Ilie Halip 14db1f0a93 objtool: Ignore unreachable trap after call to noreturn functions ...

With CONFIG_UBSAN_TRAP enabled, the compiler may insert a trap
instruction after a call to a noreturn function. In this case, objtool
warns that the UD2 instruction is unreachable.

This is a behavior seen with Clang, from the oldest version capable of
building the mainline x64_64 kernel (9.0), to the latest experimental
version (12.0).

Objtool silences similar warnings (trap after dead end instructions), so
so expand that check to include dead end functions.

Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Rong Chen <rong.a.chen@intel.com>
Cc: Marco Elver <elver@google.com>
Cc: Philip Li <philip.li@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: kasan-dev@googlegroups.com
Cc: x86@kernel.org
Cc: clang-built-linux@googlegroups.com
BugLink: https://github.com/ClangBuiltLinux/linux/issues/1148
Link: https://lore.kernel.org/lkml/CAKwvOdmptEpi8fiOyWUo=AiZJiX+Z+VHJOM2buLPrWsMTwLnyw@mail.gmail.com
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Ilie Halip <ilie.halip@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>

2020-09-21 10:20:10 -05:00

..

arch/x86

objtool: Decode unwind hint register depending on architecture

2020-09-10 10:43:13 -05:00

Documentation

objtool: Add support for intra-function calls

2020-04-30 20:14:33 +02:00

.gitignore

.gitignore: add SPDX License Identifier

2020-03-25 11:50:48 +01:00

arch.h

objtool: Decode unwind hint register depending on architecture

2020-09-10 10:43:13 -05:00

Build

objtool: Enable compilation of objtool for all architectures

2020-05-20 09:17:28 -05:00

builtin-check.c

objtool: Move ORC logic out of check()

2020-09-01 17:19:11 -05:00

builtin-orc.c

objtool: Move ORC logic out of check()

2020-09-01 17:19:11 -05:00

builtin.h

objtool: Implement noinstr validation

2020-04-22 10:53:50 +02:00

cfi.h

objtool: Fix !CFI insn_state propagation

2020-04-22 10:53:50 +02:00

check.c

objtool: Ignore unreachable trap after call to noreturn functions

2020-09-21 10:20:10 -05:00

check.h

objtool: Refactor jump table code to support other architectures

2020-09-10 10:43:13 -05:00

elf.c

x86/static_call: Add inline static call implementation for x86-64

2020-09-01 09:58:05 +02:00

elf.h

x86/static_call: Add inline static call implementation for x86-64

2020-09-01 09:58:05 +02:00

Makefile

objtool: Define 'struct orc_entry' only when needed

2020-09-01 17:19:12 -05:00

objtool.c

objtool: Move object file loading out of check()

2020-09-01 17:19:07 -05:00

objtool.h

objtool: Abstract alternative special case handling

2020-09-10 10:43:13 -05:00

orc_dump.c

objtool: Make unwind hint definitions available to other architectures

2020-09-10 10:43:13 -05:00

orc_gen.c

objtool: Make unwind hint definitions available to other architectures

2020-09-10 10:43:13 -05:00

special.c

objtool: Abstract alternative special case handling

2020-09-10 10:43:13 -05:00

special.h

objtool: Refactor jump table code to support other architectures

2020-09-10 10:43:13 -05:00

sync-check.sh

objtool: Make unwind hint definitions available to other architectures

2020-09-10 10:43:13 -05:00

warn.h

objtool: Rename find_containing_func()

2020-03-25 18:28:29 +01:00

weak.c

objtool: Abstract alternative special case handling

2020-09-10 10:43:13 -05:00