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, 0 deletions

diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h
index 7286e4a9fe84..a7acad2bc2f0 100644
--- a/arch/ia64/include/asm/sections.h
+++ b/arch/ia64/include/asm/sections.h
@@ -21,5 +21,8 @@ extern char __start_gate_brl_fsys_bubble_down_patchlist[], __end_gate_brl_fsys_b
 extern char __start_unwind[], __end_unwind[];
 extern char __start_ivt_text[], __end_ivt_text[];
 
+#undef dereference_function_descriptor
+void *dereference_function_descriptor(void *);
+
 #endif /* _ASM_IA64_SECTIONS_H */
 
diff --git a/arch/ia64/kernel/module.c b/arch/ia64/kernel/module.c
index 29aad349e0c4..545626f66a4c 100644
--- a/arch/ia64/kernel/module.c
+++ b/arch/ia64/kernel/module.c
@@ -31,9 +31,11 @@
 #include <linux/elf.h>
 #include <linux/moduleloader.h>
 #include <linux/string.h>
+#include <linux/uaccess.h>
 #include <linux/vmalloc.h>
 
 #include <asm/patch.h>
+#include <asm/sections.h>
 #include <asm/unaligned.h>
 
 #define ARCH_MODULE_DEBUG 0
@@ -941,3 +943,13 @@ module_arch_cleanup (struct module *mod)
         if (mod->arch.core_unw_table)
                 unw_remove_unwind_table(mod->arch.core_unw_table);
 }
+
+void *dereference_function_descriptor(void *ptr)
+{
+        struct fdesc *desc = ptr;
+        void *p;
+
+        if (!probe_kernel_address(&desc->ip, p))
+                ptr = p;
+        return ptr;
+}