[tip: objtool/core] objtool: Use relative pointers for annotations

From: tip-bot2 for Josh Poimboeuf
Date: Fri Mar 24 2023 - 20:25:30 EST


The following commit has been merged into the objtool/core branch of tip:

Commit-ID: 1c0c1faf5692c18c127d044ecc0cc92c7bab3477
Gitweb: https://git.kernel.org/tip/1c0c1faf5692c18c127d044ecc0cc92c7bab3477
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Wed, 01 Mar 2023 07:13:08 -08:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Thu, 23 Mar 2023 23:18:56 +01:00

objtool: Use relative pointers for annotations

They produce the needed relocations while using half the space.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/bed05c64e28200220c9b1754a2f3ce71f73076ea.1677683419.git.jpoimboe@xxxxxxxxxx
---
arch/x86/include/asm/nospec-branch.h | 6 +++---
include/linux/objtool.h | 12 ++++++------
2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 3ef70e5..78ed154 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -194,9 +194,9 @@
* builds.
*/
.macro ANNOTATE_RETPOLINE_SAFE
- .Lannotate_\@:
+.Lhere_\@:
.pushsection .discard.retpoline_safe
- _ASM_PTR .Lannotate_\@
+ .long .Lhere_\@ - .
.popsection
.endm

@@ -318,7 +318,7 @@
#define ANNOTATE_RETPOLINE_SAFE \
"999:\n\t" \
".pushsection .discard.retpoline_safe\n\t" \
- _ASM_PTR " 999b\n\t" \
+ ".long 999b - .\n\t" \
".popsection\n\t"

typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 8375792..2b0258d 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -49,7 +49,7 @@
#define ANNOTATE_NOENDBR \
"986: \n\t" \
".pushsection .discard.noendbr\n\t" \
- _ASM_PTR " 986b\n\t" \
+ ".long 986b - .\n\t" \
".popsection\n\t"

#define ASM_REACHABLE \
@@ -67,7 +67,7 @@
#define ANNOTATE_INTRA_FUNCTION_CALL \
999: \
.pushsection .discard.intra_function_calls; \
- .long 999b; \
+ .long 999b - .; \
.popsection;

/*
@@ -92,10 +92,10 @@
* inconsistencies.
*/
.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0 end=0
-.Lunwind_hint_ip_\@:
+.Lhere_\@:
.pushsection .discard.unwind_hints
/* struct unwind_hint */
- .long .Lunwind_hint_ip_\@ - .
+ .long .Lhere_\@ - .
.short \sp_offset
.byte \sp_reg
.byte \type
@@ -107,7 +107,7 @@

.macro STACK_FRAME_NON_STANDARD func:req
.pushsection .discard.func_stack_frame_non_standard, "aw"
- _ASM_PTR \func
+ .long \func - .
.popsection
.endm

@@ -120,7 +120,7 @@
.macro ANNOTATE_NOENDBR
.Lhere_\@:
.pushsection .discard.noendbr
- .quad .Lhere_\@
+ .long .Lhere_\@ - .
.popsection
.endm