use THIS_MODULE instead of the module's name

examples/providers/bsd/provider.c

@@ -6,15 +6,15 @@
 
 static int __init
 dpusm_bsd_provider_init(void) {
-    const int rc = dpusm_register_bsd(module_name(THIS_MODULE),
+    const int rc = dpusm_register_bsd(THIS_MODULE,
         &example_dpusm_provider_functions);
     printk("%s init: %d\n", module_name(THIS_MODULE), rc);
     return rc;
 }
 
 static void __exit
 dpusm_bsd_provider_exit(void) {
-    dpusm_unregister_bsd(module_name(THIS_MODULE));
+    dpusm_unregister_bsd(THIS_MODULE);
 
     printk("%s exit\n", module_name(THIS_MODULE));
 }

examples/providers/gpl/provider.c

@@ -6,15 +6,15 @@
 
 static int __init
 dpusm_gpl_provider_init(void) {
-    const int rc = dpusm_register_gpl(module_name(THIS_MODULE),
+    const int rc = dpusm_register_gpl(THIS_MODULE,
         &example_dpusm_provider_functions);
     printk("%s init: %d\n", module_name(THIS_MODULE), rc);
     return rc;
 }
 
 static void __exit
 dpusm_gpl_provider_exit(void) {
-    dpusm_unregister_gpl(module_name(THIS_MODULE));
+    dpusm_unregister_gpl(THIS_MODULE);
 
     printk("%s exit\n", module_name(THIS_MODULE));
 }

include/dpusm/provider.h

@@ -3,13 +3,14 @@
 
 #include <linux/atomic.h>
 #include <linux/list.h>
+#include <linux/module.h>
 #include <linux/spinlock.h>
 
 #include <dpusm/provider_api.h>
 
 /* single provider data */
 typedef struct dpusm_provider_handle {
-    const char *name;        /* reference to a string */
+    struct module *module;
     dpusm_pc_t capabilities; /* constant set of capabilities */
     const dpusm_pf_t *funcs; /* reference to a struct */
     atomic_t refs;           /* how many users are holding this provider */
@@ -25,11 +26,11 @@ typedef struct {
                                  /* this is not tied to the provider/count */
 } dpusm_t;
 
-int dpusm_provider_register(dpusm_t *dpusm, const char *name, const dpusm_pf_t *funcs);
+int dpusm_provider_register(dpusm_t *dpusm, struct module *module, const dpusm_pf_t *funcs);
 
 /* can't prevent provider module from unloading */
 int dpusm_provider_unregister_handle(dpusm_t *dpusm, dpusm_ph_t **provider);
-int dpusm_provider_unregister(dpusm_t *dpusm, const char *name);
+int dpusm_provider_unregister(dpusm_t *dpusm, struct module *module);
 
 dpusm_ph_t **dpusm_provider_get(dpusm_t *dpusm, const char *name);
 int dpusm_provider_put(dpusm_t *dpusm, void *handle);
@@ -42,6 +43,6 @@ void dpusm_provider_write_unlock(dpusm_t *dpusm);
  *
  * provider is not unregistered, so dpusm_unregister still needs to be called
  */
-void dpusm_provider_invalidate(dpusm_t *dpusm, const char *name);
+void dpusm_provider_invalidate(dpusm_t *dpusm, struct module *module);
 
 #endif

include/dpusm/provider_api.h

@@ -183,16 +183,16 @@ typedef struct dpusm_provider_functions {
 } dpusm_pf_t;
 
 /* returns -ERRNO instead of DPUSM_* */
-int dpusm_register_bsd(const char *name, const dpusm_pf_t *funcs);
-int dpusm_unregister_bsd(const char *name);
-int dpusm_register_gpl(const char *name, const dpusm_pf_t *funcs);
-int dpusm_unregister_gpl(const char *name);
+int dpusm_register_bsd(struct module *module, const dpusm_pf_t *funcs);
+int dpusm_unregister_bsd(struct module *module);
+int dpusm_register_gpl(struct module *module, const dpusm_pf_t *funcs);
+int dpusm_unregister_gpl(struct module *module);
 
 /*
  * call when backing DPU goes down unexpectedly
  *
  * provider is not unregistered, so dpusm_unregister still needs to be called
  */
-void dpusm_invalidate(const char *name);
+void dpusm_invalidate(struct module *module);
 
 #endif

src/dpusm.c

@@ -11,27 +11,27 @@
 static dpusm_t dpusm;
 
 int
-dpusm_register_bsd(const char *name, const dpusm_pf_t *funcs) {
-    return dpusm_provider_register(&dpusm, name, funcs);
+dpusm_register_bsd(struct module *module, const dpusm_pf_t *funcs) {
+    return dpusm_provider_register(&dpusm, module, funcs);
 }
 
 int
-dpusm_unregister_bsd(const char *name) {
-    return dpusm_provider_unregister(&dpusm, name);
+dpusm_unregister_bsd(struct module *module) {
+    return dpusm_provider_unregister(&dpusm, module);
 }
 
 /* provider facing functions */
 EXPORT_SYMBOL(dpusm_register_bsd);
 EXPORT_SYMBOL(dpusm_unregister_bsd);
 
 int
-dpusm_register_gpl(const char *name, const dpusm_pf_t *funcs) {
-    return dpusm_provider_register(&dpusm, name, funcs);
+dpusm_register_gpl(struct module *module, const dpusm_pf_t *funcs) {
+    return dpusm_provider_register(&dpusm, module, funcs);
 }
 
 int
-dpusm_unregister_gpl(const char *name) {
-    return dpusm_provider_unregister(&dpusm, name);
+dpusm_unregister_gpl(struct module *module) {
+    return dpusm_provider_unregister(&dpusm, module);
 }
 
 /* provider facing functions */
@@ -44,8 +44,8 @@ EXPORT_SYMBOL_GPL(dpusm_unregister_gpl);
  * Provider is not unregistered, so dpusm_unregister still needs to be called.
  * Using name instead of handle because the provider handle is not available to the provider.
  */
-void dpusm_invalidate(const char *name) {
-    dpusm_provider_invalidate(&dpusm, name);
+void dpusm_invalidate(struct module *module) {
+    dpusm_provider_invalidate(&dpusm, module);
 }
 EXPORT_SYMBOL(dpusm_invalidate);
 

src/provider.c

@@ -84,7 +84,7 @@ find_provider(dpusm_t *dpusm, const char *name) {
     struct list_head *it = NULL;
     list_for_each(it, &dpusm->providers) {
         dpusm_ph_t *dpusmph = list_entry(it, dpusm_ph_t, list);
-        const char *p_name = dpusmph->name;
+        const char *p_name = module_name(dpusmph->module);
         const size_t p_name_len = strlen(p_name);
         if (name_len == p_name_len) {
             if (memcmp(name, p_name, p_name_len) == 0) {
@@ -108,8 +108,9 @@ static void print_supported(const char *name, const char *func)
 }
 
 static dpusm_ph_t *
-dpusmph_init(const char *name, const dpusm_pf_t *funcs)
+dpusmph_init(struct module *module, const dpusm_pf_t *funcs)
 {
+    const char *name = module_name(module);
     dpusm_ph_t *dpusmph = dpusm_mem_alloc(sizeof(dpusm_ph_t));
     if (dpusmph) {
         /* fill in capabilities bitmasks */
@@ -223,7 +224,7 @@ dpusmph_init(const char *name, const dpusm_pf_t *funcs)
             dpusmph->capabilities.io &= ~DPUSM_IO_DISK;
         }
 
-        dpusmph->name = name;
+        dpusmph->module = module;
         dpusmph->funcs = funcs;
         dpusmph->self = dpusmph;
         atomic_set(&dpusmph->refs, 0);
@@ -234,7 +235,12 @@ dpusmph_init(const char *name, const dpusm_pf_t *funcs)
 
 /* add a new provider */
 int
-dpusm_provider_register(dpusm_t *dpusm, const char *name, const dpusm_pf_t *funcs) {
+dpusm_provider_register(dpusm_t *dpusm, struct module *module, const dpusm_pf_t *funcs) {
+    if (!try_module_get(module)) {
+        printk("Error: Could not increment reference count of %s\n", module_name(module));
+        return -ECANCELED;
+    }
+
     const int rc = dpusm_provider_sane_at_load(funcs);
     if (rc != DPUSM_OK) {
         static const size_t max =
@@ -262,22 +268,25 @@ dpusm_provider_register(dpusm_t *dpusm, const char *name, const dpusm_pf_t *func
 
         dpusm_mem_free(buf, size);
 
+        module_put(module);
         return -EINVAL;
     }
 
     dpusm_provider_write_lock(dpusm);
 
-    dpusm_ph_t **found = find_provider(dpusm, name);
+    dpusm_ph_t **found = find_provider(dpusm, module_name(module));
     if (found) {
         printk("%s: DPUSM Provider with the name \"%s\" (%p) already exists. %zu providers registered.\n",
                __func__, name, *found, dpusm->count);
         dpusm_provider_write_unlock(dpusm);
+        module_put(module);
         return -EEXIST;
     }
 
-    dpusm_ph_t *provider = dpusmph_init(name, funcs);
+    dpusm_ph_t *provider = dpusmph_init(module, funcs);
     if (!provider) {
         dpusm_provider_write_unlock(dpusm);
+        module_put(module);
         return -ECANCELED;
     }
 
@@ -321,19 +330,19 @@ dpusm_provider_unregister_handle(dpusm_t *dpusm, dpusm_ph_t **provider) {
 }
 
 int
-dpusm_provider_unregister(dpusm_t *dpusm, const char *name) {
+dpusm_provider_unregister(dpusm_t *dpusm, struct module *module) {
     dpusm_provider_write_lock(dpusm);
 
-    dpusm_ph_t **provider = find_provider(dpusm, name);
+    dpusm_ph_t **provider = find_provider(dpusm, module_name(module));
     if (!provider) {
-        printk("%s: Could not find provider with name \"%s\"\n", __func__, name);
+        printk("%s: Could not find provider with name \"%s\"\n", __func__, module_name(module);
         dpusm_provider_write_unlock(dpusm);
         return DPUSM_ERROR;
     }
 
     void *addr = *provider;
     const int rc = dpusm_provider_unregister_handle(dpusm, provider);
-    printk("%s: Unregistered \"%s\" (%p): %d\n", __func__, name, addr, rc);
+    printk("%s: Unregistered \"%s\" (%p): %d\n", __func__, module_name(module), addr, rc);
 
     dpusm_provider_write_unlock(dpusm);
     return rc;
@@ -353,7 +362,7 @@ dpusm_provider_get(dpusm_t *dpusm, const char *name) {
         atomic_inc(&(*provider)->refs);
         atomic_inc(&dpusm->active);
         printk("%s: User has been given a handle to \"%s\" (%p) (now %d users).\n",
-               __func__, (*provider)->name, *provider, atomic_read(&(*provider)->refs));
+               __func__, name, *provider, atomic_read(&(*provider)->refs));
 
         if ((*provider)->funcs->at_connect) {
             (*provider)->funcs->at_connect();
@@ -378,10 +387,11 @@ dpusm_provider_put(dpusm_t *dpusm, void *handle) {
 
     if (!atomic_read(&(*provider)->refs)) {
         printk("%s Error: Cannot decrement provider \"%s\" user count already at 0.\n",
-               __func__, (*provider)->name);
+               __func__, module_name((*provider)->module));
         return DPUSM_ERROR;
     }
 
+    module_put((*provider)->module);
     atomic_dec(&(*provider)->refs);
     atomic_dec(&dpusm->active);
 
@@ -392,7 +402,7 @@ dpusm_provider_put(dpusm_t *dpusm, void *handle) {
     }
 
     printk("%s: User has returned a handle to \"%s\" (%p) (now %d users).\n",
-           __func__, (*provider)->name, *provider, atomic_read(&(*provider)->refs));
+           __func__, (*provider)->name, module_name((*provider)->module), atomic_read(&(*provider)->refs));
     return DPUSM_OK;
 }
 
@@ -406,18 +416,18 @@ dpusm_provider_write_unlock(dpusm_t *dpusm) {
     write_unlock(&dpusm->lock);
 }
 
-void dpusm_provider_invalidate(dpusm_t *dpusm, const char *name) {
+void dpusm_provider_invalidate(dpusm_t *dpusm, struct module *module) {
     dpusm_provider_write_lock(dpusm);
-    dpusm_ph_t **provider = find_provider(dpusm, name);
+    dpusm_ph_t **provider = find_provider(dpusm, module_name(module));
     if (provider && *provider) {
         (*provider)->funcs = NULL;
         memset(&(*provider)->capabilities, 0, sizeof((*provider)->capabilities));
         printk("%s: Provider \"%s\" has been invalidated with %d users active.\n",
-               __func__, name, atomic_read(&(*provider)->refs));
+               __func__, module_name(module), atomic_read(&(*provider)->refs));
     }
     else {
         printk("%s: Error: Did not find provider \"%s\"\n",
-               __func__, name);
+               __func__, module_name(module));
     }
     dpusm_provider_write_unlock(dpusm);
 }