kprobes: Prevent probes in .noinstr.text section

Instrumentation is forbidden in the .noinstr.text section. Make kprobes
respect this.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200505134100.179862032@linutronix.de

diff --git a/include/linux/module.h b/include/linux/module.h
index 1192097..d849d06 100644 (file)
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -458,6 +458,8 @@ struct module {
        void __percpu *percpu;
        unsigned int percpu_size;
 #endif
+       void *noinstr_text_start;
+       unsigned int noinstr_text_size;
 
 #ifdef CONFIG_TRACEPOINTS
        unsigned int num_tracepoints;

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 9eb5acf..3f310df 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2229,6 +2229,12 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
        /* Symbols in __kprobes_text are blacklisted */
        ret = kprobe_add_area_blacklist((unsigned long)__kprobes_text_start,
                                        (unsigned long)__kprobes_text_end);
+       if (ret)
+               return ret;
+
+       /* Symbols in noinstr section are blacklisted */
+       ret = kprobe_add_area_blacklist((unsigned long)__noinstr_text_start,
+                                       (unsigned long)__noinstr_text_end);
 
        return ret ? : arch_populate_kprobe_blacklist();
 }
@@ -2248,6 +2254,12 @@ static void add_module_kprobe_blacklist(struct module *mod)
                end = start + mod->kprobes_text_size;
                kprobe_add_area_blacklist(start, end);
        }
+
+       start = (unsigned long)mod->noinstr_text_start;
+       if (start) {
+               end = start + mod->noinstr_text_size;
+               kprobe_add_area_blacklist(start, end);
+       }
 }
 
 static void remove_module_kprobe_blacklist(struct module *mod)
@@ -2265,6 +2277,12 @@ static void remove_module_kprobe_blacklist(struct module *mod)
                end = start + mod->kprobes_text_size;
                kprobe_remove_area_blacklist(start, end);
        }
+
+       start = (unsigned long)mod->noinstr_text_start;
+       if (start) {
+               end = start + mod->noinstr_text_size;
+               kprobe_remove_area_blacklist(start, end);
+       }
 }
 
 /* Module notifier call back, checking kprobes on the module */

diff --git a/kernel/module.c b/kernel/module.c
index faf7337..72ed2b3 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3150,6 +3150,9 @@ static int find_module_sections(struct module *mod, struct load_info *info)
        }
 #endif
 
+       mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
+                                               &mod->noinstr_text_size);
+
 #ifdef CONFIG_TRACEPOINTS
        mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
                                             sizeof(*mod->tracepoints_ptrs),