MIPS: Correct the 64-bit DSP accumulator register size

commit f5958b4 upstream.

Use the `unsigned long' rather than `__u32' type for DSP accumulator
registers, like with the regular MIPS multiply/divide accumulator and
general-purpose registers, as all are 64-bit in 64-bit implementations
and using a 32-bit data type leads to contents truncation on context
saving.

Update `arch_ptrace' and `compat_arch_ptrace' accordingly, removing
casts that are similarly not used with multiply/divide accumulator or
general-purpose register accesses.

Signed-off-by: Maciej W. Rozycki <[email protected]>
Signed-off-by: Paul Burton <[email protected]>
Fixes: e50c0a8 ("Support the MIPS32 / MIPS64 DSP ASE.")
Patchwork: https://patchwork.linux-mips.org/patch/19329/
Cc: Alexander Viro <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected] # 2.6.15+
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Maciej W. Rozycki

arch/mips/include/asm/processor.h

@@ -137,7 +137,7 @@ struct mips_fpu_struct {
 
 #define NUM_DSP_REGS   6
 
-typedef __u32 dspreg_t;
+typedef unsigned long dspreg_t;
 
 struct mips_dsp_state {
 	dspreg_t	dspr[NUM_DSP_REGS];

arch/mips/kernel/ptrace.c

@@ -878,7 +878,7 @@ long arch_ptrace(struct task_struct *child, long request,
 				goto out;
 			}
 			dregs = __get_dsp_regs(child);
-			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
+			tmp = dregs[addr - DSP_BASE];
 			break;
 		}
 		case DSP_CONTROL:

arch/mips/kernel/ptrace32.c

@@ -140,7 +140,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 				goto out;
 			}
 			dregs = __get_dsp_regs(child);
-			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
+			tmp = dregs[addr - DSP_BASE];
 			break;
 		}
 		case DSP_CONTROL: