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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-03-26 17:49:48 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-05-12 18:15:32 +0300 |
| commit | 1e6769b0aece51ea7a3dc3117c37d4a5669e4a21 (patch) | |
| tree | c2738aa86d5cd28739f7a0a754124da21881260e | |
| parent | 4fdd88877e5259dcc5e504dca449acc0324d71b9 (diff) | |
| download | linux-1e6769b0aece51ea7a3dc3117c37d4a5669e4a21.tar.xz | |
kprobes: Support __kprobes blacklist in modules
Support __kprobes attribute for blacklist functions in modules. The
__kprobes attribute functions are stored in .kprobes.text section.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200505134059.678201813@linutronix.de
| -rw-r--r-- | include/linux/module.h | 4 | ||||
| -rw-r--r-- | kernel/kprobes.c | 42 | ||||
| -rw-r--r-- | kernel/module.c | 4 |
3 files changed, 50 insertions, 0 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index 1ad393e62bef..369c354f9207 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -489,6 +489,10 @@ struct module { unsigned int num_ftrace_callsites; unsigned long *ftrace_callsites; #endif +#ifdef CONFIG_KPROBES + void *kprobes_text_start; + unsigned int kprobes_text_size; +#endif #ifdef CONFIG_LIVEPATCH bool klp; /* Is this a livepatch module? */ diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 570d60827656..b7549992b9bd 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2179,6 +2179,19 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) return 0; } +/* Remove all symbols in given area from kprobe blacklist */ +static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) +{ + struct kprobe_blacklist_entry *ent, *n; + + list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) { + if (ent->start_addr < start || ent->start_addr >= end) + continue; + list_del(&ent->list); + kfree(ent); + } +} + int __init __weak arch_populate_kprobe_blacklist(void) { return 0; @@ -2215,6 +2228,28 @@ static int __init populate_kprobe_blacklist(unsigned long *start, return ret ? : arch_populate_kprobe_blacklist(); } +static void add_module_kprobe_blacklist(struct module *mod) +{ + unsigned long start, end; + + start = (unsigned long)mod->kprobes_text_start; + if (start) { + end = start + mod->kprobes_text_size; + kprobe_add_area_blacklist(start, end); + } +} + +static void remove_module_kprobe_blacklist(struct module *mod) +{ + unsigned long start, end; + + start = (unsigned long)mod->kprobes_text_start; + if (start) { + end = start + mod->kprobes_text_size; + kprobe_remove_area_blacklist(start, end); + } +} + /* Module notifier call back, checking kprobes on the module */ static int kprobes_module_callback(struct notifier_block *nb, unsigned long val, void *data) @@ -2225,6 +2260,11 @@ static int kprobes_module_callback(struct notifier_block *nb, unsigned int i; int checkcore = (val == MODULE_STATE_GOING); + if (val == MODULE_STATE_COMING) { + mutex_lock(&kprobe_mutex); + add_module_kprobe_blacklist(mod); + mutex_unlock(&kprobe_mutex); + } if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE) return NOTIFY_DONE; @@ -2255,6 +2295,8 @@ static int kprobes_module_callback(struct notifier_block *nb, kill_kprobe(p); } } + if (val == MODULE_STATE_GOING) + remove_module_kprobe_blacklist(mod); mutex_unlock(&kprobe_mutex); return NOTIFY_DONE; } diff --git a/kernel/module.c b/kernel/module.c index 646f1e2330d2..978f3fa40850 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3194,6 +3194,10 @@ static int find_module_sections(struct module *mod, struct load_info *info) sizeof(*mod->ei_funcs), &mod->num_ei_funcs); #endif +#ifdef CONFIG_KPROBES + mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1, + &mod->kprobes_text_size); +#endif mod->extable = section_objs(info, "__ex_table", sizeof(*mod->extable), &mod->num_exentries); |