libhealthloop: Only wake up for power supply events
healthd receives power supply information as uevents and holds a
wakelock while receiving these uevents. Without uevent filter, suspend
is postponed indefinitely if a uevent is generated during suspend. Fix
this by attaching a BPF program to the uevent socket that filters out
all events that are not power supply events.
This CL replaces the following CLs:
* Lianwei Wang, healthd: Don't set all eventpoll wakeup-able,
2015-07-09
(https://android-review.googlesource.com/c/platform/system/core/+/158851).
* Stephane Lee, Add BPF filter to filter uevents for
SUBSYSTEM=powersupply, 2022-05-06.
Multiple ideas and some code in this CL have been borrowed from
Stephane Lee's CL.
Bug: 139203596
Bug: 140330870
Bug: 203131934
Bug: 203229817
Bug: 203462310
Bug: 221725014
Test: Verified that a Pixel 2024 still wakes up if a USB cable is connected or disconnected.
Test: Verified that suspend and resume still works for a Pixel 2024 device.
Test: Verified that the following text appears in the Cuttlefish logcat output: "HealthLoop: Successfully attached BPF program to uevent socket"
Test: Verified as follows that recovery mode works fine with Cuttlefish: adb reboot recovery && adb root && adb shell dmesg | grep -E 'F DEBUG|HealthLoop'
Change-Id: I64446b103d660d220880461bdef7ef0f531e1734
Signed-off-by: Bart Van Assche <bvanassche@google.com>
diff --git a/health/utils/libhealthloop/Android.bp b/health/utils/libhealthloop/Android.bp
index b266f67..4ebc575 100644
--- a/health/utils/libhealthloop/Android.bp
+++ b/health/utils/libhealthloop/Android.bp
@@ -21,6 +21,17 @@
default_applicable_licenses: ["hardware_interfaces_license"],
}
+bpf {
+ name: "filterPowerSupplyEvents.o",
+ srcs: ["filterPowerSupplyEvents.c"],
+ // "vendor: true" because all binaries that use this BPF filter are vendor
+ // binaries.
+ vendor: true,
+}
+
+// Since "required" sections are ignored in static library definitions,
+// filterPowerSupplyEvents.o has been added in
+// build/make/target/product/base_vendor.mk.
cc_library_static {
name: "libhealthloop",
vendor_available: true,
@@ -34,6 +45,7 @@
"libcutils",
],
header_libs: [
+ "bpf_headers",
"libbatteryservice_headers",
"libhealthd_headers",
"libutils_headers",
@@ -42,3 +54,30 @@
"include",
],
}
+
+genrule {
+ name: "filterPowerSupplyEvents.h",
+ out: ["filterPowerSupplyEvents.h"],
+ srcs: [":filterPowerSupplyEvents.o"],
+ cmd: "cat $(in) | od -v -tx1 | cut -c9- | grep -v '^$$' | sed 's/^/0x/;s/ /, 0x/g;s/^, //;s/$$/,/' > $(out)",
+}
+
+cc_test_host {
+ name: "filterPowerSupplyEventsTest",
+ team: "trendy_team_pixel_system_sw_storage",
+ srcs: [
+ "filterPowerSupplyEventsTest.cpp",
+ ],
+ shared_libs: [
+ "libbase",
+ "libbpf",
+ ],
+ static_libs: [
+ "libgmock",
+ ],
+ generated_headers: [
+ "filterPowerSupplyEvents.h",
+ "libbpf_headers",
+ ],
+ compile_multilib: "64",
+}