Merge tag 'v4.9.209' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux...

[platform/kernel/linux-amlogic.git] / fs / pstore / ram.c

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 4c1d59e..bbdc43a 100644 (file)
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -321,6 +321,17 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
 
        prz = cxt->przs[cxt->dump_write_cnt];
 
+       /*
+        * Since this is a new crash dump, we need to reset the buffer in
+        * case it still has an old dump present. Without this, the new dump
+        * will get appended, which would seriously confuse anything trying
+        * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
+        * expects to find a dump header in the beginning of buffer data, so
+        * we must to reset the buffer values, in order to ensure that the
+        * header will be written to the beginning of the buffer.
+        */
+       persistent_ram_zap(prz);
+
        hlen = ramoops_write_kmsg_hdr(prz, compressed);
        if (size + hlen > prz->buffer_size)
                size = prz->buffer_size - hlen;