diff options
Diffstat (limited to 'kernel/livepatch')
| -rw-r--r-- | kernel/livepatch/core.c | 6 | ||||
| -rw-r--r-- | kernel/livepatch/transition.c | 11 |
2 files changed, 14 insertions, 3 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 2398832947c6..c4ce08f43bd6 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -18,6 +18,7 @@ #include <linux/elf.h> #include <linux/moduleloader.h> #include <linux/completion.h> +#include <linux/memory.h> #include <asm/cacheflush.h> #include "core.h" #include "patch.h" @@ -718,16 +719,21 @@ static int klp_init_object_loaded(struct klp_patch *patch, struct klp_func *func; int ret; + mutex_lock(&text_mutex); + module_disable_ro(patch->mod); ret = klp_write_object_relocations(patch->mod, obj); if (ret) { module_enable_ro(patch->mod, true); + mutex_unlock(&text_mutex); return ret; } arch_klp_init_object_loaded(patch, obj); module_enable_ro(patch->mod, true); + mutex_unlock(&text_mutex); + klp_for_each_func(obj, func) { ret = klp_find_object_symbol(obj->name, func->old_name, func->old_sympos, diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index abb2a4a2cbb2..cdf318d86dd6 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -247,7 +247,6 @@ static int klp_check_stack(struct task_struct *task, char *err_buf) int ret, nr_entries; ret = stack_trace_save_tsk_reliable(task, entries, ARRAY_SIZE(entries)); - WARN_ON_ONCE(ret == -ENOSYS); if (ret < 0) { snprintf(err_buf, STACK_ERR_BUF_SIZE, "%s: %s:%d has an unreliable stack\n", @@ -281,11 +280,11 @@ static int klp_check_stack(struct task_struct *task, char *err_buf) */ static bool klp_try_switch_task(struct task_struct *task) { + static char err_buf[STACK_ERR_BUF_SIZE]; struct rq *rq; struct rq_flags flags; int ret; bool success = false; - char err_buf[STACK_ERR_BUF_SIZE]; err_buf[0] = '\0'; @@ -294,6 +293,13 @@ static bool klp_try_switch_task(struct task_struct *task) return true; /* + * For arches which don't have reliable stack traces, we have to rely + * on other methods (e.g., switching tasks at kernel exit). + */ + if (!klp_have_reliable_stack()) + return false; + + /* * Now try to check the stack for any to-be-patched or to-be-unpatched * functions. If all goes well, switch the task to the target patch * state. @@ -328,7 +334,6 @@ done: pr_debug("%s", err_buf); return success; - } /* |