Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f118c93e authored by Linux Build Service Account's avatar Linux Build Service Account Committed by Gerrit - the friendly Code Review server
Browse files

Merge "arm64: smp: Prevent raw_smp_processor_id() recursion"

parents 907c12ba 24b2191f

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ config ARM64 
	select POWER_SUPPLY

	select SPARSE_IRQ

	select SYSCTL_EXCEPTION_TRACE

	select THREAD_INFO_IN_TASK

	help

	  ARM 64-bit (AArch64) Linux support.

arch/arm64/include/asm/Kbuild

+0 −1
Original line number Diff line number Diff line 
generic-y += bugs.h

generic-y += clkdev.h

generic-y += cputime.h

generic-y += current.h

generic-y += delay.h

generic-y += div64.h

generic-y += dma.h

arch/arm64/include/asm/assembler.h

+15 −4
Original line number Diff line number Diff line
@@ -241,14 +241,25 @@ lr .req x30 // link register 
	.endm



	/*

	 * @dst: Result of per_cpu(sym, smp_processor_id())

	 * @sym: The name of the per-cpu variable

	 * @reg: Result of per_cpu(sym, smp_processor_id())

	 * @tmp: scratch register

	 */

	.macro this_cpu_ptr, sym, reg, tmp

	adr_l	\reg, \sym

	.macro adr_this_cpu, dst, sym, tmp

	adr_l	\dst, \sym

	mrs	\tmp, tpidr_el1

	add	\dst, \dst, \tmp

	.endm



	/*

	 * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id()))

	 * @sym: The name of the per-cpu variable

	 * @tmp: scratch register

	 */

	.macro ldr_this_cpu dst, sym, tmp

	adr_l	\dst, \sym

	mrs	\tmp, tpidr_el1

	add	\reg, \reg, \tmp

	ldr	\dst, [\dst, \tmp]

	.endm



/*

arch/arm64/include/asm/current.h

0 → 100644
+30 −0
Original line number Diff line number Diff line 
#ifndef __ASM_CURRENT_H

#define __ASM_CURRENT_H



#include <linux/compiler.h>



#include <asm/sysreg.h>



#ifndef __ASSEMBLY__



struct task_struct;



/*

 * We don't use read_sysreg() as we want the compiler to cache the value where

 * possible.

 */

static __always_inline struct task_struct *get_current(void)

{

	unsigned long sp_el0;



	asm ("mrs %0, sp_el0" : "=r" (sp_el0));



	return (struct task_struct *)sp_el0;

}



#define current get_current()



#endif /* __ASSEMBLY__ */



#endif /* __ASM_CURRENT_H */

arch/arm64/include/asm/smp.h

+13 −1
Original line number Diff line number Diff line
@@ -29,11 +29,22 @@ 


#ifndef __ASSEMBLY__



#include <asm/percpu.h>



#include <linux/threads.h>

#include <linux/cpumask.h>

#include <linux/thread_info.h>



#define raw_smp_processor_id() (current_thread_info()->cpu)

DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);



/*

 * We don't use this_cpu_read(cpu_number) as that has implicit writes to

 * preempt_count, and associated (compiler) barriers, that we'd like to avoid

 * the expense of. If we're preemptible, the value can be stale at use anyway.

 * And we can't use this_cpu_ptr() either, as that winds up recursing back

 * here under CONFIG_DEBUG_PREEMPT=y.

 */

#define raw_smp_processor_id() (*raw_cpu_ptr(&cpu_number))



struct seq_file;
@@ -73,6 +84,7 @@ asmlinkage void secondary_start_kernel(void); 
 */

struct secondary_data {

	void *stack;

	struct task_struct *task;

	long status;

};