![Eduard-Gabriel Munteanu](/assets/img/avatar_default.png)
DEBUG_SHIRQ generates spurious interrupts, triggering handlers such as mconsole_interrupt() or line_interrupt(). They expect data to be available to be read from their sockets/pipes, but in the case of spurious interrupts, the host didn't actually send anything, so UML hangs in read() and friends. Setting those fd's as O_NONBLOCK makes DEBUG_SHIRQ-enabled UML kernels boot and run correctly. Signed-off-by: Eduard-Gabriel Munteanu <maxdamage@aladin.ro> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
234 lines
5.7 KiB
C
234 lines
5.7 KiB
C
/*
|
|
* Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
|
|
* Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com)
|
|
* Licensed under the GPL
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/types.h>
|
|
#include <sys/uio.h>
|
|
#include <sys/un.h>
|
|
#include <unistd.h>
|
|
#include "user.h"
|
|
#include "sysdep/ptrace.h"
|
|
#include "mconsole.h"
|
|
#include "os.h"
|
|
|
|
static struct mconsole_command commands[] = {
|
|
/* With uts namespaces, uts information becomes process-specific, so
|
|
* we need a process context. If we try handling this in interrupt
|
|
* context, we may hit an exiting process without a valid uts
|
|
* namespace.
|
|
*/
|
|
{ "version", mconsole_version, MCONSOLE_PROC },
|
|
{ "halt", mconsole_halt, MCONSOLE_PROC },
|
|
{ "reboot", mconsole_reboot, MCONSOLE_PROC },
|
|
{ "config", mconsole_config, MCONSOLE_PROC },
|
|
{ "remove", mconsole_remove, MCONSOLE_PROC },
|
|
{ "sysrq", mconsole_sysrq, MCONSOLE_INTR },
|
|
{ "help", mconsole_help, MCONSOLE_INTR },
|
|
{ "cad", mconsole_cad, MCONSOLE_INTR },
|
|
{ "stop", mconsole_stop, MCONSOLE_PROC },
|
|
{ "go", mconsole_go, MCONSOLE_INTR },
|
|
{ "log", mconsole_log, MCONSOLE_INTR },
|
|
{ "proc", mconsole_proc, MCONSOLE_PROC },
|
|
{ "stack", mconsole_stack, MCONSOLE_INTR },
|
|
};
|
|
|
|
/* Initialized in mconsole_init, which is an initcall */
|
|
char mconsole_socket_name[256];
|
|
|
|
int mconsole_reply_v0(struct mc_request *req, char *reply)
|
|
{
|
|
struct iovec iov;
|
|
struct msghdr msg;
|
|
|
|
iov.iov_base = reply;
|
|
iov.iov_len = strlen(reply);
|
|
|
|
msg.msg_name = &(req->origin);
|
|
msg.msg_namelen = req->originlen;
|
|
msg.msg_iov = &iov;
|
|
msg.msg_iovlen = 1;
|
|
msg.msg_control = NULL;
|
|
msg.msg_controllen = 0;
|
|
msg.msg_flags = 0;
|
|
|
|
return sendmsg(req->originating_fd, &msg, 0);
|
|
}
|
|
|
|
static struct mconsole_command *mconsole_parse(struct mc_request *req)
|
|
{
|
|
struct mconsole_command *cmd;
|
|
int i;
|
|
|
|
for(i = 0; i < ARRAY_SIZE(commands); i++){
|
|
cmd = &commands[i];
|
|
if(!strncmp(req->request.data, cmd->command,
|
|
strlen(cmd->command))){
|
|
return cmd;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
#define MIN(a,b) ((a)<(b) ? (a):(b))
|
|
|
|
#define STRINGX(x) #x
|
|
#define STRING(x) STRINGX(x)
|
|
|
|
int mconsole_get_request(int fd, struct mc_request *req)
|
|
{
|
|
int len;
|
|
|
|
req->originlen = sizeof(req->origin);
|
|
req->len = recvfrom(fd, &req->request, sizeof(req->request),
|
|
MSG_DONTWAIT, (struct sockaddr *) req->origin,
|
|
&req->originlen);
|
|
if (req->len < 0)
|
|
return 0;
|
|
|
|
req->originating_fd = fd;
|
|
|
|
if(req->request.magic != MCONSOLE_MAGIC){
|
|
/* Unversioned request */
|
|
len = MIN(sizeof(req->request.data) - 1,
|
|
strlen((char *) &req->request));
|
|
memmove(req->request.data, &req->request, len);
|
|
req->request.data[len] = '\0';
|
|
|
|
req->request.magic = MCONSOLE_MAGIC;
|
|
req->request.version = 0;
|
|
req->request.len = len;
|
|
|
|
mconsole_reply_v0(req, "ERR Version 0 mconsole clients are "
|
|
"not supported by this driver");
|
|
return(0);
|
|
}
|
|
|
|
if(req->request.len >= MCONSOLE_MAX_DATA){
|
|
mconsole_reply(req, "Request too large", 1, 0);
|
|
return(0);
|
|
}
|
|
if(req->request.version != MCONSOLE_VERSION){
|
|
mconsole_reply(req, "This driver only supports version "
|
|
STRING(MCONSOLE_VERSION) " clients", 1, 0);
|
|
}
|
|
|
|
req->request.data[req->request.len] = '\0';
|
|
req->cmd = mconsole_parse(req);
|
|
if(req->cmd == NULL){
|
|
mconsole_reply(req, "Unknown command", 1, 0);
|
|
return(0);
|
|
}
|
|
|
|
return(1);
|
|
}
|
|
|
|
int mconsole_reply_len(struct mc_request *req, const char *str, int total,
|
|
int err, int more)
|
|
{
|
|
/* XXX This is a stack consumption problem. It'd be nice to
|
|
* make it global and serialize access to it, but there are a
|
|
* ton of callers to this function.
|
|
*/
|
|
struct mconsole_reply reply;
|
|
int len, n;
|
|
|
|
do {
|
|
reply.err = err;
|
|
|
|
/* err can only be true on the first packet */
|
|
err = 0;
|
|
|
|
len = MIN(total, MCONSOLE_MAX_DATA - 1);
|
|
|
|
if(len == total) reply.more = more;
|
|
else reply.more = 1;
|
|
|
|
memcpy(reply.data, str, len);
|
|
reply.data[len] = '\0';
|
|
total -= len;
|
|
str += len;
|
|
reply.len = len + 1;
|
|
|
|
len = sizeof(reply) + reply.len - sizeof(reply.data);
|
|
|
|
n = sendto(req->originating_fd, &reply, len, 0,
|
|
(struct sockaddr *) req->origin, req->originlen);
|
|
|
|
if(n < 0) return(-errno);
|
|
} while(total > 0);
|
|
return(0);
|
|
}
|
|
|
|
int mconsole_reply(struct mc_request *req, const char *str, int err, int more)
|
|
{
|
|
return mconsole_reply_len(req, str, strlen(str), err, more);
|
|
}
|
|
|
|
|
|
int mconsole_unlink_socket(void)
|
|
{
|
|
unlink(mconsole_socket_name);
|
|
return 0;
|
|
}
|
|
|
|
static int notify_sock = -1;
|
|
|
|
int mconsole_notify(char *sock_name, int type, const void *data, int len)
|
|
{
|
|
struct sockaddr_un target;
|
|
struct mconsole_notify packet;
|
|
int n, err = 0;
|
|
|
|
lock_notify();
|
|
if(notify_sock < 0){
|
|
notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0);
|
|
if(notify_sock < 0){
|
|
err = -errno;
|
|
printk("mconsole_notify - socket failed, errno = %d\n",
|
|
err);
|
|
}
|
|
}
|
|
unlock_notify();
|
|
|
|
if(err)
|
|
return(err);
|
|
|
|
target.sun_family = AF_UNIX;
|
|
strcpy(target.sun_path, sock_name);
|
|
|
|
packet.magic = MCONSOLE_MAGIC;
|
|
packet.version = MCONSOLE_VERSION;
|
|
packet.type = type;
|
|
len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len;
|
|
packet.len = len;
|
|
memcpy(packet.data, data, len);
|
|
|
|
err = 0;
|
|
len = sizeof(packet) + packet.len - sizeof(packet.data);
|
|
n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target,
|
|
sizeof(target));
|
|
if(n < 0){
|
|
err = -errno;
|
|
printk("mconsole_notify - sendto failed, errno = %d\n", errno);
|
|
}
|
|
return(err);
|
|
}
|
|
|
|
/*
|
|
* Overrides for Emacs so that we follow Linus's tabbing style.
|
|
* Emacs will notice this stuff at the end of the file and automatically
|
|
* adjust the settings for this buffer only. This must remain at the end
|
|
* of the file.
|
|
* ---------------------------------------------------------------------------
|
|
* Local variables:
|
|
* c-file-style: "linux"
|
|
* End:
|
|
*/
|