Merge tag 'x86-urgent-2020-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (667b6249) · Commits · 戴 / test

Pull x86 fixes from Thomas Gleixner: "Two fixes for x86: - Unbreak stack dumps for inactive tasks by interpreting the special first frame left by __switch_to_asm() correctly. The recent change not to skip the first frame so ORC and frame unwinder behave in the same way caused all entries to be unreliable, i.e. prepended with '?'. - Use cpumask_available() instead of an implicit NULL check of a cpumask_var_t in mmio trace to prevent a Clang build warning" * tag 'x86-urgent-2020-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/unwind/orc: Fix unwind_get_return_address_ptr() for inactive tasks x86/mmiotrace: Use cpumask_available() for cpumask_var_t variables

arch/x86/kernel/unwind_orc.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -320,12 +320,19 @@ EXPORT_SYMBOL_GPL(unwind_get_return_address);

		unsigned long unwind_get_return_address_ptr(struct unwind_state state)
		{
		struct task_struct *task = state->task;

		if (unwind_done(state))
		return NULL;

		if (state->regs)
		return &state->regs->ip;

		if (task != current && state->sp == task->thread.sp) {
		struct inactive_task_frame frame = (void )task->thread.sp;
		return &frame->ret_addr;
		}

		if (state->sp)
		return (unsigned long *)state->sp - 1;

arch/x86/mm/mmio-mod.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -372,7 +372,7 @@ static void enter_uniprocessor(void)
		int cpu;
		int err;

		if (downed_cpus == NULL &&
		if (!cpumask_available(downed_cpus) &&
		!alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
		pr_notice("Failed to allocate mask\n");
		goto out;
		@@ -402,7 +402,7 @@ static void leave_uniprocessor(void)
		int cpu;
		int err;

		if (downed_cpus == NULL \|\| cpumask_weight(downed_cpus) == 0)
		if (!cpumask_available(downed_cpus) \|\| cpumask_weight(downed_cpus) == 0)
		return;
		pr_notice("Re-enabling CPUs...\n");
		for_each_cpu(cpu, downed_cpus) {

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