Commit 8c8ef42a authored by Rusty Russell's avatar Rusty Russell
Browse files

module: include other structures in module version check 



With CONFIG_MODVERSIONS, we version 'struct module' using a dummy
export, but other things matter too:

1) 'struct modversion_info' determines the layout of the __versions section,
2) 'struct kernel_param' determines the layout of the __params section,
3) 'struct kernel_symbol' determines __ksymtab*.
4) 'struct marker' determines __markers.
5) 'struct tracepoint' determines __tracepoints.

So we rename 'struct_module' to 'module_layout' and include these in
the signature.  Now it's general we can add others later on without
confusion.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 9cb610d8

kernel/module.c

+13 −5
Original line number Diff line number Diff line
@@ -1052,9 +1052,9 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs, 
{

	const unsigned long *crc;



	if (!find_symbol("struct_module", NULL, &crc, true, false))

	if (!find_symbol("module_layout", NULL, &crc, true, false))

		BUG();

	return check_version(sechdrs, versindex, "struct_module", mod, crc);

	return check_version(sechdrs, versindex, "module_layout", mod, crc);

}



/* First part is kernel version, which we ignore if module has crcs. */
@@ -2858,9 +2858,17 @@ void print_modules(void) 
}



#ifdef CONFIG_MODVERSIONS

/* Generate the signature for struct module here, too, for modversions. */

void struct_module(struct module *mod) { return; }

EXPORT_SYMBOL(struct_module);

/* Generate the signature for all relevant module structures here.

 * If these change, we don't want to try to parse the module. */

void module_layout(struct module *mod,

		   struct modversion_info *ver,

		   struct kernel_param *kp,

		   struct kernel_symbol *ks,

		   struct marker *marker,

		   struct tracepoint *tp)

{

}

EXPORT_SYMBOL(module_layout);

#endif



#ifdef CONFIG_MARKERS

scripts/mod/modpost.c

+2 −2
Original line number Diff line number Diff line
@@ -1607,12 +1607,12 @@ static void read_symbols(char *modname) 


	parse_elf_finish(&info);



	/* Our trick to get versioning for struct_module - it's

	/* Our trick to get versioning for module struct etc. - it's

	 * never passed as an argument to an exported function, so

	 * the automatic versioning doesn't pick it up, but it's really

	 * important anyhow */

	if (modversions)

		mod->unres = alloc_symbol("struct_module", 0, mod->unres);

		mod->unres = alloc_symbol("module_layout", 0, mod->unres);

}



#define SZ 500

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