Release v32

Signed-off-by: Ikey Doherty <michael.i.doherty@intel.com>

configure.ac

@@ -2,7 +2,7 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ([2.66])
-AC_INIT(clr-debug-info, 31, arjan@linux.intel.com)
+AC_INIT(clr-debug-info, 32, arjan@linux.intel.com)
 AM_INIT_AUTOMAKE([foreign -Wall -W subdir-objects])
 AM_SILENT_RULES([yes])
 AC_PROG_CC
@@ -27,5 +27,32 @@ AC_ARG_WITH([systemdtmpfilesdir], AS_HELP_STRING([--with-systemdtmpfilesdir=DIR]
 test -z "${dir}" && dir=/usr/lib/tmpfiles.d
 AC_SUBST(tmpfilesdir, [${dir}])
 
+AC_CHECK_HEADER([stdatomic.h], [have_atomics="yes"], [have_atomics="no"])
+if test x$have_atomics = "xyes"; then
+        AC_DEFINE([HAVE_ATOMIC_SUPPORT], [1], [stdatomic supported by compiler])
+else
+        AC_MSG_WARN([C11 stdatomic support unavailable. Falling back to slow mutex])
+fi
+
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT
+
+AC_MSG_RESULT([
+        clr-debuginfo $VERSION
+
+        prefix:                 ${prefix}
+        libdir:                 ${libdir}
+        sysconfdir:             ${sysconfdir}
+        exec_prefix:            ${exec_prefix}
+        bindir:                 ${bindir}
+        datarootdir:            ${datarootdir}
+
+        compiler:               ${CC}
+        cflags:                 ${CFLAGS}
+        ldflags:                ${LDFLAGS}
+
+        systemd-unit-dir:       ${systemdsystemunitdir}
+        tmpfiles.d:             ${tmpfilesdir}
+
+        C11 stdatomic support:  ${have_atomics}
+])

src/server.c

@@ -27,14 +27,15 @@
 #define _GNU_SOURCE
 
 #include <errno.h>
+#include <linux/capability.h>
 #include <malloc.h>
 #include <pthread.h>
 #include <signal.h>
-#include <stdatomic.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/prctl.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -46,6 +47,12 @@
 
 #include <curl/curl.h>
 
+#include "config.h"
+
+#ifdef HAVE_ATOMIC_SUPPORT
+#include <stdatomic.h>
+#endif
+
 static pthread_mutex_t dupes_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 char *urls[2] = { "https://debuginfo.clearlinux.org/debuginfo/",
@@ -56,8 +63,6 @@ static NcHashmap *hash = NULL;
 
 #define MAX_CONNECTIONS 16
 
-static atomic_int current_connection_count = 0;
-
 static int avoid_dupes(const char *url)
 {
         int retval = 0;
@@ -85,6 +90,10 @@ static int avoid_dupes(const char *url)
         return retval;
 }
 
+#ifdef HAVE_ATOMIC_SUPPORT
+
+static atomic_int current_connection_count = 0;
+
 /**
  * Get the current connection count atomically
  */
@@ -108,6 +117,46 @@ __nc_inline__ static inline void dec_connection_count(void)
 {
         atomic_fetch_sub(&current_connection_count, 1);
 }
+#else /* HAVE_ATOMIC_SUPPORT */
+
+static int current_connection_count = 0;
+
+/* No stdatomic compiler support, fallback to pthread mutex (slower) */
+pthread_mutex_t con_count_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+/**
+ * Get the current connection count via mutex
+ */
+__nc_inline__ static inline int get_current_connection_count(void)
+{
+        int r;
+        pthread_mutex_lock(&con_count_mutex);
+        r = current_connection_count;
+        pthread_mutex_unlock(&con_count_mutex);
+        return r;
+}
+
+/**
+ * Increment the connection counter via mutex
+ */
+__nc_inline__ static inline void inc_connection_count(void)
+{
+        pthread_mutex_lock(&con_count_mutex);
+        current_connection_count++;
+        pthread_mutex_unlock(&con_count_mutex);
+}
+
+/**
+ * Decrement the connection counter via mutex
+ */
+__nc_inline__ static inline void dec_connection_count(void)
+{
+        pthread_mutex_lock(&con_count_mutex);
+        current_connection_count--;
+        pthread_mutex_unlock(&con_count_mutex);
+}
+
+#endif /* !(HAVE_ATOMIC_SUPPORT) */
 
 static int curl_get_file(const char *url, const char *prefix, time_t timestamp)
 {
@@ -300,6 +349,18 @@ int main(__nc_unused__ int argc, __nc_unused__ char **argv)
         int curl_done = 0;
         const char *required_paths[] = { "/var/cache/debuginfo/lib", "/var/cache/debuginfo/src" };
 
+        if (prctl(PR_SET_DUMPABLE, 0) != 0) {
+                fprintf(stderr,
+                        "Failed to disable PR_SET_DUMPABLE. Do NOT gdb attach this process: %s\n",
+                        strerror(errno));
+        }
+
+        if (geteuid() == 0) {
+                if (prctl(PR_CAPBSET_DROP, CAP_SYS_ADMIN) != 0) {
+                        fprintf(stderr, "Failed to drop caps: %s\n", strerror(errno));
+                }
+        }
+
         for (size_t i = 0; i < ARRAY_SIZE(required_paths); i++) {
                 const char *req_path = required_paths[i];
                 if (nc_file_exists(req_path)) {