From 40886892e996d750f5384fb8eca5f8e384307efc Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Thu, 25 Aug 2016 10:04:45 -0500 Subject: [PATCH] livepatch/module: make TAINT_LIVEPATCH module-specific There's no reliable way to determine which module tainted the kernel with TAINT_LIVEPATCH. For example, /sys/module//taint doesn't report it. Neither does the "mod -t" command in the crash tool. Make it crystal clear who the guilty party is by associating TAINT_LIVEPATCH with any module which sets the "livepatch" modinfo attribute. The flag will still get set in the kernel like before, but now it also sets the same flag in mod->taint. Note that now the taint flag gets set when the module is loaded rather than when it's enabled. I also renamed find_livepatch_modinfo() to check_modinfo_livepatch() to better reflect its purpose: it's basically a livepatch-specific sub-function of check_modinfo(). Reported-by: Chunyu Hu Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Acked-by: Jessica Yu Acked-by: Rusty Russell Signed-off-by: Josh Poimboeuf Signed-off-by: Jiri Kosina --- kernel/livepatch/core.c | 3 --- kernel/module.c | 13 +++++++++---- 2 files changed, 9 insertions(+), 7 deletions(-) diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 5fbabe0222866..af4643873e717 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -545,9 +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) { diff --git a/kernel/module.c b/kernel/module.c index 529efae9f481e..f57dd63186e63 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -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; -- 2.39.5