[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: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/kernel/mca.c b/arch/ia64/sn/kernel/mca.c
index 857774b..6546db6 100644
--- a/arch/ia64/sn/kernel/mca.c
+++ b/arch/ia64/sn/kernel/mca.c
@@ -37,6 +37,11 @@
* 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 @@
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_oemdata = oemdata;
sn_oemdata_size = oemdata_size;
sn_oemdata_bufsize = 0;
- ia64_sn_plat_specific_err_print(print_hook, (char *)sect_header);
+ *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;
}
