From 0779fc98147a298eda6475c7744c5957ac382740 Mon Sep 17 00:00:00 2001 From: David Riley Date: Thu, 10 Dec 2015 10:18:25 -0800 Subject: [PATCH] imgdiff: skip spurious gzip headers in image files dragon kernel is compressed via lz4 for boot speed and bootloader support reasons and recent prebuilts happen to include the gzip header sequence which is causing imgdiff to fail. Detect a spurious gzip header and treat the section as a normal section. Bug: 26133184 Change-Id: I369d7d576fd7d2c579c0780fc5c669a5b6ea0d3d (cherry picked from commit 0f2f6a746af517afca9e5e089a4a17be0a9766d6) Signed-off-by: David Riley --- applypatch/imgdiff.cpp | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/applypatch/imgdiff.cpp b/applypatch/imgdiff.cpp index 50cabbe6..f22502e3 100644 --- a/applypatch/imgdiff.cpp +++ b/applypatch/imgdiff.cpp @@ -407,6 +407,7 @@ unsigned char* ReadImage(const char* filename, while (pos < sz) { unsigned char* p = img+pos; + bool processed_deflate = false; if (sz - pos >= 4 && p[0] == 0x1f && p[1] == 0x8b && p[2] == 0x08 && // deflate compression @@ -460,18 +461,24 @@ unsigned char* ReadImage(const char* filename, strm.next_out = curr->data + curr->len; ret = inflate(&strm, Z_NO_FLUSH); if (ret < 0) { - printf("Error: inflate failed [%s] at file offset [%zu]\n" - "imgdiff only supports gzip kernel compression," - " did you try CONFIG_KERNEL_LZO?\n", - strm.msg, chunk_offset); - free(img); - return NULL; + if (!processed_deflate) { + // This is the first chunk, assume that it's just a spurious + // gzip header instead of a real one. + break; + } + printf("Error: inflate failed [%s] at file offset [%zu]\n" + "imgdiff only supports gzip kernel compression," + " did you try CONFIG_KERNEL_LZO?\n", + strm.msg, chunk_offset); + free(img); + return NULL; } curr->len = allocated - strm.avail_out; if (strm.avail_out == 0) { allocated *= 2; curr->data = reinterpret_cast(realloc(curr->data, allocated)); } + processed_deflate = true; } while (ret != Z_STREAM_END); curr->deflate_len = sz - strm.avail_in - pos;