Re: [PATCH] x86/alternatives: gracefully skip unrecognized indirect call instructions

[李则良]

I am currently testing the more general approach shown below. Your
review is also appreciated.

on vmlinux-O1:

   0xffffffff82f447de <+126>: ff 15 a4 a9 cf ff   call   QWORD PTR
[rip+0xffffffffffcfa9a4]        # 0xffffffff82c3f188 <pv_ops+8>
   0xffffffff82f447e4 <+132>: eb f8               jmp
0xffffffff82f447de <early_fixup_exception+126>
   0xffffffff82f447e6 <+134>: 5b                 pop    rbx
   0xffffffff82f447e7 <+135>: 41 5c               pop    r12
   0xffffffff82f447e9 <+137>: 5d                 pop    rbp

on vmlinux-O2:

   0xffffffff82f3bf4f <+127>: ff 15 33 32 d0 ff   call   QWORD PTR
[rip+0xffffffffffd03233]        # 0xffffffff82c3f188 <pv_ops+8>
   0xffffffff82f3bf55 <+133>: eb f8               jmp
0xffffffff82f3bf4f <early_fixup_exception+127>
   0xffffffff82f3bf57 <+135>: 5b                 pop    rbx
   0xffffffff82f3bf58 <+136>: 41 5c               pop    r12
   0xffffffff82f3bf5a <+138>: 5d                 pop    rbp

This is an early draft – please review. Thanks in advance.