Merge branch 'for-4.16-deprecate-printk-pf' into for-4.16

2 files changed, 64 insertions, 0 deletions

diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 708f337d780b..e4f2e5a65f14 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -9,6 +9,10 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/stddef.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+
+#include <asm/sections.h>
 
 #define KSYM_NAME_LEN 128
 #define KSYM_SYMBOL_LEN (sizeof("%s+%#lx/%#lx [%s]") + (KSYM_NAME_LEN - 1) + \
@@ -22,6 +26,56 @@
 
 struct module;
 
+static inline int is_kernel_inittext(unsigned long addr)
+{
+	if (addr >= (unsigned long)_sinittext
+	    && addr <= (unsigned long)_einittext)
+		return 1;
+	return 0;
+}
+
+static inline int is_kernel_text(unsigned long addr)
+{
+	if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) ||
+	    arch_is_kernel_text(addr))
+		return 1;
+	return in_gate_area_no_mm(addr);
+}
+
+static inline int is_kernel(unsigned long addr)
+{
+	if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
+		return 1;
+	return in_gate_area_no_mm(addr);
+}
+
+static inline int is_ksym_addr(unsigned long addr)
+{
+	if (IS_ENABLED(CONFIG_KALLSYMS_ALL))
+		return is_kernel(addr);
+
+	return is_kernel_text(addr) || is_kernel_inittext(addr);
+}
+
+static inline void *dereference_symbol_descriptor(void *ptr)
+{
+#ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR
+	struct module *mod;
+
+	ptr = dereference_kernel_function_descriptor(ptr);
+	if (is_ksym_addr((unsigned long)ptr))
+		return ptr;
+
+	preempt_disable();
+	mod = __module_address((unsigned long)ptr);
+	preempt_enable();
+
+	if (mod)
+		ptr = dereference_module_function_descriptor(mod, ptr);
+#endif
+	return ptr;
+}
+
 #ifdef CONFIG_KALLSYMS
 /* Lookup the address for a symbol. Returns 0 if not found. */
 unsigned long kallsyms_lookup_name(const char *name);
diff --git a/include/linux/module.h b/include/linux/module.h
index c69b49abe877..e6249795f9e2 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -606,6 +606,9 @@ int ref_module(struct module *a, struct module *b);
 	__mod ? __mod->name : "kernel";		\
 })
 
+/* Dereference module function descriptor */
+void *dereference_module_function_descriptor(struct module *mod, void *ptr);
+
 /* For kallsyms to ask for address resolution.  namebuf should be at
  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
  * found, otherwise NULL. */
@@ -760,6 +763,13 @@ static inline bool is_module_sig_enforced(void)
 	return false;
 }
 
+/* Dereference module function descriptor */
+static inline
+void *dereference_module_function_descriptor(struct module *mod, void *ptr)
+{
+	return ptr;
+}
+
 #endif /* CONFIG_MODULES */
 
 #ifdef CONFIG_SYSFS