--- /dev/null
+/*
+ * Kernel Probes (KProbes)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corp. 2002, 2006
+ *
+ * s390 port, used ppc64 as template. Mike Grundy <grundym@us.ibm.com>
+ */
+
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+#include <linux/preempt.h>
+#include <linux/stop_machine.h>
+#include <linux/kdebug.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/hardirq.h>
+#include <linux/ftrace.h>
+#include <asm/cacheflush.h>
+#include <asm/sections.h>
+#include <asm/dis.h>
+
+DEFINE_PER_CPU(struct kprobe *, current_kprobe);
+DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+
+struct kretprobe_blackpoint kretprobe_blacklist[] = { };
+
+DEFINE_INSN_CACHE_OPS(dmainsn);
+
+static void *alloc_dmainsn_page(void)
+{
+ return (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
+}
+
+static void free_dmainsn_page(void *page)
+{
+ free_page((unsigned long)page);
+}
+
+struct kprobe_insn_cache kprobe_dmainsn_slots = {
+ .mutex = __MUTEX_INITIALIZER(kprobe_dmainsn_slots.mutex),
+ .alloc = alloc_dmainsn_page,
+ .free = free_dmainsn_page,
+ .pages = LIST_HEAD_INIT(kprobe_dmainsn_slots.pages),
+ .insn_size = MAX_INSN_SIZE,
+};
+
+static void copy_instruction(struct kprobe *p)
+{
+ unsigned long ip = (unsigned long) p->addr;
+ s64 disp, new_disp;
+ u64 addr, new_addr;
+
+ if (ftrace_location(ip) == ip) {
+ /*
+ * If kprobes patches the instruction that is morphed by
+ * ftrace make sure that kprobes always sees the branch
+ * "jg .+24" that skips the mcount block or the "brcl 0,0"
+ * in case of hotpatch.
+ */
+ ftrace_generate_nop_insn((struct ftrace_insn *)p->ainsn.insn);
+ p->ainsn.is_ftrace_insn = 1;
+ } else
+ memcpy(p->ainsn.insn, p->addr, insn_length(*p->addr >> 8));
+ p->opcode = p->ainsn.insn[0];
+ if (!probe_is_insn_relative_long(p->ainsn.insn))
+ return;
+ /*
+ * For pc-relative instructions in RIL-b or RIL-c format patch the
+ * RI2 displacement field. We have already made sure that the insn
+ * slot for the patched instruction is within the same 2GB area
+ * as the original instruction (either kernel image or module area).
+ * Therefore the new displacement will always fit.
+ */
+ disp = *(s32 *)&p->ainsn.insn[1];
+ addr = (u64)(unsigned long)p->addr;
+ new_addr = (u64)(unsigned long)p->ainsn.insn;
+ new_disp = ((addr + (disp * 2)) - new_addr) / 2;
+ *(s32 *)&p->ainsn.insn[1] = new_disp;
+}
+NOKPROBE_SYMBOL(copy_instruction);
+
+static inline int is_kernel_addr(void *addr)
+{
+ return addr < (void *)_end;
+}
+
+static int s390_get_insn_slot(struct kprobe *p)
+{
+ /*
+ * Get an insn slot that is within the same 2GB area like the original
+ * instruction. That way instructions with a 32bit signed displacement
+ * field can be patched and executed within the insn slot.
+ */
+ p->ainsn.insn = NULL;
+ if (is_kernel_addr(p->addr))
+ p->ainsn.insn = get_dmainsn_slot();
+ else if (is_module_addr(p->addr))
+ p->ainsn.insn = get_insn_slot();
+ return p->ainsn.insn ? 0 : -ENOMEM;
+}
+NOKPROBE_SYMBOL(s390_get_insn_slot);
+
+static void s390_free_insn_slot(struct kprobe *p)
+{
+ if (!p->ainsn.insn)
+ return;
+ if (is_kernel_addr(p->addr))
+ free_dmainsn_slot(p->ainsn.insn, 0);
+ else
+ free_insn_slot(p->ainsn.insn, 0);
+ p->ainsn.insn = NULL;
+}
+NOKPROBE_SYMBOL(s390_free_insn_slot);
+
+int arch_prepare_kprobe(struct kprobe *p)
+{
+ if ((unsigned long) p->addr & 0x01)
+ return -EINVAL;
+ /* Make sure the probe isn't going on a difficult instruction */
+ if (probe_is_prohibited_opcode(p->addr))
+ return -EINVAL;
+ if (s390_get_insn_slot(p))
+ return -ENOMEM;
+ copy_instruction(p);
+ return 0;
+}
+NOKPROBE_SYMBOL(arch_prepare_kprobe);
+
+int arch_check_ftrace_location(struct kprobe *p)
+{
+ return 0;
+}
+
+struct swap_insn_args {
+ struct kprobe *p;
+ unsigned int arm_kprobe : 1;
+};
+
+static int swap_instruction(void *data)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ unsigned long status = kcb->kprobe_status;
+ struct swap_insn_args *args = data;
+ struct ftrace_insn new_insn, *insn;
+ struct kprobe *p = args->p;
+ size_t len;
+
+ new_insn.opc = args->arm_kprobe ? BREAKPOINT_INSTRUCTION : p->opcode;
+ len = sizeof(new_insn.opc);
+ if (!p->ainsn.is_ftrace_insn)
+ goto skip_ftrace;
+ len = sizeof(new_insn);
+ insn = (struct ftrace_insn *) p->addr;
+ if (args->arm_kprobe) {
+ if (is_ftrace_nop(insn))
+ new_insn.disp = KPROBE_ON_FTRACE_NOP;
+ else
+ new_insn.disp = KPROBE_ON_FTRACE_CALL;
+ } else {
+ ftrace_generate_call_insn(&new_insn, (unsigned long)p->addr);
+ if (insn->disp == KPROBE_ON_FTRACE_NOP)
+ ftrace_generate_nop_insn(&new_insn);
+ }
+skip_ftrace:
+ kcb->kprobe_status = KPROBE_SWAP_INST;
+ s390_kernel_write(p->addr, &new_insn, len);
+ kcb->kprobe_status = status;
+ return 0;
+}
+NOKPROBE_SYMBOL(swap_instruction);
+
+void arch_arm_kprobe(struct kprobe *p)
+{
+ struct swap_insn_args args = {.p = p, .arm_kprobe = 1};
+
+ stop_machine(swap_instruction, &args, NULL);
+}
+NOKPROBE_SYMBOL(arch_arm_kprobe);
+
+void arch_disarm_kprobe(struct kprobe *p)
+{
+ struct swap_insn_args args = {.p = p, .arm_kprobe = 0};
+
+ stop_machine(swap_instruction, &args, NULL);
+}
+NOKPROBE_SYMBOL(arch_disarm_kprobe);
+
+void arch_remove_kprobe(struct kprobe *p)
+{
+ s390_free_insn_slot(p);
+}
+NOKPROBE_SYMBOL(arch_remove_kprobe);
+
+static void enable_singlestep(struct kprobe_ctlblk *kcb,
+ struct pt_regs *regs,
+ unsigned long ip)
+{
+ struct per_regs per_kprobe;
+
+ /* Set up the PER control registers %cr9-%cr11 */
+ per_kprobe.control = PER_EVENT_IFETCH;
+ per_kprobe.start = ip;
+ per_kprobe.end = ip;
+
+ /* Save control regs and psw mask */
+ __ctl_store(kcb->kprobe_saved_ctl, 9, 11);
+ kcb->kprobe_saved_imask = regs->psw.mask &
+ (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT);
+
+ /* Set PER control regs, turns on single step for the given address */
+ __ctl_load(per_kprobe, 9, 11);
+ regs->psw.mask |= PSW_MASK_PER;
+ regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
+ regs->psw.addr = ip | PSW_ADDR_AMODE;
+}
+NOKPROBE_SYMBOL(enable_singlestep);
+
+static void disable_singlestep(struct kprobe_ctlblk *kcb,
+ struct pt_regs *regs,
+ unsigned long ip)
+{
+ /* Restore control regs and psw mask, set new psw address */
+ __ctl_load(kcb->kprobe_saved_ctl, 9, 11);
+ regs->psw.mask &= ~PSW_MASK_PER;
+ regs->psw.mask |= kcb->kprobe_saved_imask;
+ regs->psw.addr = ip | PSW_ADDR_AMODE;
+}
+NOKPROBE_SYMBOL(disable_singlestep);
+
+/*
+ * Activate a kprobe by storing its pointer to current_kprobe. The
+ * previous kprobe is stored in kcb->prev_kprobe. A stack of up to
+ * two kprobes can be active, see KPROBE_REENTER.
+ */
+static void push_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *p)
+{
+ kcb->prev_kprobe.kp = __this_cpu_read(current_kprobe);
+ kcb->prev_kprobe.status = kcb->kprobe_status;
+ __this_cpu_write(current_kprobe, p);
+}
+NOKPROBE_SYMBOL(push_kprobe);
+
+/*
+ * Deactivate a kprobe by backing up to the previous state. If the
+ * current state is KPROBE_REENTER prev_kprobe.kp will be non-NULL,
+ * for any other state prev_kprobe.kp will be NULL.
+ */
+static void pop_kprobe(struct kprobe_ctlblk *kcb)
+{
+ __this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
+ kcb->kprobe_status = kcb->prev_kprobe.status;
+}
+NOKPROBE_SYMBOL(pop_kprobe);
+
+void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
+{
+ ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
+
+ /* Replace the return addr with trampoline addr */
+ regs->gprs[14] = (unsigned long) &kretprobe_trampoline;
+}
+NOKPROBE_SYMBOL(arch_prepare_kretprobe);
+
+static void kprobe_reenter_check(struct kprobe_ctlblk *kcb, struct kprobe *p)
+{
+ switch (kcb->kprobe_status) {
+ case KPROBE_HIT_SSDONE:
+ case KPROBE_HIT_ACTIVE:
+ kprobes_inc_nmissed_count(p);
+ break;
+ case KPROBE_HIT_SS:
+ case KPROBE_REENTER:
+ default:
+ /*
+ * A kprobe on the code path to single step an instruction
+ * is a BUG. The code path resides in the .kprobes.text
+ * section and is executed with interrupts disabled.
+ */
+ printk(KERN_EMERG "Invalid kprobe detected at %p.\n", p->addr);
+ dump_kprobe(p);
+ BUG();
+ }
+}
+NOKPROBE_SYMBOL(kprobe_reenter_check);
+
+static int kprobe_handler(struct pt_regs *regs)
+{
+ struct kprobe_ctlblk *kcb;
+ struct kprobe *p;
+
+ /*
+ * We want to disable preemption for the entire duration of kprobe
+ * processing. That includes the calls to the pre/post handlers
+ * and single stepping the kprobe instruction.
+ */
+ preempt_disable();
+ kcb = get_kprobe_ctlblk();
+ p = get_kprobe((void *)((regs->psw.addr & PSW_ADDR_INSN) - 2));
+
+ if (p) {
+ if (kprobe_running()) {
+ /*
+ * We have hit a kprobe while another is still
+ * active. This can happen in the pre and post
+ * handler. Single step the instruction of the
+ * new probe but do not call any handler function
+ * of this secondary kprobe.
+ * push_kprobe and pop_kprobe saves and restores
+ * the currently active kprobe.
+ */
+ kprobe_reenter_check(kcb, p);
+ push_kprobe(kcb, p);
+ kcb->kprobe_status = KPROBE_REENTER;
+ } else {
+ /*
+ * If we have no pre-handler or it returned 0, we
+ * continue with single stepping. If we have a
+ * pre-handler and it returned non-zero, it prepped
+ * for calling the break_handler below on re-entry
+ * for jprobe processing, so get out doing nothing
+ * more here.
+ */
+ push_kprobe(kcb, p);
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+ if (p->pre_handler && p->pre_handler(p, regs))
+ return 1;
+ kcb->kprobe_status = KPROBE_HIT_SS;
+ }
+ enable_singlestep(kcb, regs, (unsigned long) p->ainsn.insn);
+ return 1;
+ } else if (kprobe_running()) {
+ p = __this_cpu_read(current_kprobe);
+ if (p->break_handler && p->break_handler(p, regs)) {
+ /*
+ * Continuation after the jprobe completed and
+ * caused the jprobe_return trap. The jprobe
+ * break_handler "returns" to the original
+ * function that still has the kprobe breakpoint
+ * installed. We continue with single stepping.
+ */
+ kcb->kprobe_status = KPROBE_HIT_SS;
+ enable_singlestep(kcb, regs,
+ (unsigned long) p->ainsn.insn);
+ return 1;
+ } /* else:
+ * No kprobe at this address and the current kprobe
+ * has no break handler (no jprobe!). The kernel just
+ * exploded, let the standard trap handler pick up the
+ * pieces.
+ */
+ } /* else:
+ * No kprobe at this address and no active kprobe. The trap has
+ * not been caused by a kprobe breakpoint. The race of breakpoint
+ * vs. kprobe remove does not exist because on s390 as we use
+ * stop_machine to arm/disarm the breakpoints.
+ */
+ preempt_enable_no_resched();
+ return 0;
+}
+NOKPROBE_SYMBOL(kprobe_handler);
+
+/*
+ * Function return probe trampoline:
+ * - init_kprobes() establishes a probepoint here
+ * - When the probed function returns, this probe
+ * causes the handlers to fire
+ */
+static void __used kretprobe_trampoline_holder(void)
+{
+ asm volatile(".global kretprobe_trampoline\n"
+ "kretprobe_trampoline: bcr 0,0\n");
+}
+
+/*
+ * Called when the probe at kretprobe trampoline is hit
+ */
+static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct kretprobe_instance *ri;
+ struct hlist_head *head, empty_rp;
+ struct hlist_node *tmp;
+ unsigned long flags, orig_ret_address;
+ unsigned long trampoline_address;
+ kprobe_opcode_t *correct_ret_addr;
+
+ INIT_HLIST_HEAD(&empty_rp);
+ kretprobe_hash_lock(current, &head, &flags);
+
+ /*
+ * It is possible to have multiple instances associated with a given
+ * task either because an multiple functions in the call path
+ * have a return probe installed on them, and/or more than one return
+ * return probe was registered for a target function.
+ *
+ * We can handle this because:
+ * - instances are always inserted at the head of the list
+ * - when multiple return probes are registered for the same
+ * function, the first instance's ret_addr will point to the
+ * real return address, and all the rest will point to
+ * kretprobe_trampoline
+ */
+ ri = NULL;
+ orig_ret_address = 0;
+ correct_ret_addr = NULL;
+ trampoline_address = (unsigned long) &kretprobe_trampoline;
+ hlist_for_each_entry_safe(ri, tmp, head, hlist) {
+ if (ri->task != current)
+ /* another task is sharing our hash bucket */
+ continue;
+
+ orig_ret_address = (unsigned long) ri->ret_addr;
+
+ if (orig_ret_address != trampoline_address)
+ /*
+ * This is the real return address. Any other
+ * instances associated with this task are for
+ * other calls deeper on the call stack
+ */
+ break;
+ }
+
+ kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
+ correct_ret_addr = ri->ret_addr;
+ hlist_for_each_entry_safe(ri, tmp, head, hlist) {
+ if (ri->task != current)
+ /* another task is sharing our hash bucket */
+ continue;
+
+ orig_ret_address = (unsigned long) ri->ret_addr;
+
+ if (ri->rp && ri->rp->handler) {
+ ri->ret_addr = correct_ret_addr;
+ ri->rp->handler(ri, regs);
+ }
+
+ recycle_rp_inst(ri, &empty_rp);
+
+ if (orig_ret_address != trampoline_address)
+ /*
+ * This is the real return address. Any other
+ * instances associated with this task are for
+ * other calls deeper on the call stack
+ */
+ break;
+ }
+
+ regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE;
+
+ pop_kprobe(get_kprobe_ctlblk());
+ kretprobe_hash_unlock(current, &flags);
+ preempt_enable_no_resched();
+
+ hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
+ hlist_del(&ri->hlist);
+ kfree(ri);
+ }
+ /*
+ * By returning a non-zero value, we are telling
+ * kprobe_handler() that we don't want the post_handler
+ * to run (and have re-enabled preemption)
+ */
+ return 1;
+}
+NOKPROBE_SYMBOL(trampoline_probe_handler);
+
+/*
+ * Called after single-stepping. p->addr is the address of the
+ * instruction whose first byte has been replaced by the "breakpoint"
+ * instruction. To avoid the SMP problems that can occur when we
+ * temporarily put back the original opcode to single-step, we
+ * single-stepped a copy of the instruction. The address of this
+ * copy is p->ainsn.insn.
+ */
+static void resume_execution(struct kprobe *p, struct pt_regs *regs)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ unsigned long ip = regs->psw.addr & PSW_ADDR_INSN;
+ int fixup = probe_get_fixup_type(p->ainsn.insn);
+
+ /* Check if the kprobes location is an enabled ftrace caller */
+ if (p->ainsn.is_ftrace_insn) {
+ struct ftrace_insn *insn = (struct ftrace_insn *) p->addr;
+ struct ftrace_insn call_insn;
+
+ ftrace_generate_call_insn(&call_insn, (unsigned long) p->addr);
+ /*
+ * A kprobe on an enabled ftrace call site actually single
+ * stepped an unconditional branch (ftrace nop equivalent).
+ * Now we need to fixup things and pretend that a brasl r0,...
+ * was executed instead.
+ */
+ if (insn->disp == KPROBE_ON_FTRACE_CALL) {
+ ip += call_insn.disp * 2 - MCOUNT_INSN_SIZE;
+ regs->gprs[0] = (unsigned long)p->addr + sizeof(*insn);
+ }
+ }
+
+ if (fixup & FIXUP_PSW_NORMAL)
+ ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn;
+
+ if (fixup & FIXUP_BRANCH_NOT_TAKEN) {
+ int ilen = insn_length(p->ainsn.insn[0] >> 8);
+ if (ip - (unsigned long) p->ainsn.insn == ilen)
+ ip = (unsigned long) p->addr + ilen;
+ }
+
+ if (fixup & FIXUP_RETURN_REGISTER) {
+ int reg = (p->ainsn.insn[0] & 0xf0) >> 4;
+ regs->gprs[reg] += (unsigned long) p->addr -
+ (unsigned long) p->ainsn.insn;
+ }
+
+ disable_singlestep(kcb, regs, ip);
+}
+NOKPROBE_SYMBOL(resume_execution);
+
+static int post_kprobe_handler(struct pt_regs *regs)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ struct kprobe *p = kprobe_running();
+
+ if (!p)
+ return 0;
+
+ if (kcb->kprobe_status != KPROBE_REENTER && p->post_handler) {
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ p->post_handler(p, regs, 0);
+ }
+
+ resume_execution(p, regs);
+ pop_kprobe(kcb);
+ preempt_enable_no_resched();
+
+ /*
+ * if somebody else is singlestepping across a probe point, psw mask
+ * will have PER set, in which case, continue the remaining processing
+ * of do_single_step, as if this is not a probe hit.
+ */
+ if (regs->psw.mask & PSW_MASK_PER)
+ return 0;
+
+ return 1;
+}
+NOKPROBE_SYMBOL(post_kprobe_handler);
+
+static int kprobe_trap_handler(struct pt_regs *regs, int trapnr)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ struct kprobe *p = kprobe_running();
+ const struct exception_table_entry *entry;
+
+ switch(kcb->kprobe_status) {
+ case KPROBE_SWAP_INST:
+ /* We are here because the instruction replacement failed */
+ return 0;
+ case KPROBE_HIT_SS:
+ case KPROBE_REENTER:
+ /*
+ * We are here because the instruction being single
+ * stepped caused a page fault. We reset the current
+ * kprobe and the nip points back to the probe address
+ * and allow the page fault handler to continue as a
+ * normal page fault.
+ */
+ disable_singlestep(kcb, regs, (unsigned long) p->addr);
+ pop_kprobe(kcb);
+ preempt_enable_no_resched();
+ break;
+ case KPROBE_HIT_ACTIVE:
+ case KPROBE_HIT_SSDONE:
+ /*
+ * We increment the nmissed count for accounting,
+ * we can also use npre/npostfault count for accounting
+ * these specific fault cases.
+ */
+ kprobes_inc_nmissed_count(p);
+
+ /*
+ * We come here because instructions in the pre/post
+ * handler caused the page_fault, this could happen
+ * if handler tries to access user space by
+ * copy_from_user(), get_user() etc. Let the
+ * user-specified handler try to fix it first.
+ */
+ if (p->fault_handler && p->fault_handler(p, regs, trapnr))
+ return 1;
+
+ /*
+ * In case the user-specified fault handler returned
+ * zero, try to fix up.
+ */
+ entry = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
+ if (entry) {
+ regs->psw.addr = extable_fixup(entry) | PSW_ADDR_AMODE;
+ return 1;
+ }
+
+ /*
+ * fixup_exception() could not handle it,
+ * Let do_page_fault() fix it.
+ */
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+NOKPROBE_SYMBOL(kprobe_trap_handler);
+
+int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+{
+ int ret;
+
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_disable();
+ ret = kprobe_trap_handler(regs, trapnr);
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
+ return ret;
+}
+NOKPROBE_SYMBOL(kprobe_fault_handler);
+
+/*
+ * Wrapper routine to for handling exceptions.
+ */
+int kprobe_exceptions_notify(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ struct die_args *args = (struct die_args *) data;
+ struct pt_regs *regs = args->regs;
+ int ret = NOTIFY_DONE;
+
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_disable();
+
+ switch (val) {
+ case DIE_BPT:
+ if (kprobe_handler(regs))
+ ret = NOTIFY_STOP;
+ break;
+ case DIE_SSTEP:
+ if (post_kprobe_handler(regs))
+ ret = NOTIFY_STOP;
+ break;
+ case DIE_TRAP:
+ if (!preemptible() && kprobe_running() &&
+ kprobe_trap_handler(regs, args->trapnr))
+ ret = NOTIFY_STOP;
+ break;
+ default:
+ break;
+ }
+
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
+
+ return ret;
+}
+NOKPROBE_SYMBOL(kprobe_exceptions_notify);
+
+int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct jprobe *jp = container_of(p, struct jprobe, kp);
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ unsigned long stack;
+
+ memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
+
+ /* setup return addr to the jprobe handler routine */
+ regs->psw.addr = (unsigned long) jp->entry | PSW_ADDR_AMODE;
+ regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
+
+ /* r15 is the stack pointer */
+ stack = (unsigned long) regs->gprs[15];
+
+ memcpy(kcb->jprobes_stack, (void *) stack, MIN_STACK_SIZE(stack));
+ return 1;
+}
+NOKPROBE_SYMBOL(setjmp_pre_handler);
+
+void jprobe_return(void)
+{
+ asm volatile(".word 0x0002");
+}
+NOKPROBE_SYMBOL(jprobe_return);
+
+int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ 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((void *) stack, kcb->jprobes_stack, MIN_STACK_SIZE(stack));
+ preempt_enable_no_resched();
+ return 1;
+}
+NOKPROBE_SYMBOL(longjmp_break_handler);
+
+static struct kprobe trampoline = {
+ .addr = (kprobe_opcode_t *) &kretprobe_trampoline,
+ .pre_handler = trampoline_probe_handler
+};
+
+int __init arch_init_kprobes(void)
+{
+ return register_kprobe(&trampoline);
+}
+
+int arch_trampoline_kprobe(struct kprobe *p)
+{
+ return p->addr == (kprobe_opcode_t *) &kretprobe_trampoline;
+}
+NOKPROBE_SYMBOL(arch_trampoline_kprobe);
Code Review / kvmfornfv.git / blobdiff