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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-16 01:04:08 +08:00

nds32/ftrace: Support dynamic function tracer

This patch contains the implementation of dynamic function tracer.
The mcount call is composed of three instructions, so there are three
nop for enough placeholder.

Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
This commit is contained in:
Zong Li 2018-08-15 11:00:08 +08:00 committed by Greentime Hu
parent fbf58a52ac
commit 6b1d6d2fba
3 changed files with 191 additions and 0 deletions

View File

@ -43,6 +43,7 @@ config NDS32
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_DYNAMIC_FTRACE
help
Andes(nds32) Linux support.

View File

@ -15,6 +15,32 @@
extern void _mcount(unsigned long parent_ip);
#ifdef CONFIG_DYNAMIC_FTRACE
#define FTRACE_ADDR ((unsigned long)_ftrace_caller)
#ifdef __NDS32_EL__
#define INSN_NOP 0x09000040
#define INSN_SIZE(insn) (((insn & 0x00000080) == 0) ? 4 : 2)
#define IS_SETHI(insn) ((insn & 0x000000fe) == 0x00000046)
#define ENDIAN_CONVERT(insn) be32_to_cpu(insn)
#else /* __NDS32_EB__ */
#define INSN_NOP 0x40000009
#define INSN_SIZE(insn) (((insn & 0x80000000) == 0) ? 4 : 2)
#define IS_SETHI(insn) ((insn & 0xfe000000) == 0x46000000)
#define ENDIAN_CONVERT(insn) (insn)
#endif
extern void _ftrace_caller(unsigned long parent_ip);
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr;
}
struct dyn_arch_ftrace {
};
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* CONFIG_FUNCTION_TRACER */
#endif /* __ASM_NDS32_FTRACE_H */

View File

@ -4,6 +4,7 @@
#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);
@ -35,6 +36,168 @@ noinline void _mcount(unsigned long parent_ip)
}
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");
/* 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)
@ -94,4 +257,5 @@ void __naked return_to_handler(void)
/* restore state nedded by the ABI */
"lmw.bim $r0,[$sp],$r1,#0x0 \n\t");
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */