x86/ibt: Add ANNOTATE_NOENDBR

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
This commit is contained in:
Peter Zijlstra 2022-03-08 16:30:18 +01:00
parent 156ff4a544
commit c8c301abea
2 changed files with 32 additions and 0 deletions

View File

@ -77,6 +77,12 @@ struct unwind_hint {
#define STACK_FRAME_NON_STANDARD_FP(func)
#endif
#define ANNOTATE_NOENDBR \
"986: \n\t" \
".pushsection .discard.noendbr\n\t" \
_ASM_PTR " 986b\n\t" \
".popsection\n\t"
#else /* __ASSEMBLY__ */
/*
@ -129,6 +135,13 @@ struct unwind_hint {
.popsection
.endm
.macro ANNOTATE_NOENDBR
.Lhere_\@:
.pushsection .discard.noendbr
.quad .Lhere_\@
.popsection
.endm
#endif /* __ASSEMBLY__ */
#else /* !CONFIG_STACK_VALIDATION */
@ -139,12 +152,15 @@ struct unwind_hint {
"\n\t"
#define STACK_FRAME_NON_STANDARD(func)
#define STACK_FRAME_NON_STANDARD_FP(func)
#define ANNOTATE_NOENDBR
#else
#define ANNOTATE_INTRA_FUNCTION_CALL
.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.endm
.macro ANNOTATE_NOENDBR
.endm
#endif
#endif /* CONFIG_STACK_VALIDATION */

View File

@ -77,6 +77,12 @@ struct unwind_hint {
#define STACK_FRAME_NON_STANDARD_FP(func)
#endif
#define ANNOTATE_NOENDBR \
"986: \n\t" \
".pushsection .discard.noendbr\n\t" \
_ASM_PTR " 986b\n\t" \
".popsection\n\t"
#else /* __ASSEMBLY__ */
/*
@ -129,6 +135,13 @@ struct unwind_hint {
.popsection
.endm
.macro ANNOTATE_NOENDBR
.Lhere_\@:
.pushsection .discard.noendbr
.quad .Lhere_\@
.popsection
.endm
#endif /* __ASSEMBLY__ */
#else /* !CONFIG_STACK_VALIDATION */
@ -139,12 +152,15 @@ struct unwind_hint {
"\n\t"
#define STACK_FRAME_NON_STANDARD(func)
#define STACK_FRAME_NON_STANDARD_FP(func)
#define ANNOTATE_NOENDBR
#else
#define ANNOTATE_INTRA_FUNCTION_CALL
.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.endm
.macro ANNOTATE_NOENDBR
.endm
#endif
#endif /* CONFIG_STACK_VALIDATION */