Re: [PATCH 1/1] UML: fix missing non-blocking I/O, now DEBUG_SHIRQworks

From: Eduard-Gabriel Munteanu
Date: Mon Jun 11 2007 - 15:40:14 EST

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Jeff Dike wrote:
I don't really like this section though. The casting I have now isn't
pleasant, but I don't like adding a new global to get rid of it.

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 542c9ef..02d132e 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -74,12 +74,11 @@ static DECLARE_WORK(mconsole_work, mc_work_proc);
static irqreturn_t mconsole_interrupt(int irq, void *dev_id)
- /* long to avoid size mismatch warnings from gcc */
- long fd;
+ int fd;
struct mconsole_entry *new;
static struct mc_request req; /* that's OK */
- fd = (long) dev_id;
+ fd = *((int *) dev_id);
while (mconsole_get_request(fd, &req)){
if(req.cmd->context == MCONSOLE_INTR)
@@ -798,10 +797,10 @@ void mconsole_stack(struct mc_request *req)
static char *notify_socket = NULL;
+static int sock;
static int mconsole_init(void)
- /* long to avoid size mismatch warnings from gcc */
- long sock;
int err;
char file[256];
@@ -818,7 +817,7 @@ static int mconsole_init(void)
err = um_request_irq(MCONSOLE_IRQ, sock, IRQ_READ, mconsole_interrupt,
- "mconsole", (void *)sock);
+ "mconsole", &sock);
if (err){
printk("Failed to get IRQ for management console\n");


No offense, but this is an ugly hack. What if sizeof(int) != sizeof(long)? You're calling glibc functions with that fd as a parameter. On some arches, compiling will issue warnings or simply fail.

An alternative would be to use kmalloc instead of a global static variable. Do you like this one more?
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