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Subject[PATCH -tip 3/4] kprobes: Support NOKPROBE_SYMBOL() in modules
Date
Support NOKPROBE_SYMBOL() in modules. NOKPROBE_SYMBOL() records
only symbol address in "_kprobe_blacklist" section in the
module.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
include/linux/module.h | 2 ++
kernel/kprobes.c | 17 +++++++++++++++++
kernel/module.c | 3 +++
3 files changed, 22 insertions(+)

diff --git a/include/linux/module.h b/include/linux/module.h
index 369c354f9207..1192097c9a69 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -492,6 +492,8 @@ struct module {
#ifdef CONFIG_KPROBES
void *kprobes_text_start;
unsigned int kprobes_text_size;
+ unsigned long *kprobe_blacklist;
+ unsigned int num_kprobe_blacklist;
#endif

#ifdef CONFIG_LIVEPATCH
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index b7549992b9bd..9eb5acf0a9f3 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2192,6 +2192,11 @@ static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end)
}
}

+static void kprobe_remove_ksym_blacklist(unsigned long entry)
+{
+ kprobe_remove_area_blacklist(entry, entry + 1);
+}
+
int __init __weak arch_populate_kprobe_blacklist(void)
{
return 0;
@@ -2231,6 +2236,12 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
static void add_module_kprobe_blacklist(struct module *mod)
{
unsigned long start, end;
+ int i;
+
+ if (mod->kprobe_blacklist) {
+ for (i = 0; i < mod->num_kprobe_blacklist; i++)
+ kprobe_add_ksym_blacklist(mod->kprobe_blacklist[i]);
+ }

start = (unsigned long)mod->kprobes_text_start;
if (start) {
@@ -2242,6 +2253,12 @@ static void add_module_kprobe_blacklist(struct module *mod)
static void remove_module_kprobe_blacklist(struct module *mod)
{
unsigned long start, end;
+ int i;
+
+ if (mod->kprobe_blacklist) {
+ for (i = 0; i < mod->num_kprobe_blacklist; i++)
+ kprobe_remove_ksym_blacklist(mod->kprobe_blacklist[i]);
+ }

start = (unsigned long)mod->kprobes_text_start;
if (start) {
diff --git a/kernel/module.c b/kernel/module.c
index f7712a923d63..7be011dacd8a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3197,6 +3197,9 @@ static int find_module_sections(struct module *mod, struct load_info *info)
#ifdef CONFIG_KPROBES
mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
&mod->kprobes_text_size);
+ mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
+ sizeof(unsigned long),
+ &mod->num_kprobe_blacklist);
#endif
mod->extable = section_objs(info, "__ex_table",
sizeof(*mod->extable), &mod->num_exentries);
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