linux-stable.git/tools/objtool/check.c, branch v7.0.2

x86-64: rename misleadingly named '__copy_user_nocache()' function

2026-04-22T11:32:21+00:00

commit d187a86de793f84766ea40b9ade7ac60aabbb4fe upstream.

This function was a masterclass in bad naming, for various historical
reasons.

It claimed to be a non-cached user copy.  It is literally _neither_ of
those things.  It's a specialty memory copy routine that uses
non-temporal stores for the destination (but not the source), and that
does exception handling for both source and destination accesses.

Also note that while it works for unaligned targets, any unaligned parts
(whether at beginning or end) will not use non-temporal stores, since
only words and quadwords can be non-temporal on x86.

The exception handling means that it _can_ be used for user space
accesses, but not on its own - it needs all the normal "start user space
access" logic around it.

But typically the user space access would be the source, not the
non-temporal destination.  That was the original intention of this,
where the destination was some fragile persistent memory target that
needed non-temporal stores in order to catch machine check exceptions
synchronously and deal with them gracefully.

Thus that non-descriptive name: one use case was to copy from user space
into a non-cached kernel buffer.  However, the existing users are a mix
of that intended use-case, and a couple of random drivers that just did
this as a performance tweak.

Some of those random drivers then actively misused the user copying
version (with STAC/CLAC and all) to do kernel copies without ever even
caring about the exception handling, _just_ for the non-temporal
destination.

Rename it as a first small step to actually make it halfway sane, and
change the prototype to be more normal: it doesn't take a user pointer
unless the caller has done the proper conversion, and the argument size
is the full size_t (it still won't actually copy more than 4GB in one
go, but there's also no reason to silently truncate the size argument in
the caller).

Finally, use this now sanely named function in the NTB code, which
mis-used a user copy version (with STAC/CLAC and all) of this interface
despite it not actually being a user copy at all.

Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

objtool: Fix Clang jump table detection

2026-03-16T22:31:25+00:00

With Clang, there can be a conditional forward jump between the load of
the jump table address and the indirect branch.

Fixes the following warning:

  vmlinux.o: warning: objtool: ___bpf_prog_run+0x1c5: sibling call from callable instruction with modified stack frame

Reported-by: Arnd Bergmann 
Closes: https://lore.kernel.org/a426d669-58bb-4be1-9eaa-6f3d83109e2d@app.fastmail.com
Link: https://patch.msgid.link/7d8600caed08901b6679767488acd639f6df9688.1773071992.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf

objtool: Fix another stack overflow in validate_branch()

2026-03-09T15:45:13+00:00

The insn state is getting saved on the stack twice for each recursive
iteration.  No need for that, once is enough.

Fixes the following reported stack overflow:

  drivers/scsi/qla2xxx/qla_dbg.o: error: SIGSEGV: objtool stack overflow!
  Segmentation fault

Fixes: 70589843b36f ("objtool: Add option to trace function validation")
Reported-by: Arnd Bergmann 
Closes: https://lore.kernel.org/90956545-2066-46e3-b547-10c884582eb0@app.fastmail.com
Link: https://patch.msgid.link/8b97f62d083457f3b0a29a424275f7957dd3372f.1772821683.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf

objtool: Handle Clang RSP musical chairs

2026-03-09T15:45:10+00:00

For no apparent reason (possibly related to CONFIG_KMSAN), Clang can
randomly pass the value of RSP to other registers and then back again to
RSP.  Handle that accordingly.

Fixes the following warnings:

  drivers/input/misc/uinput.o: warning: objtool: uinput_str_to_user+0x165: undefined stack state
  drivers/input/misc/uinput.o: warning: objtool: uinput_str_to_user+0x165: unknown CFA base reg -1

Reported-by: Arnd Bergmann 
Closes: https://lore.kernel.org/90956545-2066-46e3-b547-10c884582eb0@app.fastmail.com
Link: https://patch.msgid.link/240e6a172cc73292499334a3724d02ccb3247fc7.1772818491.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf

Merge tag 'rust-fixes-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

2026-02-22T16:43:31+00:00

Pull rust fixes from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Pass '-Zunstable-options' flag required by the future Rust 1.95.0

   - Fix 'objtool' warning for Rust 1.84.0

  'kernel' crate:

   - 'irq' module: add missing bound detected by the future Rust 1.95.0

   - 'list' module: add missing 'unsafe' blocks and placeholder safety
     comments to macros (an issue for future callers within the crate)

  'pin-init' crate:

   - Clean Clippy warning that changed behavior in the future Rust
     1.95.0"

* tag 'rust-fixes-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
  rust: list: Add unsafe blocks for container_of and safety comments
  rust: pin-init: replace clippy `expect` with `allow`
  rust: irq: add `'static` bounds to irq callbacks
  objtool/rust: add one more `noreturn` Rust function
  rust: kbuild: pass `-Zunstable-options` for Rust 1.95.0

Merge tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-02-11T03:01:45+00:00

Pull x86 paravirt updates from Borislav Petkov:

 - A nice cleanup to the paravirt code containing a unification of the
   paravirt clock interface, taming the include hell by splitting the
   pv_ops structure and removing of a bunch of obsolete code (Juergen
   Gross)

* tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/paravirt: Use XOR r32,r32 to clear register in pv_vcpu_is_preempted()
  x86/paravirt: Remove trailing semicolons from alternative asm templates
  x86/pvlocks: Move paravirt spinlock functions into own header
  x86/paravirt: Specify pv_ops array in paravirt macros
  x86/paravirt: Allow pv-calls outside paravirt.h
  objtool: Allow multiple pv_ops arrays
  x86/xen: Drop xen_mmu_ops
  x86/xen: Drop xen_cpu_ops
  x86/xen: Drop xen_irq_ops
  x86/paravirt: Move pv_native_*() prototypes to paravirt.c
  x86/paravirt: Introduce new paravirt-base.h header
  x86/paravirt: Move paravirt_sched_clock() related code into tsc.c
  x86/paravirt: Use common code for paravirt_steal_clock()
  riscv/paravirt: Use common code for paravirt_steal_clock()
  loongarch/paravirt: Use common code for paravirt_steal_clock()
  arm64/paravirt: Use common code for paravirt_steal_clock()
  arm/paravirt: Use common code for paravirt_steal_clock()
  sched: Move clock related paravirt code to kernel/sched
  paravirt: Remove asm/paravirt_api_clock.h
  x86/paravirt: Move thunk macros to paravirt_types.h
  ...

objtool/rust: add one more `noreturn` Rust function

2026-02-10T10:01:16+00:00

`objtool` with Rust 1.84.0 reports:

    rust/kernel.o: error: objtool: _RNvXNtNtCsaRPFapPOzLs_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix14from_str_radix()
    falls through to next function _RNvXNtNtCsaRPFapPOzLs_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix16from_u64_negated()

This is very similar to commit c18f35e49049 ("objtool/rust: add one more
`noreturn` Rust function"), which added `from_ascii_radix_panic` for Rust
1.86.0, except that Rust 1.84.0 ends up needing `from_str_radix_panic`.

Thus add it to the list to fix the warning.

Cc: FUJITA Tomonori 
Fixes: 51d9ee90ea90 ("rust: str: add radix prefixed integer parsing functions")
Reported-by: Alice Ryhl 
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/with/572427627
Tested-by: Alice Ryhl 
Link: https://patch.msgid.link/20260206204336.38462-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

Merge tag 'objtool-urgent-2026-02-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-02-07T16:21:21+00:00

Pull objtool fixes from Ingo Molnar::

 - Bump up the Clang minimum version requirements for livepatch
   builds, due to Clang assembler section handling bugs causing
   silent miscompilations

 - Strip livepatching symbol artifacts from non-livepatch modules

 - Fix livepatch build warnings when certain Clang LTO options
   are enabled

 - Fix livepatch build error when CONFIG_MEM_ALLOC_PROFILING_DEBUG=y

* tag 'objtool-urgent-2026-02-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool/klp: Fix unexported static call key access for manually built livepatch modules
  objtool/klp: Fix symbol correlation for orphaned local symbols
  livepatch: Free klp_{object,func}_ext data after initialization
  livepatch: Fix having __klp_objects relics in non-livepatch modules
  livepatch/klp-build: Require Clang assembler >= 20

objtool/klp: Fix unexported static call key access for manually built livepatch modules

2026-02-05T16:00:45+00:00

Enabling CONFIG_MEM_ALLOC_PROFILING_DEBUG with CONFIG_SAMPLE_LIVEPATCH
results in the following error:

  samples/livepatch/livepatch-shadow-fix1.o: error: objtool: static_call: can't find static_call_key symbol: __SCK__WARN_trap

This is caused an extra file->klp sanity check which was added by commit
164c9201e1da ("objtool: Add base objtool support for livepatch
modules").  That check was intended to ensure that livepatch modules
built with klp-build always have full access to their static call keys.

However, it failed to account for the fact that manually built livepatch
modules (i.e., not built with klp-build) might need access to unexported
static call keys, for which read-only access is typically allowed for
modules.

While the livepatch-shadow-fix1 module doesn't explicitly use any static
calls, it does have a memory allocation, which can cause
CONFIG_MEM_ALLOC_PROFILING_DEBUG to insert a WARN() call.  And WARN() is
now an unexported static call as of commit 860238af7a33 ("x86_64/bug:
Inline the UD1").

Fix it by removing the overzealous file->klp check, restoring the
original behavior for manually built livepatch modules.

Fixes: 164c9201e1da ("objtool: Add base objtool support for livepatch modules")
Reported-by: Arnd Bergmann 
Acked-by: Song Liu 
Tested-by: Arnd Bergmann 
Link: https://patch.msgid.link/0bd3ae9a53c3d743417fe842b740a7720e2bcd1c.1770058775.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf

livepatch: Free klp_{object,func}_ext data after initialization

2026-02-05T16:00:45+00:00

The klp_object_ext and klp_func_ext data, which are stored in the
__klp_objects and __klp_funcs sections, respectively, are not needed
after they are used to create the actual klp_object and klp_func
instances. This operation is implemented by the init function in
scripts/livepatch/init.c.

Prefix the two sections with ".init" so they are freed after the module
is initializated.

Signed-off-by: Petr Pavlu 
Acked-by: Joe Lawrence 
Acked-by: Miroslav Benes 
Reviewed-by: Aaron Tomlin 
Link: https://patch.msgid.link/20260123102825.3521961-3-petr.pavlu@suse.com
Signed-off-by: Josh Poimboeuf