1 #include <linux/spinlock.h>
2 #include <linux/hardirq.h>
3 #include <linux/ftrace.h>
4 #include <linux/percpu.h>
5 #include <linux/init.h>
6 #include <linux/list.h>
7 #include <trace/syscall.h>
9 #include <asm/ftrace.h>
11 #ifdef CONFIG_DYNAMIC_FTRACE
12 static const u32 ftrace_nop = 0x01000000;
14 static u32 ftrace_call_replace(unsigned long ip, unsigned long addr)
19 off = ((s32)addr - (s32)ip);
20 call = 0x40000000 | ((u32)off >> 2);
25 static int ftrace_modify_code(unsigned long ip, u32 old, u32 new)
31 "1: cas [%[ip]], %[old], %[new]\n"
33 " mov 0, %[faulted]\n"
35 " .section .fixup,#alloc,#execinstr\n"
37 "3: sethi %%hi(2b), %[faulted]\n"
38 " jmpl %[faulted] + %%lo(2b), %%g0\n"
39 " mov 1, %[faulted]\n"
41 " .section __ex_table,\"a\"\n"
45 : "=r" (replaced), [faulted] "=r" (faulted)
46 : [new] "0" (new), [old] "r" (old), [ip] "r" (ip)
49 if (replaced != old && replaced != new)
55 int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
57 unsigned long ip = rec->ip;
60 old = ftrace_call_replace(ip, addr);
62 return ftrace_modify_code(ip, old, new);
65 int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
67 unsigned long ip = rec->ip;
71 new = ftrace_call_replace(ip, addr);
72 return ftrace_modify_code(ip, old, new);
75 int ftrace_update_ftrace_func(ftrace_func_t func)
77 unsigned long ip = (unsigned long)(&ftrace_call);
80 old = *(u32 *) &ftrace_call;
81 new = ftrace_call_replace(ip, (unsigned long)func);
82 return ftrace_modify_code(ip, old, new);
85 int __init ftrace_dyn_arch_init(void *data)
87 unsigned long *p = data;
95 #ifdef CONFIG_FTRACE_SYSCALLS
97 extern unsigned int sys_call_table[];
99 unsigned long __init arch_syscall_addr(int nr)
101 return (unsigned long)sys_call_table[nr];