um: resurrect the right variant of mconsole_proc()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-08-19 13:00:49 -04:00
parent 483ce1d4b8
commit 723a1d7743

View File

@ -21,6 +21,9 @@
#include <linux/un.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/file.h>
#include <asm/uaccess.h>
#include <asm/switch_to.h>
@ -118,18 +121,14 @@ void mconsole_log(struct mc_request *req)
mconsole_reply(req, "", 0, 0);
}
/* This is a more convoluted version of mconsole_proc, which has some stability
* problems; however, we need it fixed, because it is expected that UML users
* mount HPPFS instead of procfs on /proc. And we want mconsole_proc to still
* show the real procfs content, not the ones from hppfs.*/
#if 0
void mconsole_proc(struct mc_request *req)
{
struct vfsmount *mnt = current->nsproxy->pid_ns->proc_mnt;
char *buf;
int len;
struct file *file;
int n;
char *ptr = req->request.data, *buf;
mm_segment_t old_fs = get_fs();
int first_chunk = 1;
char *ptr = req->request.data;
ptr += strlen("proc");
ptr = skip_spaces(ptr);
@ -137,6 +136,7 @@ void mconsole_proc(struct mc_request *req)
file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY);
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));
goto out;
}
@ -146,62 +146,13 @@ void mconsole_proc(struct mc_request *req)
goto out_fput;
}
if (file->f_op->read) {
do {
loff_t pos;
set_fs(KERNEL_DS);
n = vfs_read(file, buf, PAGE_SIZE - 1, &pos);
file_pos_write(file, pos);
set_fs(old_fs);
if (n >= 0) {
buf[n] = '\0';
mconsole_reply(req, buf, 0, (n > 0));
}
else {
mconsole_reply(req, "Read of file failed",
1, 0);
goto out_free;
}
} while (n > 0);
}
else mconsole_reply(req, "", 0, 0);
out_free:
kfree(buf);
out_fput:
fput(file);
out: ;
}
#endif
void mconsole_proc(struct mc_request *req)
{
char path[64];
char *buf;
int len;
int fd;
int first_chunk = 1;
char *ptr = req->request.data;
ptr += strlen("proc");
ptr = skip_spaces(ptr);
snprintf(path, sizeof(path), "/proc/%s", ptr);
fd = sys_open(path, 0, 0);
if (fd < 0) {
mconsole_reply(req, "Failed to open file", 1, 0);
printk(KERN_ERR "open %s: %d\n",path,fd);
goto out;
}
buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (buf == NULL) {
mconsole_reply(req, "Failed to allocate buffer", 1, 0);
goto out_close;
}
for (;;) {
len = sys_read(fd, buf, PAGE_SIZE-1);
do {
loff_t 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;
if (len < 0) {
mconsole_reply(req, "Read of file failed", 1, 0);
goto out_free;
@ -211,22 +162,14 @@ void mconsole_proc(struct mc_request *req)
mconsole_reply(req, "\n", 0, 1);
first_chunk = 0;
}
if (len == PAGE_SIZE-1) {
buf[len] = '\0';
mconsole_reply(req, buf, 0, 1);
} else {
buf[len] = '\0';
mconsole_reply(req, buf, 0, 0);
break;
}
}
buf[len] = '\0';
mconsole_reply(req, buf, 0, (len > 0));
} while (len > 0);
out_free:
kfree(buf);
out_close:
sys_close(fd);
out:
/* nothing */;
out_fput:
fput(file);
out: ;
}
#define UML_MCONSOLE_HELPTEXT \