diff options
author | Petr Mladek <pmladek@suse.com> | 2019-01-09 15:43:19 +0300 |
---|---|---|
committer | Jiri Kosina <jkosina@suse.cz> | 2019-01-11 22:51:23 +0300 |
commit | 19514910d021c93c7823ec32067e6b7dea224f0f (patch) | |
tree | 3df053de0eb62fec2557e24bd807cae328d4f21a | |
parent | 1686cc1a31f45a3fd090e5d0c6fce777422e13fa (diff) | |
download | linux-19514910d021c93c7823ec32067e6b7dea224f0f.tar.xz |
livepatch: Change unsigned long old_addr -> void *old_func in struct klp_func
The address of the to be patched function and new function is stored
in struct klp_func as:
void *new_func;
unsigned long old_addr;
The different naming scheme and type are derived from the way
the addresses are set. @old_addr is assigned at runtime using
kallsyms-based search. @new_func is statically initialized,
for example:
static struct klp_func funcs[] = {
{
.old_name = "cmdline_proc_show",
.new_func = livepatch_cmdline_proc_show,
}, { }
};
This patch changes unsigned long old_addr -> void *old_func. It removes
some confusion when these address are later used in the code. It is
motivated by a followup patch that adds special NOP struct klp_func
where we want to assign func->new_func = func->old_addr respectively
func->new_func = func->old_func.
This patch does not modify the existing behavior.
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Alice Ferrazzi <alice.ferrazzi@gmail.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-rw-r--r-- | include/linux/livepatch.h | 4 | ||||
-rw-r--r-- | kernel/livepatch/core.c | 6 | ||||
-rw-r--r-- | kernel/livepatch/patch.c | 18 | ||||
-rw-r--r-- | kernel/livepatch/patch.h | 4 | ||||
-rw-r--r-- | kernel/livepatch/transition.c | 4 |
5 files changed, 19 insertions, 17 deletions
diff --git a/include/linux/livepatch.h b/include/linux/livepatch.h index aec44b1d9582..634e13876380 100644 --- a/include/linux/livepatch.h +++ b/include/linux/livepatch.h @@ -40,7 +40,7 @@ * @new_func: pointer to the patched function code * @old_sympos: a hint indicating which symbol position the old function * can be found (optional) - * @old_addr: the address of the function being patched + * @old_func: pointer to 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 @@ -77,7 +77,7 @@ struct klp_func { unsigned long old_sympos; /* internal */ - unsigned long old_addr; + void *old_func; struct kobject kobj; struct list_head stack_node; unsigned long old_size, new_size; diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 5b77a7314e01..cb59c7fb94cb 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -648,7 +648,7 @@ static void klp_free_object_loaded(struct klp_object *obj) obj->mod = NULL; klp_for_each_func(obj, func) - func->old_addr = 0; + func->old_func = NULL; } /* @@ -721,11 +721,11 @@ static int klp_init_object_loaded(struct klp_patch *patch, klp_for_each_func(obj, func) { ret = klp_find_object_symbol(obj->name, func->old_name, func->old_sympos, - &func->old_addr); + (unsigned long *)&func->old_func); if (ret) return ret; - ret = kallsyms_lookup_size_offset(func->old_addr, + ret = kallsyms_lookup_size_offset((unsigned long)func->old_func, &func->old_size, NULL); if (!ret) { pr_err("kallsyms size lookup failed for '%s'\n", diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index 7702cb4064fc..825022d70912 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -34,7 +34,7 @@ static LIST_HEAD(klp_ops); -struct klp_ops *klp_find_ops(unsigned long old_addr) +struct klp_ops *klp_find_ops(void *old_func) { struct klp_ops *ops; struct klp_func *func; @@ -42,7 +42,7 @@ struct klp_ops *klp_find_ops(unsigned long old_addr) list_for_each_entry(ops, &klp_ops, node) { func = list_first_entry(&ops->func_stack, struct klp_func, stack_node); - if (func->old_addr == old_addr) + if (func->old_func == old_func) return ops; } @@ -142,17 +142,18 @@ static void klp_unpatch_func(struct klp_func *func) if (WARN_ON(!func->patched)) return; - if (WARN_ON(!func->old_addr)) + if (WARN_ON(!func->old_func)) return; - ops = klp_find_ops(func->old_addr); + ops = klp_find_ops(func->old_func); if (WARN_ON(!ops)) return; if (list_is_singular(&ops->func_stack)) { unsigned long ftrace_loc; - ftrace_loc = klp_get_ftrace_location(func->old_addr); + ftrace_loc = + klp_get_ftrace_location((unsigned long)func->old_func); if (WARN_ON(!ftrace_loc)) return; @@ -174,17 +175,18 @@ static int klp_patch_func(struct klp_func *func) struct klp_ops *ops; int ret; - if (WARN_ON(!func->old_addr)) + if (WARN_ON(!func->old_func)) return -EINVAL; if (WARN_ON(func->patched)) return -EINVAL; - ops = klp_find_ops(func->old_addr); + ops = klp_find_ops(func->old_func); if (!ops) { unsigned long ftrace_loc; - ftrace_loc = klp_get_ftrace_location(func->old_addr); + ftrace_loc = + klp_get_ftrace_location((unsigned long)func->old_func); if (!ftrace_loc) { pr_err("failed to find location for function '%s'\n", func->old_name); diff --git a/kernel/livepatch/patch.h b/kernel/livepatch/patch.h index e72d8250d04b..a9b16e513656 100644 --- a/kernel/livepatch/patch.h +++ b/kernel/livepatch/patch.h @@ -10,7 +10,7 @@ * struct klp_ops - structure for tracking registered ftrace ops structs * * A single ftrace_ops is shared between all enabled replacement functions - * (klp_func structs) which have the same old_addr. This allows the switch + * (klp_func structs) which have the same old_func. This allows the switch * between function versions to happen instantaneously by updating the klp_ops * struct's func_stack list. The winner is the klp_func at the top of the * func_stack (front of the list). @@ -25,7 +25,7 @@ struct klp_ops { struct ftrace_ops fops; }; -struct klp_ops *klp_find_ops(unsigned long old_addr); +struct klp_ops *klp_find_ops(void *old_func); int klp_patch_object(struct klp_object *obj); void klp_unpatch_object(struct klp_object *obj); diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c index 304d5eb8a98c..f27a378ad5e1 100644 --- a/kernel/livepatch/transition.c +++ b/kernel/livepatch/transition.c @@ -224,11 +224,11 @@ static int klp_check_stack_func(struct klp_func *func, * Check for the to-be-patched function * (the previous func). */ - ops = klp_find_ops(func->old_addr); + ops = klp_find_ops(func->old_func); if (list_is_singular(&ops->func_stack)) { /* original function */ - func_addr = func->old_addr; + func_addr = (unsigned long)func->old_func; func_size = func->old_size; } else { /* previously patched function */ |