erst: Read and write to the 'compressed' flag of pstore

In pstore write, set the section type to CPER_SECTION_TYPE_DMESG_COMPR
if the data is compressed. In pstore read, read the section type and
update the 'compressed' flag accordingly.

Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index b412e9137e36..822b1ed3b00f 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -958,6 +958,9 @@ static struct pstore_info erst_info = {
 #define CPER_SECTION_TYPE_DMESG                                         \
         UUID_LE(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,     \
                 0x94, 0x19, 0xeb, 0x12)
+#define CPER_SECTION_TYPE_DMESG_Z                                       \
+        UUID_LE(0x4f118707, 0x04dd, 0x4055, 0xb5, 0xdd, 0x95, 0x6d,     \
+                0x34, 0xdd, 0xfa, 0xc6)
 #define CPER_SECTION_TYPE_MCE                                           \
         UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,     \
                 0x04, 0x4a, 0x38, 0xfc)
@@ -1036,7 +1039,12 @@ skip:
         }
         memcpy(*buf, rcd->data, len - sizeof(*rcd));
         *id = record_id;
+        *compressed = false;
         if (uuid_le_cmp(rcd->sec_hdr.section_type,
+                        CPER_SECTION_TYPE_DMESG_Z) == 0) {
+                *type = PSTORE_TYPE_DMESG;
+                *compressed = true;
+        } else if (uuid_le_cmp(rcd->sec_hdr.section_type,
                         CPER_SECTION_TYPE_DMESG) == 0)
                 *type = PSTORE_TYPE_DMESG;
         else if (uuid_le_cmp(rcd->sec_hdr.section_type,
@@ -1087,7 +1095,10 @@ static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
         rcd->sec_hdr.flags = CPER_SEC_PRIMARY;
         switch (type) {
         case PSTORE_TYPE_DMESG:
-                rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;
+                if (compressed)
+                        rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG_Z;
+                else
+                        rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;
                 break;
         case PSTORE_TYPE_MCE:
                 rcd->sec_hdr.section_type = CPER_SECTION_TYPE_MCE;