From: Al Viro Date: Tue, 24 Oct 2006 10:15:29 +0000 (+0100) Subject: [PATCH] uml: mconsole fixes X-Git-Tag: v2.6.19-rc4~97 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=3a51237dc11efe283b40ea0248f4e26ab935dbd1;p=linux-2.6-omap-h63xx.git [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 Acked-by: Jeff Dike Signed-off-by: Linus Torvalds --- diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index d08bd036ccb..7b172160fe0 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -79,7 +79,7 @@ static irqreturn_t mconsole_interrupt(int irq, void *dev_id) /* 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 @@ static irqreturn_t mconsole_interrupt(int irq, void *dev_id) 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 @@ void mconsole_stop(struct mc_request *req) { 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 with_console(struct mc_request *req, void (*proc)(void *), 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 17068eb746c..75aef6f7ef6 100644 --- a/arch/um/drivers/mconsole_user.c +++ b/arch/um/drivers/mconsole_user.c @@ -14,6 +14,7 @@ #include #include #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 58f67d39110..2666815b6af 100644 --- a/arch/um/include/mconsole.h +++ b/arch/um/include/mconsole.h @@ -61,6 +61,7 @@ struct mc_request struct mconsole_request request; struct mconsole_command *cmd; + union uml_pt_regs regs; }; extern char mconsole_socket_name[];