[PATCH v2 2/6] Introduce new filtering architecture

Nikolay Marchuk marchuk.nikolay.a at gmail.com
Tue Jun 27 07:48:44 UTC 2017


This change introduces new filtering architecture primitives: filter,
filter_action and bool_expression. It also changes processing of -e
strace option. Now, filtering is done after decoding of syscall and
tcp->qual_flg stores filtering results.

* basic_actions.c: New file.
* basic_filters.c: Rename functions, add new filters' functions.
* defs.h (struct tcb): Change inject options variable.
(QUAL_READ, QUAL_WRITE): Change description.
(read_set, write_set): Remove global set variables.
(is_number_in_set): Change declaration.
(qualify, qual_flags): Remove old declarations ...
(filter_syscall, parse_qualify_filter,
 sort_filter_actions): ... and add new declarations.
* filter.c: New file.
* filter.h: Change declarations.
* filter_action.c: New file.
* filter_expression.c: Likewise.
* filter_qualify.c: Generate new filters.
* Makefile.am (strace_SOURCES): Add new files.
* strace.c (droptcb): Remove inject_vec freeing.
(init): Change qualify to parse_qualify_filter.
 Add sorting of filter actions.
(trace_syscall): Add filtering after syscall decoding.
* syscall.c (decode_socket_subcall): Remove qual_flags from decoder.
(decode_ipc_subcall): Likewise.
(decode_mips_subcall): Likewise.
(get_scno): Likewise.
(inject_vec, tcb_inject_opts, tamper_with_syscall_entering,
 tamper_with_syscall_exiting): Remove inject_vec support code.
(dumpio): Check tcp->qual_flg instead of global set.
---
 Makefile.am         |   4 ++
 basic_actions.c     |  98 +++++++++++++++++++++++++
 basic_filters.c     | 107 ++++++++++++++++++++-------
 defs.h              |  15 ++--
 filter.c            | 147 +++++++++++++++++++++++++++++++++++++
 filter.h            |  36 ++++++++--
 filter_action.c     | 203 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 filter_expression.c | 131 +++++++++++++++++++++++++++++++++
 filter_qualify.c    | 135 +++++++++++++++++-----------------
 strace.c            |  20 +++---
 syscall.c           |  31 ++------
 11 files changed, 783 insertions(+), 144 deletions(-)
 create mode 100644 basic_actions.c
 create mode 100644 filter.c
 create mode 100644 filter_action.c
 create mode 100644 filter_expression.c

diff --git a/Makefile.am b/Makefile.am
index 4f5ebfb..7299141 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -86,6 +86,7 @@ strace_SOURCES =	\
 	affinity.c	\
 	aio.c		\
 	alpha.c		\
+	basic_actions.c	\
 	basic_filters.c	\
 	bjm.c		\
 	block.c		\
@@ -125,7 +126,10 @@ strace_SOURCES =	\
 	fetch_struct_statfs.c \
 	file_handle.c	\
 	file_ioctl.c	\
+	filter_action.c	\
+	filter_expression.c \
 	filter_qualify.c \
+	filter.c	\
 	filter.h	\
 	fs_x_ioctl.c	\
 	flock.c		\
diff --git a/basic_actions.c b/basic_actions.c
new file mode 100644
index 0000000..de87cde
--- /dev/null
+++ b/basic_actions.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikolay.a at gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "defs.h"
+
+bool
+is_traced(struct tcb *tcp)
+{
+	return (tcp->qual_flg & QUAL_TRACE);
+}
+
+void *
+parse_null(const char *str)
+{
+	return NULL;
+}
+
+void
+free_null(void *_priv_data)
+{
+	return;
+}
+
+void
+apply_trace(struct tcb *tcp, void *_priv_data)
+{
+	tcp->qual_flg |= QUAL_TRACE;
+}
+void
+apply_inject(struct tcb *tcp, void *_priv_data)
+{
+	struct inject_opts **inject_vec = (struct inject_opts **)_priv_data;
+	tcp->qual_flg |= QUAL_INJECT;
+	tcp->inject_opts = (scno_in_range(tcp->scno) && inject_vec[current_personality])
+	       ? &inject_vec[current_personality][tcp->scno] : NULL;
+}
+void*
+parse_inject(const char *str)
+{
+	return NULL;
+}
+void free_inject(void *_priv_data)
+{
+	struct inject_opts **vec = (struct inject_opts **)_priv_data;
+	unsigned int p;
+	for (p = 0; p < SUPPORTED_PERSONALITIES; ++p)
+		if (vec[p])
+			free(vec[p]);
+	free(vec);
+}
+void
+apply_read(struct tcb *tcp, void *_priv_data)
+{
+	tcp->qual_flg |= QUAL_READ;
+}
+void
+apply_write(struct tcb *tcp, void *_priv_data)
+{
+	tcp->qual_flg |= QUAL_WRITE;
+}
+void
+apply_raw(struct tcb *tcp, void *_priv_data)
+{
+	tcp->qual_flg |= QUAL_RAW;
+}
+void
+apply_abbrev(struct tcb *tcp, void *_priv_data)
+{
+	tcp->qual_flg |= QUAL_ABBREV;
+}
+void
+apply_verbose(struct tcb *tcp, void *_priv_data)
+{
+	tcp->qual_flg |= QUAL_VERBOSE;
+}
diff --git a/basic_filters.c b/basic_filters.c
index 316b733..d0816a4 100644
--- a/basic_filters.c
+++ b/basic_filters.c
@@ -25,10 +25,8 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-
 #include "defs.h"
 #include <regex.h>
-#include "filter.h"
 
 typedef unsigned int number_slot_t;
 #define BITS_PER_SLOT (sizeof(number_slot_t) * 8)
@@ -39,6 +37,12 @@ struct number_set {
 	bool not;
 };
 
+bool
+is_empty(struct number_set *set)
+{
+	return !(set->nslots || set->not);
+}
+
 static void
 number_setbit(const unsigned int i, number_slot_t *const vec)
 {
@@ -48,9 +52,11 @@ number_setbit(const unsigned int i, number_slot_t *const vec)
 static bool
 number_isset(const unsigned int i, const number_slot_t *const vec)
 {
-	return vec[i / BITS_PER_SLOT] & ((number_slot_t) 1 << (i % BITS_PER_SLOT));
+	return (vec[i / BITS_PER_SLOT]
+	       & ((number_slot_t) 1 << (i % BITS_PER_SLOT))) ? true : false;
 }
 
+
 static void
 reallocate_number_set(struct number_set *const set, const unsigned int new_nslots)
 {
@@ -62,7 +68,7 @@ reallocate_number_set(struct number_set *const set, const unsigned int new_nslot
 	set->nslots = new_nslots;
 }
 
-void
+static void
 add_number_to_set(const unsigned int number, struct number_set *const set)
 {
 	reallocate_number_set(set, number / BITS_PER_SLOT + 1);
@@ -77,7 +83,7 @@ is_number_in_set(const unsigned int number, const struct number_set *const set)
 }
 
 static bool
-qualify_syscall_number(const char *s, struct number_set *set)
+parse_syscall_number(const char *s, struct number_set *set)
 {
 	int n = string_to_uint(s);
 	if (n < 0)
@@ -108,7 +114,7 @@ regerror_msg_and_die(int errcode, const regex_t *preg,
 }
 
 static bool
-qualify_syscall_regex(const char *s, struct number_set *set)
+parse_syscall_regex(const char *s, struct number_set *set)
 {
 	regex_t preg;
 	int rc;
@@ -180,7 +186,7 @@ lookup_class(const char *s)
 }
 
 static bool
-qualify_syscall_class(const char *s, struct number_set *set)
+parse_syscall_class(const char *s, struct number_set *set)
 {
 	const unsigned int n = lookup_class(s);
 	if (!n)
@@ -203,7 +209,7 @@ qualify_syscall_class(const char *s, struct number_set *set)
 }
 
 static bool
-qualify_syscall_name(const char *s, struct number_set *set)
+parse_syscall_name(const char *s, struct number_set *set)
 {
 	unsigned int p;
 	bool found = false;
@@ -224,8 +230,9 @@ qualify_syscall_name(const char *s, struct number_set *set)
 	return found;
 }
 
+
 static bool
-qualify_syscall(const char *token, struct number_set *set)
+parse_syscall(const char *token, struct number_set *set)
 {
 	bool ignore_fail = false;
 
@@ -234,21 +241,17 @@ qualify_syscall(const char *token, struct number_set *set)
 		ignore_fail = true;
 	}
 	if (*token >= '0' && *token <= '9')
-		return qualify_syscall_number(token, set) || ignore_fail;
+		return parse_syscall_number(token, set) || ignore_fail;
 	if (*token == '/')
-		return qualify_syscall_regex(token + 1, set) || ignore_fail;
-	return qualify_syscall_class(token, set)
-	       || qualify_syscall_name(token, set)
+		return parse_syscall_regex(token + 1, set) || ignore_fail;
+	return parse_syscall_class(token, set)
+	       || parse_syscall_name(token, set)
 	       || ignore_fail;
 }
 
-/*
- * Add syscall numbers to SETs for each supported personality
- * according to STR specification.
- */
-void
-qualify_syscall_tokens(const char *const str, struct number_set *const set,
-		       const char *const name)
+static void
+parse_syscall_set(const char *const str, struct number_set *const set,
+                  const char *const name)
 {
 	/* Clear all sets. */
 	unsigned int p;
@@ -298,7 +301,7 @@ handle_inversion:
 
 	for (token = strtok_r(copy, ",", &saveptr); token;
 	     token = strtok_r(NULL, ",", &saveptr)) {
-		done = qualify_syscall(token, set);
+		done = parse_syscall(token, set);
 		if (!done) {
 			error_msg_and_die("invalid %s '%s'", name, token);
 		}
@@ -311,11 +314,37 @@ handle_inversion:
 	}
 }
 
-/*
- * Add numbers to SET according to STR specification.
- */
+void*
+parse_syscall_filter(const char *str, const char *const name)
+{
+	struct number_set *set = xcalloc(SUPPORTED_PERSONALITIES,
+	                                 sizeof(struct number_set));
+	parse_syscall_set(str, set, name);
+	return set;
+}
+
+bool
+run_syscall_filter(struct tcb *tcp, void *_priv_data)
+{
+	struct number_set *set = (struct number_set *)_priv_data;
+	return is_number_in_set(tcp->scno, &set[current_personality]);
+}
+
 void
-qualify_tokens(const char *const str, struct number_set *const set,
+free_syscall_filter(void *_priv_data)
+{
+	struct number_set *set = (struct number_set *)_priv_data;
+	unsigned int p;
+	for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
+		free(set[p].vec);
+	}
+	free(set);
+}
+
+typedef int (*string_to_uint_func)(const char *);
+
+void
+parse_set(const char *const str, struct number_set *const set,
 	       string_to_uint_func func, const char *const name)
 {
 	/* Clear the set. */
@@ -373,3 +402,31 @@ handle_inversion:
 		error_msg_and_die("invalid %s '%s'", name, str);
 	}
 }
+
+void*
+parse_fd_filter(const char *str, const char *const name)
+{
+	struct number_set *set = xmalloc(sizeof(struct number_set));
+	memset(set, 0, sizeof(struct number_set));
+	parse_set(str, set, string_to_uint, name);
+	return set;
+}
+
+bool
+run_fd_filter(struct tcb *tcp, void *_priv_data)
+{
+	int fd = tcp->u_arg[0];
+	if (fd < 0)
+		return false;
+	struct number_set *set = (struct number_set *)_priv_data;
+	return is_number_in_set(fd, set);
+}
+
+void
+free_fd_filter(void *_priv_data)
+{
+	struct number_set *set = (struct number_set *)_priv_data;
+	free(set->vec);
+	free(set);
+	return;
+}
diff --git a/defs.h b/defs.h
index 29a681b..9242b16 100644
--- a/defs.h
+++ b/defs.h
@@ -228,7 +228,7 @@ struct tcb {
 	void (*_free_priv_data)(void *); /* Callback for freeing priv_data */
 	const struct_sysent *s_ent; /* sysent[scno] or dummy struct for bad scno */
 	const struct_sysent *s_prev_ent; /* for "resuming interrupted SYSCALL" msg */
-	struct inject_opts *inject_vec[SUPPORTED_PERSONALITIES];
+	struct inject_opts *inject_opts;
 	struct timeval stime;	/* System time usage as of last process wait */
 	struct timeval dtime;	/* Delta for system time usage */
 	struct timeval etime;	/* Syscall entry time */
@@ -272,8 +272,8 @@ struct tcb {
 #define QUAL_RAW	0x008	/* print all args in hex for this syscall */
 #define QUAL_INJECT	0x010	/* tamper with this system call on purpose */
 #define QUAL_SIGNAL	0x100	/* report events with this signal */
-#define QUAL_READ	0x200	/* dump data read from this file descriptor */
-#define QUAL_WRITE	0x400	/* dump data written to this file descriptor */
+#define QUAL_READ	0x200	/* dump data read in this syscall */
+#define QUAL_WRITE	0x400	/* dump data written in this syscall */
 
 #define DEFAULT_QUAL_FLAGS (QUAL_TRACE | QUAL_ABBREV | QUAL_VERBOSE)
 
@@ -665,13 +665,12 @@ print_struct_statfs64(struct tcb *, kernel_ulong_t addr, kernel_ulong_t size);
 extern void print_ifindex(unsigned int);
 
 struct number_set;
-extern struct number_set read_set;
-extern struct number_set write_set;
 extern struct number_set signal_set;
 
-extern bool is_number_in_set(unsigned int number, const struct number_set *);
-extern void qualify(const char *);
-extern unsigned int qual_flags(const unsigned int);
+extern bool is_number_in_set(const unsigned int, const struct number_set *);
+extern void sort_filter_actions(void);
+extern void filter_syscall(struct tcb *);
+extern void parse_qualify_filter(const char *);
 
 #define DECL_IOCTL(name)						\
 extern int								\
diff --git a/filter.c b/filter.c
new file mode 100644
index 0000000..1f2d2eb
--- /dev/null
+++ b/filter.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikolay.a at gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "defs.h"
+#include <ctype.h>
+#include "filter.h"
+
+#define DECL_FILTER(name)					\
+extern void*							\
+parse_ ## name ## _filter(const char *, const char *const);	\
+extern bool							\
+run_ ## name ## _filter(struct tcb *, void *);			\
+extern void							\
+free_ ## name ## _filter(void *)
+DECL_FILTER(syscall);
+DECL_FILTER(fd);
+DECL_FILTER(path);
+#undef DECL_FILTER
+
+#define FILTER_TYPE(name)					\
+{#name, sizeof(#name) - 1, parse_ ## name ## _filter,		\
+	run_ ## name ## _filter, free_ ## name ## _filter}
+
+static const struct filter_type {
+	const char *name;
+	const size_t name_len;
+	void *(*parse_filter)(const char *, const char *const);
+	bool (*run_filter)(struct tcb *, void *);
+	void (*free_priv_data)(void *);
+} filter_types[] = {
+	FILTER_TYPE(syscall),
+	FILTER_TYPE(fd)
+};
+
+#undef FILTER_TYPE
+
+struct filter {
+	const struct filter_type *type;
+	void *_priv_data;
+};
+
+static const struct filter_type *
+lookup_filter_type(const char *str)
+{
+	unsigned int i;
+	for (i = 0; i < ARRAY_SIZE(filter_types); i++) {
+		const char *name = filter_types[i].name;
+		const size_t len = filter_types[i].name_len;
+		if (!strncmp(name, str, len) && !isalpha(str[len])) {
+			return &filter_types[i];
+		}
+	}
+	return NULL;
+}
+
+struct filter *
+add_filter_to_array(struct filter **filters, unsigned int *nfilters,
+                    const char *name)
+{
+	const struct filter_type *type = lookup_filter_type(name);
+	if (!type)
+		return NULL;
+	*filters = xreallocarray(*filters, ++(*nfilters),
+	                         sizeof(struct filter));
+	struct filter *filter = &((*filters)[*nfilters - 1]);
+	filter->type = type;
+	return filter;
+}
+
+void
+parse_filter(struct filter *filter, const char *str, const char *const name)
+{
+	filter->_priv_data = filter->type->parse_filter(str, name);
+}
+
+static bool
+run_filter(struct tcb *tcp, struct filter *filter)
+{
+	return filter->type->run_filter(tcp, filter->_priv_data);
+}
+
+bool *
+run_filters(struct tcb *tcp, struct filter *filters, unsigned int nfilters)
+{
+	bool *variables = xcalloc(nfilters, sizeof(bool));
+	unsigned int i;
+	for (i = 0; i < nfilters; ++i) {
+		variables[i] = run_filter(tcp, &filters[i]);
+	}
+	return variables;
+}
+
+void
+free_filter(struct filter *filter)
+{
+	if (!filter)
+		return;
+	filter->type->free_priv_data(filter->_priv_data);
+}
+
+void *
+get_filter_priv_data(struct filter *filter)
+{
+	return filter ? filter->_priv_data : NULL;
+}
+
+void
+set_filter_priv_data(struct filter *filter, void *_priv_data)
+{
+	if (filter)
+		filter->_priv_data = _priv_data;
+}
+
+void
+set_filters_qualify_mode(struct filter **filters, unsigned int *nfilters)
+{
+	unsigned int i;
+	for (i = 0; i < *nfilters - 1; ++i) {
+		free_filter(*filters + i);
+	}
+	**filters = (*filters)[*nfilters - 1];
+	*filters = xreallocarray(*filters, 1, sizeof(struct filter));
+	*nfilters = 1;
+}
diff --git a/filter.h b/filter.h
index a798199..ed435c8 100644
--- a/filter.h
+++ b/filter.h
@@ -28,11 +28,37 @@
 # define STRACE_FILTER_H
 # include "defs.h"
 
+struct filter;
+
+struct filter_action;
+
+struct bool_expression;
+
+bool is_empty(const struct number_set *);
+
+extern bool is_traced(struct tcb *);
+
 typedef int (*string_to_uint_func)(const char *);
+void parse_set(const char *const, struct number_set *const,
+               string_to_uint_func, const char *const);
+
+struct filter* add_filter_to_array(struct filter **, unsigned int *nfilters,
+                                   const char *name);
+void parse_filter(struct filter *, const char *str, const char *const name);
+bool *run_filters(struct tcb *, struct filter *, unsigned int);
+void free_filter(struct filter *);
+void *get_filter_priv_data(struct filter *);
+void set_filter_priv_data(struct filter *, void *);
+void set_filters_qualify_mode(struct filter **, unsigned int *nfilters);
+
+struct filter *create_filter(struct filter_action *, const char *name);
+void set_qualify_mode(struct filter_action *);
+struct filter_action *find_or_add_action(const char *);
+void *get_filter_action_priv_data(struct filter_action *);
+void set_filter_action_priv_data(struct filter_action *, void *);
+
+struct bool_expression *create_expression();
+void set_expression_qualify_mode(struct bool_expression *);
+bool run_expression(struct bool_expression *, unsigned int, bool *);
 
-void add_number_to_set(const unsigned int, struct number_set *const);
-void qualify_tokens(const char *const, struct number_set *const,
-                    string_to_uint_func, const char *const);
-void qualify_syscall_tokens(const char *const, struct number_set *const,
-                            const char *const);
 #endif
diff --git a/filter_action.c b/filter_action.c
new file mode 100644
index 0000000..f71f140
--- /dev/null
+++ b/filter_action.c
@@ -0,0 +1,203 @@
+/*
+ * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikolay.a at gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "defs.h"
+#include <ctype.h>
+#include "filter.h"
+
+#define DECL_FILTER_ACTION(name) 		\
+extern void					\
+apply_ ## name(struct tcb *, void *)
+
+DECL_FILTER_ACTION(trace);
+DECL_FILTER_ACTION(inject);
+DECL_FILTER_ACTION(read);
+DECL_FILTER_ACTION(write);
+DECL_FILTER_ACTION(raw);
+DECL_FILTER_ACTION(abbrev);
+DECL_FILTER_ACTION(verbose);
+
+#undef DECL_FILTER_ACTION
+
+#define DECL_FILTER_ACTION_PARSER(name)		\
+extern void *					\
+parse_ ## name(const char *);			\
+extern void					\
+free_ ## name(void *)
+
+DECL_FILTER_ACTION_PARSER(null);
+DECL_FILTER_ACTION_PARSER(inject);
+
+#undef DECL_FILTER_ACTION_PARSER
+
+#define FILTER_ACTION_TYPE(NAME, PRIORITY, PARSER, PREFILTER)		\
+{#NAME, sizeof(#NAME) - 1,PRIORITY, parse_ ## PARSER, free_ ## PARSER,	\
+ PREFILTER, apply_ ## NAME}
+
+static const struct filter_action_type {
+	const char *name;
+	const size_t name_len;
+	unsigned int priority;
+	void *(*parse_args)(const char *);
+	void (*free_priv_data)(void *);
+	bool (*prefilter)(struct tcb *);
+	void (*apply)(struct tcb *, void *);
+} action_types[] = {
+	FILTER_ACTION_TYPE(trace,	2,	null,	NULL),
+	FILTER_ACTION_TYPE(inject,	2,	inject,	NULL),
+	FILTER_ACTION_TYPE(read,	1,	null,	is_traced),
+	FILTER_ACTION_TYPE(write,	1,	null,	is_traced),
+	FILTER_ACTION_TYPE(raw,		1,	null,	is_traced),
+	FILTER_ACTION_TYPE(abbrev,	1,	null,	is_traced),
+	FILTER_ACTION_TYPE(verbose,	1,	null,	is_traced)
+};
+
+#undef FILTER_ACTION_TYPE
+
+struct filter_action {
+	const struct filter_action_type *type;
+	struct bool_expression *expr;
+	unsigned int nfilters;
+	struct filter *filters;
+	void* _priv_data;
+};
+
+static struct filter_action *filter_actions;
+static unsigned int nfilter_actions;
+
+static int
+compare_action_priority(const void *a, const void *b)
+{
+	unsigned int priority_a = ((struct filter_action *)a)->type->priority;
+	unsigned int priority_b = ((struct filter_action *)b)->type->priority;
+	return (priority_a > priority_b) ? -1 :
+	       (priority_a < priority_b) ? 1 : 0;
+}
+
+void
+sort_filter_actions(void)
+{
+	qsort(filter_actions, nfilter_actions, sizeof(struct filter_action),
+	      &compare_action_priority);
+}
+
+static const struct filter_action_type *
+lookup_filter_action_type(const char *str)
+{
+	unsigned int i;
+	for (i = 0; i < ARRAY_SIZE(action_types); ++i) {
+		const char *name = action_types[i].name;
+		const size_t len = action_types[i].name_len;
+		if (!strncmp(name, str, len) && !isalpha(str[len])) {
+			return &action_types[i];
+		}
+	}
+	return NULL;
+}
+
+static struct filter_action *
+add_action(const char *name)
+{
+	const struct filter_action_type *type = lookup_filter_action_type(name);
+	if (!type)
+		error_msg_and_die("invalid filter action '%s'", name);
+	filter_actions = xreallocarray(filter_actions, ++nfilter_actions,
+	                               sizeof(struct filter_action));
+	struct filter_action *action = &filter_actions[nfilter_actions - 1];
+	memset(action, 0, sizeof(*action));
+	action->type = type;
+	action->expr = create_expression();
+	return action;
+}
+
+struct filter_action *
+find_or_add_action(const char *name)
+{
+	const struct filter_action_type *type = lookup_filter_action_type(name);
+	if (!type)
+		error_msg_and_die("invalid filter action '%s'", name);
+	if (type->parse_args != &parse_null)
+		return add_action(name);
+	unsigned int i;
+	for (i = 0; i < nfilter_actions; i++) {
+		if (filter_actions[i].type == type)
+			return &filter_actions[i];
+	}
+	return add_action(name);
+}
+
+static void
+run_filter_action(struct tcb *tcp, struct filter_action *action)
+{
+	if (action->type->prefilter && !action->type->prefilter(tcp))
+		return;
+	bool *variables = run_filters(tcp, action->filters, action->nfilters);
+	bool res = run_expression(action->expr, action->nfilters, variables);
+	free(variables);
+	if (res) {
+		action->type->apply(tcp, action->_priv_data);
+	}
+}
+
+struct filter *
+create_filter(struct filter_action *action, const char *name)
+{
+	if (!action)
+		error_msg_and_die("invalid filter action");
+	return add_filter_to_array(&action->filters,
+	                           &action->nfilters, name);
+}
+
+void
+set_qualify_mode(struct filter_action *action)
+{
+	if ((!action) || action->nfilters == 0)
+		error_msg_and_die("invalid filter action");
+	set_filters_qualify_mode(&action->filters, &action->nfilters);
+	set_expression_qualify_mode(action->expr);
+}
+
+void
+filter_syscall(struct tcb *tcp)
+{
+	unsigned int i;
+	for (i = 0; i < nfilter_actions; i++) {
+		run_filter_action(tcp, &filter_actions[i]);
+	}
+}
+
+void *
+get_filter_action_priv_data(struct filter_action *action)
+{
+	return action ? action->_priv_data : NULL;
+}
+
+void
+set_filter_action_priv_data(struct filter_action *action, void *_priv_data)
+{
+	if (action)
+		action->_priv_data = _priv_data;
+}
diff --git a/filter_expression.c b/filter_expression.c
new file mode 100644
index 0000000..ca02280
--- /dev/null
+++ b/filter_expression.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikolay.a at gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "defs.h"
+
+struct expression_token{
+	enum token_type{
+		TOK_VARIABLE,
+		TOK_OPERATOR
+	} type;
+	union token_data{
+		unsigned int variable_id;
+		enum operator_type{
+			OP_NOT,
+			OP_AND,
+			OP_OR
+		} operator_id;
+	} data;
+};
+
+struct bool_expression{
+	unsigned int ntokens;
+	struct expression_token *tokens;
+};
+
+struct bool_expression *
+create_expression(void)
+{
+	struct bool_expression *expr = xmalloc(sizeof(struct bool_expression));
+	memset(expr, 0, sizeof(struct bool_expression));
+	return expr;
+}
+
+static void
+reallocate_expression(struct bool_expression *const expr, const unsigned int new_ntokens)
+{
+	if (new_ntokens <= expr->ntokens)
+		return;
+	expr->tokens = xreallocarray(expr->tokens, new_ntokens,
+	                             sizeof(*expr->tokens));
+	memset(expr->tokens + expr->ntokens, 0,
+	       sizeof(*expr->tokens) * (new_ntokens - expr->ntokens));
+	expr->ntokens = new_ntokens;
+}
+
+#define STACK_SIZE 32
+static bool stack[STACK_SIZE];
+
+void
+set_expression_qualify_mode(struct bool_expression *expr)
+{
+	if (!expr)
+		error_msg_and_die("invalid expression");
+	reallocate_expression(expr, 1);
+	expr->tokens[0].type = TOK_VARIABLE;
+	expr->tokens[0].data.variable_id = 0;
+}
+
+bool
+run_expression(struct bool_expression *expr,
+               unsigned int variables_num, bool *variables)
+{
+	/* Current stack index */
+	unsigned int index = 0;
+	struct expression_token *tok = expr->tokens;
+	struct expression_token *const tok_end = expr->tokens + expr->ntokens;
+	for (; tok != tok_end; ++tok) {
+		switch (tok->type) {
+		case TOK_VARIABLE:
+			if (index == STACK_SIZE)
+				error_msg_and_die("stack overflow");
+			if (tok->data.variable_id >= variables_num)
+				error_msg_and_die("corrupted filter "
+				                  "expression");
+			stack[index] = variables[tok->data.variable_id];
+			index++;
+			break;
+		case TOK_OPERATOR:
+			switch (tok->data.operator_id) {
+			case OP_NOT:
+				if (index == 0)
+					error_msg_and_die("corrupted filter "
+					                  "expression");
+				stack[index - 1] = !stack[index - 1];
+				break;
+			case OP_AND:
+				if (index < 2)
+					error_msg_and_die("corrupted filter "
+					                  "expression");
+				stack[index - 2] = stack[index - 2]
+				                   && stack[index - 1];
+				--index;
+				break;
+			case OP_OR:
+				if (index < 2)
+					error_msg_and_die("corrupted filter "
+					                  "expression");
+				stack[index - 2] = stack[index - 2]
+				                   || stack[index - 1];
+				--index;
+				break;
+			}
+		}
+	}
+	if (index != 1)
+		error_msg_and_die("corrupted filter expression");
+	return stack[0];
+}
diff --git a/filter_qualify.c b/filter_qualify.c
index e23a9f1..6020ce8 100644
--- a/filter_qualify.c
+++ b/filter_qualify.c
@@ -25,13 +25,11 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-
 #include "defs.h"
 #include "nsig.h"
 #include "filter.h"
 
 typedef unsigned int number_slot_t;
-#define BITS_PER_SLOT (sizeof(number_slot_t) * 8)
 
 struct number_set {
 	number_slot_t *vec;
@@ -39,16 +37,8 @@ struct number_set {
 	bool not;
 };
 
-struct number_set read_set;
-struct number_set write_set;
 struct number_set signal_set;
 
-static struct number_set abbrev_set[SUPPORTED_PERSONALITIES];
-static struct number_set inject_set[SUPPORTED_PERSONALITIES];
-static struct number_set raw_set[SUPPORTED_PERSONALITIES];
-static struct number_set trace_set[SUPPORTED_PERSONALITIES];
-static struct number_set verbose_set[SUPPORTED_PERSONALITIES];
-
 static int
 find_errno_by_name(const char *name)
 {
@@ -184,49 +174,67 @@ parse_error:
 }
 
 static void
-qualify_read(const char *const str)
+parse_read(const char *const str)
 {
-	qualify_tokens(str, &read_set, string_to_uint, "descriptor");
+	struct filter_action *action = find_or_add_action("read");
+	struct filter *filter = create_filter(action, "fd");
+	parse_filter(filter, str, "descriptor");
+	set_qualify_mode(action);
 }
 
 static void
-qualify_write(const char *const str)
+parse_write(const char *const str)
 {
-	qualify_tokens(str, &write_set, string_to_uint, "descriptor");
+	struct filter_action *action = find_or_add_action("write");
+	struct filter *filter = create_filter(action, "fd");
+	parse_filter(filter, str, "descriptor");
+	set_qualify_mode(action);
 }
 
 static void
 qualify_signals(const char *const str)
 {
-	qualify_tokens(str, &signal_set, sigstr_to_uint, "signal");
+	parse_set(str, &signal_set, sigstr_to_uint, "signal");
 }
 
 static void
-qualify_trace(const char *const str)
+parse_trace(const char *const str)
 {
-	qualify_syscall_tokens(str, trace_set, "system call");
+	struct filter_action *action = find_or_add_action("trace");
+	struct filter *filter = create_filter(action, "syscall");
+	parse_filter(filter, str, "system call");
+	set_qualify_mode(action);
 }
 
 static void
-qualify_abbrev(const char *const str)
+parse_abbrev(const char *const str)
 {
-	qualify_syscall_tokens(str, abbrev_set, "system call");
+	struct filter_action *action = find_or_add_action("abbrev");
+	struct filter *filter = create_filter(action, "syscall");
+	parse_filter(filter, str, "system call");
+	set_qualify_mode(action);
 }
 
 static void
-qualify_verbose(const char *const str)
+parse_verbose(const char *const str)
 {
-	qualify_syscall_tokens(str, verbose_set, "system call");
+	struct filter_action *action = find_or_add_action("verbose");
+	struct filter *filter = create_filter(action, "syscall");
+	parse_filter(filter, str, "system call");
+	set_qualify_mode(action);
 }
 
 static void
-qualify_raw(const char *const str)
+parse_raw(const char *const str)
 {
-	qualify_syscall_tokens(str, raw_set, "system call");
+	struct filter_action *action = find_or_add_action("raw");
+	struct filter *filter = create_filter(action, "syscall");
+	parse_filter(filter, str, "system call");
+	set_qualify_mode(action);
 }
 
 static void
-qualify_inject_common(const char *const str,
+parse_inject_common(const char *const str,
 		      const bool fault_tokens_only,
 		      const char *const description)
 {
@@ -253,19 +261,23 @@ qualify_inject_common(const char *const str,
 		}
 	}
 
-	struct number_set tmp_set[SUPPORTED_PERSONALITIES];
-	memset(tmp_set, 0, sizeof(tmp_set));
-	qualify_syscall_tokens(name, tmp_set, description);
+	struct filter_action *action = find_or_add_action("inject");
+	struct filter *filter = create_filter(action, "syscall");
+	parse_filter(filter, name, description);
+	set_qualify_mode(action);
 
 	free(buf);
-
+	const struct number_set *tmp_set = (const struct number_set *)
+	                                    get_filter_priv_data(filter);
+	struct inject_opts **inject_vec = xcalloc(SUPPORTED_PERSONALITIES,
+	                                          sizeof(struct inject_opts *));
 	/*
 	 * Initialize inject_vec accourding to tmp_set.
-	 * Merge tmp_set into inject_set.
 	 */
+
 	unsigned int p;
 	for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
-		if (!tmp_set[p].nslots && !tmp_set[p].not) {
+		if (is_empty(&tmp_set[p])) {
 			continue;
 		}
 
@@ -277,54 +289,53 @@ qualify_inject_common(const char *const str,
 		unsigned int i;
 		for (i = 0; i < nsyscall_vec[p]; ++i) {
 			if (is_number_in_set(i, &tmp_set[p])) {
-				add_number_to_set(i, &inject_set[p]);
 				inject_vec[p][i] = opts;
 			}
 		}
-
-		free(tmp_set[p].vec);
 	}
+	set_filter_action_priv_data(action, inject_vec);
 }
 
 static void
-qualify_fault(const char *const str)
+parse_fault(const char *const str)
 {
-	qualify_inject_common(str, true, "fault argument");
+	parse_inject_common(str, true, "fault argument");
 }
 
 static void
-qualify_inject(const char *const str)
+parse_inject(const char *const str)
 {
-	qualify_inject_common(str, false, "inject argument");
+	parse_inject_common(str, false, "inject argument");
 }
 
 static const struct qual_options {
 	const char *name;
 	void (*qualify)(const char *);
 } qual_options[] = {
-	{ "trace",	qualify_trace	},
-	{ "t",		qualify_trace	},
-	{ "abbrev",	qualify_abbrev	},
-	{ "a",		qualify_abbrev	},
-	{ "verbose",	qualify_verbose	},
-	{ "v",		qualify_verbose	},
-	{ "raw",	qualify_raw	},
-	{ "x",		qualify_raw	},
+	{ "trace",	parse_trace	},
+	{ "t",		parse_trace	},
+	{ "abbrev",	parse_abbrev	},
+	{ "a",		parse_abbrev	},
+	{ "verbose",	parse_verbose	},
+	{ "v",		parse_verbose	},
+	{ "raw",	parse_raw	},
+	{ "x",		parse_raw	},
 	{ "signal",	qualify_signals	},
 	{ "signals",	qualify_signals	},
 	{ "s",		qualify_signals	},
-	{ "read",	qualify_read	},
-	{ "reads",	qualify_read	},
-	{ "r",		qualify_read	},
-	{ "write",	qualify_write	},
-	{ "writes",	qualify_write	},
-	{ "w",		qualify_write	},
-	{ "fault",	qualify_fault	},
-	{ "inject",	qualify_inject	},
+	{ "read",	parse_read	},
+	{ "reads",	parse_read	},
+	{ "r",		parse_read	},
+	{ "write",	parse_write	},
+	{ "writes",	parse_write	},
+	{ "w",		parse_write	},
+	{ "fault",	parse_fault	},
+	{ "inject",	parse_inject	},
 };
 
+
 void
-qualify(const char *str)
+parse_qualify_filter(const char *str)
 {
 	const struct qual_options *opt = qual_options;
 	unsigned int i;
@@ -340,21 +351,5 @@ qualify(const char *str)
 		opt = &qual_options[i];
 		break;
 	}
-
 	opt->qualify(str);
 }
-
-unsigned int
-qual_flags(const unsigned int scno)
-{
-	return	(is_number_in_set(scno, &trace_set[current_personality])
-		   ? QUAL_TRACE : 0)
-		| (is_number_in_set(scno, &abbrev_set[current_personality])
-		   ? QUAL_ABBREV : 0)
-		| (is_number_in_set(scno, &verbose_set[current_personality])
-		   ? QUAL_VERBOSE : 0)
-		| (is_number_in_set(scno, &raw_set[current_personality])
-		   ? QUAL_RAW : 0)
-		| (is_number_in_set(scno, &inject_set[current_personality])
-		   ? QUAL_INJECT : 0);
-}
diff --git a/strace.c b/strace.c
index 614ab9e..e48ed76 100644
--- a/strace.c
+++ b/strace.c
@@ -822,10 +822,6 @@ droptcb(struct tcb *tcp)
 	if (tcp->pid == 0)
 		return;
 
-	int p;
-	for (p = 0; p < SUPPORTED_PERSONALITIES; ++p)
-		free(tcp->inject_vec[p]);
-
 	free_tcb_priv_data(tcp);
 
 #ifdef USE_LIBUNWIND
@@ -1626,13 +1622,13 @@ init(int argc, char *argv[])
 	shared_log = stderr;
 	set_sortby(DEFAULT_SORTBY);
 	set_personality(DEFAULT_PERSONALITY);
-	qualify("trace=all");
-	qualify("abbrev=all");
-	qualify("verbose=all");
+	parse_qualify_filter("trace=all");
+	parse_qualify_filter("abbrev=all");
+	parse_qualify_filter("verbose=all");
 #if DEFAULT_QUAL_FLAGS != (QUAL_TRACE | QUAL_ABBREV | QUAL_VERBOSE)
 # error Bug in DEFAULT_QUAL_FLAGS
 #endif
-	qualify("signal=all");
+	parse_qualify_filter("signal=all");
 	while ((c = getopt(argc, argv,
 		"+b:cCdfFhiqrtTvVwxyz"
 #ifdef USE_LIBUNWIND
@@ -1699,7 +1695,7 @@ init(int argc, char *argv[])
 			show_fd_path++;
 			break;
 		case 'v':
-			qualify("abbrev=none");
+			parse_qualify_filter("abbrev=none");
 			break;
 		case 'V':
 			print_version();
@@ -1714,7 +1710,7 @@ init(int argc, char *argv[])
 				error_opt_arg(c, optarg);
 			break;
 		case 'e':
-			qualify(optarg);
+			parse_qualify_filter(optarg);
 			break;
 		case 'o':
 			outfname = xstrdup(optarg);
@@ -1762,6 +1758,8 @@ init(int argc, char *argv[])
 			break;
 		}
 	}
+	sort_filter_actions();
+
 	argv += optind;
 	/* argc -= optind; - no need, argc is not used below */
 
@@ -2459,6 +2457,8 @@ trace_syscall(struct tcb *tcp, unsigned int *sig)
 		case 0:
 			return 0;
 		case 1:
+			if (!tcp->qual_flg)
+				filter_syscall(tcp);
 			res = syscall_entering_trace(tcp, sig);
 		}
 		syscall_entering_finish(tcp, res);
diff --git a/syscall.c b/syscall.c
index 02626c7..b6e1ba3 100644
--- a/syscall.c
+++ b/syscall.c
@@ -382,7 +382,6 @@ decode_socket_subcall(struct tcb *tcp)
 		return;
 
 	tcp->scno = scno;
-	tcp->qual_flg = qual_flags(scno);
 	tcp->s_ent = &sysent[scno];
 
 	unsigned int i;
@@ -422,7 +421,6 @@ decode_ipc_subcall(struct tcb *tcp)
 	}
 
 	tcp->scno = SYS_ipc_subcall + call;
-	tcp->qual_flg = qual_flags(tcp->scno);
 	tcp->s_ent = &sysent[tcp->scno];
 
 	const unsigned int n = tcp->s_ent->nargs;
@@ -439,7 +437,6 @@ decode_mips_subcall(struct tcb *tcp)
 	if (!scno_is_valid(tcp->u_arg[0]))
 		return;
 	tcp->scno = tcp->u_arg[0];
-	tcp->qual_flg = qual_flags(tcp->scno);
 	tcp->s_ent = &sysent[tcp->scno];
 	memmove(&tcp->u_arg[0], &tcp->u_arg[1],
 		sizeof(tcp->u_arg) - sizeof(tcp->u_arg[0]));
@@ -468,7 +465,7 @@ dumpio(struct tcb *tcp)
 	if (fd < 0)
 		return;
 
-	if (is_number_in_set(fd, &read_set)) {
+	if (tcp->qual_flg & QUAL_READ) {
 		switch (tcp->s_ent->sen) {
 		case SEN_read:
 		case SEN_pread:
@@ -491,7 +488,7 @@ dumpio(struct tcb *tcp)
 			return;
 		}
 	}
-	if (is_number_in_set(fd, &write_set)) {
+	if (tcp->qual_flg & QUAL_WRITE) {
 		switch (tcp->s_ent->sen) {
 		case SEN_write:
 		case SEN_pwrite:
@@ -577,28 +574,10 @@ static void get_error(struct tcb *, const bool);
 static int arch_set_error(struct tcb *);
 static int arch_set_success(struct tcb *);
 
-struct inject_opts *inject_vec[SUPPORTED_PERSONALITIES];
-
-static struct inject_opts *
-tcb_inject_opts(struct tcb *tcp)
-{
-	return (scno_in_range(tcp->scno) && tcp->inject_vec[current_personality])
-	       ? &tcp->inject_vec[current_personality][tcp->scno] : NULL;
-}
-
-
 static long
 tamper_with_syscall_entering(struct tcb *tcp, unsigned int *signo)
 {
-	if (!tcp->inject_vec[current_personality]) {
-		tcp->inject_vec[current_personality] =
-			xcalloc(nsyscalls, sizeof(**inject_vec));
-		memcpy(tcp->inject_vec[current_personality],
-		       inject_vec[current_personality],
-		       nsyscalls * sizeof(**inject_vec));
-	}
-
-	struct inject_opts *opts = tcb_inject_opts(tcp);
+	struct inject_opts *opts = tcp->inject_opts;
 
 	if (!opts || opts->first == 0)
 		return 0;
@@ -621,7 +600,7 @@ tamper_with_syscall_entering(struct tcb *tcp, unsigned int *signo)
 static long
 tamper_with_syscall_exiting(struct tcb *tcp)
 {
-	struct inject_opts *opts = tcb_inject_opts(tcp);
+	struct inject_opts *opts = tcp->inject_opts;
 
 	if (!opts)
 		return 0;
@@ -1258,7 +1237,7 @@ get_scno(struct tcb *tcp)
 
 	if (scno_is_valid(tcp->scno)) {
 		tcp->s_ent = &sysent[tcp->scno];
-		tcp->qual_flg = qual_flags(tcp->scno);
+		tcp->qual_flg = 0;
 	} else {
 		struct sysent_buf *s = xcalloc(1, sizeof(*s));
 
-- 
2.1.4





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