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: Frantisek Hrbata <fhrbata@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Frantisek Hrbata 2013-10-14 18:08:46 +10:30 committed by Rusty Russell
parent eed380f3f5
commit eb3057df73
2 changed files with 19 additions and 2 deletions

View File

@ -473,6 +473,7 @@
#define KERNEL_CTORS() . = ALIGN(8); \
VMLINUX_SYMBOL(__ctors_start) = .; \
*(.ctors) \
*(.init_array) \
VMLINUX_SYMBOL(__ctors_end) = .;
#else
#define KERNEL_CTORS()

View File

@ -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)