There is a problem with RPMB access on systems which use eMMC as
default storage.
According to specs, RPMB requires multiple commands to be sent
right one after another, in another case, if there are some other
commands between them, RPMB will fail with status 0x0001. This case
is common for systems which use eMMC as default system storage.
In current version of mmc-utils RPMB operations are performed as
a sequence of MMC_IOC_CMD ioctl calls. Between these calls eMMC is
unlocked and may be used by mmc driver, so RPMB session will be broken.
In Linux 4.4+, there is MMC_IOC_MULTI_CMD ioctl which allows to perform
multiple IOC_CMDs in one request. This is a better way to work with
RPMB, because eMMC is supposed to be locked during ioctl.
I included the patch which tries to use MMC_IOC_MULTI_CMD for RPMB
operations. If it fails with EINVAL, it tries to use MMC_IOC_CMD
(for compatibility).
This patch was tested on ARM systems (armel) with eMMC chips from
Micron and SanDisk.
All suggestions are welcomed.
P.S. This patch was sent to Debian bug tracking system but was left
without reply, so I decided to send it here.
-- System Information:
Debian Release: buster/sid
APT prefers testing
APT policy: (900, 'testing'), (500, 'testing-debug'), (10, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 4.14.0-3-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages mmc-utils depends on:
ii libc6 2.26-6
mmc-utils recommends no packages.
mmc-utils suggests no packages.
-- no debconf information
Author: Nikita Maslov <wkernelt...@xxxxxxxxx>
Description: Use MMC_IOC_MULTI_CMD for RPMB access
On some systems which use MMC as a main storage device
it is possible that RPMB commands are mixed with
generic MMC access commands which invalidates RPMB.
This patch uses MMC_IOC_MULTI_CMD.
.
mmc-utils (0+git20170901.37c86e60-1) unstable; urgency=medium
.
* Snapshot, taken from the master (20170901).
* Update supporting version of debhelper to 10.
* Update Standards-Version to 4.1.0.
Last-Update: 2018-03-07
---
--- mmc-utils-0+git20170901.37c86e60.orig/mmc_cmds.c
+++ mmc-utils-0+git20170901.37c86e60/mmc_cmds.c
@@ -1799,6 +1799,8 @@ int do_sanitize(int nargs, char **argv)
ret;
\
})
+#define RMPB_MULTI_CMD_MAX_CMDS 3
+
enum rpmb_op_type {
MMC_RPMB_WRITE_KEY = 0x01,
MMC_RPMB_READ_CNT = 0x02,
@@ -1837,8 +1839,9 @@ static int do_rpmb_op(int fd,
{
int err;
u_int16_t rpmb_type;
+ unsigned i;
- struct mmc_ioc_cmd ioc = {
+ struct mmc_ioc_cmd ioc_base = {
.arg = 0x0,
.blksz = 512,
.blocks = 1,
@@ -1848,9 +1851,24 @@ static int do_rpmb_op(int fd,
.data_ptr = (uintptr_t)frame_in
};
+ struct mmc_ioc_multi_cmd *mioc;
+ struct mmc_ioc_cmd *ioc;
+
if (!frame_in || !frame_out || !out_cnt)
return -EINVAL;
+ /* prepare arguments for MMC_IOC_MUTLI_CMD ioctl */
+ mioc = (struct mmc_ioc_multi_cmd *)
+ malloc(sizeof (struct mmc_ioc_multi_cmd) +
+ RMPB_MULTI_CMD_MAX_CMDS * sizeof (struct
mmc_ioc_cmd));
+ if (!mioc) {
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < RMPB_MULTI_CMD_MAX_CMDS; i++) {
+ memcpy(&mioc->cmds[i], &ioc_base, sizeof (ioc_base));
+ }
+
rpmb_type = be16toh(frame_in->req_resp);
switch(rpmb_type) {
@@ -1861,33 +1879,24 @@ static int do_rpmb_op(int fd,
goto out;
}
+ /* try to use multi_cmd if possible */
+ mioc->num_of_cmds = 3;
+
/* Write request */
- ioc.write_flag |= (1<<31);
- err = ioctl(fd, MMC_IOC_CMD, &ioc);
- if (err < 0) {
- err = -errno;
- goto out;
- }
+ ioc = &mioc->cmds[0];
+ ioc->write_flag |= (1<<31);
/* Result request */
+ ioc = &mioc->cmds[1];
memset(frame_out, 0, sizeof(*frame_out));
frame_out->req_resp = htobe16(MMC_RPMB_READ_RESP);
- ioc.write_flag = 1;
- ioc.data_ptr = (uintptr_t)frame_out;
- err = ioctl(fd, MMC_IOC_CMD, &ioc);
- if (err < 0) {
- err = -errno;
- goto out;
- }
+ ioc->write_flag = 1;
+ ioc->data_ptr = (uintptr_t)frame_out;
/* Get response */
- ioc.write_flag = 0;
- ioc.opcode = MMC_READ_MULTIPLE_BLOCK;
- err = ioctl(fd, MMC_IOC_CMD, &ioc);
- if (err < 0) {
- err = -errno;
- goto out;
- }
+ ioc = &mioc->cmds[2];
+ ioc->write_flag = 0;
+ ioc->opcode = MMC_READ_MULTIPLE_BLOCK;
break;
case MMC_RPMB_READ_CNT:
@@ -1898,23 +1907,17 @@ static int do_rpmb_op(int fd,
/* fall through */
case MMC_RPMB_READ:
- /* Request */
- err = ioctl(fd, MMC_IOC_CMD, &ioc);
- if (err < 0) {
- err = -errno;
- goto out;
- }
+
+ mioc->num_of_cmds = 2;
+
+ /* Request is the same as ioc_base; don't change mioc->cmds[0]
*/
/* Get response */
- ioc.write_flag = 0;
- ioc.opcode = MMC_READ_MULTIPLE_BLOCK;
- ioc.blocks = out_cnt;
- ioc.data_ptr = (uintptr_t)frame_out;
- err = ioctl(fd, MMC_IOC_CMD, &ioc);
- if (err < 0) {
- err = -errno;
- goto out;
- }
+ ioc = &mioc->cmds[1];
+ ioc->write_flag = 0;
+ ioc->opcode = MMC_READ_MULTIPLE_BLOCK;
+ ioc->blocks = out_cnt;
+ ioc->data_ptr = (uintptr_t)frame_out;
break;
default:
@@ -1922,7 +1925,26 @@ static int do_rpmb_op(int fd,
goto out;
}
+ /* Try to use MMC_IOC_MULTI_CMD */
+ err = ioctl(fd, MMC_IOC_MULTI_CMD, mioc);
+
+ /* If MMC_IOC_MULTI_CMD is not supported, run single commands */
+ if (err < 0 && errno == EINVAL) {
+ for (i = 0; i < mioc->num_of_cmds; i++) {
+ err = ioctl(fd, MMC_IOC_CMD, &mioc->cmds[i]);
+ if (err < 0) {
+ err = -errno;
+ goto out;
+ }
+ }
+ } else if (err < 0) {
+ err = -errno;
+ goto out;
+ }
+
+
out:
+ free(mioc);
return err;
}
