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 | 28 ++++++++++++++++++++++++++++
 arch/x86/kernel/vmlinux.lds.S        |  5 ++++-
 include/linux/stackvalidate.h        | 21 +++++++++++++++++++++
 3 files changed, 53 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..2d23c23
--- /dev/null
+++ b/arch/x86/include/asm/stackvalidate.h
@@ -0,0 +1,28 @@
+#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
+       .if CONFIG_STACK_VALIDATION
+               .Ltemp_\@:
+               .pushsection __stackvalidate_ignore_insn, "a"
+               _ASM_ALIGN
+               .long .Ltemp_\@ - .
+               .popsection
+       .endif
+.endm
+
+#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..5cc5c97
--- /dev/null
+++ b/include/linux/stackvalidate.h
@@ -0,0 +1,21 @@
+#ifndef _LINUX_STACKVALIDATE_H
+#define _LINUX_STACKVALIDATE_H
+
+#include <asm/stackvalidate.h>
+
+#ifndef __ASSEMBLY__
+
+/*
+ * 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
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _LINUX_STACKVALIDATE_H */
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to