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>

2 files changed, 15 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 916018e425c4..7710e9e6660f 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -16,6 +16,9 @@ static inline int in_kernel_text(unsigned long addr)
         return 0;
 }
 
+#undef dereference_function_descriptor
+void *dereference_function_descriptor(void *);
+
 #endif
 
 #endif /* __KERNEL__ */
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index ee6a2982d567..ad79de272ff3 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -21,8 +21,9 @@
 #include <linux/err.h>
 #include <linux/vmalloc.h>
 #include <linux/bug.h>
+#include <linux/uaccess.h>
 #include <asm/module.h>
-#include <asm/uaccess.h>
+#include <asm/sections.h>
 #include <asm/firmware.h>
 #include <asm/code-patching.h>
 #include <linux/sort.h>
@@ -451,3 +452,13 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 
         return 0;
 }
+
+void *dereference_function_descriptor(void *ptr)
+{
+        struct ppc64_opd_entry *desc = ptr;
+        void *p;
+
+        if (!probe_kernel_address(&desc->funcaddr, p))
+                ptr = p;
+        return ptr;
+}