MIPS: Don't assume 64-bit FP registers for dump_{,task_}fpu (6cec7c4a) · Commits · 戴 / test

This code assumed that saved FP registers are 64 bits wide, an assumption which will no longer be true once MSA is introduced. This patch modifies the code to copy the lower 64 bits of each register in turn, which is safe for any FP register width >= 64 bits. Signed-off-by:

Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6425/ Signed-off-by:

Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/process.c

+14 −2

Original line number	Diff line number	Diff line
		@@ -157,7 +157,13 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
		/* Fill in the fpu structure for a core dump.. */
		int dump_fpu(struct pt_regs regs, elf_fpregset_t r)
		{
		memcpy(r, &current->thread.fpu, sizeof(current->thread.fpu));
		int i;

		for (i = 0; i < NUM_FPU_REGS; i++)
		memcpy(&r[i], &current->thread.fpu.fpr[i], sizeof(*r));

		memcpy(&r[NUM_FPU_REGS], &current->thread.fpu.fcr31,
		sizeof(current->thread.fpu.fcr31));

		return 1;
		}
		@@ -192,7 +198,13 @@ int dump_task_regs(struct task_struct tsk, elf_gregset_t regs)

		int dump_task_fpu(struct task_struct t, elf_fpregset_t fpr)
		{
		memcpy(fpr, &t->thread.fpu, sizeof(current->thread.fpu));
		int i;

		for (i = 0; i < NUM_FPU_REGS; i++)
		memcpy(&fpr[i], &t->thread.fpu.fpr[i], sizeof(*fpr));

		memcpy(&fpr[NUM_FPU_REGS], &t->thread.fpu.fcr31,
		sizeof(t->thread.fpu.fcr31));

		return 1;
		}

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