error simulation: library part

8 files changed, 239 insertions, 7 deletions

diff --git a/src/Makefile b/src/Makefile
index 6b849d3..e009358 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -40,6 +40,13 @@ AUDIT_OBJS+=\
 	src/sysdeps/$(CONFIG_SYSDEP_DIR)/stack.o
 endif
 
+# TODO make this for all error simulation objects
+ifeq ($(CONFIG_ARCH_HAVE_ERROR_SIM),y)
+AUDIT_OBJS+=\
+	src/sysdeps/$(CONFIG_SYSDEP_DIR)/error.o \
+	src/audit-error.o
+endif
+
 OBJS+=$(AUDIT_OBJS)
 PROGRAMS+= $(AUDIT_BIN)
 # no dependency for flex and bison definitions
diff --git a/src/audit-error.c b/src/audit-error.c
new file mode 100644
index 0000000..6a9bc50
--- /dev/null
+++ b/src/audit-error.c
@@ -0,0 +1,166 @@
+
+#include <stdio.h>
+#include <search.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <strings.h>
+#include <string.h>
+
+#include "config.h"
+
+int lt_audit_parse_init(struct lt_config_shared *cfg);
+int lt_audit_parse();
+extern FILE *lt_audit_in;
+
+#define SYMBOL_TAB_SIZE 100
+static struct hsearch_data symbol_tab;
+static int symbol_tab_init = 0;
+
+struct lt_error_sym* lt_error_sym_get(struct lt_config_shared *cfg,
+				      const char *name)
+{
+	struct lt_error_sym *sym;
+	ENTRY e, *ep;
+
+	BUG_ON(!symbol_tab_init);
+
+	PRINT_VERBOSE(cfg, 1, "request for <%s>\n", name);
+
+	e.key = (char*) name;
+	hsearch_r(e, FIND, &ep, &symbol_tab);
+
+	if (!ep) {
+		PRINT_VERBOSE(cfg, 1, "failed to find <%s>\n", name);
+		return NULL;
+	}
+
+	sym = (struct lt_error_sym*) ep->data;
+
+	PRINT_VERBOSE(cfg, 1, "found %p <%s>\n", sym, sym->name);
+	return sym;
+}
+
+extern __thread int pipe_fd;
+
+int lt_error_sym_exit(struct lt_config_audit *cfg,
+		      struct lt_symbol *sym,
+		      struct timeval *tv,
+		      La_retval *outregs)
+{
+	struct lt_error_sym *esym;
+#define LT_MAXMSG 100
+	char text[LT_MAXMSG];
+
+	/* we're not interested in this symbol */
+	if (!sym || !sym->error)
+		return -1;
+
+	esym = sym->error;
+
+	PRINT_VERBOSE(cfg, 1, "symbol %s, call %lu, n %ld\n",
+		      sym->name, esym->call, lt_sh(cfg, error_def.n));
+
+	/* we are not interested in this call number  */
+	if (esym->call++ != lt_sh(cfg, error_def.n))
+		return -1;
+
+	PRINT_VERBOSE(cfg, 1, "changing retval to %lu\n",
+		      esym->ret);
+
+	/* The fun begins right now.. let's change the return
+	 * value for the symbol */
+
+	lt_error_set_retval(cfg, esym->ret, outregs);
+
+	snprintf(text, LT_MAXMSG, "ERROR SIMULATION inserted %ld",
+			esym->ret);
+
+	if (lt_sh(cfg, pipe)) {
+		char buf[LT_FIFO_MSG_MAXLEN];
+		int len;
+
+                len = lt_fifo_mtext_get(cfg, buf, tv, text);
+                return lt_fifo_send(cfg, pipe_fd, buf, len);
+        }
+
+	lt_out_text(cfg->sh, tv, syscall(SYS_gettid), text);
+	return 0;
+}
+
+static int symbol_add(struct lt_config_audit *cfg,
+		      struct lt_error_def_sym *def_sym)
+{
+	ENTRY e, *ep;
+	struct lt_error_sym *sym;
+
+	PRINT_VERBOSE(cfg, 1, "symbol %s, ret %ld\n",
+			def_sym->symbol, def_sym->ret);
+
+	/* should be safe, since only one thread
+	 * is doing the initialization */
+	if (!symbol_tab_init) {
+		if (!hcreate_r(SYMBOL_TAB_SIZE, &symbol_tab)) {
+			perror("failed to create hash table");
+			return -1;
+		}
+		symbol_tab_init = 1;
+		PRINT_VERBOSE(cfg, 1, "symbol table initialized\n");
+	}
+
+	sym = malloc(sizeof(*sym));
+	if (!sym) {
+		PRINT_VERBOSE(cfg, 1, "failed to allocate error symbol\n");
+		return -1;
+	}
+
+	sym->name = strdup(def_sym->symbol);
+	sym->ret = def_sym->ret;
+
+	e.key = sym->name;
+	e.data = sym;
+
+	if (!hsearch_r(e, ENTER, &ep, &symbol_tab)) {
+		perror("hsearch_r failed");
+		free(sym);
+
+		PRINT_VERBOSE(cfg, 3,
+			"reached the error symbol limit %d\n",
+			SYMBOL_TAB_SIZE);
+		return -1;
+	}
+
+	PRINT_VERBOSE(cfg, 1, "ok\n");
+	return 0;
+}
+
+int lt_error_init(struct lt_config_audit *cfg)
+{
+	struct lt_error_def *error_def = &lt_sh(cfg, error_def);
+	int i = 0, ok = 1;
+
+	lt_sh(cfg, error_sim) = 0;
+
+
+	for(i = 0; (i < LT_ERROR_MAXSYM); i++) {
+		struct lt_error_def_sym *sym_def;
+
+		sym_def = &error_def->sym[i];
+		if (!*sym_def->symbol)
+			break;
+
+		if (symbol_add(cfg, sym_def)) {
+			ok = 0;
+			break;
+		}
+	}
+
+	if (!ok) {
+		if (symbol_tab_init)
+			hdestroy_r(&symbol_tab);
+		return -1;
+	}
+
+	lt_sh(cfg, error_sim) = 1;
+	return 0;
+}
diff --git a/src/audit-init.c b/src/audit-init.c
index c3f96a4..092bb0c 100644
--- a/src/audit-init.c
+++ b/src/audit-init.c
@@ -253,8 +253,18 @@ int audit_init(int argc, char **argv, char **env)
 	if (lt_sh(&cfg, not_follow_fork))
 		lt_sh(&cfg, pid) = getpid();
 
-	/* enable global symbols if needed */
-	lt_sh(&cfg, global_symbols) = lt_sh(&cfg, args_enabled);
+	/* error simulation */
+	if (lt_sh(&cfg, error_sim))
+		lt_error_init(&cfg);
+
+	/*
+	  enable global symbols if
+	    - we need to display arguments
+	    - we do the error simulation
+	*/
+	lt_sh(&cfg, global_symbols) = \
+		lt_sh(&cfg, args_enabled) ||
+		lt_sh(&cfg, error_sim);
 
 	PRINT_VERBOSE(&cfg, 1, "global_symbols %d\n", lt_sh(&cfg, global_symbols));
 
diff --git a/src/audit.c b/src/audit.c
index 40e67ee..3adfa3e 100644
--- a/src/audit.c
+++ b/src/audit.c
@@ -149,6 +149,9 @@ static int sym_exit(const char *symname, void *ptr,
 	if (lt_sh(&cfg, global_symbols))
 		sym = lt_symbol_get(cfg.sh, ptr, symname);
 
+	if (lt_sh(&cfg, error_sim))
+		lt_error_sym_exit(&cfg, sym, &tv, outregs);
+
 #ifdef CONFIG_ARCH_HAVE_ARGS
 	argret = lt_sh(&cfg, args_enabled) ?
 		lt_args_sym_exit(cfg.sh, sym,
diff --git a/src/config.h b/src/config.h
index a47a4da..b2dc73a 100644
--- a/src/config.h
+++ b/src/config.h
@@ -435,6 +435,17 @@ int lt_error_app(struct lt_config_app *cfg, struct lt_error_app *error_app);
 int lt_error_set(struct lt_config_app *cfg, char *error);
 int lt_error_run(struct lt_config_app *cfg);
 
+/* error simulation lib */
+int lt_error_init(struct lt_config_audit *cfg);
+struct lt_error_sym* lt_error_sym_get(struct lt_config_shared *cfg,
+				      const char *name);
+int lt_error_sym_exit(struct lt_config_audit *cfg,
+		      struct lt_symbol *sym,
+		      struct timeval *tv,
+		      La_retval *outregs);
+int lt_error_set_retval(struct lt_config_audit *cfg,
+			unsigned long ret, La_retval *outregs);
+
 #define PRINT(fmt, args...) \
 do { \
 	char lpbuf[1024]; \
diff --git a/src/symbol.c b/src/symbol.c
index f10045a..707fbf6 100644
--- a/src/symbol.c
+++ b/src/symbol.c
@@ -74,14 +74,19 @@ static int symbol_init(struct lt_config_shared *cfg,
 		       struct lt_symbol *sym, const char *name)
 {
 	struct lt_args_sym  *a = NULL;
+	struct lt_error_sym *e = NULL;
 
-	if (lt_sh(cfg, args_enabled)) {
+	if (lt_sh(cfg, args_enabled))
 		a = lt_args_sym_get(cfg, name);
-		if (!a)
-			return -1;
-	}
 
-	sym->args = a;
+	if (lt_sh(cfg, error_sim))
+		e = lt_error_sym_get(cfg, name);
+
+	if (!a && !e)
+		return -1;
+
+	sym->args  = a;
+	sym->error = e;
 
 	PRINT_VERBOSE(cfg, 1, "ok name %s, ptr %p, sym %p\n",
 			name, sym->ptr, sym);
diff --git a/src/sysdeps/i686/error.c b/src/sysdeps/i686/error.c
new file mode 100644
index 0000000..fd675a5
--- /dev/null
+++ b/src/sysdeps/i686/error.c
@@ -0,0 +1,15 @@
+
+#include <strings.h>
+
+#include "config.h"
+
+int lt_error_set_retval(struct lt_config_audit *cfg,
+                        unsigned long ret, La_retval *outregs)
+{
+	bzero(outregs, sizeof(*outregs));
+
+	outregs->lrv_edx = 0;
+	outregs->lrv_eax = (uint32_t) ret;
+
+	return 0;
+}
diff --git a/src/sysdeps/x86_64/error.c b/src/sysdeps/x86_64/error.c
new file mode 100644
index 0000000..36784cd
--- /dev/null
+++ b/src/sysdeps/x86_64/error.c
@@ -0,0 +1,15 @@
+
+#include <strings.h>
+
+#include "config.h"
+
+int lt_error_set_retval(struct lt_config_audit *cfg,
+                        unsigned long ret, La_retval *outregs)
+{
+	bzero(outregs, sizeof(*outregs));
+
+	outregs->lrv_rdx = 0;
+	outregs->lrv_rax = (uint32_t) ret;
+
+	return 0;
+}