pathtrace_select() is never called with NULL, remove dead code

pathtrace_select() is only called for -P FILE options,
and FILE is never a NULL pointer.

   text	   data	    bss	    dec	    hex	filename
 239453	    672	  19012	 259137	  3f441	strace.before
 239329	    672	  19012	 259013	  3f3c5	strace

* pathtrace.c (pathtrace_select): Remove "if (path == NULL)...".
(pathtrace_select): Remove code which only executes if path == NULL.
The code was also buggy, it can free non-malloced pointer.
(getfdpath): Simplify snprintf to sprintf.
(pathmatch): Use strcmp() == 0 idiom for string equality test.
(pathtrace_match): Likewise.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/pathtrace.c b/pathtrace.c
index cb31a7363f1e2b95d97592ee47a22adac1789034..ab2c69f29614a3fd54bb9a1ab1ea34d038265f19 100644 (file)
--- a/pathtrace.c
+++ b/pathtrace.c
@@ -53,7 +53,7 @@ pathmatch(const char *path)
        for (i = 0; i < ARRAY_SIZE(selected); ++i) {
                if (selected[i] == NULL)
                        return 0;
-               if (!strcmp(path, selected[i]))
+               if (strcmp(path, selected[i]) == 0)
                        return 1;
        }
        return 0;
@@ -91,20 +91,12 @@ storepath(const char *path)
 {
        unsigned int i;
 
-       if (path == NULL) {
-               for (i = 0; i < ARRAY_SIZE(selected); ++i)
-                       if (selected[i]) {
-                               free((char *) selected[i]);
-                               selected[i] = NULL;
-                       }
-               return 0;
-       }
-
-       for (i = 0; i < ARRAY_SIZE(selected); ++i)
+       for (i = 0; i < ARRAY_SIZE(selected); ++i) {
                if (!selected[i]) {
                        selected[i] = path;
                        return 0;
                }
+       }
 
        fprintf(stderr, "Max trace paths exceeded, only using first %u\n",
                (unsigned int) ARRAY_SIZE(selected));
@@ -114,16 +106,17 @@ storepath(const char *path)
 /*
  * Get path associated with fd.
  */
-const char *getfdpath(struct tcb *tcp, int fd)
+const char *
+getfdpath(struct tcb *tcp, int fd)
 {
        static char path[PATH_MAX+1];
-       char linkpath[64];
+       char linkpath[sizeof("/proc/%u/fd/%u") + 2 * sizeof(int)];
        ssize_t n;
 
        if (fd < 0)
                return NULL;
 
-       snprintf(linkpath, sizeof linkpath, "/proc/%d/fd/%d", tcp->pid, fd);
+       sprintf(linkpath, "/proc/%u/fd/%u", tcp->pid, fd);
        n = readlink(linkpath, path, (sizeof path) - 1);
        if (n <= 0)
                return NULL;
@@ -138,10 +131,7 @@ const char *getfdpath(struct tcb *tcp, int fd)
 int
 pathtrace_select(const char *path)
 {
-       char   *rpath;
-
-       if (path == NULL)
-               return storepath(path);
+       char *rpath;
 
        if (storepath(path))
                return -1;
@@ -152,7 +142,7 @@ pathtrace_select(const char *path)
                return 0;
 
        /* if realpath and specified path are same, we're done */
-       if (!strcmp(path, rpath)) {
+       if (strcmp(path, rpath) == 0) {
                free(rpath);
                return 0;
        }
@@ -343,7 +333,7 @@ pathtrace_match(struct tcb *tcp)
            s->sys_func == sys_timerfd_settime ||
            s->sys_func == sys_timerfd_gettime ||
            s->sys_func == sys_epoll_create ||
-           !strcmp(s->sys_name, "fanotify_init"))
+           strcmp(s->sys_name, "fanotify_init") == 0)
        {
                /*
                 * These have TRACE_FILE or TRACE_DESCRIPTOR set, but they