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Message-ID: <20241128094311.786598147@infradead.org>
Date: Thu, 28 Nov 2024 10:39:00 +0100
From: Peter Zijlstra <peterz@...radead.org>
To: jpoimboe@...nel.org
Cc: chenhuacai@...nel.org,
kernel@...0n.name,
x86@...nel.org,
peterz@...radead.org,
loongarch@...ts.linux.dev,
linux-kernel@...r.kernel.org,
Josh Poimboeuf <jpoimboe@...hat.com>
Subject: [PATCH v2 09/16] objtool: Collect more annotations in objtool.h
Suggested-by: Josh Poimboeuf <jpoimboe@...hat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
arch/x86/include/asm/alternative.h | 12 -----
arch/x86/include/asm/nospec-branch.h | 9 ---
include/linux/instrumentation.h | 4 -
include/linux/objtool.h | 80 +++++++++++++++++++++++------------
4 files changed, 55 insertions(+), 50 deletions(-)
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -56,12 +56,6 @@
#endif
/*
- * objtool annotation to ignore the alternatives and only consider the original
- * instruction(s).
- */
-#define ANNOTATE_IGNORE_ALTERNATIVE ASM_ANNOTATE(ANNOTYPE_IGNORE_ALTS)
-
-/*
* The patching flags are part of the upper bits of the @ft_flags parameter when
* specifying them. The split is currently like this:
*
@@ -308,12 +302,6 @@ void nop_func(void);
#endif
/*
- * objtool annotation to ignore the alternatives and only consider the original
- * instruction(s).
- */
-#define ANNOTATE_IGNORE_ALTERNATIVE ANNOTATE type=ANNOTYPE_IGNORE_ALTS
-
-/*
* Issue one struct alt_instr descriptor entry (need to put it into
* the section .altinstructions, see below). This entry contains
* enough information for the alternatives patching code to patch an
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -180,13 +180,6 @@
#ifdef __ASSEMBLY__
/*
- * This should be used immediately before an indirect jump/call. It tells
- * objtool the subsequent indirect jump/call is vouched safe for retpoline
- * builds.
- */
-#define ANNOTATE_RETPOLINE_SAFE ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE
-
-/*
* (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
* vs RETBleed validation.
*/
@@ -345,8 +338,6 @@
#else /* __ASSEMBLY__ */
-#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)
-
typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
extern retpoline_thunk_t __x86_indirect_thunk_array[];
extern retpoline_thunk_t __x86_indirect_call_thunk_array[];
--- a/include/linux/instrumentation.h
+++ b/include/linux/instrumentation.h
@@ -10,7 +10,7 @@
/* Begin/end of an instrumentation safe region */
#define __instrumentation_begin(c) ({ \
asm volatile(__stringify(c) ": nop\n\t" \
- __ASM_ANNOTATE(__ASM_BREF(c), ANNOTYPE_INSTR_BEGIN)\
+ ANNOTATE_INSTR_BEGIN(__ASM_BREF(c)) \
: : "i" (c)); \
})
#define instrumentation_begin() __instrumentation_begin(__COUNTER__)
@@ -48,7 +48,7 @@
*/
#define __instrumentation_end(c) ({ \
asm volatile(__stringify(c) ": nop\n\t" \
- __ASM_ANNOTATE(__ASM_BREF(c), ANNOTYPE_INSTR_END) \
+ ANNOTATE_INSTR_END(__ASM_BREF(c)) \
: : "i" (c)); \
})
#define instrumentation_end() __instrumentation_end(__COUNTER__)
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -63,8 +63,6 @@
"911:\n\t" \
__ASM_ANNOTATE(911b, type)
-#define ANNOTATE_NOENDBR ASM_ANNOTATE(ANNOTYPE_NOENDBR)
-
#else /* __ASSEMBLY__ */
/*
@@ -113,19 +111,6 @@
#endif
.endm
-/*
- * Use objtool to validate the entry requirement that all code paths do
- * VALIDATE_UNRET_END before RET.
- *
- * NOTE: The macro must be used at the beginning of a global symbol, otherwise
- * it will be ignored.
- */
-#if defined(CONFIG_NOINSTR_VALIDATION) && \
- (defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO))
-#define VALIDATE_UNRET_BEGIN ANNOTATE type=ANNOTYPE_UNRET_BEGIN
-#else
-#define VALIDATE_UNRET_BEGIN
-#endif
.macro REACHABLE
.Lhere_\@:
@@ -142,14 +127,6 @@
.popsection
.endm
-#define ANNOTATE_NOENDBR ANNOTATE type=ANNOTYPE_NOENDBR
-
-/*
- * This macro indicates that the following intra-function call is valid.
- * Any non-annotated intra-function call will cause objtool to issue a warning.
- */
-#define ANNOTATE_INTRA_FUNCTION_CALL ANNOTATE type=ANNOTYPE_INTRA_FUNCTION_CALL
-
#endif /* __ASSEMBLY__ */
#else /* !CONFIG_OBJTOOL */
@@ -161,16 +138,12 @@
#define STACK_FRAME_NON_STANDARD_FP(func)
#define __ASM_ANNOTATE(label, type)
#define ASM_ANNOTATE(type)
-#define ANNOTATE_NOENDBR
#define ASM_REACHABLE
#else
-#define ANNOTATE_INTRA_FUNCTION_CALL
.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.endm
-.macro ANNOTATE_NOENDBR
-.endm
.macro REACHABLE
.endm
.macro ANNOTATE type:req
@@ -179,4 +152,57 @@
#endif /* CONFIG_OBJTOOL */
+#ifndef __ASSEMBLY__
+/*
+ * Annotate away the various 'relocation to !ENDBR` complaints; knowing that
+ * these relocations will never be used for indirect calls.
+ */
+#define ANNOTATE_NOENDBR ASM_ANNOTATE(ANNOTYPE_NOENDBR)
+/*
+ * This should be used immediately before an indirect jump/call. It tells
+ * objtool the subsequent indirect jump/call is vouched safe for retpoline
+ * builds.
+ */
+#define ANNOTATE_RETPOLINE_SAFE ASM_ANNOTATE(ANNOTYPE_RETPOLINE_SAFE)
+/*
+ * See linux/instrumentation.h
+ */
+#define ANNOTATE_INSTR_BEGIN(label) __ASM_ANNOTATE(label, ANNOTYPE_INSTR_BEGIN)
+#define ANNOTATE_INSTR_END(label) __ASM_ANNOTATE(label, ANNOTYPE_INSTR_END)
+/*
+ * objtool annotation to ignore the alternatives and only consider the original
+ * instruction(s).
+ */
+#define ANNOTATE_IGNORE_ALTERNATIVE ASM_ANNOTATE(ANNOTYPE_IGNORE_ALTS)
+/*
+ * This macro indicates that the following intra-function call is valid.
+ * Any non-annotated intra-function call will cause objtool to issue a warning.
+ */
+#define ANNOTATE_INTRA_FUNCTION_CALL ASM_ANNOTATE(ANNOTYPE_INTRA_FUNCTION_CALL)
+/*
+ * Use objtool to validate the entry requirement that all code paths do
+ * VALIDATE_UNRET_END before RET.
+ *
+ * NOTE: The macro must be used at the beginning of a global symbol, otherwise
+ * it will be ignored.
+ */
+#define ANNOTATE_UNRET_BEGIN ASM_ANNOTATE(ANNOTYPE_UNRET_BEGIN)
+
+#else
+#define ANNOTATE_NOENDBR ANNOTATE type=ANNOTYPE_NOENDBR
+#define ANNOTATE_RETPOLINE_SAFE ANNOTATE type=ANNOTYPE_RETPOLINE_SAFE
+/* ANNOTATE_INSTR_BEGIN ANNOTATE type=ANNOTYPE_INSTR_BEGIN */
+/* ANNOTATE_INSTR_END ANNOTATE type=ANNOTYPE_INSTR_END */
+#define ANNOTATE_IGNORE_ALTERNATIVE ANNOTATE type=ANNOTYPE_IGNORE_ALTS
+#define ANNOTATE_INTRA_FUNCTION_CALL ANNOTATE type=ANNOTYPE_INTRA_FUNCTION_CALL
+#define ANNOTATE_UNRET_BEGIN ANNOTATE type=ANNOTYPE_UNRET_BEGIN
+#endif
+
+#if defined(CONFIG_NOINSTR_VALIDATION) && \
+ (defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO))
+#define VALIDATE_UNRET_BEGIN ANNOTATE_UNRET_BEGIN
+#else
+#define VALIDATE_UNRET_BEGIN
+#endif
+
#endif /* _LINUX_OBJTOOL_H */
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