linux-stable.git/tools/objtool, branch v5.15.97

kbuild: Allow kernel installation packaging to override pkg-config

2023-02-01T07:27:30+00:00

commit d5ea4fece4508bf8e72b659cd22fa4840d8d61e5 upstream.

Add HOSTPKG_CONFIG to allow tooling that builds the kernel to override
what pkg-config and parameters are used.

Signed-off-by: Chun-Tse Shao 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Masahiro Yamada 
[swboyd@chromium.org: Drop certs/Makefile hunk that doesn't
apply because pkg-config isn't used there, add dtc/Makefile hunk to
fix dtb builds]
Signed-off-by: Stephen Boyd 
Signed-off-by: Greg Kroah-Hartman

objtool: Add a missing comma to avoid string concatenation

2023-02-01T07:27:20+00:00

commit 1fb466dff904e4a72282af336f2c355f011eec61 upstream.

Recently the kbuild robot reported two new errors:

>> lib/kunit/kunit-example-test.o: warning: objtool: .text.unlikely: unexpected end of section
>> arch/x86/kernel/dumpstack.o: warning: objtool: oops_end() falls through to next function show_opcodes()

I don't know why they did not occur in my test setup but after digging
it I realized I had accidentally dropped a comma in
tools/objtool/check.c when I renamed rewind_stack_do_exit to
rewind_stack_and_make_dead.

Add that comma back to fix objtool errors.

Link: https://lkml.kernel.org/r/202112140949.Uq5sFKR1-lkp@intel.com
Fixes: 0e25498f8cd4 ("exit: Add and use make_task_dead.")
Reported-by: kernel test robot 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Eric Biggers 
Signed-off-by: Sasha Levin

exit: Add and use make_task_dead.

2023-02-01T07:27:20+00:00

commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream.

There are two big uses of do_exit.  The first is it's design use to be
the guts of the exit(2) system call.  The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure.  In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Eric Biggers 
Signed-off-by: Sasha Levin

objtool: Fix SEGFAULT

2023-01-12T10:58:45+00:00

[ Upstream commit efb11fdb3e1a9f694fa12b70b21e69e55ec59c36 ]

find_insn() will return NULL in case of failure. Check insn in order
to avoid a kernel Oops for NULL pointer dereference.

Tested-by: Naveen N. Rao 
Reviewed-by: Naveen N. Rao 
Acked-by: Josh Poimboeuf 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20221114175754.1131267-9-sv@linux.ibm.com
Signed-off-by: Sasha Levin

objtool, kcsan: Add volatile read/write instrumentation to whitelist

2022-12-31T12:13:57+00:00

[ Upstream commit 63646fcba5bb4b59a19031c21913f94e46a3d0d4 ]

Adds KCSAN's volatile instrumentation to objtool's uaccess whitelist.

Recent kernel change have shown that this was missing from the uaccess
whitelist (since the first upstreamed version of KCSAN):

  mm/gup.o: warning: objtool: fault_in_readable+0x101: call to __tsan_volatile_write1() with UACCESS enabled

Fixes: 75d75b7a4d54 ("kcsan: Support distinguishing volatile accesses")
Signed-off-by: Marco Elver 
Reviewed-by: Dmitry Vyukov 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Sasha Levin

objtool: Preserve special st_shndx indexes in elf_update_symbol

2022-10-26T10:34:37+00:00

[ Upstream commit 5141d3a06b2da1731ac82091298b766a1f95d3d8 ]

elf_update_symbol fails to preserve the special st_shndx values
between [SHN_LORESERVE, SHN_HIRESERVE], which results in it
converting SHN_ABS entries into SHN_UNDEF, for example. Explicitly
check for the special indexes and ensure these symbols are not
marked undefined.

Fixes: ead165fa1042 ("objtool: Fix symbol creation")
Signed-off-by: Sami Tolvanen 
Acked-by: Peter Zijlstra (Intel) 
Tested-by: Peter Zijlstra (Intel) 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20220908215504.3686827-17-samitolvanen@google.com
Signed-off-by: Sasha Levin

x86/retbleed: Add fine grained Kconfig knobs

2022-07-23T10:54:10+00:00

commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.

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) 
Signed-off-by: Borislav Petkov 
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Greg Kroah-Hartman

objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}

2022-07-23T10:54:08+00:00

commit 8faea26e611189e933ea2281975ff4dc7c1106b6 upstream.

Commit

  c536ed2fffd5 ("objtool: Remove SAVE/RESTORE hints")

removed the save/restore unwind hints because they were no longer
needed. Now they're going to be needed again so re-add them.

Signed-off-by: Josh Poimboeuf 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Greg Kroah-Hartman

objtool: Add entry UNRET validation

2022-07-23T10:54:06+00:00

commit a09a6e2399ba0595c3042b3164f3ca68a3cff33e upstream.

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) 
Signed-off-by: Borislav Petkov 
Reviewed-by: Josh Poimboeuf 
Signed-off-by: Borislav Petkov 
[cascardo: tools/objtool/builtin-check.c no link option validation]
[cascardo: tools/objtool/check.c opts.ibt is ibt]
[cascardo: tools/objtool/include/objtool/builtin.h leave unret option as bool, no struct opts]
[cascardo: objtool is still called from scripts/link-vmlinux.sh]
[cascardo: no IBT support]
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Greg Kroah-Hartman

objtool: Update Retpoline validation

2022-07-23T10:54:04+00:00

commit 9bb2ec608a209018080ca262f771e6a9ff203b6f upstream.

Update retpoline validation with the new CONFIG_RETPOLINE requirement of
not having bare naked RET instructions.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Borislav Petkov 
Reviewed-by: Josh Poimboeuf 
Signed-off-by: Borislav Petkov 
[cascardo: conflict fixup at arch/x86/xen/xen-head.S]
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Greg Kroah-Hartman