I recompiled a custom 5.15 kernel for my Android Pixel 6 phone with Android 13 with event tracing enabled (especially syscall tracepoints).
After booting, the kernel does not have the /sys/kernel/tracing/events/syscalls directory and the syscall tracepoints are not registered in /sys/kernel/debug/tracing/available_events.

When compiling for an x86_64 architecture, it works. And it also works with Android 14, kernel 6.1 and aarch64 architecture.

Here are the steps I followed:

For Android 13, kernel 5.15, aarch64 (not working)

• Use branch gs-android13-gs-raviole-5.15

• Run BUILD_CONFIG=common/build.config.gki.aarch64 build/config.sh

• Activate the following options

CONFIG_DEBUG_INFO=y 
CONFIG_DEBUG_INFO_BTF=y
CONFIG_SECURITY=y
CONFIG_SECURITYFS=y
CONFIG_SECURITY_NEWORK=y
CONFIG_FUNCTION_TRACER=y
CONFIG_FTRACE_SYSCALLS=y

• Run tools/bazel run --lto=thin //gs/google-modules/soc-modules:slider_dist

• Flash boot.img, dtbo.img, vendor_boot.img and vendor_dlkm.img as described in the “Building Pixel kernels” documentation.

I also tried without --lto=thin but without success.

For Android 13, kernel 5.15, x86_64 architecture on Cuttlefish (Working !!!)

• Use branch common-android13-5.15

• Run BUILD_CONFIG=common/build.config.gki.x86_64 build/config.sh and activate the same options as before

• Run BUILD_CONFIG=common/build.config.gki.x86_64 build/build.sh and then BUILD_CONFIG=common-modules/virtual-device/build.config.virtual_device.x86_64 build/build.sh

I inspected the custom kernel configuration through /proc/config.gz and everything seems to be consistent with the custom compilation options.

I am wondering whether the prebuilt elements could cause any problem.

Otherwise, I do not understand why it works with x86_64 (common GKI kernel) and not with aarch64 (Pixel 6 kernel that should be derived from the GKI kernel).

Any help would be very appreciated.

Thanks !