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

Commit 56063306 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390/dumpstack: implement and use return_address() 



Implement return_address() and use it instead of __builtin_return_address(n).

__builtin_return_address(n) is not guaranteed to work for n > 0,
therefore implement a private return_address() function which walks
the stack frames and returns the proper return address.

This way we get also rid of a compile warning which gcc 6.1 emits and
look like all other architectures.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent e18eb2d1

arch/s390/include/asm/ftrace.h

+3 −1
Original line number Diff line number Diff line
@@ -12,7 +12,9 @@ 


#ifndef __ASSEMBLY__



#define ftrace_return_address(n) __builtin_return_address(n)

unsigned long return_address(int depth);



#define ftrace_return_address(n) return_address(n)



void _mcount(void);

void ftrace_caller(void);

arch/s390/kernel/dumpstack.c

+24 −0
Original line number Diff line number Diff line
@@ -89,6 +89,30 @@ void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task, 
}

EXPORT_SYMBOL_GPL(dump_trace);



struct return_address_data {

	unsigned long address;

	int depth;

};



static int __return_address(void *data, unsigned long address)

{

	struct return_address_data *rd = data;



	if (rd->depth--)

		return 0;

	rd->address = address;

	return 1;

}



unsigned long return_address(int depth)

{

	struct return_address_data rd = { .depth = depth + 2 };



	dump_trace(__return_address, &rd, NULL, current_stack_pointer());

	return rd.address;

}

EXPORT_SYMBOL_GPL(return_address);



static int show_address(void *data, unsigned long address)

{

	printk("([<%016lx>] %pSR)\n", address, (void *)address);