[PATCH AUTOSEL for 4.4 069/101] ia64: fix module loading for gcc-5.4

Sasha Levin
2018-03-08T05:07:00Z

From: Sergei Trofimovich <slyfox@gentoo.org>

[ 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@users.sourceforge.net>
Cc: H J Lu <hjl.tools@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Bug: https://bugs.gentoo.org/601014
Tested-by: Émeric MASCHINO <emeric.maschino@gmail.com>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
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 b15933c31b2f..36b2c94a8eb5 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