crosvm: add debug labels to devices for improved SIGCHLD logs

Each device (Bus, Pci, Proxy, etc), gets a debug label associated with
it. When a child is spawned, the debug label for it is stored in
a map with the child's pid as the key. If a SIGCHLD is handled, this map
is used to print a more helpful message about exactly which child died.

BUG=None
TEST=run with sandboxing and a faulty child device
     check logs for message about child died
     the child should have a debug label

Change-Id: I61fbbee0a8e701249533a7a3a6a1ad48840f12e5
Reviewed-on: https://chromium-review.googlesource.com/1432835
Commit-Ready: Chih-Yang Hsia <paulhsia@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/aarch64/src/lib.rs b/aarch64/src/lib.rs
index dda7bfc..d579a17 100644
--- a/aarch64/src/lib.rs
+++ b/aarch64/src/lib.rs
@@ -227,7 +227,7 @@ impl arch::LinuxArch for AArch64 {
         let exit_evt = EventFd::new().map_err(Error::CreateEventFd)?;
 
         let pci_devices = virtio_devs(&mem, &exit_evt)?;
-        let (pci, pci_irqs) =
+        let (pci, pci_irqs, pid_debug_label_map) =
             arch::generate_pci_root(pci_devices, &mut mmio_bus, &mut resources, &mut vm)
                 .map_err(Error::CreatePciRoot)?;
         let pci_bus = Arc::new(Mutex::new(PciConfigMmio::new(pci)));
@@ -277,6 +277,7 @@ impl arch::LinuxArch for AArch64 {
             irq_chip,
             io_bus,
             mmio_bus,
+            pid_debug_label_map,
         })
     }
 }