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