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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching

Browse Source 
Pull livepatching updates from Jiri Kosina:

 - fix for patching modules that contain .altinstructions or
   .parainstructions sections, from Jessica Yu

 - make TAINT_LIVEPATCH a per-module flag (so that it's immediately
   clear which module caused the taint), from Josh Poimboeuf

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch/module: make TAINT_LIVEPATCH module-specific
  Documentation: livepatch: add section about arch-specific code
  livepatch/x86: apply alternatives and paravirt patches after relocations
  livepatch: use arch_klp_init_object_loaded() to finish arch-specific tasks
This commit is contained in:
Linus Torvalds
2016-10-07 12:02:24 -07:00
parent bc75450cc3 2992ef29ae
commit ddc4e6d232
6 changed files with 107 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
kernel/livepatch/core.c
View File

@@ -274,7 +274,6 @@ static int klp_write_object_relocations(struct module *pmod,
objname = klp_is_module(obj) ? obj->name : "vmlinux";
module_disable_ro(pmod);
/* For each klp relocation section */
for (i = 1; i < pmod->klp_info->hdr.e_shnum; i++) {
sec = pmod->klp_info->sechdrs + i;
@@ -309,7 +308,6 @@ static int klp_write_object_relocations(struct module *pmod,
break;
}
module_enable_ro(pmod, true);
return ret;
}
@@ -547,9 +545,6 @@ static int __klp_enable_patch(struct klp_patch *patch)
list_prev_entry(patch, list)->state == KLP_DISABLED)
return -EBUSY;
pr_notice_once("tainting kernel with TAINT_LIVEPATCH\n");
add_taint(TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
pr_notice("enabling patch '%s'\n", patch->mod->name);
klp_for_each_object(patch, obj) {
@@ -763,6 +758,12 @@ static int klp_init_func(struct klp_object *obj, struct klp_func *func)
func->old_sympos ? func->old_sympos : 1);
}
/* Arches may override this to finish any remaining arch-specific tasks */
void __weak arch_klp_init_object_loaded(struct klp_patch *patch,
struct klp_object *obj)
{
}
/* parts of the initialization that is done only when the object is loaded */
static int klp_init_object_loaded(struct klp_patch *patch,
struct klp_object *obj)
@@ -770,9 +771,15 @@ static int klp_init_object_loaded(struct klp_patch *patch,
struct klp_func *func;
int ret;
module_disable_ro(patch->mod);
ret = klp_write_object_relocations(patch->mod, obj);
if (ret)
if (ret) {
module_enable_ro(patch->mod, true);
return ret;
}
arch_klp_init_object_loaded(patch, obj);
module_enable_ro(patch->mod, true);
klp_for_each_func(obj, func) {
ret = klp_find_object_symbol(obj->name, func->old_name,

13
kernel/module.c
View File

@@ -1149,6 +1149,8 @@ static size_t module_flags_taint(struct module *mod, char *buf)
buf[l++] = 'C';
if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
buf[l++] = 'E';
if (mod->taints & (1 << TAINT_LIVEPATCH))
buf[l++] = 'K';
/*
* TAINT_FORCED_RMMOD: could be added.
* TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
@@ -2792,14 +2794,17 @@ static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned l
}
#ifdef CONFIG_LIVEPATCH
static int find_livepatch_modinfo(struct module *mod, struct load_info *info)
static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
{
mod->klp = get_modinfo(info, "livepatch") ? true : false;
if (get_modinfo(info, "livepatch")) {
mod->klp = true;
add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
}
return 0;
}
#else /* !CONFIG_LIVEPATCH */
static int find_livepatch_modinfo(struct module *mod, struct load_info *info)
static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
{
if (get_modinfo(info, "livepatch")) {
pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
@@ -2969,7 +2974,7 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
"is unknown, you have been warned.\n", mod->name);
}
err = find_livepatch_modinfo(mod, info);
err = check_modinfo_livepatch(mod, info);
if (err)
return err;