mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-27 14:43:58 +08:00
570a752b7a
is_percpu_thread() more elegantly handles SMP vs UP, and further checks the presence of PF_NO_SETAFFINITY. This lets us catch cases where check_preemption_disabled() can race with a concurrent sched_setaffinity(). Signed-off-by: Yejune Deng <yejune.deng@gmail.com> [Amended changelog] Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210510151024.2448573-3-valentin.schneider@arm.com
69 lines
1.4 KiB
C
69 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* lib/smp_processor_id.c
|
|
*
|
|
* DEBUG_PREEMPT variant of smp_processor_id().
|
|
*/
|
|
#include <linux/export.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/sched.h>
|
|
|
|
noinstr static
|
|
unsigned int check_preemption_disabled(const char *what1, const char *what2)
|
|
{
|
|
int this_cpu = raw_smp_processor_id();
|
|
|
|
if (likely(preempt_count()))
|
|
goto out;
|
|
|
|
if (irqs_disabled())
|
|
goto out;
|
|
|
|
if (is_percpu_thread())
|
|
goto out;
|
|
|
|
#ifdef CONFIG_SMP
|
|
if (current->migration_disabled)
|
|
goto out;
|
|
#endif
|
|
|
|
/*
|
|
* It is valid to assume CPU-locality during early bootup:
|
|
*/
|
|
if (system_state < SYSTEM_SCHEDULING)
|
|
goto out;
|
|
|
|
/*
|
|
* Avoid recursion:
|
|
*/
|
|
preempt_disable_notrace();
|
|
|
|
instrumentation_begin();
|
|
if (!printk_ratelimit())
|
|
goto out_enable;
|
|
|
|
printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",
|
|
what1, what2, preempt_count() - 1, current->comm, current->pid);
|
|
|
|
printk("caller is %pS\n", __builtin_return_address(0));
|
|
dump_stack();
|
|
instrumentation_end();
|
|
|
|
out_enable:
|
|
preempt_enable_no_resched_notrace();
|
|
out:
|
|
return this_cpu;
|
|
}
|
|
|
|
noinstr unsigned int debug_smp_processor_id(void)
|
|
{
|
|
return check_preemption_disabled("smp_processor_id", "");
|
|
}
|
|
EXPORT_SYMBOL(debug_smp_processor_id);
|
|
|
|
noinstr void __this_cpu_preempt_check(const char *op)
|
|
{
|
|
check_preemption_disabled("__this_cpu_", op);
|
|
}
|
|
EXPORT_SYMBOL(__this_cpu_preempt_check);
|