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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>
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parent
1686cc1a31
commit
19514910d0
5 changed files with 19 additions and 17 deletions
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@ -34,7 +34,7 @@
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static LIST_HEAD(klp_ops);
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struct klp_ops *klp_find_ops(unsigned long old_addr)
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struct klp_ops *klp_find_ops(void *old_func)
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{
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struct klp_ops *ops;
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struct klp_func *func;
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@ -42,7 +42,7 @@ struct klp_ops *klp_find_ops(unsigned long old_addr)
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list_for_each_entry(ops, &klp_ops, node) {
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func = list_first_entry(&ops->func_stack, struct klp_func,
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stack_node);
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if (func->old_addr == old_addr)
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if (func->old_func == old_func)
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return ops;
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}
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@ -142,17 +142,18 @@ static void klp_unpatch_func(struct klp_func *func)
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if (WARN_ON(!func->patched))
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return;
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if (WARN_ON(!func->old_addr))
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if (WARN_ON(!func->old_func))
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return;
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ops = klp_find_ops(func->old_addr);
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ops = klp_find_ops(func->old_func);
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if (WARN_ON(!ops))
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return;
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if (list_is_singular(&ops->func_stack)) {
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unsigned long ftrace_loc;
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ftrace_loc = klp_get_ftrace_location(func->old_addr);
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ftrace_loc =
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klp_get_ftrace_location((unsigned long)func->old_func);
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if (WARN_ON(!ftrace_loc))
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return;
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@ -174,17 +175,18 @@ static int klp_patch_func(struct klp_func *func)
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struct klp_ops *ops;
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int ret;
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if (WARN_ON(!func->old_addr))
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if (WARN_ON(!func->old_func))
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return -EINVAL;
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if (WARN_ON(func->patched))
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return -EINVAL;
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ops = klp_find_ops(func->old_addr);
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ops = klp_find_ops(func->old_func);
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if (!ops) {
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unsigned long ftrace_loc;
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ftrace_loc = klp_get_ftrace_location(func->old_addr);
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ftrace_loc =
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klp_get_ftrace_location((unsigned long)func->old_func);
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if (!ftrace_loc) {
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pr_err("failed to find location for function '%s'\n",
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func->old_name);
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