MIPS: math-emu: Correct user fault_addr type

The fault_addr argument to fpu_emulator_cop1Handler(), fpux_emu() and
cop1Emulate() has up until now been declared as:

  void *__user *fault_addr

This is essentially a pointer in user memory which points to a pointer
to void. This is not the intent for our code, which is actually
operating on a pointer to a pointer to void where the pointer to void is
pointing at user memory. ie. the pointer is in kernel memory & points to
user memory.

This mismatch produces a lot of sparse warnings that look like this:

arch/mips/math-emu/cp1emu.c:1485:45:
   warning: incorrect type in assignment (different address spaces)
      expected void *[noderef] <asn:1><noident>
      got unsigned int [noderef] [usertype] <asn:1>*[assigned] va

Fix these by modifying the declaration of the fault_addr argument to:

  void __user **fault_addr

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17173/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/include/asm/fpu_emulator.h b/arch/mips/include/asm/fpu_emulator.h
index c05369e..8e50fa3 100644 (file)
--- a/arch/mips/include/asm/fpu_emulator.h
+++ b/arch/mips/include/asm/fpu_emulator.h
@@ -62,7 +62,7 @@ do {                                                                  \
 
 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
                                    struct mips_fpu_struct *ctx, int has_fpu,
-                                   void *__user *fault_addr);
+                                   void __user **fault_addr);
 void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
                     struct task_struct *tsk);
 int process_fpemu_return(int sig, void __user *fault_addr,

diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 53a3b73..d225e21 100644 (file)
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -58,7 +58,7 @@ static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
        mips_instruction);
 
 static int fpux_emu(struct pt_regs *,
-       struct mips_fpu_struct *, mips_instruction, void *__user *);
+       struct mips_fpu_struct *, mips_instruction, void __user **);
 
 /* Control registers */
 
@@ -973,7 +973,7 @@ static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
  */
 
 static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
-               struct mm_decoded_insn dec_insn, void *__user *fault_addr)
+               struct mm_decoded_insn dec_insn, void __user **fault_addr)
 {
        unsigned long contpc = xcp->cp0_epc + dec_insn.pc_inc;
        unsigned int cond, cbit, bit0;
@@ -1460,7 +1460,7 @@ DEF3OP(nmadd, dp, ieee754dp_mul, ieee754dp_add, ieee754dp_neg);
 DEF3OP(nmsub, dp, ieee754dp_mul, ieee754dp_sub, ieee754dp_neg);
 
 static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
-       mips_instruction ir, void *__user *fault_addr)
+       mips_instruction ir, void __user **fault_addr)
 {
        unsigned rcsr = 0;      /* resulting csr */
 
@@ -2553,7 +2553,7 @@ dcopuop:
  * For simplicity we always terminate upon an ISA mode switch.
  */
 int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
-       int has_fpu, void *__user *fault_addr)
+       int has_fpu, void __user **fault_addr)
 {
        unsigned long oldepc, prevepc;
        struct mm_decoded_insn dec_insn;