openkylin
/
platform_system_core
mirror of https://gitee.com/openkylin/platform_system_core.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

Merge "init: more unique_fd, less goto"

This commit is contained in:
Tom Cherry 2017-08-04 20:13:10 +00:00 committed by Gerrit Code Review
parent 59b33cb01c 7c4609cfb3
commit 401c9cb330
1 changed files with 29 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

78
init/init.cpp
View File

@ -73,6 +73,7 @@ using namespace std::string_literals;
using android::base::boot_clock;
using android::base::GetProperty;
using android::base::Timer;
using android::base::unique_fd;
namespace android {
namespace init {
@ -291,65 +292,49 @@ static int wait_for_coldboot_done_action(const std::vector<std::string>& args) {
* time. We do not reboot or halt on failures, as this is a best-effort
* attempt.
*/
static int mix_hwrng_into_linux_rng_action(const std::vector<std::string>& args)
{
int result = -1;
int hwrandom_fd = -1;
int urandom_fd = -1;
char buf[512];
ssize_t chunk_size;
size_t total_bytes_written = 0;
hwrandom_fd = TEMP_FAILURE_RETRY(
open("/dev/hw_random", O_RDONLY | O_NOFOLLOW | O_CLOEXEC));
static int mix_hwrng_into_linux_rng_action(const std::vector<std::string>& args) {
unique_fd hwrandom_fd(
TEMP_FAILURE_RETRY(open("/dev/hw_random", O_RDONLY | O_NOFOLLOW | O_CLOEXEC)));
if (hwrandom_fd == -1) {
if (errno == ENOENT) {
LOG(ERROR) << "/dev/hw_random not found";
LOG(INFO) << "/dev/hw_random not found";
// It's not an error to not have a Hardware RNG.
result = 0;
} else {
PLOG(ERROR) << "Failed to open /dev/hw_random";
return 0;
}
goto ret;
PLOG(ERROR) << "Failed to open /dev/hw_random";
return -1;
}
urandom_fd = TEMP_FAILURE_RETRY(
open("/dev/urandom", O_WRONLY | O_NOFOLLOW | O_CLOEXEC));
unique_fd urandom_fd(
TEMP_FAILURE_RETRY(open("/dev/urandom", O_WRONLY | O_NOFOLLOW | O_CLOEXEC)));
if (urandom_fd == -1) {
PLOG(ERROR) << "Failed to open /dev/urandom";
goto ret;
return -1;
}
char buf[512];
size_t total_bytes_written = 0;
while (total_bytes_written < sizeof(buf)) {
chunk_size = TEMP_FAILURE_RETRY(
read(hwrandom_fd, buf, sizeof(buf) - total_bytes_written));
ssize_t chunk_size =
TEMP_FAILURE_RETRY(read(hwrandom_fd, buf, sizeof(buf) - total_bytes_written));
if (chunk_size == -1) {
PLOG(ERROR) << "Failed to read from /dev/hw_random";
goto ret;
return -1;
} else if (chunk_size == 0) {
LOG(ERROR) << "Failed to read from /dev/hw_random: EOF";
goto ret;
return -1;
}
chunk_size = TEMP_FAILURE_RETRY(write(urandom_fd, buf, chunk_size));
if (chunk_size == -1) {
PLOG(ERROR) << "Failed to write to /dev/urandom";
goto ret;
return -1;
}
total_bytes_written += chunk_size;
}
LOG(INFO) << "Mixed " << total_bytes_written << " bytes from /dev/hw_random into /dev/urandom";
result = 0;
ret:
if (hwrandom_fd != -1) {
close(hwrandom_fd);
}
if (urandom_fd != -1) {
close(urandom_fd);
}
return result;
return 0;
}
static void security_failure() {
@ -425,45 +410,40 @@ static bool __attribute__((unused)) set_mmap_rnd_bits_min(int start, int min, bo
* ec9ee4acd97c drivers: char: random: add get_random_long()
* 5ef11c35ce86 mm: ASLR: use get_random_long()
*/
static int set_mmap_rnd_bits_action(const std::vector<std::string>& args)
{
int ret = -1;
/* values are arch-dependent */
static int set_mmap_rnd_bits_action(const std::vector<std::string>& args) {
/* values are arch-dependent */
#if defined(USER_MODE_LINUX)
/* uml does not support mmap_rnd_bits */
ret = 0;
return 0;
#elif defined(__aarch64__)
/* arm64 supports 18 - 33 bits depending on pagesize and VA_SIZE */
if (set_mmap_rnd_bits_min(33, 24, false)
&& set_mmap_rnd_bits_min(16, 16, true)) {
ret = 0;
return 0;
}
#elif defined(__x86_64__)
/* x86_64 supports 28 - 32 bits */
if (set_mmap_rnd_bits_min(32, 32, false)
&& set_mmap_rnd_bits_min(16, 16, true)) {
ret = 0;
return 0;
}
#elif defined(__arm__) || defined(__i386__)
/* check to see if we're running on 64-bit kernel */
bool h64 = !access(MMAP_RND_COMPAT_PATH, F_OK);
/* supported 32-bit architecture must have 16 bits set */
if (set_mmap_rnd_bits_min(16, 16, h64)) {
ret = 0;
return 0;
}
#elif defined(__mips__) || defined(__mips64__)
// TODO: add mips support b/27788820
ret = 0;
return 0;
#else
LOG(ERROR) << "Unknown architecture";
#endif
if (ret == -1) {
LOG(ERROR) << "Unable to set adequate mmap entropy value!";
security_failure();
}
return ret;
LOG(ERROR) << "Unable to set adequate mmap entropy value!";
security_failure();
return -1;
}
#define KPTR_RESTRICT_PATH "/proc/sys/kernel/kptr_restrict"