[tip: core/kprobes] kprobes: Support NOKPROBE_SYMBOL() in modules

tip-bot2 for Masami Hiramatsu
2020-05-12T15:19:03Z

The following commit has been merged into the core/kprobes branch of tip:

Commit-ID: 16db6264c93d2d7df9eb8be5d9eb717ab30105fe
Gitweb: https://git.kernel.org/tip/16db6264c93d2d7df9eb8be5d9eb717ab30105fe
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Thu, 26 Mar 2020 23:50:00 +09:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 12 May 2020 17:15:32 +02:00

kprobes: Support NOKPROBE_SYMBOL() in modules

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>
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/20200505134059.771170126@linutronix.de

---
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 369c354..1192097 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 b754999..9eb5acf 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 978f3fa..faf7337 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);