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authorJakub Kicinski <[email protected]>2023-10-05 13:16:31 -0700
committerJakub Kicinski <[email protected]>2023-10-05 13:16:47 -0700
commit2606cf059c56bfb86d5d6bd0f41bd7eedefc8b0a (patch)
tree6bd918ad4fc55e677cc6ccb3212eab873c467c7f /kernel/crash_core.c
parent49e7265fd098fdade2bbdd9331e6b914cda7fa83 (diff)
parentf291209eca5eba0b4704fa0832af57b12dbc1a02 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. No conflicts (or adjacent changes of note). Signed-off-by: Jakub Kicinski <[email protected]>
Diffstat (limited to 'kernel/crash_core.c')
-rw-r--r--kernel/crash_core.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 03a7932cde0a..2f675ef045d4 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -740,6 +740,17 @@ subsys_initcall(crash_notes_memory_init);
#define pr_fmt(fmt) "crash hp: " fmt
/*
+ * Different than kexec/kdump loading/unloading/jumping/shrinking which
+ * usually rarely happen, there will be many crash hotplug events notified
+ * during one short period, e.g one memory board is hot added and memory
+ * regions are online. So mutex lock __crash_hotplug_lock is used to
+ * serialize the crash hotplug handling specifically.
+ */
+DEFINE_MUTEX(__crash_hotplug_lock);
+#define crash_hotplug_lock() mutex_lock(&__crash_hotplug_lock)
+#define crash_hotplug_unlock() mutex_unlock(&__crash_hotplug_lock)
+
+/*
* This routine utilized when the crash_hotplug sysfs node is read.
* It reflects the kernel's ability/permission to update the crash
* elfcorehdr directly.
@@ -748,9 +759,11 @@ int crash_check_update_elfcorehdr(void)
{
int rc = 0;
+ crash_hotplug_lock();
/* Obtain lock while reading crash information */
if (!kexec_trylock()) {
pr_info("kexec_trylock() failed, elfcorehdr may be inaccurate\n");
+ crash_hotplug_unlock();
return 0;
}
if (kexec_crash_image) {
@@ -761,6 +774,7 @@ int crash_check_update_elfcorehdr(void)
}
/* Release lock now that update complete */
kexec_unlock();
+ crash_hotplug_unlock();
return rc;
}
@@ -783,9 +797,11 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu)
{
struct kimage *image;
+ crash_hotplug_lock();
/* Obtain lock while changing crash information */
if (!kexec_trylock()) {
pr_info("kexec_trylock() failed, elfcorehdr may be inaccurate\n");
+ crash_hotplug_unlock();
return;
}
@@ -852,6 +868,7 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu)
out:
/* Release lock now that update complete */
kexec_unlock();
+ crash_hotplug_unlock();
}
static int crash_memhp_notifier(struct notifier_block *nb, unsigned long val, void *v)