Merge branch 'topic/func-desc-lkdtm' into next

Merge a topic branch we are maintaining with some cross-architecture
changes to function descriptor handling and their use in LKDTM.

From Christophe's cover letter:

Fix LKDTM for PPC64/IA64/PARISC

PPC64/IA64/PARISC have function descriptors. LKDTM doesn't work on those
three architectures because LKDTM messes up function descriptors with
functions.

This series does some cleanup in the three architectures and refactors
function descriptors so that it can then easily use it in a generic way
in LKDTM.

1 files changed, 17 insertions, 25 deletions

diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 94d14cf99bca..794720530442 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -33,20 +33,13 @@
 
 #ifdef PPC64_ELF_ABI_v2
 
-/* An address is simply the address of the function. */
-typedef unsigned long func_desc_t;
-
 static func_desc_t func_desc(unsigned long addr)
 {
-	return addr;
-}
-static unsigned long func_addr(unsigned long addr)
-{
-	return addr;
-}
-static unsigned long stub_func_addr(func_desc_t func)
-{
-	return func;
+	func_desc_t desc = {
+		.addr = addr,
+	};
+
+	return desc;
 }
 
 /* PowerPC64 specific values for the Elf64_Sym st_other field.  */
@@ -64,20 +57,9 @@ static unsigned int local_entry_offset(const Elf64_Sym *sym)
 }
 #else
 
-/* An address is address of the OPD entry, which contains address of fn. */
-typedef struct ppc64_opd_entry func_desc_t;
-
 static func_desc_t func_desc(unsigned long addr)
 {
-	return *(struct ppc64_opd_entry *)addr;
-}
-static unsigned long func_addr(unsigned long addr)
-{
-	return func_desc(addr).funcaddr;
-}
-static unsigned long stub_func_addr(func_desc_t func)
-{
-	return func.funcaddr;
+	return *(struct func_desc *)addr;
 }
 static unsigned int local_entry_offset(const Elf64_Sym *sym)
 {
@@ -94,6 +76,16 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr)
 }
 #endif
 
+static unsigned long func_addr(unsigned long addr)
+{
+	return func_desc(addr).addr;
+}
+
+static unsigned long stub_func_addr(func_desc_t func)
+{
+	return func.addr;
+}
+
 #define STUB_MAGIC 0x73747562 /* stub */
 
 /* Like PPC32, we need little trampolines to do > 24-bit jumps (into
@@ -188,7 +180,7 @@ static int relacmp(const void *_x, const void *_y)
 static unsigned long get_stubs_size(const Elf64_Ehdr *hdr,
 				    const Elf64_Shdr *sechdrs)
 {
-	/* One extra reloc so it's always 0-funcaddr terminated */
+	/* One extra reloc so it's always 0-addr terminated */
 	unsigned long relocs = 1;
 	unsigned i;