Messages in this thread Patch in this message | | | From | Josh Poimboeuf <> | Subject | [RFC PATCH v1.9 11/14] livepatch: store function sizes | Date | Fri, 25 Mar 2016 14:34:58 -0500 |
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For the consistency model we'll need to know the sizes of the old and new functions to determine if they're on stacks of any tasks.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> --- 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 6d45dc7..dd5db74 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 beaf263..b0fd31d 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -540,6 +540,22 @@ 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; -- 2.4.3
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