[PATCH v5 12/15] livepatch: store function sizes
flat view
STALE3202d
REVIEWED: 3 (2M)
From: Josh Poimboeuf <hidden>
Date: 2017-02-14 01:43:22
Also in:
linux-s390, lkml
Subsystem:
live patching, the rest · Maintainers:
Josh Poimboeuf, Miroslav Benes, Petr Mladek, Joe Lawrence, Song Liu, Linus Torvalds
Status: Reviewed.
Revision v5 (5 revisions archived); 3 review trailers (2 from subsystem maintainers).
Revisions (5)
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 <redacted>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Kamalesh Babulal <redacted>
---
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 9787a63..6602b34 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 83c4949..10ba3a1 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;
--
2.7.4