Commit eb3057df authored by Frantisek Hrbata's avatar Frantisek Hrbata Committed by Rusty Russell
Browse files

kernel: add support for init_array constructors 



This adds the .init_array section as yet another section with constructors. This
is needed because gcc could add __gcov_init calls to .init_array or .ctors
section, depending on gcc (and binutils) version .

v2: - reuse mod->ctors for .init_array section for modules, because gcc uses
      .ctors or .init_array, but not both at the same time
v3: - fail to load if that does happen somehow.

Signed-off-by: default avatarFrantisek Hrbata <fhrbata@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent eed380f3

include/asm-generic/vmlinux.lds.h

+1 −0
Original line number Diff line number Diff line
@@ -473,6 +473,7 @@ 
#define KERNEL_CTORS()	. = ALIGN(8);			   \

			VMLINUX_SYMBOL(__ctors_start) = .; \

			*(.ctors)			   \

			*(.init_array)			   \

			VMLINUX_SYMBOL(__ctors_end) = .;

#else

#define KERNEL_CTORS()

kernel/module.c

+18 −2
Original line number Diff line number Diff line
@@ -2708,7 +2708,7 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags) 
	return 0;

}



static void find_module_sections(struct module *mod, struct load_info *info)

static int find_module_sections(struct module *mod, struct load_info *info)

{

	mod->kp = section_objs(info, "__param",

			       sizeof(*mod->kp), &mod->num_kp);
@@ -2738,6 +2738,18 @@ static void find_module_sections(struct module *mod, struct load_info *info) 
#ifdef CONFIG_CONSTRUCTORS

	mod->ctors = section_objs(info, ".ctors",

				  sizeof(*mod->ctors), &mod->num_ctors);

	if (!mod->ctors)

		mod->ctors = section_objs(info, ".init_array",

				sizeof(*mod->ctors), &mod->num_ctors);

	else if (find_sec(info, ".init_array")) {

		/*

		 * This shouldn't happen with same compiler and binutils

		 * building all parts of the module.

		 */

		printk(KERN_WARNING "%s: has both .ctors and .init_array.\n",

		       mod->name);

		return -EINVAL;

	}

#endif



#ifdef CONFIG_TRACEPOINTS
@@ -2776,6 +2788,8 @@ static void find_module_sections(struct module *mod, struct load_info *info) 


	info->debug = section_objs(info, "__verbose",

				   sizeof(*info->debug), &info->num_debug);



	return 0;

}



static int move_module(struct module *mod, struct load_info *info)
@@ -3233,7 +3247,9 @@ static int load_module(struct load_info *info, const char __user *uargs, 


	/* Now we've got everything in the final locations, we can

	 * find optional sections. */

	find_module_sections(mod, info);

	err = find_module_sections(mod, info);

	if (err)

		goto free_unload;



	err = check_module_license_and_versions(mod);

	if (err)

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