On 5/5/20 3:16 PM, Thomas Gleixner wrote:
From: Masami Hiramatsu <mhira...@kernel.org>

Support NOKPROBE_SYMBOL() in modules. NOKPROBE_SYMBOL() records only symbol
address in "_kprobe_blacklist" section in the module.

Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Link: 
https://lkml.kernel.org/r/158523419989.24735.6665260504057165207.stgit@devnote2

---
  include/linux/module.h |    2 ++
  kernel/kprobes.c       |   17 +++++++++++++++++
  kernel/module.c        |    3 +++
  3 files changed, 22 insertions(+)

Reviewed-by: Alexandre Chartre <alexandre.char...@oracle.com>

alex.

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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