Whenever ptrace attempts to retrieve the FPU implementation register it
accesses it through current_cpu_data, which calls smp_processor_id().
Since the code may execute with preemption enabled, this can trigger
a warning. Fix this by using boot_cpu_data to get the IR instead.
Signed-off-by: Alex Smith <alex@xxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v3.15+
---
arch/mips/kernel/ptrace.c | 4 ++--
arch/mips/kernel/ptrace32.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index f639ccd..6063b11 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -129,7 +129,7 @@ int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
}
__put_user(child->thread.fpu.fcr31, data + 64);
- __put_user(current_cpu_data.fpu_id, data + 65);
+ __put_user(boot_cpu_data.fpu_id, data + 65);
return 0;
}
@@ -480,7 +480,7 @@ long arch_ptrace(struct task_struct *child, long request,
break;
case FPC_EIR:
/* implementation / version register */
- tmp = current_cpu_data.fpu_id;
+ tmp = boot_cpu_data.fpu_id;
break;
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;
diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c
index b40c3ca..a83fb73 100644
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -129,7 +129,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
break;
case FPC_EIR:
/* implementation / version register */
- tmp = current_cpu_data.fpu_id;
+ tmp = boot_cpu_data.fpu_id;
break;
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;
--
1.9.1
