From f5e547f4ac785c65a39211f0b8e4ffc4fe09112d Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 13 Feb 2017 19:42:39 -0600 Subject: [PATCH] livepatch: store function sizes For the consistency model we'll need to know the sizes of the old and new functions to determine if they're on the stacks of any tasks. Signed-off-by: Josh Poimboeuf Acked-by: Miroslav Benes Reviewed-by: Petr Mladek Reviewed-by: Kamalesh Babulal Signed-off-by: Jiri Kosina --- include/linux/livepatch.h | 3 +++ kernel/livepatch/core.c | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index 9787a63b57ac..6602b34bed2b 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -37,6 +37,8 @@ * @old_addr: the address of the function being patched * @kobj: kobject for sysfs resources * @stack_node: list node for klp_ops func_stack list + * @old_size: size of the old function + * @new_size: size of the new function * @patched: the func has been added to the klp_ops list */ struct klp_func { @@ -56,6 +58,7 @@ struct klp_func { unsigned long old_addr; struct kobject kobj; struct list_head stack_node; + unsigned long old_size, new_size; bool patched; }; diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 83c4949862b4..10ba3a1578bd 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -584,6 +584,22 @@ static int klp_init_object_loaded(struct klp_patch *patch, &func->old_addr); if (ret) return ret; + + ret = kallsyms_lookup_size_offset(func->old_addr, + &func->old_size, NULL); + if (!ret) { + pr_err("kallsyms size lookup failed for '%s'\n", + func->old_name); + return -ENOENT; + } + + ret = kallsyms_lookup_size_offset((unsigned long)func->new_func, + &func->new_size, NULL); + if (!ret) { + pr_err("kallsyms size lookup failed for '%s' replacement\n", + func->old_name); + return -ENOENT; + } } return 0;