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>

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index b412e9137e36a3c2806e2497ec5c331a7bf40e3c..822b1ed3b00f6460ec07a3eb3ffa1301b46cbaeb 100644 (file)
--- 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;