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Commit 656ff9be authored by Alex Smith's avatar Alex Smith Committed by Ralf Baechle
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MIPS: ptrace: Avoid smp_processor_id() when retrieving FPU IR 



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: default avatarAlex Smith <alex@alex-smith.me.uk>
Cc: <stable@vger.kernel.org> # v3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7449/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 6ee1d934

arch/mips/kernel/ptrace.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

arch/mips/kernel/ptrace32.c

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