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Commit 20e76ee1 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390/ftrace: fix compile error if CONFIG_KPROBES is disabled 



Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 0a648150

arch/s390/kernel/ftrace.c

+45 −16
Original line number Diff line number Diff line
@@ -57,6 +57,44 @@ 


unsigned long ftrace_plt;



static inline void ftrace_generate_orig_insn(struct ftrace_insn *insn)

{

#ifdef CC_USING_HOTPATCH

	/* brcl 0,0 */

	insn->opc = 0xc004;

	insn->disp = 0;

#else

	/* stg r14,8(r15) */

	insn->opc = 0xe3e0;

	insn->disp = 0xf0080024;

#endif

}



static inline int is_kprobe_on_ftrace(struct ftrace_insn *insn)

{

#ifdef CONFIG_KPROBES

	if (insn->opc == BREAKPOINT_INSTRUCTION)

		return 1;

#endif

	return 0;

}



static inline void ftrace_generate_kprobe_nop_insn(struct ftrace_insn *insn)

{

#ifdef CONFIG_KPROBES

	insn->opc = BREAKPOINT_INSTRUCTION;

	insn->disp = KPROBE_ON_FTRACE_NOP;

#endif

}



static inline void ftrace_generate_kprobe_call_insn(struct ftrace_insn *insn)

{

#ifdef CONFIG_KPROBES

	insn->opc = BREAKPOINT_INSTRUCTION;

	insn->disp = KPROBE_ON_FTRACE_CALL;

#endif

}



int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,

		       unsigned long addr)

{
@@ -72,16 +110,9 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, 
		return -EFAULT;

	if (addr == MCOUNT_ADDR) {

		/* Initial code replacement */

#ifdef CC_USING_HOTPATCH

		/* We expect to see brcl 0,0 */

		ftrace_generate_nop_insn(&orig);

#else

		/* We expect to see stg r14,8(r15) */

		orig.opc = 0xe3e0;

		orig.disp = 0xf0080024;

#endif

		ftrace_generate_orig_insn(&orig);

		ftrace_generate_nop_insn(&new);

	} else if (old.opc == BREAKPOINT_INSTRUCTION) {

	} else if (is_kprobe_on_ftrace(&old)) {

		/*

		 * If we find a breakpoint instruction, a kprobe has been

		 * placed at the beginning of the function. We write the
@@ -89,9 +120,8 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, 
		 * bytes of the original instruction so that the kprobes

		 * handler can execute a nop, if it reaches this breakpoint.

		 */

		new.opc = orig.opc = BREAKPOINT_INSTRUCTION;

		orig.disp = KPROBE_ON_FTRACE_CALL;

		new.disp = KPROBE_ON_FTRACE_NOP;

		ftrace_generate_kprobe_call_insn(&orig);

		ftrace_generate_kprobe_nop_insn(&new);

	} else {

		/* Replace ftrace call with a nop. */

		ftrace_generate_call_insn(&orig, rec->ip);
@@ -111,7 +141,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) 


	if (probe_kernel_read(&old, (void *) rec->ip, sizeof(old)))

		return -EFAULT;

	if (old.opc == BREAKPOINT_INSTRUCTION) {

	if (is_kprobe_on_ftrace(&old)) {

		/*

		 * If we find a breakpoint instruction, a kprobe has been

		 * placed at the beginning of the function. We write the
@@ -119,9 +149,8 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) 
		 * bytes of the original instruction so that the kprobes

		 * handler can execute a brasl if it reaches this breakpoint.

		 */

		new.opc = orig.opc = BREAKPOINT_INSTRUCTION;

		orig.disp = KPROBE_ON_FTRACE_NOP;

		new.disp = KPROBE_ON_FTRACE_CALL;

		ftrace_generate_kprobe_nop_insn(&orig);

		ftrace_generate_kprobe_call_insn(&new);

	} else {

		/* Replace nop with an ftrace call. */

		ftrace_generate_nop_insn(&orig);