On 22.11.24 08:31, Baoquan He wrote:
On 10/25/24 at 05:11pm, David Hildenbrand wrote:
......snip...
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 3e90416ee54e..c332a9a4920b 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -69,6 +69,8 @@ static LIST_HEAD(vmcore_cb_list);
/* Whether the vmcore has been opened once. */
static bool vmcore_opened;
+static void vmcore_process_device_ram(struct vmcore_cb *cb);
+
void register_vmcore_cb(struct vmcore_cb *cb)
{
INIT_LIST_HEAD(&cb->next);
@@ -80,6 +82,8 @@ void register_vmcore_cb(struct vmcore_cb *cb)
*/
if (vmcore_opened)
pr_warn_once("Unexpected vmcore callback registration\n");
+ else if (cb->get_device_ram)
+ vmcore_process_device_ram(cb);
Global variable 'vmcore_opened' is used to indicate if /proc/vmcore is
opened. With &vmcore_mutex, we don't need to worry about concurrent
opening and modification. However, if people just open /proc/vmcore and
close it after checking, then s390 will miss the vmcore dumping, is it
acceptable?
See my reply to your other mail (patch #3).
mutex_unlock(&vmcore_mutex);
}
EXPORT_SYMBOL_GPL(register_vmcore_cb);
@@ -1511,6 +1515,158 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
......
+
+static void vmcore_process_device_ram(struct vmcore_cb *cb)
+{
+ unsigned char *e_ident = (unsigned char *)elfcorebuf;
+ struct vmcore_mem_node *first, *m;
+ LIST_HEAD(list);
+ int count;
+
+ if (cb->get_device_ram(cb, &list)) {
+ pr_err("Kdump: obtaining device ram ranges failed\n");
+ return;
+ }
+ count = list_count_nodes(&list);
+ if (!count)
+ return;
+
+ /* We only support Elf64 dumps for now. */
+ if (WARN_ON_ONCE(e_ident[EI_CLASS] != ELFCLASS64)) {
+ pr_err("Kdump: device ram ranges only support Elf64\n");
+ goto out_free;
+ }
Only supporting Elf64 dumps seems to be a basic checking, do we need
to put it at the beginning of function? Otherwise, we spend efforts to
call cb->get_device_ram(), then fail.
The idea was that if there is nothing to add, then the elf class doesn't
matter. But yes, I can move this further up.
Thanks!
--
Cheers,
David / dhildenb
