1 // SPDX-License-Identifier: GPL-2.0-only
27 #include <asm/debug-monitors.h>
36 #include "decode-insn.h"
46 	kprobe_opcode_t *addr = p->ainsn.api.insn;  in arch_prepare_ss_slot()
52 	 * - That the I-cache maintenance for these instructions is complete  in arch_prepare_ss_slot()
54 	 *   ensures this, but just omits causing a Context-Synchronization-Event  in arch_prepare_ss_slot()
57 	 * - That the kprobe BRK results in an exception (and consequently a  in arch_prepare_ss_slot()
58 	 *   Context-Synchronoization-Event), which ensures that the CPU will  in arch_prepare_ss_slot()
59 	 *   fetch thesingle-step slot instructions *after* this, ensuring that  in arch_prepare_ss_slot()
62 	 * It supposes to place ISB after patching to guarantee I-cache maintenance  in arch_prepare_ss_slot()
63 	 * is observed on all CPUS, however, single-step slot is installed in  in arch_prepare_ss_slot()
65 	 * Contex-Synchronization-Event via ISB again.  in arch_prepare_ss_slot()
67 	aarch64_insn_patch_text_nosync(addr, p->opcode);  in arch_prepare_ss_slot()
73 	p->ainsn.api.restore = (unsigned long) p->addr +  in arch_prepare_ss_slot()
80 	p->ainsn.api.restore = 0;  in arch_prepare_simulate()
87 	if (p->ainsn.api.handler)  in arch_simulate_insn()
88 		p->ainsn.api.handler((u32)p->opcode, (long)p->addr, regs);  in arch_simulate_insn()
90 	/* single step simulated, now go for post processing */  in arch_simulate_insn()
96 	unsigned long probe_addr = (unsigned long)p->addr;  in arch_prepare_kprobe()
99 		return -EINVAL;  in arch_prepare_kprobe()
102 	p->opcode = le32_to_cpu(*p->addr);  in arch_prepare_kprobe()
105 		return -EINVAL;  in arch_prepare_kprobe()
108 	switch (arm_kprobe_decode_insn(p->addr, &p->ainsn)) {  in arch_prepare_kprobe()
110 		return -EINVAL;  in arch_prepare_kprobe()
113 		p->ainsn.api.insn = NULL;  in arch_prepare_kprobe()
117 		p->ainsn.api.insn = get_insn_slot();  in arch_prepare_kprobe()
118 		if (!p->ainsn.api.insn)  in arch_prepare_kprobe()
119 			return -ENOMEM;  in arch_prepare_kprobe()
124 	if (p->ainsn.api.insn)  in arch_prepare_kprobe()
142 	void *addr = p->addr;  in arch_arm_kprobe()
151 	void *addr = p->addr;  in arch_disarm_kprobe()
153 	aarch64_insn_patch_text(&addr, &p->opcode, 1);  in arch_disarm_kprobe()
158 	if (p->ainsn.api.insn) {  in arch_remove_kprobe()
159 		free_insn_slot(p->ainsn.api.insn, 0);  in arch_remove_kprobe()
160 		p->ainsn.api.insn = NULL;  in arch_remove_kprobe()
166 	kcb->prev_kprobe.kp = kprobe_running();  in save_previous_kprobe()
167 	kcb->prev_kprobe.status = kcb->kprobe_status;  in save_previous_kprobe()
172 	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);  in restore_previous_kprobe()
173 	kcb->kprobe_status = kcb->prev_kprobe.status;  in restore_previous_kprobe()
182  * Mask all of DAIF while executing the instruction out-of-line, to keep things
184  * the kprobe state is per-CPU and doesn't get migrated.
189 	kcb->saved_irqflag = regs->pstate & DAIF_MASK;  in kprobes_save_local_irqflag()
190 	regs->pstate |= DAIF_MASK;  in kprobes_save_local_irqflag()
196 	regs->pstate &= ~DAIF_MASK;  in kprobes_restore_local_irqflag()
197 	regs->pstate |= kcb->saved_irqflag;  in kprobes_restore_local_irqflag()
209 		kcb->kprobe_status = KPROBE_REENTER;  in setup_singlestep()
211 		kcb->kprobe_status = KPROBE_HIT_SS;  in setup_singlestep()
215 	if (p->ainsn.api.insn) {  in setup_singlestep()
217 		slot = (unsigned long)p->ainsn.api.insn;  in setup_singlestep()
231 	switch (kcb->kprobe_status) {  in reenter_kprobe()
254 	/* return addr restore if non-branching insn */  in post_kprobe_handler()
255 	if (cur->ainsn.api.restore != 0)  in post_kprobe_handler()
256 		instruction_pointer_set(regs, cur->ainsn.api.restore);  in post_kprobe_handler()
259 	if (kcb->kprobe_status == KPROBE_REENTER) {  in post_kprobe_handler()
263 	/* call post handler */  in post_kprobe_handler()
264 	kcb->kprobe_status = KPROBE_HIT_SSDONE;  in post_kprobe_handler()
265 	if (cur->post_handler)  in post_kprobe_handler()
266 		cur->post_handler(cur, regs, 0);  in post_kprobe_handler()
276 	switch (kcb->kprobe_status) {  in kprobe_fault_handler()
286 		instruction_pointer_set(regs, (unsigned long) cur->addr);  in kprobe_fault_handler()
289 		if (kcb->kprobe_status == KPROBE_REENTER) {  in kprobe_fault_handler()
300 		 * In case the user-specified fault handler returned  in kprobe_fault_handler()
327 			kcb->kprobe_status = KPROBE_HIT_ACTIVE;  in kprobe_handler()
330 			 * If we have no pre-handler or it returned 0, we  in kprobe_handler()
331 			 * continue with normal processing.  If we have a  in kprobe_handler()
332 			 * pre-handler and it returned non-zero, it will  in kprobe_handler()
336 			if (!p->pre_handler || !p->pre_handler(p, regs)) {  in kprobe_handler()
359 	if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) &&  in kprobe_breakpoint_ss_handler()
360 	    ((unsigned long)&cur->ainsn.api.insn[1] == addr)) {  in kprobe_breakpoint_ss_handler()
419 	return (void *)kretprobe_trampoline_handler(regs, (void *)regs->regs[29]);  in trampoline_probe_handler()
425 	ri->ret_addr = (kprobe_opcode_t *)regs->regs[30];  in arch_prepare_kretprobe()
426 	ri->fp = (void *)regs->regs[29];  in arch_prepare_kretprobe()
429 	regs->regs[30] = (long)&__kretprobe_trampoline;  in arch_prepare_kretprobe()