x86/unwind/orc: Fix ORC unwind table alignment
authorJosh Poimboeuf <jpoimboe@redhat.com>
Wed, 6 Mar 2019 17:07:24 +0000 (11:07 -0600)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 6 Mar 2019 19:36:32 +0000 (20:36 +0100)
commitf76a16adc485699f95bb71fce114f97c832fe664
tree92222ae219606d56fca11b5c44e34ca53219fc9b
parent78e10b5e5a849fdfd910dd7b0170a1c2ca0f3483
x86/unwind/orc: Fix ORC unwind table alignment

The .orc_unwind section is a packed array of 6-byte structs.  It's
currently aligned to 6 bytes, which is causing warnings in the LLD
linker.

Six isn't a power of two, so it's not a valid alignment value.  The
actual alignment doesn't matter much because it's an array of packed
structs.  An alignment of two is sufficient.  In reality it always gets
aligned to four bytes because it comes immediately after the
4-byte-aligned .orc_unwind_ip section.

Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder")
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: Dmitry Golovin <dima@golovin.in>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/218
Link: https://lkml.kernel.org/r/d55027ee95fe73e952dcd8be90aebd31b0095c45.1551892041.git.jpoimboe@redhat.com
include/asm-generic/vmlinux.lds.h