The following commit has been merged into the objtool/core branch of tip:
Commit-ID: 87116ae6da034242baf06e799f9f0e2a8ee6a796
Gitweb: https://git.kernel.org/tip/87116ae6da034242baf06e799f9f0e2a8ee6a796
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Thu, 28 Nov 2024 10:39:06 +01:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Mon, 02 Dec 2024 12:01:44 +01:00
objtool: Fix ANNOTATE_REACHABLE to be a normal annotation
Currently REACHABLE is weird for being on the instruction after the
instruction it modifies.
Since all REACHABLE annotations have an explicit instruction, flip
them around.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241128094312.494176035@xxxxxxxxxxxxx
---
arch/loongarch/include/asm/bug.h | 2 +-
arch/x86/entry/entry_64.S | 5 ++---
arch/x86/include/asm/bug.h | 2 +-
arch/x86/include/asm/irq_stack.h | 4 ++--
include/linux/objtool.h | 4 ++--
tools/objtool/check.c | 23 -----------------------
6 files changed, 8 insertions(+), 32 deletions(-)
diff --git a/arch/loongarch/include/asm/bug.h b/arch/loongarch/include/asm/bug.h
index e25404a..f6f254f 100644
--- a/arch/loongarch/include/asm/bug.h
+++ b/arch/loongarch/include/asm/bug.h
@@ -45,7 +45,7 @@
#define __WARN_FLAGS(flags) \
do { \
instrumentation_begin(); \
- __BUG_FLAGS(BUGFLAG_WARNING|(flags), ANNOTATE_REACHABLE);\
+ __BUG_FLAGS(BUGFLAG_WARNING|(flags), ANNOTATE_REACHABLE(10001b));\
instrumentation_end(); \
} while (0)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 9248660..f52dbe0 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -308,10 +308,9 @@ SYM_CODE_END(xen_error_entry)
movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
.endif
- call \cfunc
-
/* For some configurations \cfunc ends up being a noreturn. */
ANNOTATE_REACHABLE
+ call \cfunc
jmp error_return
.endm
@@ -529,10 +528,10 @@ SYM_CODE_START(\asmsym)
movq %rsp, %rdi /* pt_regs pointer into first argument */
movq ORIG_RAX(%rsp), %rsi /* get error code into 2nd argument*/
movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */
- call \cfunc
/* For some configurations \cfunc ends up being a noreturn. */
ANNOTATE_REACHABLE
+ call \cfunc
jmp paranoid_exit
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index dd8fb17..e85ac0c 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -92,7 +92,7 @@ do { \
do { \
__auto_type __flags = BUGFLAG_WARNING|(flags); \
instrumentation_begin(); \
- _BUG_FLAGS(ASM_UD2, __flags, ANNOTATE_REACHABLE); \
+ _BUG_FLAGS(ASM_UD2, __flags, ANNOTATE_REACHABLE(1b)); \
instrumentation_end(); \
} while (0)
diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h
index 5455747..562a547 100644
--- a/arch/x86/include/asm/irq_stack.h
+++ b/arch/x86/include/asm/irq_stack.h
@@ -100,8 +100,8 @@
}
#define ASM_CALL_ARG0 \
- "call %c[__func] \n" \
- ANNOTATE_REACHABLE
+ "1: call %c[__func] \n" \
+ ANNOTATE_REACHABLE(1b)
#define ASM_CALL_ARG1 \
"movq %[arg1], %%rdi \n" \
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index e3cb135..c722a92 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -177,11 +177,11 @@
*/
#define ANNOTATE_UNRET_BEGIN ASM_ANNOTATE(ANNOTYPE_UNRET_BEGIN)
/*
- * This should be used directly after an instruction that is considered
+ * This should be used to refer to an instruction that is considered
* terminating, like a noreturn CALL or UD2 when we know they are not -- eg
* WARN using UD2.
*/
-#define ANNOTATE_REACHABLE ASM_ANNOTATE(ANNOTYPE_REACHABLE)
+#define ANNOTATE_REACHABLE(label) __ASM_ANNOTATE(label, ANNOTYPE_REACHABLE)
#else
#define ANNOTATE_NOENDBR ANNOTATE type=ANNOTYPE_NOENDBR
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 27d0c41..26bdd3e 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -614,19 +614,6 @@ static int init_pv_ops(struct objtool_file *file)
return 0;
}
-static struct instruction *find_last_insn(struct objtool_file *file,
- struct section *sec)
-{
- struct instruction *insn = NULL;
- unsigned int offset;
- unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0;
-
- for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--)
- insn = find_insn(file, sec, offset);
-
- return insn;
-}
-
static int create_static_call_sections(struct objtool_file *file)
{
struct static_call_site *site;
@@ -2281,16 +2268,6 @@ static int read_annotate(struct objtool_file *file,
offset = reloc->sym->offset + reloc_addend(reloc);
insn = find_insn(file, reloc->sym->sec, offset);
- /*
- * Reachable annotations are 'funneh' and act on the previous instruction :/
- */
- if (type == ANNOTYPE_REACHABLE) {
- if (insn)
- insn = prev_insn_same_sec(file, insn);
- else if (offset == reloc->sym->sec->sh.sh_size)
- insn = find_last_insn(file, reloc->sym->sec);
- }
-
if (!insn) {
WARN("bad .discard.annotate_insn entry: %d of type %d", reloc_idx(reloc), type);
return -1;
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