Separate init_kprobes() into early and late phases, and do most of
initialization after setup_arch(), so we are able to use kprobes at
very early stage.
Signed-off-by: Wang Nan <wangn...@huawei.com>
---
include/linux/kprobes.h | 6 ++++++
init/main.c | 2 ++
kernel/kprobes.c | 39 ++++++++++++++++++++++++++-------------
3 files changed, 34 insertions(+), 13 deletions(-)
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index a3de759..b7cb992 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -491,8 +491,14 @@ static unsigned long __used
\
__attribute__((section("_kprobe_blacklist"))) \
_kbl_addr_##fname = (unsigned long)fname;
#define NOKPROBE_SYMBOL(fname) __NOKPROBE_SYMBOL(fname)
+
+extern void init_kprobes_early(void);
+
#else
#define NOKPROBE_SYMBOL(fname)
+
+static inline void init_kprobes_early(void) { return; }
+
#endif
#endif /* _LINUX_KPROBES_H */
diff --git a/init/main.c b/init/main.c
index 6f0f1c5f..679d49e 100644
--- a/init/main.c
+++ b/init/main.c
@@ -80,6 +80,7 @@
#include <linux/list.h>
#include <linux/integrity.h>
#include <linux/proc_ns.h>
+#include <linux/kprobes.h>
#include <asm/io.h>
#include <asm/bugs.h>
@@ -518,6 +519,7 @@ asmlinkage __visible void __init start_kernel(void)
page_address_init();
pr_notice("%s", linux_banner);
setup_arch(&command_line);
+ init_kprobes_early();
mm_init_cpumask(&init_mm);
setup_command_line(command_line);
setup_nr_cpu_ids();
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 2e728a4..614138c 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1521,6 +1521,11 @@ int register_kprobe(struct kprobe *p)
struct module *probed_mod;
kprobe_opcode_t *addr;
+#ifndef CONFIG_EARLY_KPROBES
+ if (kprobes_is_early())
+ return -EAGAIN;
+#endif
+
/* Adjust probe address from symbol */
addr = kprobe_addr(p);
if (IS_ERR(addr))
@@ -2161,11 +2166,7 @@ static struct notifier_block kprobe_module_nb = {
.priority = 0
};
-/* Markers of _kprobe_blacklist section */
-extern unsigned long __start_kprobe_blacklist[];
-extern unsigned long __stop_kprobe_blacklist[];
-
-static int __init init_kprobes(void)
+void init_kprobes_early(void)
{
int i, err = 0;
@@ -2177,14 +2178,6 @@ static int __init init_kprobes(void)
raw_spin_lock_init(&(kretprobe_table_locks[i].lock));
}
- err = populate_kprobe_blacklist(__start_kprobe_blacklist,
- __stop_kprobe_blacklist);
- if (err) {
- pr_err("kprobes: failed to populate blacklist: %d\n", err);
- pr_err("Please take care of using kprobes.\n");
- }
- kprobes_blacklist_initialized = (err == 0);
-
if (kretprobe_blacklist_size) {
/* lookup the function address from its name */
for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
@@ -2215,6 +2208,26 @@ static int __init init_kprobes(void)
err = register_module_notifier(&kprobe_module_nb);
kprobes_initialized = (err == 0);
+}
+
+static int __init init_kprobes(void)
+{
+ /* Markers of _kprobe_blacklist section */
+ extern unsigned long __start_kprobe_blacklist[];
+ extern unsigned long __stop_kprobe_blacklist[];
+ int err = 0;
+
+ err = populate_kprobe_blacklist(__start_kprobe_blacklist,
+ __stop_kprobe_blacklist);
+ if (err) {
+ pr_err("kprobes: failed to populate blacklist: %d\n", err);
+ pr_err("Please take care of using kprobes.\n");
+ }
+ kprobes_blacklist_initialized = (err == 0);
+
+ err = kprobes_is_early() ? -ENOSYS : 0;
+
+ /* TODO: deal with early kprobes. */
if (!err)
init_test_probes();
--
1.8.4
--
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