releases/6.6.26/x86-retpoline-add-noendbr-annotation-to-the-srso-dummy-return-thunk.patch

   1 From b377c66ae3509ccea596512d6afb4777711c4870 Mon Sep 17 00:00:00 2001
   2 From: "Borislav Petkov (AMD)" <bp@alien8.de>
   3 Date: Fri, 5 Apr 2024 16:46:37 +0200
   4 Subject: x86/retpoline: Add NOENDBR annotation to the SRSO dummy return thunk
   5
   6 From: Borislav Petkov (AMD) <bp@alien8.de>
   7
   8 commit b377c66ae3509ccea596512d6afb4777711c4870 upstream.
   9
  10 srso_alias_untrain_ret() is special code, even if it is a dummy
  11 which is called in the !SRSO case, so annotate it like its real
  12 counterpart, to address the following objtool splat:
  13
  14   vmlinux.o: warning: objtool: .export_symbol+0x2b290: data relocation to !ENDBR: srso_alias_untrain_ret+0x0
  15
  16 Fixes: 4535e1a4174c ("x86/bugs: Fix the SRSO mitigation on Zen3/4")
  17 Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
  18 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  19 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  20 Link: https://lore.kernel.org/r/20240405144637.17908-1-bp@kernel.org
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22 ---
  23  arch/x86/lib/retpoline.S |    1 +
  24  1 file changed, 1 insertion(+)
  25
  26 --- a/arch/x86/lib/retpoline.S
  27 +++ b/arch/x86/lib/retpoline.S
  28 @@ -223,6 +223,7 @@ SYM_CODE_END(srso_return_thunk)
  29  /* Dummy for the alternative in CALL_UNTRAIN_RET. */
  30  SYM_CODE_START(srso_alias_untrain_ret)
  31         ANNOTATE_UNRET_SAFE
  32 +       ANNOTATE_NOENDBR
  33         ret
  34         int3
  35  SYM_FUNC_END(srso_alias_untrain_ret)