Merge remote-tracking branch 'remotes/bonzini/configure' into staging

* remotes/bonzini/configure:
  build: softmmu targets do not have a "main.o" file
  configure: Disable libtool if -fPIE does not work with it (bug #1257099)
  block: convert block drivers linked with libs to modules
  Makefile: introduce common-obj-m and block-obj-m for DSO
  Makefile: install modules with "make install"
  module: implement module loading
  rules.mak: introduce DSO rules
  darwin: do not use -mdynamic-no-pic
  block: use per-object cflags and libs
  rules.mak: allow per object cflags and libs
  rules.mak: fix $(obj) to a real relative path
  util: Split out exec_dir from os_find_datadir

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 227 insertions, 2 deletions

diff --git a/util/module.c b/util/module.c
index 7acc33d076..42bc3732c9 100644
--- a/util/module.c
+++ b/util/module.c
@@ -13,6 +13,8 @@
  * GNU GPL, version 2 or (at your option) any later version.
  */
 
+#include <stdlib.h>
+#include <gmodule.h>
 #include "qemu-common.h"
 #include "qemu/queue.h"
 #include "qemu/module.h"
@@ -21,13 +23,16 @@ typedef struct ModuleEntry
 {
     void (*init)(void);
     QTAILQ_ENTRY(ModuleEntry) node;
+    module_init_type type;
 } ModuleEntry;
 
 typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList;
 
 static ModuleTypeList init_type_list[MODULE_INIT_MAX];
 
-static void init_types(void)
+static ModuleTypeList dso_init_list;
+
+static void init_lists(void)
 {
     static int inited;
     int i;
@@ -40,6 +45,8 @@ static void init_types(void)
         QTAILQ_INIT(&init_type_list[i]);
     }
 
+    QTAILQ_INIT(&dso_init_list);
+
     inited = 1;
 }
 
@@ -48,7 +55,7 @@ static ModuleTypeList *find_type(module_init_type type)
 {
     ModuleTypeList *l;
 
-    init_types();
+    init_lists();
 
     l = &init_type_list[type];
 
@@ -62,20 +69,154 @@ void register_module_init(void (*fn)(void), module_init_type type)
 
     e = g_malloc0(sizeof(*e));
     e->init = fn;
+    e->type = type;
 
     l = find_type(type);
 
     QTAILQ_INSERT_TAIL(l, e, node);
 }
 
+void register_dso_module_init(void (*fn)(void), module_init_type type)
+{
+    ModuleEntry *e;
+
+    init_lists();
+
+    e = g_malloc0(sizeof(*e));
+    e->init = fn;
+    e->type = type;
+
+    QTAILQ_INSERT_TAIL(&dso_init_list, e, node);
+}
+
+static void module_load(module_init_type type);
+
 void module_call_init(module_init_type type)
 {
     ModuleTypeList *l;
     ModuleEntry *e;
 
+    module_load(type);
     l = find_type(type);
 
     QTAILQ_FOREACH(e, l, node) {
         e->init();
     }
 }
+
+#ifdef CONFIG_MODULES
+static int module_load_file(const char *fname)
+{
+    GModule *g_module;
+    void (*sym)(void);
+    const char *dsosuf = HOST_DSOSUF;
+    int len = strlen(fname);
+    int suf_len = strlen(dsosuf);
+    ModuleEntry *e, *next;
+    int ret;
+
+    if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) {
+        /* wrong suffix */
+        ret = -EINVAL;
+        goto out;
+    }
+    if (access(fname, F_OK)) {
+        ret = -ENOENT;
+        goto out;
+    }
+
+    assert(QTAILQ_EMPTY(&dso_init_list));
+
+    g_module = g_module_open(fname, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
+    if (!g_module) {
+        fprintf(stderr, "Failed to open module: %s\n",
+                g_module_error());
+        ret = -EINVAL;
+        goto out;
+    }
+    if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) {
+        fprintf(stderr, "Failed to initialize module: %s\n",
+                fname);
+        /* Print some info if this is a QEMU module (but from different build),
+         * this will make debugging user problems easier. */
+        if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer *)&sym)) {
+            fprintf(stderr,
+                    "Note: only modules from the same build can be loaded.\n");
+        }
+        g_module_close(g_module);
+        ret = -EINVAL;
+    } else {
+        QTAILQ_FOREACH(e, &dso_init_list, node) {
+            register_module_init(e->init, e->type);
+        }
+        ret = 0;
+    }
+
+    QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) {
+        QTAILQ_REMOVE(&dso_init_list, e, node);
+        g_free(e);
+    }
+out:
+    return ret;
+}
+#endif
+
+void module_load(module_init_type type)
+{
+#ifdef CONFIG_MODULES
+    char *fname = NULL;
+    const char **mp;
+    static const char *block_modules[] = {
+        CONFIG_BLOCK_MODULES
+    };
+    char *exec_dir;
+    char *dirs[3];
+    int i = 0;
+    int ret;
+
+    if (!g_module_supported()) {
+        fprintf(stderr, "Module is not supported by system.\n");
+        return;
+    }
+
+    switch (type) {
+    case MODULE_INIT_BLOCK:
+        mp = block_modules;
+        break;
+    default:
+        /* no other types have dynamic modules for now*/
+        return;
+    }
+
+    exec_dir = qemu_get_exec_dir();
+    dirs[i++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR);
+    dirs[i++] = g_strdup_printf("%s/..", exec_dir ? : "");
+    dirs[i++] = g_strdup_printf("%s", exec_dir ? : "");
+    assert(i == ARRAY_SIZE(dirs));
+    g_free(exec_dir);
+    exec_dir = NULL;
+
+    for ( ; *mp; mp++) {
+        for (i = 0; i < ARRAY_SIZE(dirs); i++) {
+            fname = g_strdup_printf("%s/%s%s", dirs[i], *mp, HOST_DSOSUF);
+            ret = module_load_file(fname);
+            /* Try loading until loaded a module file */
+            if (!ret) {
+                break;
+            }
+            g_free(fname);
+            fname = NULL;
+        }
+        if (ret == -ENOENT) {
+            fprintf(stderr, "Can't find module: %s\n", *mp);
+        }
+
+        g_free(fname);
+    }
+
+    for (i = 0; i < ARRAY_SIZE(dirs); i++) {
+        g_free(dirs[i]);
+    }
+
+#endif
+}
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index d5dca4729a..c2eeb4fe40 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -57,6 +57,7 @@ extern int daemon(int, int);
 #include "trace.h"
 #include "qemu/sockets.h"
 #include <sys/mman.h>
+#include <libgen.h>
 
 #ifdef CONFIG_LINUX
 #include <sys/syscall.h>
@@ -274,3 +275,56 @@ void qemu_set_tty_echo(int fd, bool echo)
 
     tcsetattr(fd, TCSANOW, &tty);
 }
+
+static char exec_dir[PATH_MAX];
+
+void qemu_init_exec_dir(const char *argv0)
+{
+    char *dir;
+    char *p = NULL;
+    char buf[PATH_MAX];
+
+    assert(!exec_dir[0]);
+
+#if defined(__linux__)
+    {
+        int len;
+        len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
+        if (len > 0) {
+            buf[len] = 0;
+            p = buf;
+        }
+    }
+#elif defined(__FreeBSD__)
+    {
+        static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
+        size_t len = sizeof(buf) - 1;
+
+        *buf = '\0';
+        if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
+            *buf) {
+            buf[sizeof(buf) - 1] = '\0';
+            p = buf;
+        }
+    }
+#endif
+    /* If we don't have any way of figuring out the actual executable
+       location then try argv[0].  */
+    if (!p) {
+        if (!argv0) {
+            return;
+        }
+        p = realpath(argv0, buf);
+        if (!p) {
+            return;
+        }
+    }
+    dir = dirname(p);
+
+    pstrcpy(exec_dir, sizeof(exec_dir), dir);
+}
+
+char *qemu_get_exec_dir(void)
+{
+    return g_strdup(exec_dir);
+}
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index 50be0440f2..93f7d351d3 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -208,3 +208,33 @@ void qemu_set_tty_echo(int fd, bool echo)
                        dwMode & ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT));
     }
 }
+
+static char exec_dir[PATH_MAX];
+
+void qemu_init_exec_dir(const char *argv0)
+{
+
+    char *p;
+    char buf[MAX_PATH];
+    DWORD len;
+
+    len = GetModuleFileName(NULL, buf, sizeof(buf) - 1);
+    if (len == 0) {
+        return;
+    }
+
+    buf[len] = 0;
+    p = buf + len - 1;
+    while (p != buf && *p != '\\') {
+        p--;
+    }
+    *p = 0;
+    if (access(buf, R_OK) == 0) {
+        pstrcpy(exec_dir, sizeof(exec_dir), buf);
+    }
+}
+
+char *qemu_get_exec_dir(void)
+{
+    return g_strdup(exec_dir);
+}