Re: [patch] 2.4.25 sync unwind code with 2.6.3

From: Bjorn Helgaas <bjorn.helgaas_at_hp.com>
Date: 2004-03-04 10:53:36
On Sunday 22 February 2004 7:46 pm, Keith Owens wrote:
> The unwind code in 2.4.25 has drifted away from the 2.6.3 version,
> including some missing bug fixes.

> +	/* Kludge: 2.4 has down_write_trylock on semaphores but not write_trylock on
> +	 * spinlocks, even though they are both in 2.6 and are identical.  Pretend
> +	 * that script lock is a rw_semaphore so we can use the only 2.4 code that
> +	 * avoids a deadlock.  KAO.
> +	 */
> +	if (!down_write_trylock((struct rw_semaphore *)(&script->lock)))
> +		return NULL;

Should we consider putting write_trylock() in 2.4?  It looks like
i386, x86_64, and ppc64 already have it.

We also have this diff wrt. 2.6:

@@ -1426,7 +1416,7 @@
 
              case UNW_WHERE_FR:
                if (rval <= 5)
-                       val = unw.preg_index[UNW_REG_F2  + (rval -  1)];
+                       val = unw.preg_index[UNW_REG_F2  + (rval -  2)];
                else if (rval >= 16 && rval <= 31)
                        val = unw.preg_index[UNW_REG_F16 + (rval - 16)];
                else {

You didn't change this, but I'd feel better if I understood why
this is different.

I applied your patch, and also twidded the UNW_DEBUG bits to
make 2.4 more like 2.6.  Thanks for keeping them in sync!

Bjorn

-
To unsubscribe from this list: send the line "unsubscribe linux-ia64" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Received on Wed Mar 3 18:57:50 2004

This archive was generated by hypermail 2.1.8 : 2005-08-02 09:20:24 EST