Messages in this thread Patch in this message | | | Date | Fri, 7 Dec 2018 18:58:05 +0100 | From | Andrea Righi <> | Subject | Re: [PATCH] kprobes: x86_64: blacklist non-attachable interrupt functions |
| |
On Sat, Dec 08, 2018 at 01:01:20AM +0900, Masami Hiramatsu wrote: > Hi Andrea and Ingo, > > Here is the patch what I meant. I just ran it on qemu-x86, and seemed working. > After introducing this patch, I will start adding arch_populate_kprobe_blacklist() > to some arches. > > Thank you, > > [RFC] kprobes: x86/kprobes: Blacklist symbols in arch-defined prohibited area > > From: Masami Hiramatsu <mhiramat@kernel.org> > > Blacklist symbols in arch-defined probe-prohibited areas. > With this change, user can see all symbols which are prohibited > to probe in debugfs. > > All archtectures which have custom prohibit areas should define > its own arch_populate_kprobe_blacklist() function, but unless that, > all symbols marked __kprobes are blacklisted.
What about iterating all symbols and use arch_within_kprobe_blacklist() to check if we need to blacklist them or not.
In this way we don't have to introduce an arch_populate_kprobe_blacklist() for each architecture.
Something like the following maybe.
Thanks.
[RFC] kprobes: blacklist all symbols in arch-defined prohibited area
From: Andrea Righi <righi.andrea@gmail.com>
Blacklist symbols in arch-defined probe-prohibited areas. With this change, user can see all symbols which are prohibited to probe in debugfs.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Andrea Righi <righi.andrea@gmail.com> --- kernel/kprobes.c | 55 +++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 41 insertions(+), 14 deletions(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 90e98e233647..e67598dd7468 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2093,6 +2093,35 @@ void dump_kprobe(struct kprobe *kp) } NOKPROBE_SYMBOL(dump_kprobe); +static int kprobe_blacklist_add(unsigned long entry) +{ + struct kprobe_blacklist_entry *ent; + unsigned long offset = 0, size = 0; + + if (!kernel_text_address(entry) || + !kallsyms_lookup_size_offset(entry, &size, &offset)) + return -EINVAL; + + ent = kmalloc(sizeof(*ent), GFP_KERNEL); + if (!ent) + return -ENOMEM; + ent->start_addr = entry; + ent->end_addr = entry + size; + INIT_LIST_HEAD(&ent->list); + list_add_tail(&ent->list, &kprobe_blacklist); + + return 0; +} + +static int arch_populate_kprobe_blacklist(void *data, const char *name, + struct module *mod, + unsigned long entry) +{ + if (arch_within_kprobe_blacklist(entry)) + kprobe_blacklist_add(entry); + return 0; +} + /* * Lookup and populate the kprobe_blacklist. * @@ -2104,24 +2133,22 @@ NOKPROBE_SYMBOL(dump_kprobe); static int __init populate_kprobe_blacklist(unsigned long *start, unsigned long *end) { - unsigned long *iter; - struct kprobe_blacklist_entry *ent; - unsigned long entry, offset = 0, size = 0; + unsigned long entry, *iter; + int ret; + /* Blacklist all arch_within_kprobe_blacklist() symbols */ + mutex_lock(&module_mutex); + kallsyms_on_each_symbol(arch_populate_kprobe_blacklist, NULL); + mutex_unlock(&module_mutex); + + /* Add explicitly blacklisted symbols */ for (iter = start; iter < end; iter++) { entry = arch_deref_entry_point((void *)*iter); - - if (!kernel_text_address(entry) || - !kallsyms_lookup_size_offset(entry, &size, &offset)) + ret = kprobe_blacklist_add(entry); + if (ret == -EINVAL) continue; - - ent = kmalloc(sizeof(*ent), GFP_KERNEL); - if (!ent) - return -ENOMEM; - ent->start_addr = entry; - ent->end_addr = entry + size; - INIT_LIST_HEAD(&ent->list); - list_add_tail(&ent->list, &kprobe_blacklist); + if (ret < 0) + return ret; } return 0; }
| |