Use a more standard prologue for saving the stack pointer before
realigning the stack.
This enables ORC unwinding by allowing objtool to understand the stack
realignment.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Link: https://lore.kernel.org/r/fdaaf8670ed1f52f55ba9a6bbac98c1afddc1af6.1614182415.git.jpoimboe@redhat.com
RESERVE_STACK = (W_SIZE*4 + 8+24)
/* Align stack */
- mov %rsp, %rbx
+ push %rbp
+ mov %rsp, %rbp
and $~(0x20-1), %rsp
- push %rbx
sub $RESERVE_STACK, %rsp
avx2_zeroupper
avx2_zeroupper
- add $RESERVE_STACK, %rsp
- pop %rsp
+ mov %rbp, %rsp
+ pop %rbp
pop %r15
pop %r14