x86/umip: Fix insn_get_code_seg_params()'s return value

In order to save on redundant structs definitions
insn_get_code_seg_params() was made to return two 4-bit values in a char
but clang complains:

  arch/x86/lib/insn-eval.c:780:10: warning: implicit conversion from 'int' to 'char'
	  changes value from 132 to -124 [-Wconstant-conversion]
                  return INSN_CODE_SEG_PARAMS(4, 8);
                  ~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~
  ./arch/x86/include/asm/insn-eval.h:16:57: note: expanded from macro 'INSN_CODE_SEG_PARAMS'
  #define INSN_CODE_SEG_PARAMS(oper_sz, addr_sz) (oper_sz | (addr_sz << 4))

Those two values do get picked apart afterwards the opposite way of how
they were ORed so wrt to the LSByte, the return value is the same.

But this function returns -EINVAL in the error case, which is an int. So
make it return an int which is the native word size anyway and thus fix
the clang warning.

Reported-by: Kees Cook <keescook@google.com>
Reported-by: Nick Desaulniers <nick.desaulniers@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ricardo.neri-calderon@linux.intel.com
Link: https://lkml.kernel.org/r/20171123091951.1462-1-bp@alien8.de

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/x86/include/asm/insn-eval.h b/arch/x86/include/asm/insn-eval.h
index e1d3b4ce8a92..2b6ccf2c49f1 100644
--- a/arch/x86/include/asm/insn-eval.h
+++ b/arch/x86/include/asm/insn-eval.h
@@ -18,6 +18,6 @@
 void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs);
 int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs);
 unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx);
-char insn_get_code_seg_params(struct pt_regs *regs);
+int insn_get_code_seg_params(struct pt_regs *regs);
 
 #endif /* _ASM_X86_INSN_EVAL_H */