Commit bd78acc8 authored by Song Chen's avatar Song Chen Committed by Masami Hiramatsu (Google)
Browse files

kernel/trace: extract common part in process_fetch_insn 



Each probe has an instance of process_fetch_insn respectively,
but they have something in common.

This patch aims to extract the common part into
process_common_fetch_insn which can be shared by each probe,
and they only need to focus on their special cases.

Signed-off-by: default avatarSong Chen <chensong_2000@189.cn>
Suggested-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
parent 672a2bf8

kernel/trace/trace_eprobe.c

+6 −20
Original line number Diff line number Diff line
@@ -396,19 +396,11 @@ static int get_eprobe_size(struct trace_probe *tp, void *rec) 
			case FETCH_OP_TP_ARG:

				val = get_event_field(code, rec);

				break;

			case FETCH_OP_IMM:

				val = code->immediate;

				break;

			case FETCH_OP_COMM:

				val = (unsigned long)current->comm;

				break;

			case FETCH_OP_DATA:

				val = (unsigned long)code->data;

				break;

			case FETCH_NOP_SYMBOL:	/* Ignore a place holder */

				code++;

				goto retry;

			default:

				if (process_common_fetch_insn(code, &val) < 0)

					continue;

			}

			code++;
@@ -429,26 +421,20 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 
		   void *base)

{

	unsigned long val;

	int ret;



 retry:

	switch (code->op) {

	case FETCH_OP_TP_ARG:

		val = get_event_field(code, rec);

		break;

	case FETCH_OP_IMM:

		val = code->immediate;

		break;

	case FETCH_OP_COMM:

		val = (unsigned long)current->comm;

		break;

	case FETCH_OP_DATA:

		val = (unsigned long)code->data;

		break;

	case FETCH_NOP_SYMBOL:	/* Ignore a place holder */

		code++;

		goto retry;

	default:

		return -EILSEQ;

		ret = process_common_fetch_insn(code, &val);

		if (ret < 0)

			return ret;

	}

	code++;

	return process_fetch_insn_bottom(code, val, dest, base);

kernel/trace/trace_kprobe.c

+4 −10
Original line number Diff line number Diff line
@@ -1225,6 +1225,7 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 
{

	struct pt_regs *regs = rec;

	unsigned long val;

	int ret;



retry:

	/* 1st stage: get value from context */
@@ -1241,15 +1242,6 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 
	case FETCH_OP_RETVAL:

		val = regs_return_value(regs);

		break;

	case FETCH_OP_IMM:

		val = code->immediate;

		break;

	case FETCH_OP_COMM:

		val = (unsigned long)current->comm;

		break;

	case FETCH_OP_DATA:

		val = (unsigned long)code->data;

		break;

#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API

	case FETCH_OP_ARG:

		val = regs_get_kernel_argument(regs, code->param);
@@ -1259,7 +1251,9 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 
		code++;

		goto retry;

	default:

		return -EILSEQ;

		ret = process_common_fetch_insn(code, &val);

		if (ret < 0)

			return ret;

	}

	code++;

kernel/trace/trace_probe_tmpl.h

+20 −0
Original line number Diff line number Diff line
@@ -98,6 +98,26 @@ fetch_store_symstring(unsigned long addr, void *dest, void *base) 
	return sprint_symbol(__dest, addr);

}



/* common part of process_fetch_insn*/

static nokprobe_inline int

process_common_fetch_insn(struct fetch_insn *code, unsigned long *val)

{

	switch (code->op) {

	case FETCH_OP_IMM:

		*val = code->immediate;

		break;

	case FETCH_OP_COMM:

		*val = (unsigned long)current->comm;

		break;

	case FETCH_OP_DATA:

		*val = (unsigned long)code->data;

		break;

	default:

		return -EILSEQ;

	}

	return 0;

}



/* From the 2nd stage, routine is same */

static nokprobe_inline int

process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,

kernel/trace/trace_uprobe.c

+4 −7
Original line number Diff line number Diff line
@@ -220,6 +220,7 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 
{

	struct pt_regs *regs = rec;

	unsigned long val;

	int ret;



	/* 1st stage: get value from context */

	switch (code->op) {
@@ -235,20 +236,16 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 
	case FETCH_OP_RETVAL:

		val = regs_return_value(regs);

		break;

	case FETCH_OP_IMM:

		val = code->immediate;

		break;

	case FETCH_OP_COMM:

		val = FETCH_TOKEN_COMM;

		break;

	case FETCH_OP_DATA:

		val = (unsigned long)code->data;

		break;

	case FETCH_OP_FOFFS:

		val = translate_user_vaddr(code->immediate);

		break;

	default:

		return -EILSEQ;

		ret = process_common_fetch_insn(code, &val);

		if (ret < 0)

			return ret;

	}

	code++;