commit be67b6050105bcf5cc52542202a16f32a9d4c185
author Daniel Verkamp <dverkamp@chromium.org> Tue Feb 21 12:32:02 2023 -0800
committer crosvm LUCI <crosvm-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Feb 28 19:10:44 2023 +0000
tree a83f068f6c01dd176fda1590454f038e4411ef65
parent ab9d6a02ce0516d47d150303c05a6336f5a3745b

aarch64: dump device tree blob before length check

In case the final devicetree blob is too large to fit in the memory
reserved for it, it could be useful to inspect the generated FDT. Move
the code that dumps the FDT to a file before the length check so it will
be written out even if the size is too large.

BUG=None
TEST=crosvm run --dump-device-tree-blob /tmp/fdt # on aarch64

Change-Id: I1344d08cee5cb7eb0fd369314f2b765e37f18215
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/4277621
Reviewed-by: Keiichi Watanabe <keiichiw@chromium.org>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Shin Kawamura <kawasin@google.com>

aarch64/src/fdt.rs

diff --git a/aarch64/src/fdt.rs b/aarch64/src/fdt.rs
index 979204c..83450e6 100644
--- a/aarch64/src/fdt.rs
+++ b/aarch64/src/fdt.rs
@@ -593,6 +593,11 @@
 
     let fdt_final = fdt.finish()?;
 
+    if let Some(file_path) = dump_device_tree_blob {
+        std::fs::write(&file_path, &fdt_final)
+            .map_err(|e| Error::FdtDumpIoError(e, file_path.clone()))?;
+    }
+
     if fdt_final.len() > fdt_max_size {
         return Err(Error::TotalSizeTooLarge);
     }
@@ -604,11 +609,6 @@
         return Err(Error::FdtGuestMemoryWriteError);
     }
 
-    if let Some(file_path) = dump_device_tree_blob {
-        std::fs::write(&file_path, &fdt_final)
-            .map_err(|e| Error::FdtDumpIoError(e, file_path.clone()))?;
-    }
-
     Ok(())
 }