296 lines
7.4 KiB
C
296 lines
7.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
#include <linux/ftrace.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/cacheflush.h>
|
|
|
|
#ifndef CONFIG_DYNAMIC_FTRACE
|
|
extern void (*ftrace_trace_function)(unsigned long, unsigned long,
|
|
struct ftrace_ops*, struct pt_regs*);
|
|
extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
|
|
extern void ftrace_graph_caller(void);
|
|
|
|
noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *op, struct pt_regs *regs)
|
|
{
|
|
__asm__ (""); /* avoid to optimize as pure function */
|
|
}
|
|
|
|
noinline void _mcount(unsigned long parent_ip)
|
|
{
|
|
/* save all state by the compiler prologue */
|
|
|
|
unsigned long ip = (unsigned long)__builtin_return_address(0);
|
|
|
|
if (ftrace_trace_function != ftrace_stub)
|
|
ftrace_trace_function(ip - MCOUNT_INSN_SIZE, parent_ip,
|
|
NULL, NULL);
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
if (ftrace_graph_return != (trace_func_graph_ret_t)ftrace_stub
|
|
|| ftrace_graph_entry != ftrace_graph_entry_stub)
|
|
ftrace_graph_caller();
|
|
#endif
|
|
|
|
/* restore all state by the compiler epilogue */
|
|
}
|
|
EXPORT_SYMBOL(_mcount);
|
|
|
|
#else /* CONFIG_DYNAMIC_FTRACE */
|
|
|
|
noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *op, struct pt_regs *regs)
|
|
{
|
|
__asm__ (""); /* avoid to optimize as pure function */
|
|
}
|
|
|
|
noinline void __naked _mcount(unsigned long parent_ip)
|
|
{
|
|
__asm__ (""); /* avoid to optimize as pure function */
|
|
}
|
|
EXPORT_SYMBOL(_mcount);
|
|
|
|
#define XSTR(s) STR(s)
|
|
#define STR(s) #s
|
|
void _ftrace_caller(unsigned long parent_ip)
|
|
{
|
|
/* save all state needed by the compiler prologue */
|
|
|
|
/*
|
|
* prepare arguments for real tracing function
|
|
* first arg : __builtin_return_address(0) - MCOUNT_INSN_SIZE
|
|
* second arg : parent_ip
|
|
*/
|
|
__asm__ __volatile__ (
|
|
"move $r1, %0 \n\t"
|
|
"addi $r0, %1, #-" XSTR(MCOUNT_INSN_SIZE) "\n\t"
|
|
:
|
|
: "r" (parent_ip), "r" (__builtin_return_address(0)));
|
|
|
|
/* a placeholder for the call to a real tracing function */
|
|
__asm__ __volatile__ (
|
|
"ftrace_call: \n\t"
|
|
"nop \n\t"
|
|
"nop \n\t"
|
|
"nop \n\t");
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
/* a placeholder for the call to ftrace_graph_caller */
|
|
__asm__ __volatile__ (
|
|
"ftrace_graph_call: \n\t"
|
|
"nop \n\t"
|
|
"nop \n\t"
|
|
"nop \n\t");
|
|
#endif
|
|
/* restore all state needed by the compiler epilogue */
|
|
}
|
|
|
|
int __init ftrace_dyn_arch_init(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int ftrace_arch_code_modify_prepare(void)
|
|
{
|
|
set_all_modules_text_rw();
|
|
return 0;
|
|
}
|
|
|
|
int ftrace_arch_code_modify_post_process(void)
|
|
{
|
|
set_all_modules_text_ro();
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long gen_sethi_insn(unsigned long addr)
|
|
{
|
|
unsigned long opcode = 0x46000000;
|
|
unsigned long imm = addr >> 12;
|
|
unsigned long rt_num = 0xf << 20;
|
|
|
|
return ENDIAN_CONVERT(opcode | rt_num | imm);
|
|
}
|
|
|
|
static unsigned long gen_ori_insn(unsigned long addr)
|
|
{
|
|
unsigned long opcode = 0x58000000;
|
|
unsigned long imm = addr & 0x0000fff;
|
|
unsigned long rt_num = 0xf << 20;
|
|
unsigned long ra_num = 0xf << 15;
|
|
|
|
return ENDIAN_CONVERT(opcode | rt_num | ra_num | imm);
|
|
}
|
|
|
|
static unsigned long gen_jral_insn(unsigned long addr)
|
|
{
|
|
unsigned long opcode = 0x4a000001;
|
|
unsigned long rt_num = 0x1e << 20;
|
|
unsigned long rb_num = 0xf << 10;
|
|
|
|
return ENDIAN_CONVERT(opcode | rt_num | rb_num);
|
|
}
|
|
|
|
static void ftrace_gen_call_insn(unsigned long *call_insns,
|
|
unsigned long addr)
|
|
{
|
|
call_insns[0] = gen_sethi_insn(addr); /* sethi $r15, imm20u */
|
|
call_insns[1] = gen_ori_insn(addr); /* ori $r15, $r15, imm15u */
|
|
call_insns[2] = gen_jral_insn(addr); /* jral $lp, $r15 */
|
|
}
|
|
|
|
static int __ftrace_modify_code(unsigned long pc, unsigned long *old_insn,
|
|
unsigned long *new_insn, bool validate)
|
|
{
|
|
unsigned long orig_insn[3];
|
|
|
|
if (validate) {
|
|
if (probe_kernel_read(orig_insn, (void *)pc, MCOUNT_INSN_SIZE))
|
|
return -EFAULT;
|
|
if (memcmp(orig_insn, old_insn, MCOUNT_INSN_SIZE))
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (probe_kernel_write((void *)pc, new_insn, MCOUNT_INSN_SIZE))
|
|
return -EPERM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ftrace_modify_code(unsigned long pc, unsigned long *old_insn,
|
|
unsigned long *new_insn, bool validate)
|
|
{
|
|
int ret;
|
|
|
|
ret = __ftrace_modify_code(pc, old_insn, new_insn, validate);
|
|
if (ret)
|
|
return ret;
|
|
|
|
flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int ftrace_update_ftrace_func(ftrace_func_t func)
|
|
{
|
|
unsigned long pc = (unsigned long)&ftrace_call;
|
|
unsigned long old_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};
|
|
unsigned long new_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};
|
|
|
|
if (func != ftrace_stub)
|
|
ftrace_gen_call_insn(new_insn, (unsigned long)func);
|
|
|
|
return ftrace_modify_code(pc, old_insn, new_insn, false);
|
|
}
|
|
|
|
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
|
|
{
|
|
unsigned long pc = rec->ip;
|
|
unsigned long nop_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};
|
|
unsigned long call_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};
|
|
|
|
ftrace_gen_call_insn(call_insn, addr);
|
|
|
|
return ftrace_modify_code(pc, nop_insn, call_insn, true);
|
|
}
|
|
|
|
int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
|
|
unsigned long addr)
|
|
{
|
|
unsigned long pc = rec->ip;
|
|
unsigned long nop_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};
|
|
unsigned long call_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};
|
|
|
|
ftrace_gen_call_insn(call_insn, addr);
|
|
|
|
return ftrace_modify_code(pc, call_insn, nop_insn, true);
|
|
}
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
|
|
unsigned long frame_pointer)
|
|
{
|
|
unsigned long return_hooker = (unsigned long)&return_to_handler;
|
|
unsigned long old;
|
|
|
|
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
|
|
return;
|
|
|
|
old = *parent;
|
|
|
|
if (!function_graph_enter(old, self_addr, frame_pointer, NULL))
|
|
*parent = return_hooker;
|
|
}
|
|
|
|
noinline void ftrace_graph_caller(void)
|
|
{
|
|
unsigned long *parent_ip =
|
|
(unsigned long *)(__builtin_frame_address(2) - 4);
|
|
|
|
unsigned long selfpc =
|
|
(unsigned long)(__builtin_return_address(1) - MCOUNT_INSN_SIZE);
|
|
|
|
unsigned long frame_pointer =
|
|
(unsigned long)__builtin_frame_address(3);
|
|
|
|
prepare_ftrace_return(parent_ip, selfpc, frame_pointer);
|
|
}
|
|
|
|
extern unsigned long ftrace_return_to_handler(unsigned long frame_pointer);
|
|
void __naked return_to_handler(void)
|
|
{
|
|
__asm__ __volatile__ (
|
|
/* save state needed by the ABI */
|
|
"smw.adm $r0,[$sp],$r1,#0x0 \n\t"
|
|
|
|
/* get original return address */
|
|
"move $r0, $fp \n\t"
|
|
"bal ftrace_return_to_handler\n\t"
|
|
"move $lp, $r0 \n\t"
|
|
|
|
/* restore state nedded by the ABI */
|
|
"lmw.bim $r0,[$sp],$r1,#0x0 \n\t");
|
|
}
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
extern unsigned long ftrace_graph_call;
|
|
|
|
static int ftrace_modify_graph_caller(bool enable)
|
|
{
|
|
unsigned long pc = (unsigned long)&ftrace_graph_call;
|
|
unsigned long nop_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};
|
|
unsigned long call_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};
|
|
|
|
ftrace_gen_call_insn(call_insn, (unsigned long)ftrace_graph_caller);
|
|
|
|
if (enable)
|
|
return ftrace_modify_code(pc, nop_insn, call_insn, true);
|
|
else
|
|
return ftrace_modify_code(pc, call_insn, nop_insn, true);
|
|
}
|
|
|
|
int ftrace_enable_ftrace_graph_caller(void)
|
|
{
|
|
return ftrace_modify_graph_caller(true);
|
|
}
|
|
|
|
int ftrace_disable_ftrace_graph_caller(void)
|
|
{
|
|
return ftrace_modify_graph_caller(false);
|
|
}
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
|
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
|
noinline void __trace_hardirqs_off(void)
|
|
{
|
|
trace_hardirqs_off();
|
|
}
|
|
noinline void __trace_hardirqs_on(void)
|
|
{
|
|
trace_hardirqs_on();
|
|
}
|
|
#endif /* CONFIG_TRACE_IRQFLAGS */
|