Add new stackvalidate ignore macros: STACKVALIDATE_IGNORE_INSN and
STACKVALIDATE_IGNORE_FUNC. These can be used to tell stackvalidate to
skip validation of an instruction or a function, respectively.
Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
---
arch/x86/include/asm/stackvalidate.h | 45 ++++++++++++++++++++++++++++++++++++
arch/x86/kernel/vmlinux.lds.S | 5 +++-
include/linux/stackvalidate.h | 28 ++++++++++++++++++++++
3 files changed, 77 insertions(+), 1 deletion(-)
create mode 100644 arch/x86/include/asm/stackvalidate.h
create mode 100644 include/linux/stackvalidate.h
diff --git a/arch/x86/include/asm/stackvalidate.h
b/arch/x86/include/asm/stackvalidate.h
new file mode 100644
index 0000000..95db052
--- /dev/null
+++ b/arch/x86/include/asm/stackvalidate.h
@@ -0,0 +1,45 @@
+#ifndef _ASM_X86_STACKVALIDATE_H
+#define _ASM_X86_STACKVALIDATE_H
+
+#include <asm/asm.h>
+
+#ifdef __ASSEMBLY__
+
+/*
+ * This asm macro tells the stack validation script to ignore the instruction
+ * immediately after the macro. It should only be used in special cases where
+ * you're 100% sure it won't affect the reliability of frame pointers and
+ * kernel stack traces.
+ *
+ * For more information, see Documentation/stack-validation.txt.
+ */
+.macro STACKVALIDATE_IGNORE_INSN
+#ifdef CONFIG_STACK_VALIDATION
+ .Lstackvalidate_ignore_\@:
+ .pushsection __stackvalidate_ignore_insn, "a"
+ _ASM_ALIGN
+ .long .Lstackvalidate_ignore_\@ - .
+ .popsection
+#endif
+.endm
+
+#else /* !__ASSEMBLY__ */
+
+#ifdef CONFIG_STACK_VALIDATION
+
+#define STACKVALIDATE_IGNORE_INSN \
+ "1:\n" \
+ ".pushsection __stackvalidate_ignore_insn, \"a\"\n" \
+ _ASM_ALIGN "\n" \
+ ".long 1b - .\n" \
+ ".popsection\n"
+
+#else /* !CONFIG_STACK_VALIDATION */
+
+#define STACKVALIDATE_IGNORE_INSN ""
+
+#endif /* CONFIG_STACK_VALIDATION */
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_X86_STACKVALIDATE_H */
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 00bf300..f2f8d7a 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -332,7 +332,10 @@ SECTIONS
/* Sections to be discarded */
DISCARDS
- /DISCARD/ : { *(.eh_frame) }
+ /DISCARD/ : {
+ *(.eh_frame)
+ *(__stackvalidate_ignore_*)
+ }
}
diff --git a/include/linux/stackvalidate.h b/include/linux/stackvalidate.h
new file mode 100644
index 0000000..4ae242c
--- /dev/null
+++ b/include/linux/stackvalidate.h
@@ -0,0 +1,28 @@
+#ifndef _LINUX_STACKVALIDATE_H
+#define _LINUX_STACKVALIDATE_H
+
+#include <asm/stackvalidate.h>
+
+#ifndef __ASSEMBLY__
+
+#ifdef CONFIG_STACK_VALIDATION
+/*
+ * This C macro tells the stack validation script to ignore the function. It
+ * should only be used in special cases where you're 100% sure it won't affect
+ * the reliability of frame pointers and kernel stack traces.
+ *
+ * For more information, see Documentation/stack-validation.txt.
+ */
+#define STACKVALIDATE_IGNORE_FUNC(_func) \
+ static void __used __section(__stackvalidate_ignore_func) \
+ *__stackvalidate_ignore_func_##_func = _func
+
+#else /* !CONFIG_STACK_VALIDATION */
+
+#define STACKVALIDATE_IGNORE_FUNC(_func)
+
+#endif /* CONFIG_STACK_VALIDATION */
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _LINUX_STACKVALIDATE_H */
--
2.4.3
--
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