aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/kernel/module/kmod.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--kernel/module/kmod.c (renamed from kernel/kmod.c)49
1 files changed, 26 insertions, 23 deletions
diff --git a/kernel/kmod.c b/kernel/module/kmod.c
index b717134ebe17..0800d9891692 100644
--- a/kernel/kmod.c
+++ b/kernel/module/kmod.c
@@ -1,6 +1,9 @@
/*
* kmod - the kernel module loader
+ *
+ * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
*/
+
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sched/task.h>
@@ -27,6 +30,7 @@
#include <linux/uaccess.h>
#include <trace/events/module.h>
+#include "internal.h"
/*
* Assuming:
@@ -40,8 +44,7 @@
* effect. Systems like these are very unlikely if modules are enabled.
*/
#define MAX_KMOD_CONCURRENT 50
-static atomic_t kmod_concurrent_max = ATOMIC_INIT(MAX_KMOD_CONCURRENT);
-static DECLARE_WAIT_QUEUE_HEAD(kmod_wq);
+static DEFINE_SEMAPHORE(kmod_concurrent_max, MAX_KMOD_CONCURRENT);
/*
* This is a restriction on having *all* MAX_KMOD_CONCURRENT threads
@@ -66,7 +69,7 @@ static void free_modprobe_argv(struct subprocess_info *info)
kfree(info->argv);
}
-static int call_modprobe(char *module_name, int wait)
+static int call_modprobe(char *orig_module_name, int wait)
{
struct subprocess_info *info;
static char *envp[] = {
@@ -75,12 +78,14 @@ static int call_modprobe(char *module_name, int wait)
"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
NULL
};
+ char *module_name;
+ int ret;
char **argv = kmalloc(sizeof(char *[5]), GFP_KERNEL);
if (!argv)
goto out;
- module_name = kstrdup(module_name, GFP_KERNEL);
+ module_name = kstrdup(orig_module_name, GFP_KERNEL);
if (!module_name)
goto free_argv;
@@ -95,13 +100,16 @@ static int call_modprobe(char *module_name, int wait)
if (!info)
goto free_module_name;
- return call_usermodehelper_exec(info, wait | UMH_KILLABLE);
+ ret = call_usermodehelper_exec(info, wait | UMH_KILLABLE);
+ kmod_dup_request_announce(orig_module_name, ret);
+ return ret;
free_module_name:
kfree(module_name);
free_argv:
kfree(argv);
out:
+ kmod_dup_request_announce(orig_module_name, -ENOMEM);
return -ENOMEM;
}
@@ -125,7 +133,7 @@ int __request_module(bool wait, const char *fmt, ...)
{
va_list args;
char module_name[MODULE_NAME_LEN];
- int ret;
+ int ret, dup_ret;
/*
* We don't allow synchronous module loading from async. Module
@@ -148,29 +156,24 @@ int __request_module(bool wait, const char *fmt, ...)
if (ret)
return ret;
- if (atomic_dec_if_positive(&kmod_concurrent_max) < 0) {
- pr_warn_ratelimited("request_module: kmod_concurrent_max (%u) close to 0 (max_modprobes: %u), for module %s, throttling...",
- atomic_read(&kmod_concurrent_max),
- MAX_KMOD_CONCURRENT, module_name);
- ret = wait_event_killable_timeout(kmod_wq,
- atomic_dec_if_positive(&kmod_concurrent_max) >= 0,
- MAX_KMOD_ALL_BUSY_TIMEOUT * HZ);
- if (!ret) {
- pr_warn_ratelimited("request_module: modprobe %s cannot be processed, kmod busy with %d threads for more than %d seconds now",
- module_name, MAX_KMOD_CONCURRENT, MAX_KMOD_ALL_BUSY_TIMEOUT);
- return -ETIME;
- } else if (ret == -ERESTARTSYS) {
- pr_warn_ratelimited("request_module: sigkill sent for modprobe %s, giving up", module_name);
- return ret;
- }
+ ret = down_timeout(&kmod_concurrent_max, MAX_KMOD_ALL_BUSY_TIMEOUT * HZ);
+ if (ret) {
+ pr_warn_ratelimited("request_module: modprobe %s cannot be processed, kmod busy with %d threads for more than %d seconds now",
+ module_name, MAX_KMOD_CONCURRENT, MAX_KMOD_ALL_BUSY_TIMEOUT);
+ return ret;
}
trace_module_request(module_name, wait, _RET_IP_);
+ if (kmod_dup_request_exists_wait(module_name, wait, &dup_ret)) {
+ ret = dup_ret;
+ goto out;
+ }
+
ret = call_modprobe(module_name, wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
- atomic_inc(&kmod_concurrent_max);
- wake_up(&kmod_wq);
+out:
+ up(&kmod_concurrent_max);
return ret;
}