config: Add SYM_NOEXIT option

Added SYM_NOEXIT option to be able to run only pltentry
callback for specified symbols.

This option is needed for setjmp symbol, otherwise the
tracee segfaults. The "_setjmp" symbol is added as default
value to the global config file.

8 files changed, 44 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 16a5e6b..4fc640b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,7 +3,7 @@
 	* make tracer return actual tracee status
 	* move all tests to scripts
 	* added following options
-	  LIBS, LIBS_TO, LIBS_FROM, SYM, SYM_OMIT, SYM_BELOW
+	  LIBS, LIBS_TO, LIBS_FROM, SYM, SYM_OMIT, SYM_BELOW, SYM_NOEXIT
 
 2011-06-02 Jiri Olsa <olsajiri@gmail.com>
 	* adding large file support
diff --git a/etc/latrace.d/latrace.conf.in b/etc/latrace.d/latrace.conf.in
index a14c51a..2126021 100644
--- a/etc/latrace.d/latrace.conf.in
+++ b/etc/latrace.d/latrace.conf.in
@@ -64,7 +64,7 @@ OPTIONS {
 
 	# Following options:
 	# LIBS/LIBS_TO/LIBS_FROM
-	# SYM/SYM_OMIT/SYM_BELOW
+	# SYM/SYM_OMIT/SYM_BELOW/SYM_NOEXIT
 	#
 	# use list of names as value.  Single names in the list are
 	# separated by comma ','. If the first char of a single name
@@ -88,4 +88,7 @@ OPTIONS {
 
 	# -b, --flow-below
 	# SYM_BELOW = krava
+
+	# no command line option equivalent
+	SYM_NOEXIT = _setjmp
 }
diff --git a/src/audit-init.c b/src/audit-init.c
index 27e38f5..f36fee3 100644
--- a/src/audit-init.c
+++ b/src/audit-init.c
@@ -204,6 +204,14 @@ int audit_init(int argc, char **argv, char **env)
 		return -1;
 	}
 
+	/* SYM_NOEXIT option */
+	if ((*lt_sh(&cfg, symbols_noexit)) &&
+	    (-1 == (cfg.symbols_noexit_cnt = get_names(&cfg, lt_sh(&cfg, symbols_noexit),
+						       cfg.symbols_noexit)))) {
+		printf("latrace failed to parse noexit symbols\n");
+		return -1;
+	}
+
 	/* -b */
 	if ((*lt_sh(&cfg, flow_below)) &&
 	    (-1 == (cfg.flow_below_cnt = get_names(&cfg, lt_sh(&cfg, flow_below),
diff --git a/src/audit.c b/src/audit.c
index 2d00c88..97cbaf3 100644
--- a/src/audit.c
+++ b/src/audit.c
@@ -245,12 +245,20 @@ static unsigned int la_symbind(ElfW(Sym) *sym, const char *symname)
 {
 	unsigned int flags = 0;
 
+	/* particular symbols specified, omit all others */
 	if (cfg.symbols_cnt) {
 		flags = LA_SYMB_NOPLTENTER|LA_SYMB_NOPLTEXIT;
 		if (check_names((char*) symname, cfg.symbols))
 			flags = 0;
 	}
 
+	/* we might want just pltenter for some.. eg for _setjmp */
+	if (cfg.symbols_noexit_cnt) {
+		if (check_names((char*) symname, cfg.symbols_noexit))
+			flags = LA_SYMB_NOPLTEXIT;
+	}
+
+	/* and keep omit options the strongest */
 	if (cfg.symbols_omit_cnt) {
 		if (check_names((char*) symname, cfg.symbols_omit))
 			flags = LA_SYMB_NOPLTENTER|LA_SYMB_NOPLTEXIT;
diff --git a/src/config-bison.y b/src/config-bison.y
index 0000907..cc7d88b 100644
--- a/src/config-bison.y
+++ b/src/config-bison.y
@@ -64,7 +64,7 @@ static struct lt_list_head ln_names;
 %token OPT_DEMANGLE OPT_BRACES OPT_ENABLE_ARGS
 %token OPT_DETAIL_ARGS OPT_OUTPUT_TTY
 %token OPT_LIBS OPT_LIBS_TO OPT_LIBS_FROM
-%token OPT_SYM OPT_SYM_OMIT OPT_SYM_BELOW
+%token OPT_SYM OPT_SYM_OMIT OPT_SYM_BELOW OPT_SYM_NOEXIT
 
 %union
 {
@@ -240,6 +240,16 @@ OPTIONS_DEF OPT_SYM_BELOW '=' list_names_comma
 	OPTION_ADD(LT_OPT_SYM_BELOW, sym_below, -1);
 }
 |
+OPTIONS_DEF OPT_SYM_NOEXIT '=' list_names_comma
+{
+	char sym_noexit[LT_SYMBOLS_MAXSIZE];
+
+	if (lt_config_ln_fill(&ln_names, sym_noexit, LT_SYMBOLS_MAXSIZE))
+		ERROR("failed to process sym_below option");
+
+	OPTION_ADD(LT_OPT_SYM_NOEXIT, sym_noexit, -1);
+}
+|
 /* left blank intentionally */
 
 list_names_comma:
diff --git a/src/config-flex.l b/src/config-flex.l
index a15a687..89de981 100644
--- a/src/config-flex.l
+++ b/src/config-flex.l
@@ -90,6 +90,7 @@ OPTIONS				{ BEGIN(options); return OPTIONS; }
 <options>SYM			{ return OPT_SYM; }
 <options>SYM_OMIT		{ return OPT_SYM_OMIT; }
 <options>SYM_BELOW		{ return OPT_SYM_BELOW; }
+<options>SYM_NOEXIT		{ return OPT_SYM_NOEXIT; }
 
 <options>{bool}		{ RETURN_STR(BOOL); }
 <options>{value}	{ RETURN_LONG(VALUE); }
diff --git a/src/config.c b/src/config.c
index 4ab9f97..20eaa45 100644
--- a/src/config.c
+++ b/src/config.c
@@ -319,6 +319,12 @@ static int process_option_val(struct lt_config_app *cfg, int idx,
 			      lt_sh(cfg, flow_below));
 		break;
 
+	case LT_OPT_SYM_NOEXIT:
+		strcpy(lt_sh(cfg, symbols_noexit), sval);
+		PRINT_VERBOSE(cfg, 1, "SYM_NOEXIT '%s'\n",
+			      lt_sh(cfg, symbols_noexit));
+		break;
+
 	default:
 		return -1;
 	}
diff --git a/src/config.h b/src/config.h
index 2006f7e..9f0b5d7 100644
--- a/src/config.h
+++ b/src/config.h
@@ -90,6 +90,7 @@ enum {
 	LT_OPT_SYM,
 	LT_OPT_SYM_OMIT,
 	LT_OPT_SYM_BELOW,
+	LT_OPT_SYM_NOEXIT,
 };
 
 struct lt_config_opt {
@@ -114,6 +115,7 @@ struct lt_config_shared {
 #define LT_SYMBOLS_MAXSIZE  200
 	char symbols[LT_SYMBOLS_MAXSIZE];
 	char symbols_omit[LT_SYMBOLS_MAXSIZE];
+	char symbols_noexit[LT_SYMBOLS_MAXSIZE];
 
 	char flow_below[LT_SYMBOLS_MAXSIZE];
 
@@ -224,6 +226,9 @@ struct lt_config_audit {
 	char *symbols_omit[LT_NAMES_MAX];
 	int symbols_omit_cnt;
 
+	char *symbols_noexit[LT_NAMES_MAX];
+	int symbols_noexit_cnt;
+
 	char *flow_below[LT_NAMES_MAX];
 	int flow_below_cnt;