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Diffstat (limited to 'arch/um/drivers/mconsole_kern.c')
-rw-r--r--arch/um/drivers/mconsole_kern.c93
1 files changed, 52 insertions, 41 deletions
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 3df3bd544492..ff4bda95b9c7 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -1,7 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
* Copyright (C) 2001 - 2008 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
*/
#include <linux/console.h>
@@ -12,7 +12,9 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/notifier.h>
+#include <linux/panic_notifier.h>
#include <linux/reboot.h>
+#include <linux/sched/debug.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
@@ -24,7 +26,7 @@
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/file.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include <asm/switch_to.h>
#include <init.h>
@@ -35,6 +37,8 @@
#include "mconsole_kern.h"
#include <os.h>
+static struct vfsmount *proc_mnt = NULL;
+
static int do_unlink_socket(struct notifier_block *notifier,
unsigned long what, void *data)
{
@@ -95,7 +99,6 @@ static irqreturn_t mconsole_interrupt(int irq, void *dev_id)
}
if (!list_empty(&mc_requests))
schedule_work(&mconsole_work);
- reactivate_fd(fd, MCONSOLE_IRQ);
return IRQ_HANDLED;
}
@@ -123,17 +126,22 @@ void mconsole_log(struct mc_request *req)
void mconsole_proc(struct mc_request *req)
{
- struct vfsmount *mnt = task_active_pid_ns(current)->proc_mnt;
+ struct vfsmount *mnt = proc_mnt;
char *buf;
int len;
struct file *file;
int first_chunk = 1;
char *ptr = req->request.data;
+ loff_t pos = 0;
ptr += strlen("proc");
ptr = skip_spaces(ptr);
- file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY);
+ if (!mnt) {
+ mconsole_reply(req, "Proc not available", 1, 0);
+ goto out;
+ }
+ file = file_open_root_mnt(mnt, ptr, O_RDONLY, 0);
if (IS_ERR(file)) {
mconsole_reply(req, "Failed to open file", 1, 0);
printk(KERN_ERR "open /proc/%s: %ld\n", ptr, PTR_ERR(file));
@@ -147,12 +155,7 @@ void mconsole_proc(struct mc_request *req)
}
do {
- loff_t pos = file->f_pos;
- mm_segment_t old_fs = get_fs();
- set_fs(KERNEL_DS);
- len = vfs_read(file, buf, PAGE_SIZE - 1, &pos);
- set_fs(old_fs);
- file->f_pos = pos;
+ len = kernel_read(file, buf, PAGE_SIZE - 1, &pos);
if (len < 0) {
mconsole_reply(req, "Read of file failed", 1, 0);
goto out_free;
@@ -221,7 +224,7 @@ void mconsole_go(struct mc_request *req)
void mconsole_stop(struct mc_request *req)
{
- deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
+ block_signals();
os_set_fd_block(req->originating_fd, 1);
mconsole_reply(req, "stopped", 0, 0);
for (;;) {
@@ -243,8 +246,8 @@ void mconsole_stop(struct mc_request *req)
(*req->cmd->handler)(req);
}
os_set_fd_block(req->originating_fd, 0);
- reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
mconsole_reply(req, "", 0, 0);
+ unblock_signals();
}
static DEFINE_SPINLOCK(mc_devices_lock);
@@ -280,7 +283,7 @@ struct unplugged_pages {
};
static DEFINE_MUTEX(plug_mem_mutex);
-static unsigned long long unplugged_pages_count = 0;
+static unsigned long long unplugged_pages_count;
static LIST_HEAD(unplugged_pages);
static int unplug_index = UNPLUGGED_PER_PAGE;
@@ -551,7 +554,7 @@ struct mconsole_output {
static DEFINE_SPINLOCK(client_lock);
static LIST_HEAD(clients);
-static char console_buf[MCONSOLE_MAX_DATA];
+static char console_buf[MCONSOLE_MAX_DATA] __nonstring;
static void console_write(struct console *console, const char *string,
unsigned int len)
@@ -564,7 +567,7 @@ static void console_write(struct console *console, const char *string,
while (len > 0) {
n = min((size_t) len, ARRAY_SIZE(console_buf));
- strncpy(console_buf, string, n);
+ memcpy(console_buf, string, n);
string += n;
len -= n;
@@ -645,11 +648,9 @@ void mconsole_sysrq(struct mc_request *req)
static void stack_proc(void *arg)
{
- struct task_struct *from = current, *to = arg;
+ struct task_struct *task = arg;
- to->thread.saved_task = from;
- rcu_user_hooks_switch(from, to);
- switch_to(from, to, from);
+ show_stack(task, NULL, KERN_INFO);
}
/*
@@ -690,6 +691,24 @@ void mconsole_stack(struct mc_request *req)
with_console(req, stack_proc, to);
}
+static int __init mount_proc(void)
+{
+ struct file_system_type *proc_fs_type;
+ struct vfsmount *mnt;
+
+ proc_fs_type = get_fs_type("proc");
+ if (!proc_fs_type)
+ return -ENODEV;
+
+ mnt = kern_mount(proc_fs_type);
+ put_filesystem(proc_fs_type);
+ if (IS_ERR(mnt))
+ return PTR_ERR(mnt);
+
+ proc_mnt = mnt;
+ return 0;
+}
+
/*
* Changed by mconsole_setup, which is __setup, and called before SMP is
* active.
@@ -703,6 +722,8 @@ static int __init mconsole_init(void)
int err;
char file[UNIX_PATH_MAX];
+ mount_proc();
+
if (umid_file_name("mconsole", file, sizeof(file)))
return -1;
snprintf(mconsole_socket_name, sizeof(file), "%s", file);
@@ -719,7 +740,7 @@ static int __init mconsole_init(void)
err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
IRQF_SHARED, "mconsole", (void *)sock);
- if (err) {
+ if (err < 0) {
printk(KERN_ERR "Failed to get IRQ for management console\n");
goto out;
}
@@ -750,27 +771,18 @@ static ssize_t mconsole_proc_write(struct file *file,
{
char *buf;
- buf = kmalloc(count + 1, GFP_KERNEL);
- if (buf == NULL)
- return -ENOMEM;
-
- if (copy_from_user(buf, buffer, count)) {
- count = -EFAULT;
- goto out;
- }
-
- buf[count] = '\0';
+ buf = memdup_user_nul(buffer, count);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
mconsole_notify(notify_socket, MCONSOLE_USER_NOTIFY, buf, count);
- out:
kfree(buf);
return count;
}
-static const struct file_operations mconsole_proc_fops = {
- .owner = THIS_MODULE,
- .write = mconsole_proc_write,
- .llseek = noop_llseek,
+static const struct proc_ops mconsole_proc_ops = {
+ .proc_write = mconsole_proc_write,
+ .proc_lseek = noop_llseek,
};
static int create_proc_mconsole(void)
@@ -780,7 +792,7 @@ static int create_proc_mconsole(void)
if (notify_socket == NULL)
return 0;
- ent = proc_create("mconsole", 0200, NULL, &mconsole_proc_fops);
+ ent = proc_create("mconsole", 0200, NULL, &mconsole_proc_ops);
if (ent == NULL) {
printk(KERN_INFO "create_proc_mconsole : proc_create failed\n");
return 0;
@@ -834,13 +846,12 @@ static int notify_panic(struct notifier_block *self, unsigned long unused1,
mconsole_notify(notify_socket, MCONSOLE_PANIC, message,
strlen(message) + 1);
- return 0;
+ return NOTIFY_DONE;
}
static struct notifier_block panic_exit_notifier = {
- .notifier_call = notify_panic,
- .next = NULL,
- .priority = 1
+ .notifier_call = notify_panic,
+ .priority = INT_MAX, /* run as soon as possible */
};
static int add_notifier(void)
generated by cgit (git 2.34.1) at 2025-12-25 03:31:21 +0000