diff options
Diffstat (limited to 'arch/sparc64/kernel/kprobes.c')
| -rw-r--r-- | arch/sparc64/kernel/kprobes.c | 444 |
1 files changed, 0 insertions, 444 deletions
diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c deleted file mode 100644 index 0d66d07c8c6..00000000000 --- a/arch/sparc64/kernel/kprobes.c +++ /dev/null @@ -1,444 +0,0 @@ -/* arch/sparc64/kernel/kprobes.c - * - * Copyright (C) 2004 David S. Miller <davem@davemloft.net> - */ - -#include <linux/config.h> -#include <linux/kernel.h> -#include <linux/kprobes.h> -#include <asm/kdebug.h> -#include <asm/signal.h> -#include <asm/cacheflush.h> - -/* We do not have hardware single-stepping on sparc64. - * So we implement software single-stepping with breakpoint - * traps. The top-level scheme is similar to that used - * in the x86 kprobes implementation. - * - * In the kprobe->ainsn.insn[] array we store the original - * instruction at index zero and a break instruction at - * index one. - * - * When we hit a kprobe we: - * - Run the pre-handler - * - Remember "regs->tnpc" and interrupt level stored in - * "regs->tstate" so we can restore them later - * - Disable PIL interrupts - * - Set regs->tpc to point to kprobe->ainsn.insn[0] - * - Set regs->tnpc to point to kprobe->ainsn.insn[1] - * - Mark that we are actively in a kprobe - * - * At this point we wait for the second breakpoint at - * kprobe->ainsn.insn[1] to hit. When it does we: - * - Run the post-handler - * - Set regs->tpc to "remembered" regs->tnpc stored above, - * restore the PIL interrupt level in "regs->tstate" as well - * - Make any adjustments necessary to regs->tnpc in order - * to handle relative branches correctly. See below. - * - Mark that we are no longer actively in a kprobe. - */ - -int __kprobes arch_prepare_kprobe(struct kprobe *p) -{ - return 0; -} - -void __kprobes arch_copy_kprobe(struct kprobe *p) -{ - p->ainsn.insn[0] = *p->addr; - p->ainsn.insn[1] = BREAKPOINT_INSTRUCTION_2; - p->opcode = *p->addr; -} - -void __kprobes arch_arm_kprobe(struct kprobe *p) -{ - *p->addr = BREAKPOINT_INSTRUCTION; - flushi(p->addr); -} - -void __kprobes arch_disarm_kprobe(struct kprobe *p) -{ - *p->addr = p->opcode; - flushi(p->addr); -} - -void __kprobes arch_remove_kprobe(struct kprobe *p) -{ -} - -static struct kprobe *current_kprobe; -static unsigned long current_kprobe_orig_tnpc; -static unsigned long current_kprobe_orig_tstate_pil; -static unsigned int kprobe_status; -static struct kprobe *kprobe_prev; -static unsigned long kprobe_orig_tnpc_prev; -static unsigned long kprobe_orig_tstate_pil_prev; -static unsigned int kprobe_status_prev; - -static inline void save_previous_kprobe(void) -{ - kprobe_status_prev = kprobe_status; - kprobe_orig_tnpc_prev = current_kprobe_orig_tnpc; - kprobe_orig_tstate_pil_prev = current_kprobe_orig_tstate_pil; - kprobe_prev = current_kprobe; -} - -static inline void restore_previous_kprobe(void) -{ - kprobe_status = kprobe_status_prev; - current_kprobe_orig_tnpc = kprobe_orig_tnpc_prev; - current_kprobe_orig_tstate_pil = kprobe_orig_tstate_pil_prev; - current_kprobe = kprobe_prev; -} - -static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs) -{ - current_kprobe_orig_tnpc = regs->tnpc; - current_kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL); - current_kprobe = p; -} - -static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) -{ - regs->tstate |= TSTATE_PIL; - - /*single step inline, if it a breakpoint instruction*/ - if (p->opcode == BREAKPOINT_INSTRUCTION) { - regs->tpc = (unsigned long) p->addr; - regs->tnpc = current_kprobe_orig_tnpc; - } else { - regs->tpc = (unsigned long) &p->ainsn.insn[0]; - regs->tnpc = (unsigned long) &p->ainsn.insn[1]; - } -} - -static int __kprobes kprobe_handler(struct pt_regs *regs) -{ - struct kprobe *p; - void *addr = (void *) regs->tpc; - int ret = 0; - - preempt_disable(); - - if (kprobe_running()) { - /* We *are* holding lock here, so this is safe. - * Disarm the probe we just hit, and ignore it. - */ - p = get_kprobe(addr); - if (p) { - if (kprobe_status == KPROBE_HIT_SS) { - regs->tstate = ((regs->tstate & ~TSTATE_PIL) | - current_kprobe_orig_tstate_pil); - unlock_kprobes(); - goto no_kprobe; - } - /* We have reentered the kprobe_handler(), since - * another probe was hit while within the handler. - * We here save the original kprobes variables and - * just single step on the instruction of the new probe - * without calling any user handlers. - */ - save_previous_kprobe(); - set_current_kprobe(p, regs); - p->nmissed++; - kprobe_status = KPROBE_REENTER; - prepare_singlestep(p, regs); - return 1; - } else { - p = current_kprobe; - if (p->break_handler && p->break_handler(p, regs)) - goto ss_probe; - } - /* If it's not ours, can't be delete race, (we hold lock). */ - goto no_kprobe; - } - - lock_kprobes(); - p = get_kprobe(addr); - if (!p) { - unlock_kprobes(); - if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) { - /* - * The breakpoint instruction was removed right - * after we hit it. Another cpu has removed - * either a probepoint or a debugger breakpoint - * at this address. In either case, no further - * handling of this interrupt is appropriate. - */ - ret = 1; - } - /* Not one of ours: let kernel handle it */ - goto no_kprobe; - } - - set_current_kprobe(p, regs); - kprobe_status = KPROBE_HIT_ACTIVE; - if (p->pre_handler && p->pre_handler(p, regs)) - return 1; - -ss_probe: - prepare_singlestep(p, regs); - kprobe_status = KPROBE_HIT_SS; - return 1; - -no_kprobe: - preempt_enable_no_resched(); - return ret; -} - -/* If INSN is a relative control transfer instruction, - * return the corrected branch destination value. - * - * The original INSN location was REAL_PC, it actually - * executed at PC and produced destination address NPC. - */ -static unsigned long __kprobes relbranch_fixup(u32 insn, unsigned long real_pc, - unsigned long pc, - unsigned long npc) -{ - /* Branch not taken, no mods necessary. */ - if (npc == pc + 0x4UL) - return real_pc + 0x4UL; - - /* The three cases are call, branch w/prediction, - * and traditional branch. - */ - if ((insn & 0xc0000000) == 0x40000000 || - (insn & 0xc1c00000) == 0x00400000 || - (insn & 0xc1c00000) == 0x00800000) { - /* The instruction did all the work for us - * already, just apply the offset to the correct - * instruction location. - */ - return (real_pc + (npc - pc)); - } - - return real_pc + 0x4UL; -} - -/* If INSN is an instruction which writes it's PC location - * into a destination register, fix that up. - */ -static void __kprobes retpc_fixup(struct pt_regs *regs, u32 insn, - unsigned long real_pc) -{ - unsigned long *slot = NULL; - - /* Simplest cast is call, which always uses %o7 */ - if ((insn & 0xc0000000) == 0x40000000) { - slot = ®s->u_regs[UREG_I7]; - } - - /* Jmpl encodes the register inside of the opcode */ - if ((insn & 0xc1f80000) == 0x81c00000) { - unsigned long rd = ((insn >> 25) & 0x1f); - - if (rd <= 15) { - slot = ®s->u_regs[rd]; - } else { - /* Hard case, it goes onto the stack. */ - flushw_all(); - - rd -= 16; - slot = (unsigned long *) - (regs->u_regs[UREG_FP] + STACK_BIAS); - slot += rd; - } - } - if (slot != NULL) - *slot = real_pc; -} - -/* - * 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. - * - * This function prepares to return from the post-single-step - * breakpoint trap. - */ -static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) -{ - u32 insn = p->ainsn.insn[0]; - - regs->tpc = current_kprobe_orig_tnpc; - regs->tnpc = relbranch_fixup(insn, - (unsigned long) p->addr, - (unsigned long) &p->ainsn.insn[0], - regs->tnpc); - retpc_fixup(regs, insn, (unsigned long) p->addr); - - regs->tstate = ((regs->tstate & ~TSTATE_PIL) | - current_kprobe_orig_tstate_pil); -} - -static inline int post_kprobe_handler(struct pt_regs *regs) -{ - if (!kprobe_running()) - return 0; - - if ((kprobe_status != KPROBE_REENTER) && current_kprobe->post_handler) { - kprobe_status = KPROBE_HIT_SSDONE; - current_kprobe->post_handler(current_kprobe, regs, 0); - } - - resume_execution(current_kprobe, regs); - - /*Restore back the original saved kprobes variables and continue. */ - if (kprobe_status == KPROBE_REENTER) { - restore_previous_kprobe(); - goto out; - } - unlock_kprobes(); -out: - preempt_enable_no_resched(); - - return 1; -} - -/* Interrupts disabled, kprobe_lock held. */ -static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) -{ - if (current_kprobe->fault_handler - && current_kprobe->fault_handler(current_kprobe, regs, trapnr)) - return 1; - - if (kprobe_status & KPROBE_HIT_SS) { - resume_execution(current_kprobe, regs); - - unlock_kprobes(); - preempt_enable_no_resched(); - } - return 0; -} - -/* - * Wrapper routine to for handling exceptions. - */ -int __kprobes kprobe_exceptions_notify(struct notifier_block *self, - unsigned long val, void *data) -{ - struct die_args *args = (struct die_args *)data; - switch (val) { - case DIE_DEBUG: - if (kprobe_handler(args->regs)) - return NOTIFY_STOP; - break; - case DIE_DEBUG_2: - if (post_kprobe_handler(args->regs)) - return NOTIFY_STOP; - break; - case DIE_GPF: - if (kprobe_running() && - kprobe_fault_handler(args->regs, args->trapnr)) - return NOTIFY_STOP; - break; - case DIE_PAGE_FAULT: - if (kprobe_running() && - kprobe_fault_handler(args->regs, args->trapnr)) - return NOTIFY_STOP; - break; - default: - break; - } - return NOTIFY_DONE; -} - -asmlinkage void __kprobes kprobe_trap(unsigned long trap_level, - struct pt_regs *regs) -{ - BUG_ON(trap_level != 0x170 && trap_level != 0x171); - - if (user_mode(regs)) { - local_irq_enable(); - bad_trap(regs, trap_level); - return; - } - - /* trap_level == 0x170 --> ta 0x70 - * trap_level == 0x171 --> ta 0x71 - */ - if (notify_die((trap_level == 0x170) ? DIE_DEBUG : DIE_DEBUG_2, - (trap_level == 0x170) ? "debug" : "debug_2", - regs, 0, trap_level, SIGTRAP) != NOTIFY_STOP) - bad_trap(regs, trap_level); -} - -/* Jprobes support. */ -static struct pt_regs jprobe_saved_regs; -static struct pt_regs *jprobe_saved_regs_location; -static struct sparc_stackf jprobe_saved_stack; - -int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) -{ - struct jprobe *jp = container_of(p, struct jprobe, kp); - - jprobe_saved_regs_location = regs; - memcpy(&jprobe_saved_regs, regs, sizeof(*regs)); - - /* Save a whole stack frame, this gets arguments - * pushed onto the stack after using up all the - * arg registers. - */ - memcpy(&jprobe_saved_stack, - (char *) (regs->u_regs[UREG_FP] + STACK_BIAS), - sizeof(jprobe_saved_stack)); - - regs->tpc = (unsigned long) jp->entry; - regs->tnpc = ((unsigned long) jp->entry) + 0x4UL; - regs->tstate |= TSTATE_PIL; - - return 1; -} - -void __kprobes jprobe_return(void) -{ - preempt_enable_no_resched(); - __asm__ __volatile__( - ".globl jprobe_return_trap_instruction\n" -"jprobe_return_trap_instruction:\n\t" - "ta 0x70"); -} - -extern void jprobe_return_trap_instruction(void); - -extern void __show_regs(struct pt_regs * regs); - -int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) -{ - u32 *addr = (u32 *) regs->tpc; - - if (addr == (u32 *) jprobe_return_trap_instruction) { - if (jprobe_saved_regs_location != regs) { - printk("JPROBE: Current regs (%p) does not match " - "saved regs (%p).\n", - regs, jprobe_saved_regs_location); - printk("JPROBE: Saved registers\n"); - __show_regs(jprobe_saved_regs_location); - printk("JPROBE: Current registers\n"); - __show_regs(regs); - BUG(); - } - /* Restore old register state. Do pt_regs - * first so that UREG_FP is the original one for - * the stack frame restore. - */ - memcpy(regs, &jprobe_saved_regs, sizeof(*regs)); - - memcpy((char *) (regs->u_regs[UREG_FP] + STACK_BIAS), - &jprobe_saved_stack, - sizeof(jprobe_saved_stack)); - - return 1; - } - return 0; -} - -/* architecture specific initialization */ -int arch_init_kprobes(void) -{ - return 0; -} |