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-rw-r--r--kernel/kexec_core.c37
1 files changed, 31 insertions, 6 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 11b64a63c0f8..8dc659144869 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -310,12 +310,9 @@ static void kimage_free_pages(struct page *page)
void kimage_free_page_list(struct list_head *list)
{
- struct list_head *pos, *next;
+ struct page *page, *next;
- list_for_each_safe(pos, next, list) {
- struct page *page;
-
- page = list_entry(pos, struct page, lru);
+ list_for_each_entry_safe(page, next, list, lru) {
list_del(&page->lru);
kimage_free_pages(page);
}
@@ -853,7 +850,12 @@ struct kimage *kexec_image;
struct kimage *kexec_crash_image;
int kexec_load_disabled;
-void crash_kexec(struct pt_regs *regs)
+/*
+ * No panic_cpu check version of crash_kexec(). This function is called
+ * only when panic_cpu holds the current CPU number; this is the only CPU
+ * which processes crash_kexec routines.
+ */
+void __crash_kexec(struct pt_regs *regs)
{
/* Take the kexec_mutex here to prevent sys_kexec_load
* running on one cpu from replacing the crash kernel
@@ -876,6 +878,29 @@ void crash_kexec(struct pt_regs *regs)
}
}
+void crash_kexec(struct pt_regs *regs)
+{
+ int old_cpu, this_cpu;
+
+ /*
+ * Only one CPU is allowed to execute the crash_kexec() code as with
+ * panic(). Otherwise parallel calls of panic() and crash_kexec()
+ * may stop each other. To exclude them, we use panic_cpu here too.
+ */
+ this_cpu = raw_smp_processor_id();
+ old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu);
+ if (old_cpu == PANIC_CPU_INVALID) {
+ /* This is the 1st CPU which comes here, so go ahead. */
+ __crash_kexec(regs);
+
+ /*
+ * Reset panic_cpu to allow another panic()/crash_kexec()
+ * call.
+ */
+ atomic_set(&panic_cpu, PANIC_CPU_INVALID);
+ }
+}
+
size_t crash_get_memory_size(void)
{
size_t size = 0;
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