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 <[email protected]>
Signed

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 <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/0ea76f4b0e7a370711ed9f75fd0792bb5979c2bf.1743481539.git.jpoimboe@kernel.org

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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 typ

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: c5995abe1547 ("objtool: Improve error handling")
Reported-by: Stephen Rothwell <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Tested-by: Stephen Rothwell <[email protected]>
Link: https://lore.kernel.org/r/a814ed8b08fb410be29498a20a5fbbb26e907ecf.1742952512.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/[email protected]

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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 o

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 <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/d61df69f64b396fa6b2a1335588aad7a34ea9e71.1742852846.git.jpoimboe@kernel.org

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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 consist

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 <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/3094bb4463dad29b6bd1bea03848d1571ace771c.1742852846.git.jpoimboe@kernel.org

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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/includ

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 <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]

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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 th

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 <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/7571e30636359b3e173ce6e122419452bb31882f.1741975349.git.jpoimboe@kernel.org

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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 livep

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 <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/e423ea4ec297f510a108aa6c78b52b9fe30fa8c1.1741975349.git.jpoimboe@kernel.org

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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 jus

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 <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/0da308d42d82b3bbed16a31a72d6bde52afcd6bd.1741975349.git.jpoimboe@kernel.org

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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 <[email protected]>
Signed-off-by:

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 <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Brendan Jackman <[email protected]>
Link: https://lore.kernel.org/r/8380bbf3a0fa86e03fd63f60568ae06a48146bc1.1741975349.git.jpoimboe@kernel.org

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objtool: Consolidate option validation

The option validations are a bit scattered, consolidate them.

Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <peter

objtool: Consolidate option validation

The option validations are a bit scattered, consolidate them.

Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Brendan Jackman <[email protected]>
Link: https://lore.kernel.org/r/8f886502fda1d15f39d7351b70d4ebe5903da627.1741975349.git.jpoimboe@kernel.org

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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

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 <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/c6f5635784a28ed4b10ac4307b1858e015e6eff0.1741975349.git.jpoimboe@kernel.org

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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 message

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 <[email protected]>
Signed-off-by: Josh Poimboeuf <[email protected]>

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objtool: Add verbose option for disassembling affected functions

When a warning is associated with a function, add an option to
disassemble that function.

This makes it easier for reporters to subm

objtool: Add verbose option for disassembling affected functions

When a warning is associated with a function, add an option to
disassemble that function.

This makes it easier for reporters to submit the information needed to
diagnose objtool warnings.

Reviewed-by: Miroslav Benes <[email protected]>
Link: https://lore.kernel.org/r/dd0fe13428ede186f09c74059a8001f4adcea5fc.1681853186.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <[email protected]>

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objtool: Make struct check_options static

It is not used outside of builtin-check.c.

Also remove the unused declaration from builtin.h .

Signed-off-by: Thomas Weißschuh <[email protected]>
Link

objtool: Make struct check_options static

It is not used outside of builtin-check.c.

Also remove the unused declaration from builtin.h .

Signed-off-by: Thomas Weißschuh <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Josh Poimboeuf <[email protected]>

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objtool: Add --mnop as an option to --mcount

Some architectures (powerpc) may not support ftrace locations being nop'ed
out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as
a

objtool: Add --mnop as an option to --mcount

Some architectures (powerpc) may not support ftrace locations being nop'ed
out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as
a means for architectures to enable nop'ing of ftrace locations. Add --mnop
as an option to objtool --mcount, to indicate support for the same.

Also, make sure that --mnop can be passed as an option to objtool only when
--mcount is passed.

Tested-by: Naveen N. Rao <[email protected]>
Reviewed-by: Naveen N. Rao <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Sathvika Vasireddy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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objtool: Add --cfi to generate the .cfi_sites section

Add the location of all __cfi_##name symbols (as generated by kCFI) to
a section such that we might re-write things at kernel boot.

Notably; bo

objtool: Add --cfi to generate the .cfi_sites section

Add the location of all __cfi_##name symbols (as generated by kCFI) to
a section such that we might re-write things at kernel boot.

Notably; boot time re-hashing and FineIBT are the intended use of
this.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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objtool: Add option to generate prefix symbols

When code is compiled with:

-fpatchable-function-entry=${PADDING_BYTES},${PADDING_BYTES}

functions will have PADDING_BYTES of NOP in front of them.

objtool: Add option to generate prefix symbols

When code is compiled with:

-fpatchable-function-entry=${PADDING_BYTES},${PADDING_BYTES}

functions will have PADDING_BYTES of NOP in front of them. Unwinders
and other things that symbolize code locations will typically
attribute these bytes to the preceding function.

Given that these bytes nominally belong to the following symbol this
mis-attribution is confusing.

Inspired by the fact that CFI_CLANG emits __cfi_##name symbols to
claim these bytes, allow objtool to emit __pfx_##name symbols to do
the same.

Therefore add the objtool --prefix=N argument, to conditionally place
a __pfx_##name symbol at N bytes ahead of symbol 'name' when: all
these preceding bytes are NOP and name-N is an instruction boundary.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Yujie Liu <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

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objtool: Add --hacks=skylake

Make the call/func sections selectable via the --hacks option.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Thomas Gleixner <tglx@linutro

objtool: Add --hacks=skylake

Make the call/func sections selectable via the --hacks option.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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x86/retbleed: Add fine grained Kconfig knobs

Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't support return thunks this will
silently 'upgrade' your mitig

x86/retbleed: Add fine grained Kconfig knobs

Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't support return thunks this will
silently 'upgrade' your mitigation to IBPB, you might not like this.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>

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objtool: Add entry UNRET validation

Since entry asm is tricky, add a validation pass that ensures the
retbleed mitigation has been done before the first actual RET
instruction.

Entry points are tho

objtool: Add entry UNRET validation

Since entry asm is tricky, add a validation pass that ensures the
retbleed mitigation has been done before the first actual RET
instruction.

Entry points are those that either have UNWIND_HINT_ENTRY, which acts
as UNWIND_HINT_EMPTY but marks the instruction as an entry point, or
those that have UWIND_HINT_IRET_REGS at +0.

This is basically a variant of validate_branch() that is
intra-function and it will simply follow all branches from marked
entry points and ensures that all paths lead to ANNOTATE_UNRET_END.

If a path hits RET or an indirection the path is a fail and will be
reported.

There are 3 ANNOTATE_UNRET_END instances:

- UNTRAIN_RET itself
- exception from-kernel; this path doesn't need UNTRAIN_RET
- all early exceptions; these also don't need UNTRAIN_RET

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>

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objtool: Remove --lto and --vmlinux in favor of --link

The '--lto' option is a confusing way of telling objtool to do stack
validation despite it being a linked object. It's no longer needed now
th

objtool: Remove --lto and --vmlinux in favor of --link

The '--lto' option is a confusing way of telling objtool to do stack
validation despite it being a linked object. It's no longer needed now
that an explicit '--stackval' option exists. The '--vmlinux' option is
also redundant.

Remove both options in favor of a straightforward '--link' option which
identifies a linked object.

Also, implicitly set '--link' with a warning if the user forgets to do
so and we can tell that it's a linked object. This makes it easier for
manual vmlinux runs.

Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Link: https://lkml.kernel.org/r/dcd3ceffd15a54822c6183e5766d21ad06082b45.1650300597.git.jpoimboe@redhat.com

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objtool: Make noinstr hacks optional

Objtool has some hacks in place to workaround toolchain limitations
which otherwise would break no-instrumentation rules. Make the hacks
explicit (and optional

objtool: Make noinstr hacks optional

Objtool has some hacks in place to workaround toolchain limitations
which otherwise would break no-instrumentation rules. Make the hacks
explicit (and optional for other arches) by turning it into a cmdline
option and kernel config option.

Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Link: https://lkml.kernel.org/r/b326eeb9c33231b9dfbb925f194ed7ee40edcd7c.1650300597.git.jpoimboe@redhat.com

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objtool: Make jump label hack optional

Objtool secretly does a jump label hack to overcome the limitations of
the toolchain. Make the hack explicit (and optional for other arches)
by turning it int

objtool: Make jump label hack optional

Objtool secretly does a jump label hack to overcome the limitations of
the toolchain. Make the hack explicit (and optional for other arches)
by turning it into a cmdline option and kernel config option.

Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Link: https://lkml.kernel.org/r/3bdcbfdd27ecb01ddec13c04bdf756a583b13d24.1650300597.git.jpoimboe@redhat.com

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objtool: Make static call annotation optional

As part of making objtool more modular, put the existing static call
code behind a new '--static-call' option.

Signed-off-by: Josh Poimboeuf <jpoimboe@

objtool: Make static call annotation optional

As part of making objtool more modular, put the existing static call
code behind a new '--static-call' option.

Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Link: https://lkml.kernel.org/r/d59ac57ef3d6d8380cdce20322314c9e2e556750.1650300597.git.jpoimboe@redhat.com

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objtool: Make stack validation frame-pointer-specific

Now that CONFIG_STACK_VALIDATION is frame-pointer specific, do the same
for the '--stackval' option. Now the '--no-fp' option is redundant and

objtool: Make stack validation frame-pointer-specific

Now that CONFIG_STACK_VALIDATION is frame-pointer specific, do the same
for the '--stackval' option. Now the '--no-fp' option is redundant and
can be removed.

Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Link: https://lkml.kernel.org/r/f563fa064b3b63d528de250c72012d49e14742a3.1650300597.git.jpoimboe@redhat.com

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