[patch 14/15] Allow KGDB to work well with loaded modules

[Tom Rini]

CC: Amit S. Kale <[EMAIL PROTECTED]>
This allows for KGDB to better deal with autoloaded modules.

---

 linux-2.6.13-rc3-trini/include/linux/module.h |   16 +++++++
 linux-2.6.13-rc3-trini/kernel/module.c        |   56 ++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff -puN include/linux/module.h~module include/linux/module.h
--- linux-2.6.13-rc3/include/linux/module.h~module      2005-07-29 
11:55:34.000000000 -0700
+++ linux-2.6.13-rc3-trini/include/linux/module.h       2005-07-29 
11:55:34.000000000 -0700
@@ -210,8 +210,17 @@ enum module_state
        MODULE_STATE_LIVE,
        MODULE_STATE_COMING,
        MODULE_STATE_GOING,
+       MODULE_STATE_GONE,
 };
 
+#ifdef CONFIG_KGDB
+#define MAX_SECTNAME 31
+struct mod_section {
+       void *address;
+       char name[MAX_SECTNAME + 1];
+};
+#endif
+
 /* Similar stuff for section attributes. */
 #define MODULE_SECT_NAME_LEN 32
 struct module_sect_attr
@@ -239,6 +248,13 @@ struct module
        /* Unique handle for this module */
        char name[MODULE_NAME_LEN];
 
+#ifdef CONFIG_KGDB
+       /* keep kgdb info at the begining so that gdb doesn't have a chance to
+        * miss out any fields */
+       unsigned long num_sections;
+       struct mod_section *mod_sections;
+#endif
+
        /* Sysfs stuff. */
        struct module_kobject mkobj;
        struct module_param_attrs *param_attrs;
diff -puN kernel/module.c~module kernel/module.c
--- linux-2.6.13-rc3/kernel/module.c~module     2005-07-29 11:55:34.000000000 
-0700
+++ linux-2.6.13-rc3-trini/kernel/module.c      2005-07-29 11:55:34.000000000 
-0700
@@ -617,6 +617,12 @@ sys_delete_module(const char __user *nam
        if (ret != 0)
                goto out;
 
+       down(&notify_mutex);
+       notifier_call_chain(&module_notify_list, MODULE_STATE_GOING,
+                               mod);
+       up(&notify_mutex);
+
+
        /* Never wait if forced. */
        if (!forced && module_refcount(mod) != 0)
                wait_for_zero_refcount(mod);
@@ -629,6 +635,11 @@ sys_delete_module(const char __user *nam
        }
        free_module(mod);
 
+       down(&notify_mutex);
+       notifier_call_chain(&module_notify_list, MODULE_STATE_GONE,
+                       NULL);
+       up(&notify_mutex);
+
  out:
        up(&module_mutex);
        return ret;
@@ -1167,6 +1178,11 @@ static void free_module(struct module *m
        /* Arch-specific cleanup. */
        module_arch_cleanup(mod);
 
+#ifdef CONFIG_KGDB
+       /* kgdb info */
+       vfree(mod->mod_sections);
+#endif
+
        /* Module unload stuff */
        module_unload_free(mod);
 
@@ -1401,6 +1417,31 @@ static void setup_modinfo(struct module 
 }
 #endif
 
+#ifdef CONFIG_KGDB
+int add_modsects (struct module *mod, Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const
+                char *secstrings)
+{
+        int i;
+
+        mod->num_sections = hdr->e_shnum - 1;
+        mod->mod_sections = vmalloc((hdr->e_shnum - 1)*
+               sizeof (struct mod_section));
+
+        if (mod->mod_sections == NULL) {
+                return -ENOMEM;
+        }
+
+        for (i = 1; i < hdr->e_shnum; i++) {
+                mod->mod_sections[i - 1].address = (void *)sechdrs[i].sh_addr;
+                strncpy(mod->mod_sections[i - 1].name, secstrings +
+                                sechdrs[i].sh_name, MAX_SECTNAME);
+                mod->mod_sections[i - 1].name[MAX_SECTNAME] = '\0';
+       }
+
+       return 0;
+}
+#endif
+
 #ifdef CONFIG_KALLSYMS
 int is_exported(const char *name, const struct module *mod)
 {
@@ -1768,6 +1809,12 @@ static struct module *load_module(void _
 
        add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
 
+#ifdef CONFIG_KGDB
+        if ((err = add_modsects(mod, hdr, sechdrs, secstrings)) < 0) {
+                goto nomodsectinfo;
+        }
+#endif
+
        err = module_finalize(hdr, sechdrs, mod);
        if (err < 0)
                goto cleanup;
@@ -1815,6 +1862,11 @@ static struct module *load_module(void _
  arch_cleanup:
        module_arch_cleanup(mod);
  cleanup:
+
+#ifdef CONFIG_KGDB
+nomodsectinfo:
+       vfree(mod->mod_sections);
+#endif
        module_unload_free(mod);
        module_free(mod, mod->module_init);
  free_core:
@@ -1902,6 +1954,10 @@ sys_init_module(void __user *umod,
                /* Init routine failed: abort.  Try to protect us from
                    buggy refcounters. */
                mod->state = MODULE_STATE_GOING;
+               down(&notify_mutex);
+               notifier_call_chain(&module_notify_list, MODULE_STATE_GOING,
+                               mod);
+               up(&notify_mutex);
                synchronize_sched();
                if (mod->unsafe)
                        printk(KERN_ERR "%s: module is now stuck!\n",
_
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