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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:
- Comprehensive interface overhaul:
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Objtool's interface has some issues:
- Several features are done unconditionally, without any way to
turn them off. Some of them might be surprising. This makes
objtool tricky to use, and prevents porting individual features
to other arches.
- The config dependencies are too coarse-grained. Objtool
enablement is tied to CONFIG_STACK_VALIDATION, but it has several
other features independent of that.
- The objtool subcmds ("check" and "orc") are clumsy: "check" is
really a subset of "orc", so it has all the same options.
The subcmd model has never really worked for objtool, as it only
has a single purpose: "do some combination of things on an object
file".
- The '--lto' and '--vmlinux' options are nonsensical and have
surprising behavior.
Overhaul the interface:
- get rid of subcmds
- make all features individually selectable
- remove and/or clarify confusing/obsolete options
- update the documentation
- fix some bugs found along the way
- Fix x32 regression
- Fix Kbuild cleanup bugs
- Add scripts/objdump-func helper script to disassemble a single
function from an object file.
- Rewrite scripts/faddr2line to be section-aware, by basing it on
'readelf', moving it away from 'nm', which doesn't handle multiple
sections well, which can result in decoding failure.
- Rewrite & fix symbol handling - which had a number of bugs wrt.
object files that don't have global symbols - which is rare but
possible. Also fix a bunch of symbol handling bugs found along the
way.
* tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
objtool: Fix objtool regression on x32 systems
objtool: Fix symbol creation
scripts/faddr2line: Fix overlapping text section failures
scripts: Create objdump-func helper script
objtool: Remove libsubcmd.a when make clean
objtool: Remove inat-tables.c when make clean
objtool: Update documentation
objtool: Remove --lto and --vmlinux in favor of --link
objtool: Add HAVE_NOINSTR_VALIDATION
objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"
objtool: Make noinstr hacks optional
objtool: Make jump label hack optional
objtool: Make static call annotation optional
objtool: Make stack validation frame-pointer-specific
objtool: Add CONFIG_OBJTOOL
objtool: Extricate sls from stack validation
objtool: Rework ibt and extricate from stack validation
objtool: Make stack validation optional
objtool: Add option to print section addresses
objtool: Don't print parentheses in function addresses
...
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STACK_FRAME_NON_STANDARD results in inconsistent relocation types
depending on .c or .S usage:
Relocation section '.rela.discard.func_stack_frame_non_standard' at offset 0x3c01090 contains 5 entries:
Offset Info Type Symbol's Value Symbol's Name + Addend
0000000000000000 00020c2200000002 R_X86_64_PC32 0000000000047b40 do_suspend_lowlevel + 0
0000000000000008 0002461e00000001 R_X86_64_64 00000000000480a0 machine_real_restart + 0
0000000000000010 0000001400000001 R_X86_64_64 0000000000000000 .rodata + b3d4
0000000000000018 0002444600000002 R_X86_64_PC32 00000000000678a0 __efi64_thunk + 0
0000000000000020 0002659d00000001 R_X86_64_64 0000000000113160 __crash_kexec + 0
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220506121631.508692613@infradead.org
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Now that stack validation is an optional feature of objtool, add
CONFIG_OBJTOOL and replace most usages of CONFIG_STACK_VALIDATION with
it.
CONFIG_STACK_VALIDATION can now be considered to be frame-pointer
specific. CONFIG_UNWINDER_ORC is already inherently valid for live
patching, so no need to "validate" it.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/939bf3d85604b2a126412bf11af6e3bd3b872bcb.1650300597.git.jpoimboe@redhat.com
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Because we need a variant for .S files too.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Yi9gOW9f1GGwwUD6@hirez.programming.kicks-ass.net
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In order to have objtool warn about code references to !ENDBR
instruction, we need an annotation to allow this for non-control-flow
instances -- consider text range checks, text patching, or return
trampolines etc.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.578968224@infradead.org
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Add a CONFIG_FRAME_POINTER-specific version of
STACK_FRAME_NON_STANDARD() for the case where a function is
intentionally missing frame pointer setup, but otherwise needs
objtool/ORC coverage when frame pointers are disabled.
Link: https://lkml.kernel.org/r/163163047364.489837.17377799909553689661.stgit@devnote2
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The ORC metadata generated for UNWIND_HINT_FUNC isn't actually very
func-like. With certain usages it can cause stack state mismatches
because it doesn't set the return address (CFI_RA).
Also, users of UNWIND_HINT_RET_OFFSET no longer need to set a custom
return stack offset. Instead they just need to specify a func-like
situation, so the current ret_offset code is hacky for no good reason.
Solve both problems by simplifying the RET_OFFSET handling and
converting it into a more useful UNWIND_HINT_FUNC.
If we end up needing the old 'ret_offset' functionality again in the
future, we should be able to support it pretty easily with the addition
of a custom 'sp_offset' in UNWIND_HINT_FUNC.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/db9d1f5d79dddfbb3725ef6d8ec3477ad199948d.1611263462.git.jpoimboe@redhat.com
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To be used for adding asm functions to the ignore list. The "aw" is
needed to help the ELF section metadata match GCC-created sections.
Otherwise the linker creates duplicate sections instead of combining
them.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/8faa476f9a5ac89af27944ec184c89f95f3c6c49.1611263462.git.jpoimboe@redhat.com
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Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.
Remove the quote operator # from compiler_attributes.h __section macro.
Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.
Conversion done using the script at:
https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Unwind hints are useful to provide objtool with information about stack
states in non-standard functions/code.
While the type of information being provided might be very arch
specific, the mechanism to provide the information can be useful for
other architectures.
Move the relevant unwint hint definitions for all architectures to
see.
[ jpoimboe: REGS_IRET -> REGS_PARTIAL ]
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
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