Remove CONFIG_MODULES dependency by flagging out the dependent code. This
allows to use kprobes in a kernel without support for loadable modules,
which is an useful feature for test kernels and embedded kernels.
Cc: linux-mm@xxxxxxxxx
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
arch/Kconfig | 2 +-
include/linux/module.h | 14 +++++------
kernel/kprobes.c | 48 +++++++++++++++++++++++--------------
kernel/trace/trace_kprobe.c | 16 +++++++++++--
4 files changed, 52 insertions(+), 28 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 8cc35dc556c7..e3d6b6868ccb 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -61,7 +61,7 @@ config OPROFILE_NMI_TIMER
config KPROBES
bool "Kprobes"
- depends on MODULES
+ depends on MODULES || ARCH_HAS_TEXT_ALLOC
depends on HAVE_KPROBES
select KALLSYMS
help
diff --git a/include/linux/module.h b/include/linux/module.h
index 8850b9692b8f..22c646cff6bd 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -290,6 +290,13 @@ extern typeof(name) __mod_##type##__##name##_device_table \
struct notifier_block;
+enum module_state {
+ MODULE_STATE_LIVE, /* Normal state. */
+ MODULE_STATE_COMING, /* Full formed, running module_init. */
+ MODULE_STATE_GOING, /* Going away. */
+ MODULE_STATE_UNFORMED, /* Still setting it up. */
+};
+
#ifdef CONFIG_MODULES
extern int modules_disabled; /* for sysctl */
@@ -305,13 +312,6 @@ struct module_use {
struct module *source, *target;
};
-enum module_state {
- MODULE_STATE_LIVE, /* Normal state. */
- MODULE_STATE_COMING, /* Full formed, running module_init. */
- MODULE_STATE_GOING, /* Going away. */
- MODULE_STATE_UNFORMED, /* Still setting it up. */
-};
-
struct mod_tree_node {
struct module *mod;
struct latch_tree_node node;
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 611fcda9f6bf..bb2e3070481a 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1617,6 +1617,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
goto out;
}
+#ifdef CONFIG_MODULES
/*
* If the module freed .init.text, we couldn't insert
* kprobes in there.
@@ -1627,6 +1628,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
*probed_mod = NULL;
ret = -ENOENT;
}
+#endif
}
out:
preempt_enable();
@@ -2223,24 +2225,6 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end)
return 0;
}
-/* Remove all symbols in given area from kprobe blacklist */
-static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end)
-{
- struct kprobe_blacklist_entry *ent, *n;
-
- list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) {
- if (ent->start_addr < start || ent->start_addr >= end)
- continue;
- list_del(&ent->list);
- kfree(ent);
- }
-}
-
-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;
@@ -2283,6 +2267,25 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
return ret ? : arch_populate_kprobe_blacklist();
}
+#ifdef CONFIG_MODULES
+/* Remove all symbols in given area from kprobe blacklist */
+static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end)
+{
+ struct kprobe_blacklist_entry *ent, *n;
+
+ list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) {
+ if (ent->start_addr < start || ent->start_addr >= end)
+ continue;
+ list_del(&ent->list);
+ kfree(ent);
+ }
+}
+
+static void kprobe_remove_ksym_blacklist(unsigned long entry)
+{
+ kprobe_remove_area_blacklist(entry, entry + 1);
+}
+
static void add_module_kprobe_blacklist(struct module *mod)
{
unsigned long start, end;
@@ -2328,6 +2331,15 @@ static void remove_module_kprobe_blacklist(struct module *mod)
kprobe_remove_area_blacklist(start, end);
}
}
+#else
+static void add_module_kprobe_blacklist(struct module *mod)
+{
+}
+
+static void remove_module_kprobe_blacklist(struct module *mod)
+{
+}
+#endif /* CONFIG_MODULES */
/* Module notifier call back, checking kprobes on the module */
static int kprobes_module_callback(struct notifier_block *nb,
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 710ec6a6aa8f..881c998d0162 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -103,8 +103,9 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
return !!(kprobe_gone(&tk->rp.kp));
}
+#ifdef CONFIG_MODULES
static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
- struct module *mod)
+ struct module *mod)
{
int len = strlen(mod->name);
const char *name = trace_kprobe_symbol(tk);
@@ -129,6 +130,17 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
return ret;
}
+#else
+static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
+ struct module *mod)
+{
+ return false;
+}
+static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
+{
+ return false;
+}
+#endif
static bool trace_kprobe_is_busy(struct dyn_event *ev)
{
@@ -688,7 +700,7 @@ static int trace_kprobe_module_callback(struct notifier_block *nb,
if (ret)
pr_warn("Failed to re-register probe %s on %s: %d\n",
trace_probe_name(&tk->tp),
- mod->name, ret);
+ module_name(mod), ret);
}
}
mutex_unlock(&event_mutex);
--
2.25.1
