[PATCH AUTOSEL for 3.18 40/53] ia64: fix module loading for gcc-5.4

[Sasha Levin]

From: Sergei Trofimovich <slyfox@xxxxxxxxxx>

[ Upstream commit a25fb8508c1b80dce742dbeaa4d75a1e9f2c5617 ]

Starting from gcc-5.4+ gcc generates MLX instructions in more cases to
refer local symbols:

    https://gcc.gnu.org/PR60465

That caused ia64 module loader to choke on such instructions:

    fuse: invalid slot number 1 for IMM64

The Linux kernel used to handle only case where relocation pointed to
slot=2 instruction in the bundle.  That limitation was fixed in linux by
commit 9c184a073bfd ("[IA64] Fix 2.6 kernel for the new ia64 assembler")
See

    http://sources.redhat.com/bugzilla/show_bug.cgi?id=1433

This change lifts the slot=2 restriction from the kernel module loader.

Tested on 'fuse' and 'btrfs' kernel modules.

Cc: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
Cc: H J Lu <hjl.tools@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Bug: https://bugs.gentoo.org/601014
Tested-by: Ãmeric MASCHINO <emeric.maschino@xxxxxxxxx>
Signed-off-by: Sergei Trofimovich <slyfox@xxxxxxxxxx>
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 arch/ia64/kernel/module.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/ia64/kernel/module.c b/arch/ia64/kernel/module.c
index 24603be24c14..67f09b93dab7 100644
--- a/arch/ia64/kernel/module.c
+++ b/arch/ia64/kernel/module.c
@@ -153,7 +153,7 @@ slot (const struct insn *insn)
 static int
 apply_imm64 (struct module *mod, struct insn *insn, uint64_t val)
 {
-	if (slot(insn) != 2) {
+	if (slot(insn) != 1 && slot(insn) != 2) {
 		printk(KERN_ERR "%s: invalid slot number %d for IMM64\n",
 		       mod->name, slot(insn));
 		return 0;
@@ -165,7 +165,7 @@ apply_imm64 (struct module *mod, struct insn *insn, uint64_t val)
 static int
 apply_imm60 (struct module *mod, struct insn *insn, uint64_t val)
 {
-	if (slot(insn) != 2) {
+	if (slot(insn) != 1 && slot(insn) != 2) {
 		printk(KERN_ERR "%s: invalid slot number %d for IMM60\n",
 		       mod->name, slot(insn));
 		return 0;
-- 
2.14.1