livepatch/arm64: Fix incorrect endian conversion when long jump

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4ZII6

--------------------------------

Kernel panic happened on 'arm64 big endian' board after calling function
that has been live-patched. It can be reproduced as follows:
  1. Insert 'livepatch-sample.ko' to patch function 'cmdline_proc_show';
  2. Enable patch by execute:
     echo 1 > /sys/kernel/livepatch/livepatch-sample/enabled
  3. Call 'cmdline_proc_show' by execute:
     cat /proc/cmdline
  4. Then we get following panic logs:
     > kernel BUG at arch/arm64/kernel/traps.c:408!
     > Internal error: Oops - BUG: 0 [#1] SMP
     > Modules linked in: dump_mem(OE) livepatch_cmdline1(OEK)
     > [last unloaded: dump_mem]
     > CPU: 3 PID: 1752 Comm: cat Session: 0 Tainted: G           OE K
     > 5.10.0+ #2
     > Hardware name: Hisilicon PhosphorHi1382 (DT)
     > pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--)
     > pc : do_undefinstr+0x23c/0x2b4
     > lr : do_undefinstr+0x5c/0x2b4
     > sp : ffffffc010ac3a80
     > x29: ffffffc010ac3a80 x28: ffffff82eb0a8000
     > x27: 0000000000000000 x26: 0000000000000001
     > x25: 0000000000000000 x24: 0000000000001000
     > x23: 0000000000000000 x22: ffffffd0e0f16000
     > x21: ffffffd0e0ae7000 x20: ffffffc010ac3b00
     > x19: 0000000000021fd6 x18: ffffffd0e04aad94
     > x17: 0000000000000000 x16: 0000000000000000
     > x15: ffffffd0e04b519c x14: 0000000000000000
     > x13: 0000000000000000 x12: 0000000000000000
     > x11: 0000000000000000 x10: 0000000000000000
     > x9 : 0000000000000000 x8 : 0000000000000000
     > x7 : 0000000000000000 x6 : ffffffd0e0f16100
     > x5 : 0000000000000000 x4 : 00000000d5300000
     > x3 : 0000000000000000 x2 : ffffffd0e0f160f0
     > x1 : ffffffd0e0f16103 x0 : 0000000000000005
     > Call trace:
     >  do_undefinstr+0x23c/0x2b4
     >  el1_undef+0x2c/0x44
     >  el1_sync_handler+0xa4/0xb0
     >  el1_sync+0x74/0x100
     >  cmdline_proc_show+0xc/0x44
     >  proc_reg_read_iter+0xb0/0xc4
     >  new_sync_read+0x10c/0x15c
     >  vfs_read+0x144/0x18c
     >  ksys_read+0x78/0xe8
     >  __arm64_sys_read+0x24/0x30

We compare first 6 instructions of 'cmdline_proc_show' before and after
patch (see below). There are 4 instructions modified, so this is case
that offset between old and new function is out of 128M. And we found
that instruction at 'cmdline_proc_show+0xc' seems incorrect (it expects
to be '00021fd6').
  origin:     patched:
  --------    --------
  fd7bbea9    929ff7f0
  21d500f0    f2a91b30
  fd030091    f2d00010
  211040f9    d61f0200 <-- cmdline_proc_show+0xc (expect is '00021fd6')
  f30b00f9    f30b00f9
  f30300aa    f30300aa

It is caused by an incorrect big-to-little endian conversion, and we
correct it.

Fixes: e429c61d livepatch/arm64: Support livepatch without ftrace
Signed-off-by: NZheng Yejian <zhengyejian1@huawei.com>
Reviewed-by: NKuohai Xu <xukuohai@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/kernel/livepatch.c

@@ -358,10 +358,10 @@ static int do_patch(unsigned long pc, unsigned long new_addr)
 #ifdef CONFIG_ARM64_MODULE_PLTS
 		int i;
 
-		insns[0] = cpu_to_le32(0x92800010 | (((~new_addr) & 0xffff)) << 5);
-		insns[1] = cpu_to_le32(0xf2a00010 | (((new_addr >> 16) & 0xffff)) << 5);
-		insns[2] = cpu_to_le32(0xf2c00010 | (((new_addr >> 32) & 0xffff)) << 5);
-		insns[3] = cpu_to_le32(0xd61f0200);
+		insns[0] = 0x92800010 | (((~new_addr) & 0xffff)) << 5;
+		insns[1] = 0xf2a00010 | (((new_addr >> 16) & 0xffff)) << 5;
+		insns[2] = 0xf2c00010 | (((new_addr >> 32) & 0xffff)) << 5;
+		insns[3] = 0xd61f0200;
 		for (i = 0; i < LJMP_INSN_SIZE; i++) {
 			ret = aarch64_insn_patch_text_nosync(((u32 *)pc) + i, insns[i]);
 			if (ret) {