X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Flttng-filter-interpreter.c;h=337cd71f888a4f7e7c66bc96a88af25755c88452;hb=0bcedee9330c118a554bd2446303712a2702e491;hp=5ba7e230094458fd864bc7500ce60bf6988dc391;hpb=cfa6cc1d0f01c2cfcc1a679abf3a6572d411c309;p=lttng-modules.git

diff --git a/src/lttng-filter-interpreter.c b/src/lttng-filter-interpreter.c
index 5ba7e230..337cd71f 100644
--- a/src/lttng-filter-interpreter.c
+++ b/src/lttng-filter-interpreter.c
@@ -81,16 +81,14 @@ static
 int stack_star_glob_match(struct estack *stack, int top, const char *cmp_type)
 {
 	bool has_user = false;
-	mm_segment_t old_fs;
 	int result;
 	struct estack_entry *pattern_reg;
 	struct estack_entry *candidate_reg;
 
+	/* Disable the page fault handler when reading from userspace. */
 	if (estack_bx(stack, top)->u.s.user
 			|| estack_ax(stack, top)->u.s.user) {
 		has_user = true;
-		old_fs = get_fs();
-		set_fs(KERNEL_DS);
 		pagefault_disable();
 	}
 
@@ -106,10 +104,8 @@ int stack_star_glob_match(struct estack *stack, int top, const char *cmp_type)
 	/* Perform the match operation. */
 	result = !strutils_star_glob_match_char_cb(get_char_at_cb,
 		pattern_reg, get_char_at_cb, candidate_reg);
-	if (has_user) {
+	if (has_user)
 		pagefault_enable();
-		set_fs(old_fs);
-	}
 
 	return result;
 }
@@ -119,13 +115,10 @@ int stack_strcmp(struct estack *stack, int top, const char *cmp_type)
 {
 	size_t offset_bx = 0, offset_ax = 0;
 	int diff, has_user = 0;
-	mm_segment_t old_fs;
 
 	if (estack_bx(stack, top)->u.s.user
 			|| estack_ax(stack, top)->u.s.user) {
 		has_user = 1;
-		old_fs = get_fs();
-		set_fs(KERNEL_DS);
 		pagefault_disable();
 	}
 
@@ -210,10 +203,9 @@ int stack_strcmp(struct estack *stack, int top, const char *cmp_type)
 		offset_bx++;
 		offset_ax++;
 	}
-	if (has_user) {
+	if (has_user)
 		pagefault_enable();
-		set_fs(old_fs);
-	}
+
 	return diff;
 }
 
@@ -221,7 +213,7 @@ uint64_t lttng_filter_false(void *filter_data,
 		struct lttng_probe_ctx *lttng_probe_ctx,
 		const char *filter_stack_data)
 {
-	return 0;
+	return LTTNG_FILTER_DISCARD;
 }
 
 #ifdef INTERPRETER_USE_SWITCH
@@ -234,7 +226,7 @@ uint64_t lttng_filter_false(void *filter_data,
 	start_pc = &bytecode->data[0];					\
 	for (pc = next_pc = start_pc; pc - start_pc < bytecode->len;	\
 			pc = next_pc) {					\
-		dbg_printk("Executing op %s (%u)\n",			\
+		dbg_printk("LTTng: Executing op %s (%u)\n",		\
 			lttng_filter_print_op((unsigned int) *(filter_opcode_t *) pc), \
 			(unsigned int) *(filter_opcode_t *) pc); 	\
 		switch (*(filter_opcode_t *) pc)	{
@@ -317,11 +309,11 @@ static int context_get_index(struct lttng_probe_ctx *lttng_probe_ctx,
 	}
 	case atype_array_nestable:
 		if (!lttng_is_bytewise_integer(field->type.u.array_nestable.elem_type)) {
-			printk(KERN_WARNING "Array nesting only supports integer types.\n");
+			printk(KERN_WARNING "LTTng: filter: Array nesting only supports integer types.\n");
 			return -EINVAL;
 		}
 		if (field->type.u.array_nestable.elem_type->u.integer.encoding == lttng_encode_none) {
-			printk(KERN_WARNING "Only string arrays are supported for contexts.\n");
+			printk(KERN_WARNING "LTTng: filter: Only string arrays are supported for contexts.\n");
 			return -EINVAL;
 		}
 		ptr->object_type = OBJECT_TYPE_STRING;
@@ -330,11 +322,11 @@ static int context_get_index(struct lttng_probe_ctx *lttng_probe_ctx,
 		break;
 	case atype_sequence_nestable:
 		if (!lttng_is_bytewise_integer(field->type.u.sequence_nestable.elem_type)) {
-			printk(KERN_WARNING "Sequence nesting only supports integer types.\n");
+			printk(KERN_WARNING "LTTng: filter: Sequence nesting only supports integer types.\n");
 			return -EINVAL;
 		}
 		if (field->type.u.sequence_nestable.elem_type->u.integer.encoding == lttng_encode_none) {
-			printk(KERN_WARNING "Only string sequences are supported for contexts.\n");
+			printk(KERN_WARNING "LTTng: filter: Only string sequences are supported for contexts.\n");
 			return -EINVAL;
 		}
 		ptr->object_type = OBJECT_TYPE_STRING;
@@ -347,13 +339,13 @@ static int context_get_index(struct lttng_probe_ctx *lttng_probe_ctx,
 		ptr->ptr = v.str;
 		break;
 	case atype_struct_nestable:
-		printk(KERN_WARNING "Structure type cannot be loaded.\n");
+		printk(KERN_WARNING "LTTng: filter: Structure type cannot be loaded.\n");
 		return -EINVAL;
 	case atype_variant_nestable:
-		printk(KERN_WARNING "Variant type cannot be loaded.\n");
+		printk(KERN_WARNING "LTTng: filter: Variant type cannot be loaded.\n");
 		return -EINVAL;
 	default:
-		printk(KERN_WARNING "Unknown type: %d", (int) field->type.atype);
+		printk(KERN_WARNING "LTTng: filter: Unknown type: %d", (int) field->type.atype);
 		return -EINVAL;
 	}
 	return 0;
@@ -412,12 +404,12 @@ static int dynamic_get_index(struct lttng_probe_ctx *lttng_probe_ctx,
 			break;
 		}
 		case OBJECT_TYPE_STRUCT:
-			printk(KERN_WARNING "Nested structures are not supported yet.\n");
+			printk(KERN_WARNING "LTTng: filter: Nested structures are not supported yet.\n");
 			ret = -EINVAL;
 			goto end;
 		case OBJECT_TYPE_VARIANT:
 		default:
-			printk(KERN_WARNING "Unexpected get index type %d",
+			printk(KERN_WARNING "LTTng: filter: Unexpected get index type %d",
 				(int) stack_top->u.ptr.object_type);
 			ret = -EINVAL;
 			goto end;
@@ -511,7 +503,7 @@ static int dynamic_load_field(struct estack_entry *stack_top)
 	{
 		uint16_t tmp;
 
-		dbg_printk("op load field s16\n");
+		dbg_printk("op load field u16\n");
 		tmp = *(uint16_t *) stack_top->u.ptr.ptr;
 		if (stack_top->u.ptr.rev_bo)
 			__swab16s(&tmp);
@@ -588,7 +580,7 @@ static int dynamic_load_field(struct estack_entry *stack_top)
 	case OBJECT_TYPE_ARRAY:
 	case OBJECT_TYPE_STRUCT:
 	case OBJECT_TYPE_VARIANT:
-		printk(KERN_WARNING "Sequences, arrays, struct and variant cannot be loaded (nested types).\n");
+		printk(KERN_WARNING "LTTng: filter: Sequences, arrays, struct and variant cannot be loaded (nested types).\n");
 		ret = -EINVAL;
 		goto end;
 	}
@@ -764,14 +756,14 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
 #ifdef INTERPRETER_USE_SWITCH
 		default:
 #endif /* INTERPRETER_USE_SWITCH */
-			printk(KERN_WARNING "unknown bytecode op %u\n",
+			printk(KERN_WARNING "LTTng: filter: unknown bytecode op %u\n",
 				(unsigned int) *(filter_opcode_t *) pc);
 			ret = -EINVAL;
 			goto end;
 
 		OP(FILTER_OP_RETURN):
 		OP(FILTER_OP_RETURN_S64):
-			/* LTTNG_FILTER_DISCARD  or LTTNG_FILTER_RECORD_FLAG */
+			/* LTTNG_FILTER_DISCARD or LTTNG_FILTER_RECORD_FLAG */
 			retval = !!estack_ax_v;
 			ret = 0;
 			goto end;
@@ -782,7 +774,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
 		OP(FILTER_OP_MOD):
 		OP(FILTER_OP_PLUS):
 		OP(FILTER_OP_MINUS):
-			printk(KERN_WARNING "unsupported bytecode op %u\n",
+			printk(KERN_WARNING "LTTng: filter: unsupported bytecode op %u\n",
 				(unsigned int) *(filter_opcode_t *) pc);
 			ret = -EINVAL;
 			goto end;
@@ -793,7 +785,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
 		OP(FILTER_OP_LT):
 		OP(FILTER_OP_GE):
 		OP(FILTER_OP_LE):
-			printk(KERN_WARNING "unsupported non-specialized bytecode op %u\n",
+			printk(KERN_WARNING "LTTng: filter: unsupported non-specialized bytecode op %u\n",
 				(unsigned int) *(filter_opcode_t *) pc);
 			ret = -EINVAL;
 			goto end;
@@ -1034,7 +1026,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
 		OP(FILTER_OP_UNARY_PLUS):
 		OP(FILTER_OP_UNARY_MINUS):
 		OP(FILTER_OP_UNARY_NOT):
-			printk(KERN_WARNING "unsupported non-specialized bytecode op %u\n",
+			printk(KERN_WARNING "LTTng: filter: unsupported non-specialized bytecode op %u\n",
 				(unsigned int) *(filter_opcode_t *) pc);
 			ret = -EINVAL;
 			goto end;
@@ -1237,7 +1229,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
 
 		/* cast */
 		OP(FILTER_OP_CAST_TO_S64):
-			printk(KERN_WARNING "unsupported non-specialized bytecode op %u\n",
+			printk(KERN_WARNING "LTTng: filter: unsupported non-specialized bytecode op %u\n",
 				(unsigned int) *(filter_opcode_t *) pc);
 			ret = -EINVAL;
 			goto end;
@@ -1391,7 +1383,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
 			dbg_printk("op get symbol\n");
 			switch (estack_ax(stack, top)->u.ptr.type) {
 			case LOAD_OBJECT:
-				printk(KERN_WARNING "Nested fields not implemented yet.\n");
+				printk(KERN_WARNING "LTTng: filter: Nested fields not implemented yet.\n");
 				ret = -EINVAL;
 				goto end;
 			case LOAD_ROOT_CONTEXT:
@@ -1567,9 +1559,9 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data,
 
 	END_OP
 end:
-	/* return 0 (discard) on error */
+	/* Return _DISCARD on error. */
 	if (ret)
-		return 0;
+		return LTTNG_FILTER_DISCARD;
 	return retval;
 }