[PATCH 3.16 046/328] MIPS: Correct the 64-bit DSP accumulator register size

Ben Hutchings
2018-12-09T22:06:08Z

From: "Maciej W. Rozycki" <macro@mips.com>

commit f5958b4cf4fc38ed4583ab83fb7c4cd1ab05f47b 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 <macro@mips.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.")
Patchwork: https://patchwork.linux-mips.org/patch/19329/
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/mips/include/asm/processor.h | 2 +-
arch/mips/kernel/ptrace.c | 2 +-
arch/mips/kernel/ptrace32.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -143,7 +143,7 @@ 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];
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -790,7 +790,7 @@ long arch_ptrace(struct task_struct *chi
goto out;
}
dregs = __get_dsp_regs(child);
- tmp = (unsigned long) (dregs[addr - DSP_BASE]);
+ tmp = dregs[addr - DSP_BASE];
break;
}
case DSP_CONTROL:
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -140,7 +140,7 @@ long compat_arch_ptrace(struct task_stru
goto out;
}
dregs = __get_dsp_regs(child);
- tmp = (unsigned long) (dregs[addr - DSP_BASE]);
+ tmp = dregs[addr - DSP_BASE];
break;
}