Commit 93a4fa62 authored by Qing Zhang's avatar Qing Zhang Committed by Huacai Chen
Browse files

LoongArch: Add STACKTRACE support 



1. Use common arch_stack_walk() infrastructure to avoid duplicated code
   and avoid taking care of the stack storage and filtering.
2. Add sched_ra (means sched return address) and sched_cfa (means sched
   call frame address) to thread_info, and store them in switch_to().
3. Add __get_wchan() implementation.

Now we can print the process stack and wait channel by cat /proc/*/stack
and /proc/*/wchan.

Signed-off-by: default avatarQing Zhang <zhangqing@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 49aef111

arch/loongarch/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ config LOONGARCH 
	select ARCH_MIGHT_HAVE_PC_PARPORT

	select ARCH_MIGHT_HAVE_PC_SERIO

	select ARCH_SPARSEMEM_ENABLE

	select ARCH_STACKWALK

	select ARCH_SUPPORTS_ACPI

	select ARCH_SUPPORTS_ATOMIC_RMW

	select ARCH_SUPPORTS_HUGETLBFS
@@ -151,6 +152,10 @@ config LOCKDEP_SUPPORT 
	bool

	default y



config STACKTRACE_SUPPORT

	bool

	default y



# MACH_LOONGSON32 and MACH_LOONGSON64 are delibrately carried over from the

# MIPS Loongson code, to preserve Loongson-specific code paths in drivers that

# are shared between architectures, and specifically expecting the symbols.

arch/loongarch/include/asm/processor.h

+9 −0
Original line number Diff line number Diff line
@@ -101,6 +101,10 @@ struct thread_struct { 
	unsigned long reg23, reg24, reg25, reg26; /* s0-s3 */

	unsigned long reg27, reg28, reg29, reg30, reg31; /* s4-s8 */



	/* __schedule() return address / call frame address */

	unsigned long sched_ra;

	unsigned long sched_cfa;



	/* CSR registers */

	unsigned long csr_prmd;

	unsigned long csr_crmd;
@@ -129,6 +133,9 @@ struct thread_struct { 
	struct loongarch_fpu fpu FPU_ALIGN;

};



#define thread_saved_ra(tsk)	(tsk->thread.sched_ra)

#define thread_saved_fp(tsk)	(tsk->thread.sched_cfa)



#define INIT_THREAD  {						\

	/*							\

	 * Main processor registers				\
@@ -145,6 +152,8 @@ struct thread_struct { 
	.reg29			= 0,				\

	.reg30			= 0,				\

	.reg31			= 0,				\

	.sched_ra		= 0,				\

	.sched_cfa		= 0,				\

	.csr_crmd		= 0,				\

	.csr_prmd		= 0,				\

	.csr_euen		= 0,				\

arch/loongarch/include/asm/switch_to.h

+9 −5
Original line number Diff line number Diff line
@@ -15,12 +15,15 @@ struct task_struct; 
 * @prev:	The task previously executed.

 * @next:	The task to begin executing.

 * @next_ti:	task_thread_info(next).

 * @sched_ra:	__schedule return address.

 * @sched_cfa:	__schedule call frame address.

 *

 * This function is used whilst scheduling to save the context of prev & load

 * the context of next. Returns prev.

 */

extern asmlinkage struct task_struct *__switch_to(struct task_struct *prev,

			struct task_struct *next, struct thread_info *next_ti);

			struct task_struct *next, struct thread_info *next_ti,

			void *sched_ra, void *sched_cfa);



/*

 * For newly created kernel threads switch_to() will return to
@@ -31,7 +34,8 @@ extern asmlinkage struct task_struct *__switch_to(struct task_struct *prev, 
#define switch_to(prev, next, last)						\

do {										\

	lose_fpu_inatomic(1, prev);						\

	(last) = __switch_to(prev, next, task_thread_info(next));	\

	(last) = __switch_to(prev, next, task_thread_info(next),		\

		 __builtin_return_address(0), __builtin_frame_address(0));	\

} while (0)



#endif /* _ASM_SWITCH_TO_H */

arch/loongarch/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ obj-$(CONFIG_EFI) += efi.o 
obj-$(CONFIG_CPU_HAS_FPU)	+= fpu.o



obj-$(CONFIG_MODULES)		+= module.o module-sections.o

obj-$(CONFIG_STACKTRACE)	+= stacktrace.o



obj-$(CONFIG_PROC_FS)		+= proc.o

arch/loongarch/kernel/asm-offsets.c

+2 −0
Original line number Diff line number Diff line
@@ -103,6 +103,8 @@ void output_thread_defines(void) 
	OFFSET(THREAD_REG29, task_struct, thread.reg29);

	OFFSET(THREAD_REG30, task_struct, thread.reg30);

	OFFSET(THREAD_REG31, task_struct, thread.reg31);

	OFFSET(THREAD_SCHED_RA, task_struct, thread.sched_ra);

	OFFSET(THREAD_SCHED_CFA, task_struct, thread.sched_cfa);

	OFFSET(THREAD_CSRCRMD, task_struct,

	       thread.csr_crmd);

	OFFSET(THREAD_CSRPRMD, task_struct,