[patch V3 04/23] kprobes: Prevent probes in .noinstr.text section

[Thomas Gleixner]

Instrumentation is forbidden in the .noinstr.text section. Make kprobes
respect this.

This lacks support for .noinstr.text sections in modules, which is required
to handle VMX and SVM.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 kernel/kprobes.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1443,10 +1443,21 @@ static bool __within_kprobe_blacklist(un
 	return false;
 }
 
+/* Functions in .noinstr.text must not be probed */
+static bool within_noinstr_text(unsigned long addr)
+{
+	/* FIXME: Handle module .noinstr.text */
+	return addr >= (unsigned long)__noinstr_text_start &&
+	       addr < (unsigned long)__noinstr_text_end;
+}
+
 bool within_kprobe_blacklist(unsigned long addr)
 {
 	char symname[KSYM_NAME_LEN], *p;
 
+	if (within_noinstr_text(addr))
+		return true;
+
 	if (__within_kprobe_blacklist(addr))
 		return true;