Merge "ueventd: scans /apex/*/firmware for firmwares" (62ccfa0c) · Commits · e / os / android_system_core

init/README.ueventd.md

+2 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,8 @@ Ueventd by default serves firmware requests by searching through a list of firmw
		for a file matching the uevent `FIRMWARE`. It then forks a process to serve this firmware to the
		kernel.

		`/apex/*/firmware` is also searched after a list of firmware directories.

		The list of firmware directories is customized by a `firmware_directories` line in a ueventd.rc
		file. This line takes the format of

init/firmware_handler.cpp

+39 −7

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		#include "firmware_handler.h"

		#include <fcntl.h>
		#include <glob.h>
		#include <pwd.h>
		#include <signal.h>
		#include <stdlib.h>
		@@ -30,6 +31,7 @@
		#include <android-base/chrono_utils.h>
		#include <android-base/file.h>
		#include <android-base/logging.h>
		#include <android-base/scopeguard.h>
		#include <android-base/strings.h>
		#include <android-base/unique_fd.h>

		@@ -203,25 +205,28 @@ void FirmwareHandler::ProcessFirmwareEvent(const std::string& root,
		}

		std::vector<std::string> attempted_paths_and_errors;

		int booting = IsBooting();
		try_loading_again:
		attempted_paths_and_errors.clear();
		for (const auto& firmware_directory : firmware_directories_) {
		auto TryLoadFirmware = [&](const std::string& firmware_directory) {
		std::string file = firmware_directory + firmware;
		unique_fd fw_fd(open(file.c_str(), O_RDONLY \| O_CLOEXEC));
		if (fw_fd == -1) {
		attempted_paths_and_errors.emplace_back("firmware: attempted " + file +
		", open failed: " + strerror(errno));
		continue;
		return false;
		}
		struct stat sb;
		if (fstat(fw_fd, &sb) == -1) {
		attempted_paths_and_errors.emplace_back("firmware: attempted " + file +
		", fstat failed: " + strerror(errno));
		continue;
		return false;
		}
		LoadFirmware(firmware, root, fw_fd, sb.st_size, loading_fd, data_fd);
		return true;
		};

		int booting = IsBooting();
		try_loading_again:
		attempted_paths_and_errors.clear();
		if (ForEachFirmwareDirectory(TryLoadFirmware)) {
		return;
		}

		@@ -242,6 +247,33 @@ try_loading_again:
		write(loading_fd, "-1", 2);
		}

		bool FirmwareHandler::ForEachFirmwareDirectory(
		std::function<bool(const std::string&)> handler) const {
		for (const std::string& firmware_directory : firmware_directories_) {
		if (std::invoke(handler, firmware_directory)) {
		return true;
		}
		}

		glob_t glob_result;
		glob("/apex/*/firmware/", GLOB_MARK, nullptr, &glob_result);
		auto free_glob = android::base::make_scope_guard(std::bind(&globfree, &glob_result));
		for (size_t i = 0; i < glob_result.gl_pathc; i++) {
		char* apex_firmware_directory = glob_result.gl_pathv[i];
		// Filter-out /apex/<name>@<ver> paths. The paths are bind-mounted to
		// /apex/<name> paths, so unless we filter them out, we will look into the
		// same apex twice.
		if (strchr(apex_firmware_directory, '@')) {
		continue;
		}
		if (std::invoke(handler, apex_firmware_directory)) {
		return true;
		}
		}

		return false;
		}

		void FirmwareHandler::HandleUevent(const Uevent& uevent) {
		if (uevent.subsystem != "firmware" \|\| uevent.action != "add") return;

init/firmware_handler.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@

		#include <pwd.h>

		#include <functional>
		#include <string>
		#include <vector>

		@@ -52,6 +53,7 @@ class FirmwareHandler : public UeventHandler {
		const Uevent& uevent) const;
		std::string GetFirmwarePath(const Uevent& uevent) const;
		void ProcessFirmwareEvent(const std::string& root, const std::string& firmware) const;
		bool ForEachFirmwareDirectory(std::function<bool(const std::string&)> handler) const;

		std::vector<std::string> firmware_directories_;
		std::vector<ExternalFirmwareHandler> external_firmware_handlers_;