conf: remove thread-unsafe strsignal + improve log

The thread-unsafe functions strsignal() is called in run_buffer() which in turn
is called in run_buffer_argv() which is responsible for running __all__ lxc
hooks. This is pretty dangerous for multi-threaded users like LXD.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 7b66e3747a0fee4906f131b6d7bd90a5d8438002..fb080aa5e3001e8dfc678df7d3477c66540551d1 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -375,32 +375,31 @@ static int run_buffer(char *buffer)
 
        f = lxc_popen(buffer);
        if (!f) {
-               SYSERROR("popen failed");
+               SYSERROR("Failed to popen() %s.", buffer);
                return -1;
        }
 
        output = malloc(LXC_LOG_BUFFER_SIZE);
        if (!output) {
-               ERROR("failed to allocate memory for script output");
+               ERROR("Failed to allocate memory for %s.", buffer);
                lxc_pclose(f);
                return -1;
        }
 
-       while(fgets(output, LXC_LOG_BUFFER_SIZE, f->f))
-               DEBUG("script output: %s", output);
+       while (fgets(output, LXC_LOG_BUFFER_SIZE, f->f))
+               DEBUG("Script %s with output: %s.", buffer, output);
 
        free(output);
 
        ret = lxc_pclose(f);
        if (ret == -1) {
-               SYSERROR("Script exited on error");
+               SYSERROR("Script exited with error.");
                return -1;
        } else if (WIFEXITED(ret) && WEXITSTATUS(ret) != 0) {
-               ERROR("Script exited with status %d", WEXITSTATUS(ret));
+               ERROR("Script exited with status %d.", WEXITSTATUS(ret));
                return -1;
        } else if (WIFSIGNALED(ret)) {
-               ERROR("Script terminated by signal %d (%s)", WTERMSIG(ret),
-                     strsignal(WTERMSIG(ret)));
+               ERROR("Script terminated by signal %d.", WTERMSIG(ret));
                return -1;
        }
 
@@ -408,17 +407,17 @@ static int run_buffer(char *buffer)
 }
 
 static int run_script_argv(const char *name, const char *section,
-                     const char *script, const char *hook, const char *lxcpath,
-                     char **argsin)
+                          const char *script, const char *hook,
+                          const char *lxcpath, char **argsin)
 {
        int ret, i;
        char *buffer;
        size_t size = 0;
 
-       INFO("Executing script '%s' for container '%s', config section '%s'",
+       INFO("Executing script \"%s\" for container \"%s\", config section \"%s\".",
             script, name, section);
 
-       for (i=0; argsin && argsin[i]; i++)
+       for (i = 0; argsin && argsin[i]; i++)
                size += strlen(argsin[i]) + 1;
 
        size += strlen(hook) + 1;
@@ -433,22 +432,23 @@ static int run_script_argv(const char *name, const char *section,
 
        buffer = alloca(size);
        if (!buffer) {
-               ERROR("failed to allocate memory");
+               ERROR("Failed to allocate memory.");
                return -1;
        }
 
-       ret = snprintf(buffer, size, "%s %s %s %s", script, name, section, hook);
-       if (ret < 0 || ret >= size) {
-               ERROR("Script name too long");
+       ret =
+           snprintf(buffer, size, "%s %s %s %s", script, name, section, hook);
+       if (ret < 0 || (size_t)ret >= size) {
+               ERROR("Script name too long.");
                return -1;
        }
 
-       for (i=0; argsin && argsin[i]; i++) {
-               int len = size-ret;
+       for (i = 0; argsin && argsin[i]; i++) {
+               int len = size - ret;
                int rc;
                rc = snprintf(buffer + ret, len, " %s", argsin[i]);
                if (rc < 0 || rc >= len) {
-                       ERROR("Script args too long");
+                       ERROR("Script args too long.");
                        return -1;
                }
                ret += rc;
@@ -457,15 +457,15 @@ static int run_script_argv(const char *name, const char *section,
        return run_buffer(buffer);
 }
 
-static int run_script(const char *name, const char *section,
-                     const char *script, ...)
+static int run_script(const char *name, const char *section, const char *script,
+                     ...)
 {
        int ret;
        char *buffer, *p;
        size_t size = 0;
        va_list ap;
 
-       INFO("Executing script '%s' for container '%s', config section '%s'",
+       INFO("Executing script \"%s\" for container \"%s\", config section \"%s\".",
             script, name, section);
 
        va_start(ap, script);
@@ -483,23 +483,23 @@ static int run_script(const char *name, const char *section,
 
        buffer = alloca(size);
        if (!buffer) {
-               ERROR("failed to allocate memory");
+               ERROR("Failed to allocate memory.");
                return -1;
        }
 
        ret = snprintf(buffer, size, "%s %s %s", script, name, section);
        if (ret < 0 || ret >= size) {
-               ERROR("Script name too long");
+               ERROR("Script name too long.");
                return -1;
        }
 
        va_start(ap, script);
        while ((p = va_arg(ap, char *))) {
-               int len = size-ret;
+               int len = size - ret;
                int rc;
                rc = snprintf(buffer + ret, len, " %s", p);
                if (rc < 0 || rc >= len) {
-                       ERROR("Script args too long");
+                       ERROR("Script args too long.");
                        return -1;
                }
                ret += rc;