Add a new stacktool ignore macro, STACKTOOL_IGNORE_FUNC, which can be
used to tell stacktool to skip validation of a function.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
MAINTAINERS | 1 +
arch/x86/kernel/vmlinux.lds.S | 5 ++++-
include/linux/stacktool.h | 23 +++++++++++++++++++++++
3 files changed, 28 insertions(+), 1 deletion(-)
create mode 100644 include/linux/stacktool.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 7ecbea9..80b26ec 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10190,6 +10190,7 @@ STACK METADATA VALIDATION
M: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
S: Supported
F: tools/stacktool/
+F: include/linux/stacktool.h
STAGING SUBSYSTEM
M: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 4f19942..c08c283c 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -333,7 +333,10 @@ SECTIONS
/* Sections to be discarded */
DISCARDS
- /DISCARD/ : { *(.eh_frame) }
+ /DISCARD/ : {
+ *(.eh_frame)
+ *(__stacktool_ignore_*)
+ }
}
diff --git a/include/linux/stacktool.h b/include/linux/stacktool.h
new file mode 100644
index 0000000..0d90db7
--- /dev/null
+++ b/include/linux/stacktool.h
@@ -0,0 +1,23 @@
+#ifndef _LINUX_STACKTOOL_H
+#define _LINUX_STACKTOOL_H
+
+#ifdef CONFIG_STACK_VALIDATION
+/*
+ * This C macro tells stacktool to ignore the function when doing stack
+ * metadata validation. 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 tools/stacktool/Documentation/stack-validation.txt.
+ */
+#define STACKTOOL_IGNORE_FUNC(_func) \
+ static void __used __section(__stacktool_ignore_func) \
+ *__stacktool_ignore_func_##_func = _func
+
+#else /* !CONFIG_STACK_VALIDATION */
+
+#define STACKTOOL_IGNORE_FUNC(_func)
+
+#endif /* CONFIG_STACK_VALIDATION */
+
+#endif /* _LINUX_STACKTOOL_H */
--
2.4.3
--
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