Each struct ghes has an worst-case sized buffer for storing the
estatus. If an error is being processed by ghes_proc() in process
context this buffer will be in use. If the error source then triggers
an NMI-like notification, the same buffer will be used by
_in_nmi_notify_one() to stage the estatus data, before
__process_error() copys it into a queued estatus entry.

Merge __process_error()s work into _in_nmi_notify_one() so that
the queued estatus entry is used from the beginning. Use the
ghes_peek_estatus() so we know how much memory to allocate from
the ghes_estatus_pool before we read the records.

Reported-by: Borislav Petkov <[email protected]>
Signed-off-by: James Morse <[email protected]>
---
 drivers/acpi/apei/ghes.c | 45 ++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 23 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 055176ed68ac..a0c10b60ad44 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -722,40 +722,32 @@ static void ghes_print_queued_estatus(void)
        }
 }
 
-/* Save estatus for further processing in IRQ context */
-static void __process_error(struct ghes *ghes,
-                           struct acpi_hest_generic_status *ghes_estatus)
+static int _in_nmi_notify_one(struct ghes *ghes, int fixmap_idx)
 {
+       u64 buf_paddr;
+       int sev, rc = 0;
        u32 len, node_len;
        struct ghes_estatus_node *estatus_node;
        struct acpi_hest_generic_status *estatus;
 
-       if (ghes_estatus_cached(ghes_estatus))
-               return;
+       rc = ghes_peek_estatus(ghes, fixmap_idx, &buf_paddr, &len);
+       if (rc)
+               return rc;
 
-       len = cper_estatus_len(ghes_estatus);
        node_len = GHES_ESTATUS_NODE_LEN(len);
 
        estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool, node_len);
        if (!estatus_node)
-               return;
+               return -ENOMEM;
 
        estatus_node->ghes = ghes;
        estatus_node->generic = ghes->generic;
        estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
-       memcpy(estatus, ghes_estatus, len);
-       llist_add(&estatus_node->llnode, &ghes_estatus_llist);
-}
-
-static int _in_nmi_notify_one(struct ghes *ghes, int fixmap_idx)
-{
-       int sev;
-       u64 buf_paddr;
-       struct acpi_hest_generic_status *estatus = ghes->estatus;
 
-       if (ghes_read_estatus(ghes, estatus, &buf_paddr, fixmap_idx)) {
+       if (__ghes_read_estatus(estatus, buf_paddr, len, fixmap_idx)) {
                ghes_clear_estatus(estatus, buf_paddr, fixmap_idx);
-               return -ENOENT;
+               rc = -ENOENT;
+               goto no_work;
        }
 
        sev = ghes_severity(estatus->error_severity);
@@ -764,13 +756,20 @@ static int _in_nmi_notify_one(struct ghes *ghes, int 
fixmap_idx)
                __ghes_panic(ghes, estatus);
        }
 
-       if (!buf_paddr)
-               return 0;
-
-       __process_error(ghes, estatus);
        ghes_clear_estatus(estatus, buf_paddr, fixmap_idx);
 
-       return 0;
+       if (!buf_paddr || ghes_estatus_cached(estatus))
+               goto no_work;
+
+       llist_add(&estatus_node->llnode, &ghes_estatus_llist);
+
+       return rc;
+
+no_work:
+       gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node,
+                             node_len);
+
+       return rc;
 }
 
 static int ghes_estatus_queue_notified(struct list_head *rcu_list,
-- 
2.19.0

_______________________________________________
kvmarm mailing list
[email protected]
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Reply via email to