Commit 85a9793e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus-6.15a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip 

Pull xen fix from Juergen Gross:
 "Just a single fix for the Xen multicall driver avoiding a percpu
  variable referencing initdata by its initializer"

* tag 'for-linus-6.15a-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: fix multicall debug feature
parents e2516abf 715ad3e0

arch/x86/xen/multicalls.c

+14 −12
Original line number Diff line number Diff line
@@ -54,14 +54,20 @@ struct mc_debug_data { 


static DEFINE_PER_CPU(struct mc_buffer, mc_buffer);

static struct mc_debug_data mc_debug_data_early __initdata;

static DEFINE_PER_CPU(struct mc_debug_data *, mc_debug_data) =

	&mc_debug_data_early;

static struct mc_debug_data __percpu *mc_debug_data_ptr;

DEFINE_PER_CPU(unsigned long, xen_mc_irq_flags);



static struct static_key mc_debug __ro_after_init;

static bool mc_debug_enabled __initdata;



static struct mc_debug_data * __ref get_mc_debug(void)

{

	if (!mc_debug_data_ptr)

		return &mc_debug_data_early;



	return this_cpu_ptr(mc_debug_data_ptr);

}



static int __init xen_parse_mc_debug(char *arg)

{

	mc_debug_enabled = true;
@@ -71,20 +77,16 @@ static int __init xen_parse_mc_debug(char *arg) 
}

early_param("xen_mc_debug", xen_parse_mc_debug);



void mc_percpu_init(unsigned int cpu)

{

	per_cpu(mc_debug_data, cpu) = per_cpu_ptr(mc_debug_data_ptr, cpu);

}



static int __init mc_debug_enable(void)

{

	unsigned long flags;

	struct mc_debug_data __percpu *mcdb;



	if (!mc_debug_enabled)

		return 0;



	mc_debug_data_ptr = alloc_percpu(struct mc_debug_data);

	if (!mc_debug_data_ptr) {

	mcdb = alloc_percpu(struct mc_debug_data);

	if (!mcdb) {

		pr_err("xen_mc_debug inactive\n");

		static_key_slow_dec(&mc_debug);

		return -ENOMEM;
@@ -93,7 +95,7 @@ static int __init mc_debug_enable(void) 
	/* Be careful when switching to percpu debug data. */

	local_irq_save(flags);

	xen_mc_flush();

	mc_percpu_init(0);

	mc_debug_data_ptr = mcdb;

	local_irq_restore(flags);



	pr_info("xen_mc_debug active\n");
@@ -155,7 +157,7 @@ void xen_mc_flush(void) 
	trace_xen_mc_flush(b->mcidx, b->argidx, b->cbidx);



	if (static_key_false(&mc_debug)) {

		mcdb = __this_cpu_read(mc_debug_data);

		mcdb = get_mc_debug();

		memcpy(mcdb->entries, b->entries,

		       b->mcidx * sizeof(struct multicall_entry));

	}
@@ -235,7 +237,7 @@ struct multicall_space __xen_mc_entry(size_t args) 


	ret.mc = &b->entries[b->mcidx];

	if (static_key_false(&mc_debug)) {

		struct mc_debug_data *mcdb = __this_cpu_read(mc_debug_data);

		struct mc_debug_data *mcdb = get_mc_debug();



		mcdb->caller[b->mcidx] = __builtin_return_address(0);

		mcdb->argsz[b->mcidx] = args;

arch/x86/xen/smp_pv.c

+0 −1
Original line number Diff line number Diff line
@@ -305,7 +305,6 @@ static int xen_pv_kick_ap(unsigned int cpu, struct task_struct *idle) 
		return rc;



	xen_pmu_init(cpu);

	mc_percpu_init(cpu);



	/*

	 * Why is this a BUG? If the hypercall fails then everything can be

arch/x86/xen/xen-ops.h

+0 −3
Original line number Diff line number Diff line
@@ -261,9 +261,6 @@ void xen_mc_callback(void (*fn)(void *), void *data); 
 */

struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size);



/* Do percpu data initialization for multicalls. */

void mc_percpu_init(unsigned int cpu);



extern bool is_xen_pmu;



irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id);