Merge branch 'linus' into core/debug
Conflicts:
lib/vsprintf.c
Manual merge:
include/linux/kernel.h
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2651f80..3f30557b 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -187,6 +187,8 @@
extern int core_kernel_text(unsigned long addr);
extern int __kernel_text_address(unsigned long addr);
extern int kernel_text_address(unsigned long addr);
+extern int func_ptr_is_kernel_text(void *ptr);
+
struct pid;
extern struct pid *session_of_pgrp(struct pid *pgrp);
diff --git a/kernel/extable.c b/kernel/extable.c
index a26cb2e..adf0cc9 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -66,3 +66,19 @@
return 1;
return module_text_address(addr) != NULL;
}
+
+/*
+ * On some architectures (PPC64, IA64) function pointers
+ * are actually only tokens to some data that then holds the
+ * real function address. As a result, to find if a function
+ * pointer is part of the kernel text, we need to do some
+ * special dereferencing first.
+ */
+int func_ptr_is_kernel_text(void *ptr)
+{
+ unsigned long addr;
+ addr = (unsigned long) dereference_function_descriptor(ptr);
+ if (core_kernel_text(addr))
+ return 1;
+ return module_text_address(addr) != NULL;
+}
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 823be115..0f39e39 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -82,6 +82,14 @@
while (nb && nr_to_call) {
next_nb = rcu_dereference(nb->next);
+
+#ifdef CONFIG_DEBUG_NOTIFIERS
+ if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) {
+ WARN(1, "Invalid notifier called!");
+ nb = next_nb;
+ continue;
+ }
+#endif
ret = nb->notifier_call(nb, val, v);
if (nr_calls)
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index cb838ee..b9a528f 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -164,7 +164,7 @@
/*
* Zero means infinite timeout - no checking done:
*/
-unsigned long __read_mostly sysctl_hung_task_timeout_secs = 120;
+unsigned long __read_mostly sysctl_hung_task_timeout_secs = 480;
unsigned long __read_mostly sysctl_hung_task_warnings = 10;
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 0b50481..4116e10 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -536,6 +536,16 @@
If unsure, say N.
+config DEBUG_NOTIFIERS
+ bool "Debug notifier call chains"
+ depends on DEBUG_KERNEL
+ help
+ Enable this to turn on sanity checking for notifier call chains.
+ This is most useful for kernel developers to make sure that
+ modules properly unregister themselves from notifier chains.
+ This is a relatively cheap check but if you care about maximum
+ performance, say N.
+
config FRAME_POINTER
bool "Compile the kernel with frame pointers"
depends on DEBUG_KERNEL && \