Use kprobe_blackpoint for blacklisting .entry.text and .kprobees.text
instead of arch_within_kprobe_blacklist. This also makes them visible
via (debugfs)/kprobes/blacklist.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Ananth N Mavinakayanahalli <ana...@in.ibm.com>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Andrew Morton <a...@linux-foundation.org>
---
 arch/x86/kernel/kprobes/core.c |   11 +------
 include/linux/kprobes.h        |    1 +
 kernel/kprobes.c               |   64 ++++++++++++++++++++++++++++------------
 3 files changed, 48 insertions(+), 28 deletions(-)

diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index d00103a..4767fda 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -1065,17 +1065,10 @@ int longjmp_break_handler(struct kprobe *p, struct 
pt_regs *regs)
 }
 NOKPROBE_SYMBOL(longjmp_break_handler);
 
-bool arch_within_kprobe_blacklist(unsigned long addr)
-{
-       return  (addr >= (unsigned long)__kprobes_text_start &&
-                addr < (unsigned long)__kprobes_text_end) ||
-               (addr >= (unsigned long)__entry_text_start &&
-                addr < (unsigned long)__entry_text_end);
-}
-
 int __init arch_init_kprobes(void)
 {
-       return 0;
+       return kprobe_blacklist_add_range((unsigned long)__entry_text_start,
+                                         (unsigned long) __entry_text_end);
 }
 
 int arch_trampoline_kprobe(struct kprobe *p)
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index e059507..e81bced 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -266,6 +266,7 @@ extern int arch_init_kprobes(void);
 extern void show_registers(struct pt_regs *regs);
 extern void kprobes_inc_nmissed_count(struct kprobe *p);
 extern bool arch_within_kprobe_blacklist(unsigned long addr);
+extern int kprobe_blacklist_add_range(unsigned long start, unsigned long end);
 
 struct kprobe_insn_cache {
        struct mutex mutex;
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 8319048..abdede5 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1325,13 +1325,6 @@ out:
        return ret;
 }
 
-bool __weak arch_within_kprobe_blacklist(unsigned long addr)
-{
-       /* The __kprobes marked functions and entry code must not be probed */
-       return addr >= (unsigned long)__kprobes_text_start &&
-              addr < (unsigned long)__kprobes_text_end;
-}
-
 static struct kprobe_blacklist_entry *find_blacklist_entry(unsigned long addr)
 {
        struct kprobe_blacklist_entry *ent;
@@ -1346,8 +1339,6 @@ static struct kprobe_blacklist_entry 
*find_blacklist_entry(unsigned long addr)
 
 static bool within_kprobe_blacklist(unsigned long addr)
 {
-       if (arch_within_kprobe_blacklist(addr))
-               return true;
        /*
         * If there exists a kprobe_blacklist, verify and
         * fail any probe registration in the prohibited area
@@ -2032,6 +2023,40 @@ void dump_kprobe(struct kprobe *kp)
 }
 NOKPROBE_SYMBOL(dump_kprobe);
 
+static int __kprobe_blacklist_add(unsigned long start, unsigned long end)
+{
+       struct kprobe_blacklist_entry *ent;
+
+       ent = kmalloc(sizeof(*ent), GFP_KERNEL);
+       if (!ent)
+               return -ENOMEM;
+
+       ent->start_addr = start;
+       ent->end_addr = end;
+       INIT_LIST_HEAD(&ent->list);
+       list_add_tail(&ent->list, &kprobe_blacklist);
+       return 0;
+}
+
+int kprobe_blacklist_add_range(unsigned long start, unsigned long end)
+{
+       unsigned long offset = 0, size = 0;
+       int err = 0;
+
+       mutex_lock(&kprobe_blacklist_mutex);
+       while (!err && start < end) {
+               if (!kallsyms_lookup_size_offset(start, &size, &offset) ||
+                   size == 0) {
+                       err = -ENOENT;
+                       break;
+               }
+               err = __kprobe_blacklist_add(start, start + size);
+               start += size;
+       }
+       mutex_unlock(&kprobe_blacklist_mutex);
+       return err;
+}
+
 /*
  * Lookup and populate the kprobe_blacklist.
  *
@@ -2043,8 +2068,8 @@ NOKPROBE_SYMBOL(dump_kprobe);
 static int populate_kprobe_blacklist(unsigned long *start, unsigned long *end)
 {
        unsigned long *iter;
-       struct kprobe_blacklist_entry *ent;
        unsigned long offset = 0, size = 0;
+       int ret;
 
        mutex_lock(&kprobe_blacklist_mutex);
        for (iter = start; iter < end; iter++) {
@@ -2052,14 +2077,7 @@ static int populate_kprobe_blacklist(unsigned long 
*start, unsigned long *end)
                        pr_err("Failed to find blacklist %p\n", (void *)*iter);
                        continue;
                }
-
-               ent = kmalloc(sizeof(*ent), GFP_KERNEL);
-               if (!ent)
-                       return -ENOMEM;
-               ent->start_addr = *iter;
-               ent->end_addr = *iter + size;
-               INIT_LIST_HEAD(&ent->list);
-               list_add_tail(&ent->list, &kprobe_blacklist);
+               ret = __kprobe_blacklist_add(*iter, *iter + size);
        }
        mutex_unlock(&kprobe_blacklist_mutex);
 
@@ -2154,7 +2172,15 @@ static int __init init_kprobes(void)
 
        err = populate_kprobe_blacklist(__start_kprobe_blacklist,
                                        __stop_kprobe_blacklist);
-       if (err) {
+
+       if (err >= 0 && __kprobes_text_start != __kprobes_text_end) {
+               /* The __kprobes marked functions must not be probed */
+               err = kprobe_blacklist_add_range(
+                                       (unsigned long)__kprobes_text_start,
+                                       (unsigned long)__kprobes_text_end);
+       }
+
+       if (err < 0) {
                pr_err("kprobes: failed to populate blacklist: %d\n", err);
                pr_err("Please take care of using kprobes.\n");
        }


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