kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist

Introduce NOKPROBE_SYMBOL() macro which builds a kprobes
blacklist at kernel build time.

The usage of this macro is similar to EXPORT_SYMBOL(),
placed after the function definition:

  NOKPROBE_SYMBOL(function);

Since this macro will inhibit inlining of static/inline
functions, this patch also introduces a nokprobe_inline macro
for static/inline functions. In this case, we must use
NOKPROBE_SYMBOL() for the inline function caller.

When CONFIG_KPROBES=y, the macro stores the given function
address in the "_kprobe_blacklist" section.

Since the data structures are not fully initialized by the
macro (because there is no "size" information),  those
are re-initialized at boot time by using kallsyms.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20140417081705.26341.96719.stgit@ltc230.yrl.intra.hitachi.co.jp
Cc: Alok Kataria <akataria@vmware.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christopher Li <sparse@chrisli.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jan-Simon Möller <dl9pf@gmx.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-sparse@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 19 insertions, 3 deletions

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index ee7239ea1583..0300c0f5c88b 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -374,7 +374,9 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
 /* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
 #ifdef CONFIG_KPROBES
 # define __kprobes      __attribute__((__section__(".kprobes.text")))
+# define nokprobe_inline        __always_inline
 #else
 # define __kprobes
+# define nokprobe_inline        inline
 #endif
 #endif /* __LINUX_COMPILER_H */
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index cdf9251f8249..e059507c465d 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -205,10 +205,10 @@ struct kretprobe_blackpoint {
         void *addr;
 };
 
-struct kprobe_blackpoint {
-        const char *name;
+struct kprobe_blacklist_entry {
+        struct list_head list;
         unsigned long start_addr;
-        unsigned long range;
+        unsigned long end_addr;
 };
 
 #ifdef CONFIG_KPROBES
@@ -477,4 +477,18 @@ static inline int enable_jprobe(struct jprobe *jp)
         return enable_kprobe(&jp->kp);
 }
 
+#ifdef CONFIG_KPROBES
+/*
+ * Blacklist ganerating macro. Specify functions which is not probed
+ * by using this macro.
+ */
+#define __NOKPROBE_SYMBOL(fname)                        \
+static unsigned long __used                             \
+        __attribute__((section("_kprobe_blacklist")))   \
+        _kbl_addr_##fname = (unsigned long)fname;
+#define NOKPROBE_SYMBOL(fname)  __NOKPROBE_SYMBOL(fname)
+#else
+#define NOKPROBE_SYMBOL(fname)
+#endif
+
 #endif /* _LINUX_KPROBES_H */