Commit 32709d8a authored by Keith Owens's avatar Keith Owens Committed by Tony Luck
Browse files

[IA64] SAL to OS callbacks cannot call sleeping 



When SAL calls back into the OS, the OS code is running with preempt
disabled so it cannot call sleeping functions.

Signed-off-by: default avatarKeith Owens <kaos@sgi.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent b1b901c2

arch/ia64/sn/kernel/mca.c

+21 −13
Original line number Diff line number Diff line
@@ -37,6 +37,11 @@ static u64 *sn_oemdata_size, sn_oemdata_bufsize; 
 * This function is the callback routine that SAL calls to log error

 * info for platform errors.  buf is appended to sn_oemdata, resizing as

 * required.

 * Note: this is a SAL to OS callback, running under the same rules as the SAL

 * code.  SAL calls are run with preempt disabled so this routine must not

 * sleep.  vmalloc can sleep so print_hook cannot resize the output buffer

 * itself, instead it must set the required size and return to let the caller

 * resize the buffer then redrive the SAL call.

 */

static int print_hook(const char *fmt, ...)

{
@@ -47,18 +52,8 @@ static int print_hook(const char *fmt, ...) 
	vsnprintf(buf, sizeof(buf), fmt, args);

	va_end(args);

	len = strlen(buf);

	while (*sn_oemdata_size + len + 1 > sn_oemdata_bufsize) {

		u8 *newbuf = vmalloc(sn_oemdata_bufsize += 1000);

		if (!newbuf) {

			printk(KERN_ERR "%s: unable to extend sn_oemdata\n",

			       __FUNCTION__);

			return 0;

		}

		memcpy(newbuf, *sn_oemdata, *sn_oemdata_size);

		vfree(*sn_oemdata);

		*sn_oemdata = newbuf;

	}

	memcpy(*sn_oemdata + *sn_oemdata_size, buf, len + 1);

	if (*sn_oemdata_size + len <= sn_oemdata_bufsize)

		memcpy(*sn_oemdata + *sn_oemdata_size, buf, len);

	*sn_oemdata_size += len;

	return 0;

}
@@ -98,7 +93,20 @@ sn_platform_plat_specific_err_print(const u8 * sect_header, u8 ** oemdata, 
	sn_oemdata = oemdata;

	sn_oemdata_size = oemdata_size;

	sn_oemdata_bufsize = 0;

	*sn_oemdata_size = PAGE_SIZE;	/* first guess at how much data will be generated */

	while (*sn_oemdata_size > sn_oemdata_bufsize) {

		u8 *newbuf = vmalloc(*sn_oemdata_size);

		if (!newbuf) {

			printk(KERN_ERR "%s: unable to extend sn_oemdata\n",

			       __FUNCTION__);

			return 1;

		}

		vfree(*sn_oemdata);

		*sn_oemdata = newbuf;

		sn_oemdata_bufsize = *sn_oemdata_size;

		*sn_oemdata_size = 0;

		ia64_sn_plat_specific_err_print(print_hook, (char *)sect_header);

	}

	up(&sn_oemdata_mutex);

	return 0;

}