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-rw-r--r--arch/loongarch/include/asm/bug.h13
-rw-r--r--arch/x86/entry/entry_64.S9
-rw-r--r--arch/x86/include/asm/alternative.h22
-rw-r--r--arch/x86/include/asm/bug.h2
-rw-r--r--arch/x86/include/asm/irq_stack.h4
-rw-r--r--arch/x86/include/asm/nospec-branch.h18
-rw-r--r--arch/x86/kernel/process.c2
-rw-r--r--arch/x86/kernel/reboot.c2
-rw-r--r--arch/x86/kvm/svm/sev.c2
-rw-r--r--arch/x86/mm/fault.c2
-rw-r--r--include/linux/compiler-gcc.h12
-rw-r--r--include/linux/compiler.h37
-rw-r--r--include/linux/instrumentation.h11
-rw-r--r--include/linux/objtool.h126
-rw-r--r--include/linux/objtool_types.h12
-rw-r--r--tools/include/linux/objtool_types.h12
-rw-r--r--tools/objtool/arch/loongarch/special.c3
-rw-r--r--tools/objtool/arch/powerpc/special.c3
-rw-r--r--tools/objtool/arch/x86/special.c4
-rw-r--r--tools/objtool/check.c426
-rw-r--r--tools/objtool/include/objtool/check.h5
-rw-r--r--tools/objtool/include/objtool/special.h3
22 files changed, 267 insertions, 463 deletions
diff --git a/arch/loongarch/include/asm/bug.h b/arch/loongarch/include/asm/bug.h
index 08388876ade4..f6f254f2c5db 100644
--- a/arch/loongarch/include/asm/bug.h
+++ b/arch/loongarch/include/asm/bug.h
@@ -4,6 +4,7 @@
#include <asm/break.h>
#include <linux/stringify.h>
+#include <linux/objtool.h>
#ifndef CONFIG_DEBUG_BUGVERBOSE
#define _BUGVERBOSE_LOCATION(file, line)
@@ -33,25 +34,25 @@
#define ASM_BUG_FLAGS(flags) \
__BUG_ENTRY(flags) \
- break BRK_BUG
+ break BRK_BUG;
#define ASM_BUG() ASM_BUG_FLAGS(0)
-#define __BUG_FLAGS(flags) \
- asm_inline volatile (__stringify(ASM_BUG_FLAGS(flags)));
+#define __BUG_FLAGS(flags, extra) \
+ asm_inline volatile (__stringify(ASM_BUG_FLAGS(flags)) \
+ extra);
#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)
#define BUG() \
do { \
instrumentation_begin(); \
- __BUG_FLAGS(0); \
+ __BUG_FLAGS(0, ""); \
unreachable(); \
} while (0)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 1b5be07f8669..f52dbe0ad93c 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. */
- REACHABLE
+ 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. */
- REACHABLE
+ ANNOTATE_REACHABLE
+ call \cfunc
jmp paranoid_exit
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index dc03a647776d..e3903b731305 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -4,6 +4,7 @@
#include <linux/types.h>
#include <linux/stringify.h>
+#include <linux/objtool.h>
#include <asm/asm.h>
#define ALT_FLAGS_SHIFT 16
@@ -55,16 +56,6 @@
#endif
/*
- * objtool annotation to ignore the alternatives and only consider the original
- * instruction(s).
- */
-#define ANNOTATE_IGNORE_ALTERNATIVE \
- "999:\n\t" \
- ".pushsection .discard.ignore_alts\n\t" \
- ".long 999b\n\t" \
- ".popsection\n\t"
-
-/*
* The patching flags are part of the upper bits of the @ft_flags parameter when
* specifying them. The split is currently like this:
*
@@ -311,17 +302,6 @@ void nop_func(void);
#endif
/*
- * objtool annotation to ignore the alternatives and only consider the original
- * instruction(s).
- */
-.macro ANNOTATE_IGNORE_ALTERNATIVE
- .Lannotate_\@:
- .pushsection .discard.ignore_alts
- .long .Lannotate_\@
- .popsection
-.endm
-
-/*
* 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
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index 806649c7f23d..e85ac0c7c039 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, ASM_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 b71ad173f877..562a547c29a5 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" \
- ASM_REACHABLE
+ "1: call %c[__func] \n" \
+ ANNOTATE_REACHABLE(1b)
#define ASM_CALL_ARG1 \
"movq %[arg1], %%rdi \n" \
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 96b410b1d4e8..7e8bf78c03d5 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -180,18 +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.
- */
-.macro ANNOTATE_RETPOLINE_SAFE
-.Lhere_\@:
- .pushsection .discard.retpoline_safe
- .long .Lhere_\@
- .popsection
-.endm
-
-/*
* (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
* vs RETBleed validation.
*/
@@ -350,12 +338,6 @@
#else /* __ASSEMBLY__ */
-#define ANNOTATE_RETPOLINE_SAFE \
- "999:\n\t" \
- ".pushsection .discard.retpoline_safe\n\t" \
- ".long 999b\n\t" \
- ".popsection\n\t"
-
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[];
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 69f786791f1a..6da6769d7254 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -839,7 +839,7 @@ void __noreturn stop_this_cpu(void *dummy)
#ifdef CONFIG_SMP
if (smp_ops.stop_this_cpu) {
smp_ops.stop_this_cpu();
- unreachable();
+ BUG();
}
#endif
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 615922838c51..dc1dd3f3e67f 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -883,7 +883,7 @@ static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
if (smp_ops.stop_this_cpu) {
smp_ops.stop_this_cpu();
- unreachable();
+ BUG();
}
/* Assume hlt works */
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 943bd074a5d3..fe6cc763fd51 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3820,7 +3820,7 @@ next_range:
goto next_range;
}
- unreachable();
+ BUG();
}
static int __sev_snp_update_protected_guest_state(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index e6c469b323cc..ac52255fab01 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -678,7 +678,7 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code,
ASM_CALL_ARG3,
, [arg1] "r" (regs), [arg2] "r" (address), [arg3] "r" (&info));
- unreachable();
+ BUG();
}
#endif
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index d0ed9583743f..c9b58188ec61 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -52,18 +52,6 @@
*/
#define barrier_before_unreachable() asm volatile("")
-/*
- * Mark a position in code as unreachable. This can be used to
- * suppress control flow warnings after asm blocks that transfer
- * control elsewhere.
- */
-#define unreachable() \
- do { \
- annotate_unreachable(); \
- barrier_before_unreachable(); \
- __builtin_unreachable(); \
- } while (0)
-
#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 240c632c5b95..efd43df3a99a 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -109,44 +109,21 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
/* Unreachable code */
#ifdef CONFIG_OBJTOOL
-/*
- * These macros help objtool understand GCC code flow for unreachable code.
- * The __COUNTER__ based labels are a hack to make each instance of the macros
- * unique, to convince GCC not to merge duplicate inline asm statements.
- */
-#define __stringify_label(n) #n
-
-#define __annotate_reachable(c) ({ \
- asm volatile(__stringify_label(c) ":\n\t" \
- ".pushsection .discard.reachable\n\t" \
- ".long " __stringify_label(c) "b - .\n\t" \
- ".popsection\n\t"); \
-})
-#define annotate_reachable() __annotate_reachable(__COUNTER__)
-
-#define __annotate_unreachable(c) ({ \
- asm volatile(__stringify_label(c) ":\n\t" \
- ".pushsection .discard.unreachable\n\t" \
- ".long " __stringify_label(c) "b - .\n\t" \
- ".popsection\n\t" : : "i" (c)); \
-})
-#define annotate_unreachable() __annotate_unreachable(__COUNTER__)
-
/* Annotate a C jump table to allow objtool to follow the code flow */
#define __annotate_jump_table __section(".rodata..c_jump_table,\"a\",@progbits #")
-
#else /* !CONFIG_OBJTOOL */
-#define annotate_reachable()
-#define annotate_unreachable()
#define __annotate_jump_table
#endif /* CONFIG_OBJTOOL */
-#ifndef unreachable
-# define unreachable() do { \
- annotate_unreachable(); \
+/*
+ * Mark a position in code as unreachable. This can be used to
+ * suppress control flow warnings after asm blocks that transfer
+ * control elsewhere.
+ */
+#define unreachable() do { \
+ barrier_before_unreachable(); \
__builtin_unreachable(); \
} while (0)
-#endif
/*
* KENTRY - kernel entry point
diff --git a/include/linux/instrumentation.h b/include/linux/instrumentation.h
index bc7babe91b2e..bf675a8aef8a 100644
--- a/include/linux/instrumentation.h
+++ b/include/linux/instrumentation.h
@@ -4,14 +4,14 @@
#ifdef CONFIG_NOINSTR_VALIDATION
+#include <linux/objtool.h>
#include <linux/stringify.h>
/* Begin/end of an instrumentation safe region */
#define __instrumentation_begin(c) ({ \
asm volatile(__stringify(c) ": nop\n\t" \
- ".pushsection .discard.instr_begin\n\t" \
- ".long " __stringify(c) "b - .\n\t" \
- ".popsection\n\t" : : "i" (c)); \
+ ANNOTATE_INSTR_BEGIN(__ASM_BREF(c)) \
+ : : "i" (c)); \
})
#define instrumentation_begin() __instrumentation_begin(__COUNTER__)
@@ -48,9 +48,8 @@
*/
#define __instrumentation_end(c) ({ \
asm volatile(__stringify(c) ": nop\n\t" \
- ".pushsection .discard.instr_end\n\t" \
- ".long " __stringify(c) "b - .\n\t" \
- ".popsection\n\t" : : "i" (c)); \
+ ANNOTATE_INSTR_END(__ASM_BREF(c)) \
+ : : "i" (c)); \
})
#define instrumentation_end() __instrumentation_end(__COUNTER__)
#else /* !CONFIG_NOINSTR_VALIDATION */
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index b3b8d3dab52d..c722a921165b 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -45,29 +45,25 @@
#define STACK_FRAME_NON_STANDARD_FP(func)
#endif
-#define ANNOTATE_NOENDBR \
- "986: \n\t" \
- ".pushsection .discard.noendbr\n\t" \
- ".long 986b\n\t" \
- ".popsection\n\t"
-
#define ASM_REACHABLE \
"998:\n\t" \
".pushsection .discard.reachable\n\t" \
".long 998b\n\t" \
".popsection\n\t"
-#else /* __ASSEMBLY__ */
+#define __ASM_BREF(label) label ## b
-/*
- * 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 \
- 999: \
- .pushsection .discard.intra_function_calls; \
- .long 999b; \
- .popsection;
+#define __ASM_ANNOTATE(label, type) \
+ ".pushsection .discard.annotate_insn,\"M\",@progbits,8\n\t" \
+ ".long " __stringify(label) " - .\n\t" \
+ ".long " __stringify(type) "\n\t" \
+ ".popsection\n\t"
+
+#define ASM_ANNOTATE(type) \
+ "911:\n\t" \
+ __ASM_ANNOTATE(911b, type)
+
+#else /* __ASSEMBLY__ */
/*
* In asm, there are two kinds of code: normal C-type callable functions and
@@ -115,34 +111,11 @@
#endif
.endm
-.macro ANNOTATE_NOENDBR
+.macro ANNOTATE type:req
.Lhere_\@:
- .pushsection .discard.noendbr
- .long .Lhere_\@
- .popsection
-.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.
- */
-.macro VALIDATE_UNRET_BEGIN
-#if defined(CONFIG_NOINSTR_VALIDATION) && \
- (defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO))
-.Lhere_\@:
- .pushsection .discard.validate_unret
+ .pushsection .discard.annotate_insn,"M",@progbits,8
.long .Lhere_\@ - .
- .popsection
-#endif
-.endm
-
-.macro REACHABLE
-.Lhere_\@:
- .pushsection .discard.reachable
- .long .Lhere_\@
+ .long \type
.popsection
.endm
@@ -155,20 +128,77 @@
#define UNWIND_HINT(type, sp_reg, sp_offset, signal) "\n\t"
#define STACK_FRAME_NON_STANDARD(func)
#define STACK_FRAME_NON_STANDARD_FP(func)
-#define ANNOTATE_NOENDBR
-#define ASM_REACHABLE
+#define __ASM_ANNOTATE(label, type)
+#define ASM_ANNOTATE(type)
#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
+.macro ANNOTATE type:req
.endm
#endif
#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)
+/*
+ * 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(label) __ASM_ANNOTATE(label, ANNOTYPE_REACHABLE)
+
+#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
+#define ANNOTATE_REACHABLE ANNOTATE type=ANNOTYPE_REACHABLE
+#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 */
diff --git a/include/linux/objtool_types.h b/include/linux/objtool_types.h
index 453a4f4ef39d..df5d9fa84dba 100644
--- a/include/linux/objtool_types.h
+++ b/include/linux/objtool_types.h
@@ -54,4 +54,16 @@ struct unwind_hint {
#define UNWIND_HINT_TYPE_SAVE 6
#define UNWIND_HINT_TYPE_RESTORE 7
+/*
+ * Annotate types
+ */
+#define ANNOTYPE_NOENDBR 1
+#define ANNOTYPE_RETPOLINE_SAFE 2
+#define ANNOTYPE_INSTR_BEGIN 3
+#define ANNOTYPE_INSTR_END 4
+#define ANNOTYPE_UNRET_BEGIN 5
+#define ANNOTYPE_IGNORE_ALTS 6
+#define ANNOTYPE_INTRA_FUNCTION_CALL 7
+#define ANNOTYPE_REACHABLE 8
+
#endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
index 453a4f4ef39d..df5d9fa84dba 100644
--- a/tools/include/linux/objtool_types.h
+++ b/tools/include/linux/objtool_types.h
@@ -54,4 +54,16 @@ struct unwind_hint {
#define UNWIND_HINT_TYPE_SAVE 6
#define UNWIND_HINT_TYPE_RESTORE 7
+/*
+ * Annotate types
+ */
+#define ANNOTYPE_NOENDBR 1
+#define ANNOTYPE_RETPOLINE_SAFE 2
+#define ANNOTYPE_INSTR_BEGIN 3
+#define ANNOTYPE_INSTR_END 4
+#define ANNOTYPE_UNRET_BEGIN 5
+#define ANNOTYPE_IGNORE_ALTS 6
+#define ANNOTYPE_INTRA_FUNCTION_CALL 7
+#define ANNOTYPE_REACHABLE 8
+
#endif /* _LINUX_OBJTOOL_TYPES_H */
diff --git a/tools/objtool/arch/loongarch/special.c b/tools/objtool/arch/loongarch/special.c
index 9bba1e9318e0..87230ed570fd 100644
--- a/tools/objtool/arch/loongarch/special.c
+++ b/tools/objtool/arch/loongarch/special.c
@@ -9,7 +9,8 @@ bool arch_support_alt_relocation(struct special_alt *special_alt,
}
struct reloc *arch_find_switch_table(struct objtool_file *file,
- struct instruction *insn)
+ struct instruction *insn,
+ unsigned long *table_size)
{
return NULL;
}
diff --git a/tools/objtool/arch/powerpc/special.c b/tools/objtool/arch/powerpc/special.c
index d33868147196..51610689abf7 100644
--- a/tools/objtool/arch/powerpc/special.c
+++ b/tools/objtool/arch/powerpc/special.c
@@ -13,7 +13,8 @@ bool arch_support_alt_relocation(struct special_alt *special_alt,
}
struct reloc *arch_find_switch_table(struct objtool_file *file,
- struct instruction *insn)
+ struct instruction *insn,
+ unsigned long *table_size)
{
exit(-1);
}
diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c
index 4ea0f9815fda..9c1c9df09aaa 100644
--- a/tools/objtool/arch/x86/special.c
+++ b/tools/objtool/arch/x86/special.c
@@ -109,7 +109,8 @@ bool arch_support_alt_relocation(struct special_alt *special_alt,
* NOTE: MITIGATION_RETPOLINE made it harder still to decode dynamic jumps.
*/
struct reloc *arch_find_switch_table(struct objtool_file *file,
- struct instruction *insn)
+ struct instruction *insn,
+ unsigned long *table_size)
{
struct reloc *text_reloc, *rodata_reloc;
struct section *table_sec;
@@ -158,5 +159,6 @@ struct reloc *arch_find_switch_table(struct objtool_file *file,
if (reloc_type(text_reloc) == R_X86_64_PC32)
file->ignore_unreachables = true;
+ *table_size = 0;
return rodata_reloc;
}
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 76060da755b5..753dbc4f8198 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -150,6 +150,15 @@ static inline struct reloc *insn_jump_table(struct instruction *insn)
return NULL;
}
+static inline unsigned long insn_jump_table_size(struct instruction *insn)
+{
+ if (insn->type == INSN_JUMP_DYNAMIC ||
+ insn->type == INSN_CALL_DYNAMIC)
+ return insn->_jump_table_size;
+
+ return 0;
+}
+
static bool is_jump_table_jump(struct instruction *insn)
{
struct alt_group *alt_group = insn->alt_group;
@@ -614,108 +623,6 @@ 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;
-}
-
-/*
- * Mark "ud2" instructions and manually annotated dead ends.
- */
-static int add_dead_ends(struct objtool_file *file)
-{
- struct section *rsec;
- struct reloc *reloc;
- struct instruction *insn;
- uint64_t offset;
-
- /*
- * Check for manually annotated dead ends.
- */
- rsec = find_section_by_name(file->elf, ".rela.discard.unreachable");
- if (!rsec)
- goto reachable;
-
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type == STT_SECTION) {
- offset = reloc_addend(reloc);
- } else if (reloc->sym->local_label) {
- offset = reloc->sym->offset;
- } else {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
-
- insn = find_insn(file, reloc->sym->sec, offset);
- 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("can't find unreachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, offset);
- return -1;
- }
- } else {
- WARN("can't find unreachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, offset);
- return -1;
- }
-
- insn->dead_end = true;
- }
-
-reachable:
- /*
- * These manually annotated reachable checks are needed for GCC 4.4,
- * where the Linux unreachable() macro isn't supported. In that case
- * GCC doesn't know the "ud2" is fatal, so it generates code as if it's
- * not a dead end.
- */
- rsec = find_section_by_name(file->elf, ".rela.discard.reachable");
- if (!rsec)
- return 0;
-
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type == STT_SECTION) {
- offset = reloc_addend(reloc);
- } else if (reloc->sym->local_label) {
- offset = reloc->sym->offset;
- } else {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
-
- insn = find_insn(file, reloc->sym->sec, offset);
- 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("can't find reachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, offset);
- return -1;
- }
- } else {
- WARN("can't find reachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, offset);
- return -1;
- }
-
- insn->dead_end = false;
- }
-
- return 0;
-}
-
static int create_static_call_sections(struct objtool_file *file)
{
struct static_call_site *site;
@@ -1310,40 +1217,6 @@ static void add_uaccess_safe(struct objtool_file *file)
}
/*
- * FIXME: For now, just ignore any alternatives which add retpolines. This is
- * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline.
- * But it at least allows objtool to understand the control flow *around* the
- * retpoline.
- */
-static int add_ignore_alternatives(struct objtool_file *file)
-{
- struct section *rsec;
- struct reloc *reloc;
- struct instruction *insn;
-
- rsec = find_section_by_name(file->elf, ".rela.discard.ignore_alts");
- if (!rsec)
- return 0;
-
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
-
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.ignore_alts entry");
- return -1;
- }
-
- insn->ignore_alts = true;
- }
-
- return 0;
-}
-
-/*
* Symbols that replace INSN_CALL_DYNAMIC, every (tail) call to such a symbol
* will be added to the .retpoline_sites section.
*/
@@ -2073,6 +1946,7 @@ out:
static int add_jump_table(struct objtool_file *file, struct instruction *insn,
struct reloc *next_table)
{
+ unsigned long table_size = insn_jump_table_size(insn);
struct symbol *pfunc = insn_func(insn)->pfunc;
struct reloc *table = insn_jump_table(insn);
struct instruction *dest_insn;
@@ -2087,6 +1961,8 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
for_each_reloc_from(table->sec, reloc) {
/* Check for the end of the table: */
+ if (table_size && reloc_offset(reloc) - reloc_offset(table) >= table_size)
+ break;
if (reloc != table && reloc == next_table)
break;
@@ -2131,12 +2007,12 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
* find_jump_table() - Given a dynamic jump, find the switch jump table
* associated with it.
*/
-static struct reloc *find_jump_table(struct objtool_file *file,
- struct symbol *func,
- struct instruction *insn)
+static void find_jump_table(struct objtool_file *file, struct symbol *func,
+ struct instruction *insn)
{
struct reloc *table_reloc;
struct instruction *dest_insn, *orig_insn = insn;
+ unsigned long table_size;
/*
* Backward search using the @first_jump_src links, these help avoid
@@ -2157,17 +2033,17 @@ static struct reloc *find_jump_table(struct objtool_file *file,
insn->jump_dest->offset > orig_insn->offset))
break;
- table_reloc = arch_find_switch_table(file, insn);
+ table_reloc = arch_find_switch_table(file, insn, &table_size);
if (!table_reloc)
continue;
dest_insn = find_insn(file, table_reloc->sym->sec, reloc_addend(table_reloc));
if (!dest_insn || !insn_func(dest_insn) || insn_func(dest_insn)->pfunc != func)
continue;
- return table_reloc;
+ orig_insn->_jump_table = table_reloc;
+ orig_insn->_jump_table_size = table_size;
+ break;
}
-
- return NULL;
}
/*
@@ -2178,7 +2054,6 @@ static void mark_func_jump_tables(struct objtool_file *file,
struct symbol *func)
{
struct instruction *insn, *last = NULL;
- struct reloc *reloc;
func_for_each_insn(file, func, insn) {
if (!last)
@@ -2201,9 +2076,7 @@ static void mark_func_jump_tables(struct objtool_file *file,
if (insn->type != INSN_JUMP_DYNAMIC)
continue;
- reloc = find_jump_table(file, func, insn);
- if (reloc)
- insn->_jump_table = reloc;
+ find_jump_table(file, func, insn);
}
}
@@ -2373,185 +2246,147 @@ static int read_unwind_hints(struct objtool_file *file)
return 0;
}
-static int read_noendbr_hints(struct objtool_file *file)
+static int read_annotate(struct objtool_file *file,
+ int (*func)(struct objtool_file *file, int type, struct instruction *insn))
{
+ struct section *sec;
struct instruction *insn;
- struct section *rsec;
struct reloc *reloc;
+ uint64_t offset;
+ int type, ret;
- rsec = find_section_by_name(file->elf, ".rela.discard.noendbr");
- if (!rsec)
+ sec = find_section_by_name(file->elf, ".discard.annotate_insn");
+ if (!sec)
return 0;
- for_each_reloc(rsec, reloc) {
- insn = find_insn(file, reloc->sym->sec,
- reloc->sym->offset + reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.noendbr entry");
- return -1;
- }
+ if (!sec->rsec)
+ return 0;
- insn->noendbr = 1;
+ if (sec->sh.sh_entsize != 8) {
+ static bool warned = false;
+ if (!warned) {
+ WARN("%s: dodgy linker, sh_entsize != 8", sec->name);
+ warned = true;
+ }
+ sec->sh.sh_entsize = 8;
}
- return 0;
-}
-
-static int read_retpoline_hints(struct objtool_file *file)
-{
- struct section *rsec;
- struct instruction *insn;
- struct reloc *reloc;
-
- rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
- if (!rsec)
- return 0;
+ for_each_reloc(sec->rsec, reloc) {
+ type = *(u32 *)(sec->data->d_buf + (reloc_idx(reloc) * sec->sh.sh_entsize) + 4);
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
+ offset = reloc->sym->offset + reloc_addend(reloc);
+ insn = find_insn(file, reloc->sym->sec, offset);
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
- WARN("bad .discard.retpoline_safe entry");
+ WARN("bad .discard.annotate_insn entry: %d of type %d", reloc_idx(reloc), type);
return -1;
}
- if (insn->type != INSN_JUMP_DYNAMIC &&
- insn->type != INSN_CALL_DYNAMIC &&
- insn->type != INSN_RETURN &&
- insn->type != INSN_NOP) {
- WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
- return -1;
- }
-
- insn->retpoline_safe = true;
+ ret = func(file, type, insn);
+ if (ret < 0)
+ return ret;
}
return 0;
}
-static int read_instr_hints(struct objtool_file *file)
+static int __annotate_early(struct objtool_file *file, int type, struct instruction *insn)
{
- struct section *rsec;
- struct instruction *insn;
- struct reloc *reloc;
+ switch (type) {
+ case ANNOTYPE_IGNORE_ALTS:
+ insn->ignore_alts = true;
+ break;
- rsec = find_section_by_name(file->elf, ".rela.discard.instr_end");
- if (!rsec)
- return 0;
+ /*
+ * Must be before read_unwind_hints() since that needs insn->noendbr.
+ */
+ case ANNOTYPE_NOENDBR:
+ insn->noendbr = 1;
+ break;
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
+ default:
+ break;
+ }
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.instr_end entry");
- return -1;
- }
+ return 0;
+}
- insn->instr--;
- }
+static int __annotate_ifc(struct objtool_file *file, int type, struct instruction *insn)
+{
+ unsigned long dest_off;
- rsec = find_section_by_name(file->elf, ".rela.discard.instr_begin");
- if (!rsec)
+ if (type != ANNOTYPE_INTRA_FUNCTION_CALL)
return 0;
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
+ if (insn->type != INSN_CALL) {
+ WARN_INSN(insn, "intra_function_call not a direct call");
+ return -1;
+ }
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.instr_begin entry");
- return -1;
- }
+ /*
+ * Treat intra-function CALLs as JMPs, but with a stack_op.
+ * See add_call_destinations(), which strips stack_ops from
+ * normal CALLs.
+ */
+ insn->type = INSN_JUMP_UNCONDITIONAL;
- insn->instr++;
+ dest_off = arch_jump_destination(insn);
+ insn->jump_dest = find_insn(file, insn->sec, dest_off);
+ if (!insn->jump_dest) {
+ WARN_INSN(insn, "can't find call dest at %s+0x%lx",
+ insn->sec->name, dest_off);
+ return -1;
}
return 0;
}
-static int read_validate_unret_hints(struct objtool_file *file)
+static int __annotate_late(struct objtool_file *file, int type, struct instruction *insn)
{
- struct section *rsec;
- struct instruction *insn;
- struct reloc *reloc;
-
- rsec = find_section_by_name(file->elf, ".rela.discard.validate_unret");
- if (!rsec)
- return 0;
-
- for_each_reloc(rsec, reloc) {
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", rsec->name);
- return -1;
- }
+ switch (type) {
+ case ANNOTYPE_NOENDBR:
+ /* early */
+ break;
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.instr_end entry");
+ case ANNOTYPE_RETPOLINE_SAFE:
+ if (insn->type != INSN_JUMP_DYNAMIC &&
+ insn->type != INSN_CALL_DYNAMIC &&
+ insn->type != INSN_RETURN &&
+ insn->type != INSN_NOP) {
+ WARN_INSN(insn, "retpoline_safe hint not an indirect jump/call/ret/nop");
return -1;
}
- insn->unret = 1;
- }
-
- return 0;
-}
-
-static int read_intra_function_calls(struct objtool_file *file)
-{
- struct instruction *insn;
- struct section *rsec;
- struct reloc *reloc;
+ insn->retpoline_safe = true;
+ break;
- rsec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls");
- if (!rsec)
- return 0;
+ case ANNOTYPE_INSTR_BEGIN:
+ insn->instr++;
+ break;
- for_each_reloc(rsec, reloc) {
- unsigned long dest_off;
+ case ANNOTYPE_INSTR_END:
+ insn->instr--;
+ break;
- if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s",
- rsec->name);
- return -1;
- }
+ case ANNOTYPE_UNRET_BEGIN:
+ insn->unret = 1;
+ break;
- insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
- if (!insn) {
- WARN("bad .discard.intra_function_call entry");
- return -1;
- }
+ case ANNOTYPE_IGNORE_ALTS:
+ /* early */
+ break;
- if (insn->type != INSN_CALL) {
- WARN_INSN(insn, "intra_function_call not a direct call");
- return -1;
- }
+ case ANNOTYPE_INTRA_FUNCTION_CALL:
+ /* ifc */
+ break;
- /*
- * Treat intra-function CALLs as JMPs, but with a stack_op.
- * See add_call_destinations(), which strips stack_ops from
- * normal CALLs.
- */
- insn->type = INSN_JUMP_UNCONDITIONAL;
+ case ANNOTYPE_REACHABLE:
+ insn->dead_end = false;
+ break;
- dest_off = arch_jump_destination(insn);
- insn->jump_dest = find_insn(file, insn->sec, dest_off);
- if (!insn->jump_dest) {
- WARN_INSN(insn, "can't find call dest at %s+0x%lx",
- insn->sec->name, dest_off);
- return -1;
- }
+ default:
+ WARN_INSN(insn, "Unknown annotation type: %d", type);
+ break;
}
return 0;
@@ -2666,14 +2501,7 @@ static int decode_sections(struct objtool_file *file)
add_ignores(file);
add_uaccess_safe(file);
- ret = add_ignore_alternatives(file);
- if (ret)
- return ret;
-
- /*
- * Must be before read_unwind_hints() since that needs insn->noendbr.
- */
- ret = read_noendbr_hints(file);
+ ret = read_annotate(file, __annotate_early);
if (ret)
return ret;
@@ -2695,7 +2523,7 @@ static int decode_sections(struct objtool_file *file)
* Must be before add_call_destination(); it changes INSN_CALL to
* INSN_JUMP.
*/
- ret = read_intra_function_calls(file);
+ ret = read_annotate(file, __annotate_ifc);
if (ret)
return ret;
@@ -2703,14 +2531,6 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
- /*
- * Must be after add_call_destinations() such that it can override
- * dead_end_function() marks.
- */
- ret = add_dead_ends(file);
- if (ret)
- return ret;
-
ret = add_jump_table_alts(file);
if (ret)
return ret;
@@ -2719,15 +2539,11 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
- ret = read_retpoline_hints(file);
- if (ret)
- return ret;
-
- ret = read_instr_hints(file);
- if (ret)
- return ret;
-
- ret = read_validate_unret_hints(file);
+ /*
+ * Must be after add_call_destinations() such that it can override
+ * dead_end_function() marks.
+ */
+ ret = read_annotate(file, __annotate_late);
if (ret)
return ret;
diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h
index daa46f1f0965..e1cd13cd28a3 100644
--- a/tools/objtool/include/objtool/check.h
+++ b/tools/objtool/include/objtool/check.h
@@ -71,7 +71,10 @@ struct instruction {
struct instruction *first_jump_src;
union {
struct symbol *_call_dest;
- struct reloc *_jump_table;
+ struct {
+ struct reloc *_jump_table;
+ unsigned long _jump_table_size;
+ };
};
struct alternative *alts;
struct symbol *sym;
diff --git a/tools/objtool/include/objtool/special.h b/tools/objtool/include/objtool/special.h
index 86d4af9c5aa9..e7ee7ffccefd 100644
--- a/tools/objtool/include/objtool/special.h
+++ b/tools/objtool/include/objtool/special.h
@@ -38,5 +38,6 @@ bool arch_support_alt_relocation(struct special_alt *special_alt,
struct instruction *insn,
struct reloc *reloc);
struct reloc *arch_find_switch_table(struct objtool_file *file,
- struct instruction *insn);
+ struct instruction *insn,
+ unsigned long *table_size);
#endif /* _SPECIAL_H */
generated by cgit (git 2.34.1) at 2025-04-19 07:13:30 +0000