From: Daan De Meyer <daan.j.demeyer@gmail.com>

Preparation for adding support for zstd compressed efi zboot kernel
images.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Daan De Meyer <daan.j.demeyer@gmail.com>
Message-ID: <20251124123521.1058183-2-daan.j.demeyer@gmail.com>
[PMD: Wrap long line to avoid checkpatch.pl warning]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/hw/core/loader.h | 2 +-
 hw/arm/boot.c            | 4 ++--
 hw/core/loader.c         | 9 +++++----
 hw/nvram/fw_cfg.c        | 3 ++-
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/hw/core/loader.h b/include/hw/core/loader.h
index 6f917035034..1f14dccbca9 100644
--- a/include/hw/core/loader.h
+++ b/include/hw/core/loader.h
@@ -82,7 +82,7 @@ ssize_t load_image_mr(const char *filename, MemoryRegion *mr);
  * load_image_gzipped_buffer() will read. It prevents
  * g_malloc() in those functions from allocating a huge amount of memory.
  */
-#define LOAD_IMAGE_MAX_GUNZIP_BYTES (256 << 20)
+#define LOAD_IMAGE_MAX_DECOMPRESSED_BYTES (256 << 20)
 
 ssize_t load_image_gzipped_buffer(const char *filename, uint64_t max_sz,
                                   uint8_t **buffer);
diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index e22609de93a..c97d4c4e118 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -816,14 +816,14 @@ static ssize_t arm_load_elf(struct arm_boot_info *info, uint64_t *pentry,
 static uint64_t load_aarch64_image(const char *filename, hwaddr mem_base,
                                    hwaddr *entry, AddressSpace *as)
 {
+    const size_t max_bytes = LOAD_IMAGE_MAX_DECOMPRESSED_BYTES;
     hwaddr kernel_load_offset = KERNEL64_LOAD_ADDR;
     uint64_t kernel_size = 0;
     uint8_t *buffer;
     ssize_t size;
 
     /* On aarch64, it's the bootloader's job to uncompress the kernel. */
-    size = load_image_gzipped_buffer(filename, LOAD_IMAGE_MAX_GUNZIP_BYTES,
-                                     &buffer);
+    size = load_image_gzipped_buffer(filename, max_bytes, &buffer);
 
     if (size < 0) {
         gsize len;
diff --git a/hw/core/loader.c b/hw/core/loader.c
index f4581f76b9a..79cb96b4664 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -829,8 +829,8 @@ ssize_t load_image_gzipped_buffer(const char *filename, uint64_t max_sz,
         goto out;
     }
 
-    if (max_sz > LOAD_IMAGE_MAX_GUNZIP_BYTES) {
-        max_sz = LOAD_IMAGE_MAX_GUNZIP_BYTES;
+    if (max_sz > LOAD_IMAGE_MAX_DECOMPRESSED_BYTES) {
+        max_sz = LOAD_IMAGE_MAX_DECOMPRESSED_BYTES;
     }
 
     data = g_malloc(max_sz);
@@ -896,6 +896,7 @@ struct linux_efi_zboot_header {
  */
 ssize_t unpack_efi_zboot_image(uint8_t **buffer, ssize_t *size)
 {
+    const size_t max_bytes = LOAD_IMAGE_MAX_DECOMPRESSED_BYTES;
     const struct linux_efi_zboot_header *header;
     uint8_t *data = NULL;
     ssize_t ploff, plsize;
@@ -931,8 +932,8 @@ ssize_t unpack_efi_zboot_image(uint8_t **buffer, ssize_t *size)
         return -1;
     }
 
-    data = g_malloc(LOAD_IMAGE_MAX_GUNZIP_BYTES);
-    bytes = gunzip(data, LOAD_IMAGE_MAX_GUNZIP_BYTES, *buffer + ploff, plsize);
+    data = g_malloc(max_bytes);
+    bytes = gunzip(data, max_bytes, *buffer + ploff, plsize);
     if (bytes < 0) {
         fprintf(stderr, "failed to decompress EFI zboot image\n");
         g_free(data);
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 437ab6e210f..69e97361453 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -1115,7 +1115,8 @@ void load_image_to_fw_cfg(FWCfgState *fw_cfg, uint16_t size_key,
 
     if (try_decompress) {
         size = load_image_gzipped_buffer(image_name,
-                                         LOAD_IMAGE_MAX_GUNZIP_BYTES, &data);
+                                         LOAD_IMAGE_MAX_DECOMPRESSED_BYTES,
+                                         &data);
     }
 
     if (size == (size_t)-1) {
-- 
2.52.0