From ca4787b779dd698a2a33a328aa5fa90a3e954077 Mon Sep 17 00:00:00 2001 From: Tim Abbott Date: Mon, 5 Jan 2009 08:40:10 -0600 Subject: kernel/module.c: compare symbol values when marking symbols as exported in /proc/kallsyms. When there are two symbols in a module with the same name, one of which is exported, both will be marked as exported in /proc/kallsyms. There aren't any instances of this in the current kernel, but it is easy to construct a simple module with two compilation units that exhibits the problem. $ objdump -j .text -t testmod.ko | grep foo 00000000 l F .text 00000032 foo 00000080 g F .text 00000001 foo $ sudo insmod testmod.ko $ grep "T foo" /proc/kallsyms c28e8000 T foo [testmod] c28e8080 T foo [testmod] Fix this by comparing the symbol values once we've found the exported symbol table entry matching the symbol name. Tested using Ksplice: $ ksplice-create --patch=this_commit.patch --id=bar . $ sudo ksplice-apply ksplice-bar.tar.gz Done! $ grep "T foo" /proc/kallsyms c28e8080 T foo [testmod] Signed-off-by: Tim Abbott Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Rusty Russell --- kernel/module.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index dd2a54155b5..895c5675edb 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1725,15 +1725,15 @@ static const struct kernel_symbol *lookup_symbol(const char *name, return NULL; } -static int is_exported(const char *name, const struct module *mod) +static int is_exported(const char *name, unsigned long value, + const struct module *mod) { - if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab)) - return 1; + const struct kernel_symbol *ks; + if (!mod) + ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab); else - if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms)) - return 1; - else - return 0; + ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms); + return ks != NULL && ks->value == value; } /* As per nm */ @@ -2504,7 +2504,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, strlcpy(name, mod->strtab + mod->symtab[symnum].st_name, KSYM_NAME_LEN); strlcpy(module_name, mod->name, MODULE_NAME_LEN); - *exported = is_exported(name, mod); + *exported = is_exported(name, *value, mod); preempt_enable(); return 0; } -- cgit v1.2.3-70-g09d2 From d1e99d7ae4e6bbd1ebb5e81ecd3af2b8793efee0 Mon Sep 17 00:00:00 2001 From: Jianjun Kong Date: Mon, 8 Dec 2008 14:26:29 +0800 Subject: module: fix warning of unused function when !CONFIG_PROC_FS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix this warning: kernel/module.c:824: warning: ‘print_unload_info’ defined but not used print_unload_info() just was used when CONFIG_PROC_FS was defined. This patch mark print_unload_info() inline to solve the problem. Signed-off-by: Jianjun Kong Signed-off-by: Rusty Russell CC: Ingo Molnar CC: Américo Wang --- kernel/module.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 895c5675edb..d3d254571bd 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -820,7 +820,7 @@ sys_delete_module(const char __user *name_user, unsigned int flags) return ret; } -static void print_unload_info(struct seq_file *m, struct module *mod) +static inline void print_unload_info(struct seq_file *m, struct module *mod) { struct module_use *use; int printed_something = 0; @@ -893,7 +893,7 @@ void module_put(struct module *module) EXPORT_SYMBOL(module_put); #else /* !CONFIG_MODULE_UNLOAD */ -static void print_unload_info(struct seq_file *m, struct module *mod) +static inline void print_unload_info(struct seq_file *m, struct module *mod) { /* We don't know the usage count, or what modules are using. */ seq_printf(m, " - -"); -- cgit v1.2.3-70-g09d2 From 088af9a6e05d51e7c3dc85d45d8b7a52c3ee08d7 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Wed, 31 Dec 2008 12:31:18 +0100 Subject: module: fix module loading failure of large kernel modules for parisc When creating the final layout of a kernel module in memory, allow the module loader to reserve some additional memory in front of a given section. This is currently only needed for the parisc port which needs to put the stub entries there to fulfill the 17/22bit PCREL relocations with large kernel modules like xfs. Signed-off-by: Helge Deller Signed-off-by: Rusty Russell (renamed fn) --- include/linux/moduleloader.h | 3 +++ kernel/module.c | 16 +++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-) (limited to 'kernel/module.c') diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h index eb103395748..c1f40c2f7ff 100644 --- a/include/linux/moduleloader.h +++ b/include/linux/moduleloader.h @@ -13,6 +13,9 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, char *secstrings, struct module *mod); +/* Additional bytes needed by arch in front of individual sections */ +unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section); + /* Allocator used for allocating struct module, core sections and init sections. Returns NULL on failure. */ void *module_alloc(unsigned long size); diff --git a/kernel/module.c b/kernel/module.c index d3d254571bd..4299aefc20b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1578,11 +1578,21 @@ static int simplify_symbols(Elf_Shdr *sechdrs, return ret; } +/* Additional bytes needed by arch in front of individual sections */ +unsigned int __weak arch_mod_section_prepend(struct module *mod, + unsigned int section) +{ + /* default implementation just returns zero */ + return 0; +} + /* Update size with this section: return offset. */ -static long get_offset(unsigned int *size, Elf_Shdr *sechdr) +static long get_offset(struct module *mod, unsigned int *size, + Elf_Shdr *sechdr, unsigned int section) { long ret; + *size += arch_mod_section_prepend(mod, section); ret = ALIGN(*size, sechdr->sh_addralign ?: 1); *size = ret + sechdr->sh_size; return ret; @@ -1622,7 +1632,7 @@ static void layout_sections(struct module *mod, || strncmp(secstrings + s->sh_name, ".init", 5) == 0) continue; - s->sh_entsize = get_offset(&mod->core_size, s); + s->sh_entsize = get_offset(mod, &mod->core_size, s, i); DEBUGP("\t%s\n", secstrings + s->sh_name); } if (m == 0) @@ -1640,7 +1650,7 @@ static void layout_sections(struct module *mod, || strncmp(secstrings + s->sh_name, ".init", 5) != 0) continue; - s->sh_entsize = (get_offset(&mod->init_size, s) + s->sh_entsize = (get_offset(mod, &mod->init_size, s, i) | INIT_OFFSET_MASK); DEBUGP("\t%s\n", secstrings + s->sh_name); } -- cgit v1.2.3-70-g09d2 From 9e01892c4234070bbcf3a9f582514c8b91464375 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 22 Dec 2008 12:36:31 +0100 Subject: module: convert to stop_machine_create/destroy. The module code relies on a non-failing stop_machine call. So we create the kstop threads in advance and with that make sure the call won't fail. Signed-off-by: Heiko Carstens Signed-off-by: Rusty Russell --- kernel/module.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 4299aefc20b..f47cce910f2 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -757,8 +757,16 @@ sys_delete_module(const char __user *name_user, unsigned int flags) return -EFAULT; name[MODULE_NAME_LEN-1] = '\0'; - if (mutex_lock_interruptible(&module_mutex) != 0) - return -EINTR; + /* Create stop_machine threads since free_module relies on + * a non-failing stop_machine call. */ + ret = stop_machine_create(); + if (ret) + return ret; + + if (mutex_lock_interruptible(&module_mutex) != 0) { + ret = -EINTR; + goto out_stop; + } mod = find_module(name); if (!mod) { @@ -817,6 +825,8 @@ sys_delete_module(const char __user *name_user, unsigned int flags) out: mutex_unlock(&module_mutex); +out_stop: + stop_machine_destroy(); return ret; } @@ -1875,6 +1885,13 @@ static noinline struct module *load_module(void __user *umod, /* vmalloc barfs on "unusual" numbers. Check here */ if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL) return ERR_PTR(-ENOMEM); + + /* Create stop_machine threads since the error path relies on + * a non-failing stop_machine call. */ + err = stop_machine_create(); + if (err) + goto free_hdr; + if (copy_from_user(hdr, umod, len) != 0) { err = -EFAULT; goto free_hdr; @@ -2258,6 +2275,7 @@ static noinline struct module *load_module(void __user *umod, /* Get rid of temporary copy */ vfree(hdr); + stop_machine_destroy(); /* Done! */ return mod; @@ -2280,6 +2298,7 @@ static noinline struct module *load_module(void __user *umod, kfree(args); free_hdr: vfree(hdr); + stop_machine_destroy(); return ERR_PTR(err); truncated: -- cgit v1.2.3-70-g09d2