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Commit f7f242ff authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

kprobes: introduce weak arch_check_ftrace_location() helper function 



Introduce weak arch_check_ftrace_location() helper function which
architectures can override in order to implement handling of kprobes
on function tracer call sites on their own, without depending on
common code or implementing the KPROBES_ON_FTRACE feature.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 3ac8e380

include/linux/kprobes.h

+1 −0
Original line number Diff line number Diff line
@@ -335,6 +335,7 @@ extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, 
extern int arch_prepare_kprobe_ftrace(struct kprobe *p);

#endif



int arch_check_ftrace_location(struct kprobe *p);



/* Get the kprobe at this addr (if any) - called with preemption disabled */

struct kprobe *get_kprobe(void *addr);

kernel/kprobes.c

+11 −7
Original line number Diff line number Diff line
@@ -1410,16 +1410,10 @@ static inline int check_kprobe_rereg(struct kprobe *p) 
	return ret;

}



static int check_kprobe_address_safe(struct kprobe *p,

				     struct module **probed_mod)

int __weak arch_check_ftrace_location(struct kprobe *p)

{

	int ret = 0;

	unsigned long ftrace_addr;



	/*

	 * If the address is located on a ftrace nop, set the

	 * breakpoint to the following instruction.

	 */

	ftrace_addr = ftrace_location((unsigned long)p->addr);

	if (ftrace_addr) {

#ifdef CONFIG_KPROBES_ON_FTRACE
@@ -1431,7 +1425,17 @@ static int check_kprobe_address_safe(struct kprobe *p, 
		return -EINVAL;

#endif

	}

	return 0;

}



static int check_kprobe_address_safe(struct kprobe *p,

				     struct module **probed_mod)

{

	int ret;



	ret = arch_check_ftrace_location(p);

	if (ret)

		return ret;

	jump_label_lock();

	preempt_disable();