Merge remote-tracking branch 'origin/lineage-19.1' into v1-s (927a8415) · Commits · e / os / android_system_core

libcutils/ashmem-dev.cpp

+25 −4

Original line number	Original line	Diff line number	Diff line
	@@ -349,6 +349,12 @@ static int memfd_create_region(const char* name, size_t size) {
	return -1;		return -1;
	}		}

			// forbid size changes to match ashmem behaviour
			if (fcntl(fd, F_ADD_SEALS, F_SEAL_GROW \| F_SEAL_SHRINK) == -1) {
			ALOGE("memfd_create(%s, %zd) F_ADD_SEALS failed: %m", name, size);
			return -1;
			}

	if (debug_log) {		if (debug_log) {
	ALOGE("memfd_create(%s, %zd) success. fd=%d\n", name, size, fd.get());		ALOGE("memfd_create(%s, %zd) success. fd=%d\n", name, size, fd.get());
	}		}
	@@ -400,14 +406,29 @@ error:
	}		}

	static int memfd_set_prot_region(int fd, int prot) {		static int memfd_set_prot_region(int fd, int prot) {
	/* Only proceed if an fd needs to be write-protected */		int seals = fcntl(fd, F_GET_SEALS);
			if (seals == -1) {
			ALOGE("memfd_set_prot_region(%d, %d): F_GET_SEALS failed: %s\n", fd, prot, strerror(errno));
			return -1;
			}

	if (prot & PROT_WRITE) {		if (prot & PROT_WRITE) {
			/* Now we want the buffer to be read-write, let's check if the buffer
			* has been previously marked as read-only before, if so return error
			*/
			if (seals & F_SEAL_FUTURE_WRITE) {
			ALOGE("memfd_set_prot_region(%d, %d): region is write protected\n", fd, prot);
			errno = EINVAL; // inline with ashmem error code, if already in
			// read-only mode
			return -1;
			}
	return 0;		return 0;
	}		}

	if (fcntl(fd, F_ADD_SEALS, F_SEAL_FUTURE_WRITE) == -1) {		/* We would only allow read-only for any future file operations */
	ALOGE("memfd_set_prot_region(%d, %d): F_SEAL_FUTURE_WRITE seal failed: %s\n", fd, prot,		if (fcntl(fd, F_ADD_SEALS, F_SEAL_FUTURE_WRITE \| F_SEAL_SEAL) == -1) {
	strerror(errno));		ALOGE("memfd_set_prot_region(%d, %d): F_SEAL_FUTURE_WRITE \| F_SEAL_SEAL seal failed: %s\n",
			fd, prot, strerror(errno));
	return -1;		return -1;
	}		}