lib: Correct printk %pF to work on all architectures

It was introduced by "vsprintf: add support for '%pS' and '%pF' pointer
formats" in commit 0fe1ef24f7bd0020f29ffe287dfdb9ead33ca0b2.  However,
the current way its coded doesn't work on parisc64.  For two reasons: 1)
parisc isn't in the #ifdef and 2) parisc has a different format for
function descriptors

Make dereference_function_descriptor() more accommodating by allowing
architecture overrides.  I put the three overrides (for parisc64, ppc64
and ia64) in arch/kernel/module.c because that's where the kernel
internal linker which knows how to deal with function descriptors sits.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index fdacdd4341c9..44138c3e6ea7 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -47,7 +47,9 @@
 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/bug.h>
+#include <linux/uaccess.h>
 
+#include <asm/sections.h>
 #include <asm/unwind.h>
 
 #if 0
@@ -860,3 +862,15 @@ void module_arch_cleanup(struct module *mod)
         deregister_unwind_table(mod);
         module_bug_cleanup(mod);
 }
+
+#ifdef CONFIG_64BIT
+void *dereference_function_descriptor(void *ptr)
+{
+        Elf64_Fdesc *desc = ptr;
+        void *p;
+
+        if (!probe_kernel_address(&desc->addr, p))
+                ptr = p;
+        return ptr;
+}
+#endif