From 29736faa92d5e4b4242786ee583ce339263d6adb Mon Sep 17 00:00:00 2001

From: Laszlo Ersek <lersek@redhat.com>

Date: Mon, 22 Dec 2014 13:11:43 +0100

Subject: [PATCH 12/15] hw/loader: split out load_image_gzipped_buffer()

In the next patch we'd like to reuse the image decompression facility

without installing the output as a ROM at a specific guest-phys address.

In addition, expose LOAD_IMAGE_MAX_GUNZIP_BYTES, because that's a

straightforward "max_sz" argument for the new load_image_gzipped_buffer().

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Message-id: 1419250305-31062-10-git-send-email-pbonzini@redhat.com

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

(cherry picked from commit 7d48a0f7217474899c5f5920b21f4cfdf4efa8d1)

---

 hw/core/loader.c    | 30 +++++++++++++++++++++---------

 include/hw/loader.h |  9 +++++++++

 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/hw/core/loader.c b/hw/core/loader.c

index 7527fd3..f2b34da 100644

--- a/hw/core/loader.c

+++ b/hw/core/loader.c

@@ -614,14 +614,9 @@ int load_ramdisk(const char *filename, hwaddr addr, uint64_t max_sz)

                             NULL, NULL);

 }

-/* This simply prevents g_malloc in the function below from allocating

- * a huge amount of memory, by placing a limit on the maximum

- * uncompressed image size that load_image_gzipped will read.

- */

-#define LOAD_IMAGE_MAX_GUNZIP_BYTES (256 << 20)

-

-/* Load a gzip-compressed kernel. */

-int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz)

+/* Load a gzip-compressed kernel to a dynamically allocated buffer. */

+int load_image_gzipped_buffer(const char *filename, uint64_t max_sz,

+                              uint8_t **buffer)

 {

     uint8_t *compressed_data = NULL;

     uint8_t *data = NULL;

@@ -653,8 +648,11 @@ int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz)

         goto out;

     }

-    rom_add_blob_fixed(filename, data, bytes, addr);

+    /* trim to actual size and return to caller */

+    *buffer = g_realloc(data, bytes);

     ret = bytes;

+    /* ownership has been transferred to caller */

+    data = NULL;

  out:

     g_free(compressed_data);

@@ -662,6 +660,20 @@ int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz)

     return ret;

 }

+/* Load a gzip-compressed kernel. */

+int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz)

+{

+    int bytes;

+    uint8_t *data;

+

+    bytes = load_image_gzipped_buffer(filename, max_sz, &data);

+    if (bytes != -1) {

+        rom_add_blob_fixed(filename, data, bytes, addr);

+        g_free(data);

+    }

+    return bytes;

+}

+

 /*

  * Functions for reboot-persistent memory regions.

  *  - used for vga bios and option roms.

diff --git a/include/hw/loader.h b/include/hw/loader.h

index 6481639..8997620 100644

--- a/include/hw/loader.h

+++ b/include/hw/loader.h

@@ -16,6 +16,15 @@ int load_image(const char *filename, uint8_t *addr); /* deprecated */

 ssize_t load_image_size(const char *filename, void *addr, size_t size);

 int load_image_targphys(const char *filename, hwaddr,

                         uint64_t max_sz);

+

+/* This is the limit on the maximum uncompressed image size that

+ * load_image_gzipped_buffer() and load_image_gzipped() will read. It prevents

+ * g_malloc() in those functions from allocating a huge amount of memory.

+ */

+#define LOAD_IMAGE_MAX_GUNZIP_BYTES (256 << 20)

+

+int load_image_gzipped_buffer(const char *filename, uint64_t max_sz,

+                              uint8_t **buffer);

 int load_image_gzipped(const char *filename, hwaddr addr, uint64_t max_sz);

 #define ELF_LOAD_FAILED       -1

-- 

2.1.0