1 // SPDX-License-Identifier: GPL-2.0-only
31 #include "../decode-arm.h"
32 #include "../decode-thumb.h"
37 	    (unsigned long)current_thread_info() + THREAD_START_SP - (addr))
52 	unsigned long addr = (unsigned long)p->addr;  in arch_prepare_kprobe()
77 		return -EINVAL;  in arch_prepare_kprobe()
78 	insn = __mem_to_opcode_arm(*p->addr);  in arch_prepare_kprobe()
84 	p->opcode = insn;  in arch_prepare_kprobe()
85 	p->ainsn.insn = tmp_insn;  in arch_prepare_kprobe()
87 	switch ((*decode_insn)(insn, &p->ainsn, true, actions, checkers)) {  in arch_prepare_kprobe()
89 		return -EINVAL;  in arch_prepare_kprobe()
92 		p->ainsn.insn = get_insn_slot();  in arch_prepare_kprobe()
93 		if (!p->ainsn.insn)  in arch_prepare_kprobe()
94 			return -ENOMEM;  in arch_prepare_kprobe()
96 			p->ainsn.insn[is] = tmp_insn[is];  in arch_prepare_kprobe()
97 		flush_insns(p->ainsn.insn,  in arch_prepare_kprobe()
98 				sizeof(p->ainsn.insn[0]) * MAX_INSN_SIZE);  in arch_prepare_kprobe()
99 		p->ainsn.insn_fn = (probes_insn_fn_t *)  in arch_prepare_kprobe()
100 					((uintptr_t)p->ainsn.insn | thumb);  in arch_prepare_kprobe()
104 		p->ainsn.insn = NULL;  in arch_prepare_kprobe()
109 	 * Never instrument insn like 'str r0, [sp, +/-r1]'. Also, insn likes  in arch_prepare_kprobe()
110 	 * 'str r0, [sp, #-68]' should also be prohibited.  in arch_prepare_kprobe()
113 	if ((p->ainsn.stack_space < 0) ||  in arch_prepare_kprobe()
114 			(p->ainsn.stack_space > MAX_STACK_SIZE))  in arch_prepare_kprobe()
115 		return -EINVAL;  in arch_prepare_kprobe()
127 		addr = (void *)((uintptr_t)p->addr & ~1);  in arch_arm_kprobe()
129 		if (is_wide_instruction(p->opcode))  in arch_arm_kprobe()
134 		kprobe_opcode_t insn = p->opcode;  in arch_arm_kprobe()
136 		addr = p->addr;  in arch_arm_kprobe()
153  * memory. It is also needed to atomically set the two half-words of a 32-bit
164 	__patch_text(p->addr, p->insn);  in __kprobes_remove_breakpoint()
180 	kprobes_remove_breakpoint((void *)((uintptr_t)p->addr & ~1),  in arch_disarm_kprobe()
181 			p->opcode);  in arch_disarm_kprobe()
186 	if (p->ainsn.insn) {  in arch_remove_kprobe()
187 		free_insn_slot(p->ainsn.insn, 0);  in arch_remove_kprobe()
188 		p->ainsn.insn = NULL;  in arch_remove_kprobe()
194 	kcb->prev_kprobe.kp = kprobe_running();  in save_previous_kprobe()
195 	kcb->prev_kprobe.status = kcb->kprobe_status;  in save_previous_kprobe()
200 	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);  in restore_previous_kprobe()
201 	kcb->kprobe_status = kcb->prev_kprobe.status;  in restore_previous_kprobe()
213 	regs->ARM_cpsr = it_advance(regs->ARM_cpsr);  in singlestep_skip()
214 	if (is_wide_instruction(p->opcode))  in singlestep_skip()
215 		regs->ARM_pc += 4;  in singlestep_skip()
217 		regs->ARM_pc += 2;  in singlestep_skip()
219 	regs->ARM_pc += 4;  in singlestep_skip()
226 	p->ainsn.insn_singlestep(p->opcode, &p->ainsn, regs);  in singlestep()
231  * all the way until processing this kprobe is complete.  The current
250 	p = get_kprobe((kprobe_opcode_t *)(regs->ARM_pc | 1));  in kprobe_handler()
252 		p = get_kprobe((kprobe_opcode_t *)regs->ARM_pc);  in kprobe_handler()
255 	p = get_kprobe((kprobe_opcode_t *)regs->ARM_pc);  in kprobe_handler()
259 		if (!p->ainsn.insn_check_cc(regs->ARM_cpsr)) {  in kprobe_handler()
269 			switch (kcb->kprobe_status) {  in kprobe_handler()
273 				/* A pre- or post-handler probe got us here. */  in kprobe_handler()
277 				kcb->kprobe_status = KPROBE_REENTER;  in kprobe_handler()
293 			kcb->kprobe_status = KPROBE_HIT_ACTIVE;  in kprobe_handler()
296 			 * If we have no pre-handler or it returned 0, we  in kprobe_handler()
297 			 * continue with normal processing. If we have a  in kprobe_handler()
298 			 * pre-handler and it returned non-zero, it will  in kprobe_handler()
302 			if (!p->pre_handler || !p->pre_handler(p, regs)) {  in kprobe_handler()
303 				kcb->kprobe_status = KPROBE_HIT_SS;  in kprobe_handler()
305 				if (p->post_handler) {  in kprobe_handler()
306 					kcb->kprobe_status = KPROBE_HIT_SSDONE;  in kprobe_handler()
307 					p->post_handler(p, regs, 0);  in kprobe_handler()
336 	switch (kcb->kprobe_status) {  in kprobe_fault_handler()
346 		regs->ARM_pc = (long)cur->addr;  in kprobe_fault_handler()
347 		if (kcb->kprobe_status == KPROBE_REENTER) {  in kprobe_fault_handler()
371  * give a view of registers r0-r11, sp, lr, and pc to the user
372  * return-handler. This is not a complete pt_regs structure, but that
385 		/* In clang case, pt_regs->ip = lr. */  in __kretprobe_trampoline()
386 		"stmdb	sp!, {r0 - r11, lr}	\n\t"  in __kretprobe_trampoline()
387 		/* fp points regs->r11 (fp) */  in __kretprobe_trampoline()
390 		/* In gcc case, pt_regs->ip = fp. */  in __kretprobe_trampoline()
393 		"stmdb	sp!, {r0 - r11}		\n\t"  in __kretprobe_trampoline()
394 		/* fp points regs->r15 (pc) */  in __kretprobe_trampoline()
399 		"stmdb	sp!, {r0 - r11}		\n\t"  in __kretprobe_trampoline()
404 		"ldmia	sp!, {r0 - r11}		\n\t"  in __kretprobe_trampoline()
417 	return (void *)kretprobe_trampoline_handler(regs, (void *)regs->ARM_fp);  in trampoline_handler()
423 	ri->ret_addr = (kprobe_opcode_t *)regs->ARM_lr;  in arch_prepare_kretprobe()
424 	ri->fp = (void *)regs->ARM_fp;  in arch_prepare_kretprobe()
427 	regs->ARM_lr = (unsigned long)&__kretprobe_trampoline;  in arch_prepare_kretprobe()