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Commit 92b8cbf1 authored by Martin Schwidefsky's avatar Martin Schwidefsky Committed by Martin Schwidefsky
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[S390] kprobes: jprobe save and restore 



Register %r14 and %r15 are already stored in jprobe_saved_regs, no need
to store them a second time in jprobe_saved_r14 / jprobe_saved_r15.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 371db06b

arch/s390/include/asm/kprobes.h

+1 −3
Original line number Diff line number Diff line
@@ -70,10 +70,8 @@ struct kprobe_ctlblk { 
	unsigned long kprobe_status;

	unsigned long kprobe_saved_imask;

	unsigned long kprobe_saved_ctl[3];

	struct pt_regs jprobe_saved_regs;

	unsigned long jprobe_saved_r14;

	unsigned long jprobe_saved_r15;

	struct prev_kprobe prev_kprobe;

	struct pt_regs jprobe_saved_regs;

	kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];

};

arch/s390/kernel/kprobes.c

+7 −10
Original line number Diff line number Diff line
@@ -585,8 +585,8 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, 
int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)

{

	struct jprobe *jp = container_of(p, struct jprobe, kp);

	unsigned long addr;

	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

	unsigned long stack;



	memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
@@ -594,14 +594,10 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) 
	regs->psw.addr = (unsigned long)(jp->entry) | PSW_ADDR_AMODE;

	regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);



	/* r14 is the function return address */

	kcb->jprobe_saved_r14 = (unsigned long)regs->gprs[14];

	/* r15 is the stack pointer */

	kcb->jprobe_saved_r15 = (unsigned long)regs->gprs[15];

	addr = (unsigned long)kcb->jprobe_saved_r15;

	stack = (unsigned long) regs->gprs[15];



	memcpy(kcb->jprobes_stack, (kprobe_opcode_t *) addr,

	       MIN_STACK_SIZE(addr));

	memcpy(kcb->jprobes_stack, (void *) stack, MIN_STACK_SIZE(stack));

	return 1;

}
@@ -618,13 +614,14 @@ void __kprobes jprobe_return_end(void) 
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)

{

	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

	unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_r15);

	unsigned long stack;



	stack = (unsigned long) kcb->jprobe_saved_regs.gprs[15];



	/* Put the regs back */

	memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));

	/* put the stack back */

	memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,

	       MIN_STACK_SIZE(stack_addr));

	memcpy((void *) stack, kcb->jprobes_stack, MIN_STACK_SIZE(stack));

	preempt_enable_no_resched();

	return 1;

}