Messages in this thread Patch in this message | | | From | Tom Rini <> | Subject | [PATCH,RFC 2.6.14 15/15] KGDB: Better support for loaded modules | Date | Thu, 10 Nov 2005 11:45:14 -0500 |
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This allows for KGDB to better deal with autoloaded modules. The way this works, requires a patch to GDB. This patch can be found at ftp://source.mvista.com/pub/kgdb/gdb-6.3-kgdb-module-notification.patch
The way this works is that the solib-search-path must contain the location of any module to be debugged, and then when a module is loaded GDB acts like a shared library has been loaded now, and can be used that way.
include/linux/module.h | 16 ++++++++++++++ kernel/module.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+)
Index: linux-2.6.14/include/linux/module.h =================================================================== --- linux-2.6.14.orig/include/linux/module.h +++ linux-2.6.14/include/linux/module.h @@ -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; Index: linux-2.6.14/kernel/module.c =================================================================== --- linux-2.6.14.orig/kernel/module.c +++ linux-2.6.14/kernel/module.c @@ -624,6 +624,12 @@ sys_delete_module(const char __user *nam if (ret != 0) goto out; + down(¬ify_mutex); + notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, + mod); + up(¬ify_mutex); + + /* Never wait if forced. */ if (!forced && module_refcount(mod) != 0) wait_for_zero_refcount(mod); @@ -636,6 +642,11 @@ sys_delete_module(const char __user *nam } free_module(mod); + down(¬ify_mutex); + notifier_call_chain(&module_notify_list, MODULE_STATE_GONE, + NULL); + up(¬ify_mutex); + out: up(&module_mutex); return ret; @@ -1174,6 +1185,11 @@ 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); @@ -1408,6 +1424,31 @@ 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) { @@ -1777,6 +1818,12 @@ 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; @@ -1842,6 +1889,11 @@ 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: @@ -1915,6 +1967,10 @@ sys_init_module(void __user *umod, /* Init routine failed: abort. Try to protect us from buggy refcounters. */ mod->state = MODULE_STATE_GOING; + down(¬ify_mutex); + notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, + mod); + up(¬ify_mutex); synchronize_sched(); if (mod->unsafe) printk(KERN_ERR "%s: module is now stuck!\n", -- Tom - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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