[PATCH] uml: mconsole fixes
* when we have stop/sysrq/go, we get pt_regs of whatever executes
mc_work_proc(). Would be better to see what we had at the time of
interrupt that got us stop.
* stop/stop/stop..... will give stack overflow. Shouldn't allow stop
from mconsole_stop().
* stop/stop/go leaves us inside mconsole_stop() with
os_set_fd_block(req->originating_fd, 0);
reactivate_fd(req->originating_fd, MCONSOLE_IRQ);
just done by nested mconsole_stop(). Ditto.
* once we'd seen stop, there's a period when INTR commands are executed
out of order (as they should; we might have the things stuck badly
enough to never reach mconsole_stop(), but still not badly enough to
block mconsole_interrupt(); in that situation we _want_ things like
"cad" to be executed immediately). Once we enter monsole_stop(), all
INTR commands will be executed in order, mixed with PROC ones. We'd
better let user see that such change of behaviour has happened.
(Suggested by lennert).
* stack footprint of monsole_interrupt() is an atrocity; AFAICS we can
safely make struct mc_request req; static in function there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index d08bd03..7b17216 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -79,7 +79,7 @@
/* long to avoid size mismatch warnings from gcc */
long fd;
struct mconsole_entry *new;
- struct mc_request req;
+ static struct mc_request req; /* that's OK */
fd = (long) dev_id;
while (mconsole_get_request(fd, &req)){
@@ -91,6 +91,7 @@
mconsole_reply(&req, "Out of memory", 1, 0);
else {
new->request = req;
+ new->request.regs = get_irq_regs()->regs;
list_add(&new->list, &mc_requests);
}
}
@@ -314,9 +315,21 @@
{
deactivate_fd(req->originating_fd, MCONSOLE_IRQ);
os_set_fd_block(req->originating_fd, 1);
- mconsole_reply(req, "", 0, 0);
- while(mconsole_get_request(req->originating_fd, req)){
- if(req->cmd->handler == mconsole_go) break;
+ mconsole_reply(req, "stopped", 0, 0);
+ while (mconsole_get_request(req->originating_fd, req)) {
+ if (req->cmd->handler == mconsole_go)
+ break;
+ if (req->cmd->handler == mconsole_stop) {
+ mconsole_reply(req, "Already stopped", 1, 0);
+ continue;
+ }
+ if (req->cmd->handler == mconsole_sysrq) {
+ struct pt_regs *old_regs;
+ old_regs = set_irq_regs((struct pt_regs *)&req->regs);
+ mconsole_sysrq(req);
+ set_irq_regs(old_regs);
+ continue;
+ }
(*req->cmd->handler)(req);
}
os_set_fd_block(req->originating_fd, 0);
@@ -673,9 +686,7 @@
static void sysrq_proc(void *arg)
{
char *op = arg;
- struct pt_regs *old_regs = set_irq_regs(¤t->thread.regs);
handle_sysrq(*op, NULL);
- set_irq_regs(old_regs);
}
void mconsole_sysrq(struct mc_request *req)
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
index 17068eb..75aef6f 100644
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -14,6 +14,7 @@
#include <sys/un.h>
#include <unistd.h>
#include "user.h"
+#include "sysdep/ptrace.h"
#include "mconsole.h"
#include "umid.h"
#include "user_util.h"
diff --git a/arch/um/include/mconsole.h b/arch/um/include/mconsole.h
index 58f67d3..2666815 100644
--- a/arch/um/include/mconsole.h
+++ b/arch/um/include/mconsole.h
@@ -61,6 +61,7 @@
struct mconsole_request request;
struct mconsole_command *cmd;
+ union uml_pt_regs regs;
};
extern char mconsole_socket_name[];
