[Xen-changelog] [xen-unstable] [IA64] MCA: Avoid calling xmcalloc from interrupt handler

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
# Date 1234490161 -32400
# Node ID af992824b5cfa3b81dbe68293216a5df3ec0bdf4
# Parent  46b4096813dca3c707a60148f560aba31f521c56
[IA64] MCA: Avoid calling xmcalloc from interrupt handler

This patch fixes to avoid calling xmalloc() from the interrupt handler.
Calling xmalloc() with interrupt disabled triggers the following
BUG_ON().
> (XEN) Xen BUG at xmalloc_tlsf.c:548

Signed-off-by: Kazuhiro Suzuki <kaz@xxxxxxxxxxxxxx>
---
 xen/arch/ia64/linux-xen/mca.c |   15 ++++++++++++---
 xen/arch/ia64/xen/fw_emul.c   |   13 ++++++++-----
 2 files changed, 20 insertions(+), 8 deletions(-)

diff -r 46b4096813dc -r af992824b5cf xen/arch/ia64/linux-xen/mca.c
--- a/xen/arch/ia64/linux-xen/mca.c     Mon Feb 02 11:11:36 2009 +0900
+++ b/xen/arch/ia64/linux-xen/mca.c     Fri Feb 13 10:56:01 2009 +0900
@@ -210,6 +210,7 @@ static ia64_state_log_t ia64_state_log[I
 #define IA64_LOG_COUNT(it)         ia64_state_log[it].isl_count
 
 #ifdef XEN
+sal_queue_entry_t sal_entry[NR_CPUS][IA64_MAX_LOG_TYPES];
 struct list_head *sal_queue, sal_log_queues[IA64_MAX_LOG_TYPES];
 sal_log_record_header_t *sal_record;
 DEFINE_SPINLOCK(sal_queue_lock);
@@ -358,6 +359,7 @@ ia64_log_queue(int sal_info_type, int vi
 
        if (total_len) {
                int queue_type;
+               int cpuid = smp_processor_id();
 
                spin_lock_irqsave(&sal_queue_lock, flags);
 
@@ -366,15 +368,22 @@ ia64_log_queue(int sal_info_type, int vi
                else
                        queue_type = sal_info_type;
 
-               e = xmalloc(sal_queue_entry_t);
-               BUG_ON(e == NULL);
-               e->cpuid = smp_processor_id();
+               /* Skip if sal_entry is already listed in sal_queue */
+               list_for_each_entry(e, &sal_queue[queue_type], list) {
+                       if (e == &sal_entry[cpuid][queue_type])
+                               goto found;
+               }
+               e = &sal_entry[cpuid][queue_type];
+               memset(e, 0, sizeof(sal_queue_entry_t));
+               e->cpuid = cpuid;
                e->sal_info_type = sal_info_type;
                e->vector = IA64_CMC_VECTOR;
                e->virq = virq;
                e->length = total_len;
 
                list_add_tail(&e->list, &sal_queue[queue_type]);
+
+       found:
                spin_unlock_irqrestore(&sal_queue_lock, flags);
 
                IA64_LOG_INDEX_INC(sal_info_type);
diff -r 46b4096813dc -r af992824b5cf xen/arch/ia64/xen/fw_emul.c
--- a/xen/arch/ia64/xen/fw_emul.c       Mon Feb 02 11:11:36 2009 +0900
+++ b/xen/arch/ia64/xen/fw_emul.c       Fri Feb 13 10:56:01 2009 +0900
@@ -95,7 +95,7 @@ void get_state_info_on(void *data) {
                       rec_name[arg->type], smp_processor_id(), arg->ret);
        if (arg->corrected) {
                sal_record->severity = sal_log_severity_corrected;
-               IA64_SAL_DEBUG("%s: 
IA64_SAL_CLEAR_STATE_INFO(SAL_INFO_TYPE_MCA)"
+               IA64_SAL_DEBUG("%s: IA64_SAL_GET_STATE_INFO(SAL_INFO_TYPE_MCA)"
                               " force\n", __FUNCTION__);
        }
        if (arg->ret > 0) {
@@ -293,9 +293,7 @@ sal_emulator (long index, unsigned long 
                        }
                        r9 = arg.ret;
                        status = arg.status;
-                       if (r9 == 0) {
-                               xfree(e);
-                       } else {
+                       if (r9 != 0) {
                                /* Re-add the entry to sal_queue */
                                spin_lock_irqsave(&sal_queue_lock, flags);
                                list_add(&e->list, &sal_queue[in1]);
@@ -359,7 +357,12 @@ sal_emulator (long index, unsigned long 
                        }
                        r9 = arg.ret;
                        status = arg.status;
-                       xfree(e);
+                       if (r9 >= 0) {
+                               IA64_SAL_DEBUG("SAL_CLEAR_STATE_INFO: more 
errors are available\n");
+                               spin_lock_irqsave(&sal_queue_lock, flags);
+                               list_add(&e->list, &sal_queue[in1]);
+                               spin_unlock_irqrestore(&sal_queue_lock, flags);
+                       }
                }
                break;
            case SAL_MC_RENDEZ:

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