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MIPS: math-emu: Correct user fault_addr type

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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>
This commit is contained in:
Paul Burton
2017-08-23 11:17:51 -07:00
committed by Ralf Baechle
parent 2aa7687c3c
commit 445a58ce34
2 changed files with 5 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/mips/include/asm/fpu_emulator.h
View File

@@ -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,

8
arch/mips/math-emu/cp1emu.c
View File

@@ -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;