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Commit 445a58ce authored by Paul Burton's avatar Paul Burton Committed by Ralf Baechle
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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: default avatarPaul 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: default avatarRalf Baechle <ralf@linux-mips.org>
parent 2aa7687c

arch/mips/include/asm/fpu_emulator.h

+1 −1
Original line number Diff line number Diff line
@@ -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,

arch/mips/math-emu/cp1emu.c

+4 −4
Original line number Diff line number Diff line
@@ -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 @@ static int fpu_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx, 
 * 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;