Linus, please apply if you agree.
Tridge reported getting burned by gcc 3.2 compiled (Debian) XFree
modules not working on his gcc 2.95-compiled kernel. Interestingly,
(as Tridge points out) modversions probably would not have caught the
change in spinlock size, since the ioctl takes a void*, not a
structure pointer...
Simple bitmask, allows extension later, and prevents this kind of
thing (maybe a warning is more appropriate: this refuses to load it).
Rusty.
-- Anyone who quotes me in their sig is an idiot. -- Rusty Russell.Name: Module Sanity Check Author: Rusty Russell Status: Tested on 2.5.56
D: Stores a simple bitmask in the module structure, for SMP, PREEMPT D: and compiler version (spinlocks change size on UP with gcc major, D: at least). Also printks on modules with common section (becoming D: an FAQ for third-party modules).
diff -urNp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/include/linux/module.h working-2.5-bk-compilerversion/include/linux/module.h --- linux-2.5-bk/include/linux/module.h Mon Jan 13 11:17:32 2003 +++ working-2.5-bk-compilerversion/include/linux/module.h Mon Jan 13 15:33:03 2003 @@ -32,6 +32,21 @@ #define MODULE_SYMBOL_PREFIX "" #endif +/* Simply sanity stamp to place in each module */ +#ifdef CONFIG_SMP +#define MODULE_SANITY_SMP 1 +#else +#define MODULE_SANITY_SMP 0 +#endif +#ifdef CONFIG_PREEMPT +#define MODULE_SANITY_PREEMPT 1 +#else +#define MODULE_SANITY_PREEMPT 0 +#endif +#define MODULE_SANITY \ + ((MODULE_SANITY_SMP<<16) | (MODULE_SANITY_PREEMPT<<17) \ + | (__GNUC__<<8) | (__GNUC_MINOR__)) + #define MODULE_NAME_LEN (64 - sizeof(unsigned long)) struct kernel_symbol { @@ -168,6 +183,9 @@ struct module { enum module_state state; + /* Simple compatibility bitmask (useful for non-modversions). */ + int sanity; + /* Member of list of modules */ struct list_head list; @@ -378,6 +396,7 @@ __attribute__((section(".gnu.linkonce.th #ifdef CONFIG_MODULE_UNLOAD .exit = cleanup_module, #endif + .sanity = MODULE_SANITY, }; #endif /* KBUILD_MODNAME */ #endif /* MODULE */ diff -urNp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5-bk/kernel/module.c working-2.5-bk-compilerversion/kernel/module.c --- linux-2.5-bk/kernel/module.c Fri Jan 10 10:55:43 2003 +++ working-2.5-bk-compilerversion/kernel/module.c Mon Jan 13 16:07:40 2003 @@ -846,6 +846,8 @@ static int simplify_symbols(Elf_Shdr *se /* We compiled with -fno-common. These are not supposed to happen. */ DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name); + printk("%s: probably not cimpiled with -fno-common\n", + mod->name); return -ENOEXEC; case SHN_ABS: @@ -1094,6 +1096,13 @@ static struct module *load_module(void * goto free_hdr; } mod = (void *)sechdrs[modindex].sh_addr; + + if (mod->sanity != MODULE_SANITY) { + printk(KERN_ERR "Module %s version %08x not %08x\n", + mod->name, mod->sanity, MODULE_SANITY); + err = -ENOEXEC; + goto free_hdr; + } /* Now copy in args */ err = strlen_user(uargs); - 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/
This archive was generated by hypermail 2b29 : Wed Jan 15 2003 - 22:00:44 EST