#include <linux/preempt.h>
#include <linux/stop_machine.h>
#include <linux/kdebug.h>
+#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
-#include <asm/uaccess.h>
#include <linux/module.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
static int __kprobes swap_instruction(void *aref)
{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ unsigned long status = kcb->kprobe_status;
struct ins_replace_args *args = aref;
- u32 *addr;
- u32 instr;
- int err = -EFAULT;
+ int rc;
- /*
- * Text segment is read-only, hence we use stura to bypass dynamic
- * address translation to exchange the instruction. Since stura
- * always operates on four bytes, but we only want to exchange two
- * bytes do some calculations to get things right. In addition we
- * shall not cross any page boundaries (vmalloc area!) when writing
- * the new instruction.
- */
- addr = (u32 *)((unsigned long)args->ptr & -4UL);
- if ((unsigned long)args->ptr & 2)
- instr = ((*addr) & 0xffff0000) | args->new;
- else
- instr = ((*addr) & 0x0000ffff) | args->new << 16;
-
- asm volatile(
- " lra %1,0(%1)\n"
- "0: stura %2,%1\n"
- "1: la %0,0\n"
- "2:\n"
- EX_TABLE(0b,2b)
- : "+d" (err)
- : "a" (addr), "d" (instr)
- : "memory", "cc");
-
- return err;
+ kcb->kprobe_status = KPROBE_SWAP_INST;
+ rc = probe_kernel_write(args->ptr, &args->new, sizeof(args->new));
+ kcb->kprobe_status = status;
+ return rc;
}
void __kprobes arch_arm_kprobe(struct kprobe *p)
{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long status = kcb->kprobe_status;
struct ins_replace_args args;
args.ptr = p->addr;
args.old = p->opcode;
args.new = BREAKPOINT_INSTRUCTION;
-
- kcb->kprobe_status = KPROBE_SWAP_INST;
stop_machine(swap_instruction, &args, NULL);
- kcb->kprobe_status = status;
}
void __kprobes arch_disarm_kprobe(struct kprobe *p)
{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- unsigned long status = kcb->kprobe_status;
struct ins_replace_args args;
args.ptr = p->addr;
args.old = BREAKPOINT_INSTRUCTION;
args.new = p->opcode;
-
- kcb->kprobe_status = KPROBE_SWAP_INST;
stop_machine(swap_instruction, &args, NULL);
- kcb->kprobe_status = status;
}
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
- mutex_lock(&kprobe_mutex);
- free_insn_slot(p->ainsn.insn, 0);
- mutex_unlock(&kprobe_mutex);
+ if (p->ainsn.insn) {
+ free_insn_slot(p->ainsn.insn, 0);
+ p->ainsn.insn = NULL;
+ }
}
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
/*
* 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 then one return
+ * 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: