+/* Squeeze out each line's <n> severity prefix. */
+static size_t elide_severities(char *buf, size_t len)
+{
+ char *in, *out, *buf_end = buf + len;
+ /* Assume a <n> at the very beginning marks the start of a line. */
+ int newline = 1;
+
+ in = out = buf;
+ while (in < buf_end) {
+ if (newline && in+3 <= buf_end &&
+ *in == '<' && isdigit(in[1]) && in[2] == '>') {
+ in += 3;
+ newline = 0;
+ } else {
+ newline = (*in == '\n');
+ *out++ = *in++;
+ }
+ }
+ return out - buf;
+}
+
+/* Derived from logfs_compress() */
+static int nvram_compress(const void *in, void *out, size_t inlen,
+ size_t outlen)
+{
+ int err, ret;
+
+ ret = -EIO;
+ err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
+ MEM_LEVEL, Z_DEFAULT_STRATEGY);
+ if (err != Z_OK)
+ goto error;
+
+ stream.next_in = in;
+ stream.avail_in = inlen;
+ stream.total_in = 0;
+ stream.next_out = out;
+ stream.avail_out = outlen;
+ stream.total_out = 0;
+
+ err = zlib_deflate(&stream, Z_FINISH);
+ if (err != Z_STREAM_END)
+ goto error;
+
+ err = zlib_deflateEnd(&stream);
+ if (err != Z_OK)
+ goto error;
+
+ if (stream.total_out >= stream.total_in)
+ goto error;
+
+ ret = stream.total_out;
+error:
+ return ret;
+}
+
+/* Compress the text from big_oops_buf into oops_buf. */
+static int zip_oops(size_t text_len)
+{
+ int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
+ oops_data_sz);
+ if (zipped_len < 0) {
+ pr_err("nvram: compression failed; returned %d\n", zipped_len);
+ pr_err("nvram: logging uncompressed oops/panic report\n");
+ return -1;
+ }
+ *oops_len = (u16) zipped_len;
+ return 0;
+}
+
+/*
+ * This is our kmsg_dump callback, called after an oops or panic report
+ * has been written to the printk buffer. We want to capture as much
+ * of the printk buffer as possible. First, capture as much as we can
+ * that we think will compress sufficiently to fit in the lnx,oops-log
+ * partition. If that's too much, go back and capture uncompressed text.
+ */