1 files changed, 38 insertions, 19 deletions

diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index e54a8b7f5c64..742735acd8b6 100644
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -29,6 +29,13 @@
 /* Max bytes to read/write in one go */
 #define NVRW_CNT 0x20
 
+/*
+ * Set oops header version to distingush between old and new format header.
+ * lnx,oops-log partition max size is 4000, header version > 4000 will
+ * help in identifying new header.
+ */
+#define OOPS_HDR_VERSION 5000
+
 static unsigned int nvram_size;
 static int nvram_fetch, nvram_store;
 static char nvram_buf[NVRW_CNT];        /* assume this is in the first 4GB */
@@ -67,6 +74,12 @@ static const char *pseries_nvram_os_partitions[] = {
         NULL
 };
 
+struct oops_log_info {
+        u16 version;
+        u16 report_length;
+        u64 timestamp;
+} __attribute__((packed));
+
 static void oops_to_nvram(struct kmsg_dumper *dumper,
                           enum kmsg_dump_reason reason);
 
@@ -83,28 +96,28 @@ static unsigned long last_unread_rtas_event;	/* timestamp */
 
  * big_oops_buf[] holds the uncompressed text we're capturing.
  *
- * oops_buf[] holds the compressed text, preceded by a prefix.
- * The prefix is just a u16 holding the length of the compressed* text.
- * (*Or uncompressed, if compression fails.)  oops_buf[] gets written
- * to NVRAM.
+ * oops_buf[] holds the compressed text, preceded by a oops header.
+ * oops header has u16 holding the version of oops header (to differentiate
+ * between old and new format header) followed by u16 holding the length of
+ * the compressed* text (*Or uncompressed, if compression fails.) and u64
+ * holding the timestamp. oops_buf[] gets written to NVRAM.
  *
- * oops_len points to the prefix.  oops_data points to the compressed text.
+ * oops_log_info points to the header. oops_data points to the compressed text.
  *
  * +- oops_buf
- * |            +- oops_data
- * v            v
- * +------------+-----------------------------------------------+
- * | length     | text                                          |
- * | (2 bytes)  | (oops_data_sz bytes)                          |
- * +------------+-----------------------------------------------+
+ * |                                   +- oops_data
+ * v                                   v
+ * +-----------+-----------+-----------+------------------------+
+ * | version   | length    | timestamp | text                   |
+ * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes)   |
+ * +-----------+-----------+-----------+------------------------+
  * ^
- * +- oops_len
+ * +- oops_log_info
  *
  * We preallocate these buffers during init to avoid kmalloc during oops/panic.
  */
 static size_t big_oops_buf_sz;
 static char *big_oops_buf, *oops_buf;
-static u16 *oops_len;
 static char *oops_data;
 static size_t oops_data_sz;
 
@@ -425,9 +438,8 @@ static void __init nvram_init_oops_partition(int rtas_partition_exists)
                                                 oops_log_partition.name);
                 return;
         }
-        oops_len = (u16*) oops_buf;
-        oops_data = oops_buf + sizeof(u16);
-        oops_data_sz = oops_log_partition.size - sizeof(u16);
+        oops_data = oops_buf + sizeof(struct oops_log_info);
+        oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
 
         /*
          * Figure compression (preceded by elimination of each line's <n>
@@ -555,6 +567,7 @@ error:
 /* Compress the text from big_oops_buf into oops_buf. */
 static int zip_oops(size_t text_len)
 {
+        struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
         int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
                                                                 oops_data_sz);
         if (zipped_len < 0) {
@@ -562,7 +575,9 @@ static int zip_oops(size_t text_len)
                 pr_err("nvram: logging uncompressed oops/panic report\n");
                 return -1;
         }
-        *oops_len = (u16) zipped_len;
+        oops_hdr->version = OOPS_HDR_VERSION;
+        oops_hdr->report_length = (u16) zipped_len;
+        oops_hdr->timestamp = get_seconds();
         return 0;
 }
 
@@ -576,6 +591,7 @@ static int zip_oops(size_t text_len)
 static void oops_to_nvram(struct kmsg_dumper *dumper,
                           enum kmsg_dump_reason reason)
 {
+        struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
         static unsigned int oops_count = 0;
         static bool panicking = false;
         static DEFINE_SPINLOCK(lock);
@@ -622,11 +638,14 @@ static void oops_to_nvram(struct kmsg_dumper *dumper,
                 kmsg_dump_get_buffer(dumper, false,
                                      oops_data, oops_data_sz, &text_len);
                 err_type = ERR_TYPE_KERNEL_PANIC;
-                *oops_len = (u16) text_len;
+                oops_hdr->version = OOPS_HDR_VERSION;
+                oops_hdr->report_length = (u16) text_len;
+                oops_hdr->timestamp = get_seconds();
         }
 
         (void) nvram_write_os_partition(&oops_log_partition, oops_buf,
-                (int) (sizeof(*oops_len) + *oops_len), err_type, ++oops_count);
+                (int) (sizeof(*oops_hdr) + oops_hdr->report_length), err_type,
+                ++oops_count);
 
         spin_unlock_irqrestore(&lock, flags);
 }