96 objtool/klp: Add the debian-based package name of xxhash to the hint
Add the debian package name for the devel version of the xxHash package
"libxxhash-dev".

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20251017194732.7713-1-bp@kernel.org
2025-10-22 13:51:11 +02:00
Josh Poimboeuf a3493b3338 objtool/klp: Add --debug-checksum=<funcs> to show per-instruction checksums
Add a --debug-checksum=<funcs> option to the check subcommand to print
the calculated checksum of each instruction in the given functions.

This is useful for determining where two versions of a function begin to
diverge.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14 14:50:18 -07:00
Josh Poimboeuf 0d83da43b1 objtool/klp: Add --checksum option to generate per-function checksums
In preparation for the objtool klp diff subcommand, add a command-line
option to generate a unique checksum for each function.  This will
enable detection of functions which have changed between two versions of
an object file.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14 14:50:17 -07:00
Josh Poimboeuf 03c19a99ee objtool: Add elf_create_file()
Add interface to enable the creation of a new ELF file.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14 14:46:49 -07:00
Josh Poimboeuf 935c0b6a05 objtool: Reindent check_options[]
Bring the cmdline check_options[] array back into vertical alignment for
better readability.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14 14:46:48 -07:00
Josh Poimboeuf 2b91479776 objtool: Resurrect --backup option
The --backup option was removed with the following commit:

  aa8b3e64fd ("objtool: Create backup on error and print args")

... which tied the backup functionality to --verbose, and only for
warnings/errors.

It's a bit inelegant and out of scope to tie that to --verbose.

Bring back the old --backup option, but with the new behavior: only on
warnings/errors, and print the args to make it easier to recreate.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14 14:46:48 -07:00
Josh Poimboeuf 56754f0f46 objtool: Rename --Werror to --werror
The objtool --Werror option name is stylistically inconsistent: halfway
between GCC's single-dash capitalized -Werror and objtool's double-dash
--lowercase convention, making it unnecessarily hard to remember.

Make the 'W' lower case (--werror) for consistency with objtool's other
options.

Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14 14:46:48 -07:00
Chen NiandJosh Poimboeuf 2e985fdb7e objtool: Remove unneeded semicolon
Remove unnecessary semicolons reported by Coccinelle/coccicheck and the
semantic patch at scripts/coccinelle/misc/semicolon.cocci.

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14 14:45:20 -07:00
Ard BiesheuvelandBorislav Petkov (AMD) 0d6e4563fc objtool: Add action to check for absence of absolute relocations
The x86 startup code must not use absolute references to code or data,
as it executes before the kernel virtual mapping is up.

Add an action to objtool to check all allocatable sections (with the
exception of __patchable_function_entries, which uses absolute
references for nebulous reasons) and raise an error if any absolute
references are found.

Note that debug sections typically contain lots of absolute references
too, but those are not allocatable so they will be ignored.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/20250828102202.1849035-39-ardb+git@google.com
2025-09-03 17:59:51 +02:00
Josh PoimboeufandIngo Molnar 3e7be63593 objtool: Change "warning:" to "error: " for fatal errors
This is similar to GCC's behavior and makes it more obvious why the
build failed.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/0ea76f4b0e7a370711ed9f75fd0792bb5979c2bf.1743481539.git.jpoimboe@kernel.org
2025-04-01 09:07:13 +02:00
Josh PoimboeufandIngo Molnar d9a595c385 objtool: Fix NULL printf() '%s' argument in builtin-check.c:save_argv()
It's probably not the best idea to pass a string pointer to printf()
right after confirming said pointer is NULL.  Fix the typo and use
argv[i] instead.

Fixes: c5995abe15 ("objtool: Improve error handling")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/a814ed8b08fb410be29498a20a5fbbb26e907ecf.1742952512.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/20250326103854.309e3c60@canb.auug.org.au
2025-03-28 14:38:09 +01:00
Josh PoimboeufandIngo Molnar d39f82a058 objtool: Reduce CONFIG_OBJTOOL_WERROR verbosity
Remove the following from CONFIG_OBJTOOL_WERROR:

  * backtrace

  * "upgraded warnings to errors" message

  * cmdline args

This makes the default output less cluttered and makes it easier to spot
the actual warnings.  Note the above options are still are available
with --verbose or OBJTOOL_VERBOSE=1.

Also, do the cmdline arg printing on all warnings, regardless of werror.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/d61df69f64b396fa6b2a1335588aad7a34ea9e71.1742852846.git.jpoimboe@kernel.org
2025-03-25 09:20:27 +01:00
Josh PoimboeufandIngo Molnar c5995abe15 objtool: Improve error handling
Fix some error handling issues, improve error messages, properly
distinguish betwee errors and warnings, and generally try to make all
the error handling more consistent.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/3094bb4463dad29b6bd1bea03848d1571ace771c.1742852846.git.jpoimboe@kernel.org
2025-03-25 09:20:27 +01:00
Ingo Molnar 73070466ed objtool: Use O_CREAT with explicit mode mask
Recent Ubuntu enforces 3-argument open() with O_CREAT:

      CC      /home/mingo/tip/tools/objtool/builtin-check.o
    In file included from /usr/include/fcntl.h:341,
                     from builtin-check.c:9:
    In function ‘open’,
        inlined from ‘copy_file’ at builtin-check.c:201:11:
    /usr/include/x86_64-linux-gnu/bits/fcntl2.h:52:11: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments
       52 |           __open_missing_mode ();
          |           ^~~~~~~~~~~~~~~~~~~~~~

Use 0400 as the most restrictive mode for the new file.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
2025-03-17 12:24:02 +01:00
Josh PoimboeufandPeter Zijlstra aa8b3e64fd objtool: Create backup on error and print args
Recreating objtool errors can be a manual process.  Kbuild removes the
object, so it has to be compiled or linked again before running objtool.
Then the objtool args need to be reversed engineered.

Make that all easier by automatically making a backup of the object file
on error, and print a modified version of the args which can be used to
recreate.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/7571e30636359b3e173ce6e122419452bb31882f.1741975349.git.jpoimboe@kernel.org
2025-03-17 11:36:02 +01:00
Josh PoimboeufandPeter Zijlstra bb62243943 objtool: Add --Werror option
Any objtool warning has the potential of reflecting (or triggering) a
major bug in the kernel or compiler which could result in crashing the
kernel or breaking the livepatch consistency model.

In preparation for failing the build on objtool errors/warnings, add a
new --Werror option.

[ jpoimboe: commit log, comments, error out on fatal errors too ]

Co-developed-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/e423ea4ec297f510a108aa6c78b52b9fe30fa8c1.1741975349.git.jpoimboe@kernel.org
2025-03-17 11:36:01 +01:00
Josh PoimboeufandPeter Zijlstra 5a406031d0 objtool: Add --output option
Add option to allow writing the changed binary to a separate file rather
than changing it in place.

Libelf makes this suprisingly hard, so take the easy way out and just
copy the file before editing it.

Also steal the -o short option from --orc.  Nobody will notice ;-)

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/0da308d42d82b3bbed16a31a72d6bde52afcd6bd.1741975349.git.jpoimboe@kernel.org
2025-03-17 11:36:01 +01:00
Josh PoimboeufandPeter Zijlstra fdf5ff2934 objtool: Upgrade "Linked object detected" warning to error
Force the user to fix their cmdline if they forget the '--link' option.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/r/8380bbf3a0fa86e03fd63f60568ae06a48146bc1.1741975349.git.jpoimboe@kernel.org
2025-03-17 11:36:01 +01:00
Josh PoimboeufandPeter Zijlstra acc8c6a798 objtool: Consolidate option validation
The option validations are a bit scattered, consolidate them.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/r/8f886502fda1d15f39d7351b70d4ebe5903da627.1741975349.git.jpoimboe@kernel.org
2025-03-17 11:36:01 +01:00
Josh PoimboeufandPeter Zijlstra 764d956145 objtool: Remove --unret dependency on --rethunk
With unret validation enabled and IBT/LTO disabled, objtool runs on TUs
with --rethunk and on vmlinux.o with --unret.  So this dependency isn't
valid as they don't always run on the same object.

This error never triggered before because --unret is always coupled with
--noinstr, so the first conditional in opts_valid() returns early due to
opts.noinstr being true.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/c6f5635784a28ed4b10ac4307b1858e015e6eff0.1741975349.git.jpoimboe@kernel.org
2025-03-17 11:36:00 +01:00
Siddh Raman PantandJosh Poimboeuf b13e9f6da4 objtool: Use "action" in error message to be consistent with help
The help message mentions the main options as "actions", which is
different from the optional "options". But the check error messages
outputs "option" or "command" for referring to actions.

Make the error messages consistent with help.

Signed-off-by: Siddh Raman Pant <siddh.raman.pant@oracle.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-07-02 23:40:24 -07:00