[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v2 25/28] tpm-emulator: protect concurrent ctrl_chr
From: |
Marc-André Lureau |
Subject: |
[Qemu-devel] [PATCH v2 25/28] tpm-emulator: protect concurrent ctrl_chr access |
Date: |
Mon, 6 Nov 2017 19:39:22 +0100 |
The control chardev is being used from the data thread to set the
locality of the next request. Altough the chr has a write mutex, we
may potentially read the reply from another thread request.
Add a mutex to protect from concurrent control commands.
Signed-off-by: Marc-André Lureau <address@hidden>
---
hw/tpm/tpm_emulator.c | 44 ++++++++++++++++++++++++++++----------------
1 file changed, 28 insertions(+), 16 deletions(-)
diff --git a/hw/tpm/tpm_emulator.c b/hw/tpm/tpm_emulator.c
index b77c0238c7..24cb61162f 100644
--- a/hw/tpm/tpm_emulator.c
+++ b/hw/tpm/tpm_emulator.c
@@ -71,15 +71,21 @@ typedef struct TPMEmulator {
ptm_cap caps; /* capabilities of the TPM */
uint8_t cur_locty_number; /* last set locality */
Error *migration_blocker;
+
+ QemuMutex mutex;
} TPMEmulator;
-static int tpm_emulator_ctrlcmd(CharBackend *dev, unsigned long cmd, void *msg,
+static int tpm_emulator_ctrlcmd(TPMEmulator *tpm, unsigned long cmd, void *msg,
size_t msg_len_in, size_t msg_len_out)
{
+ CharBackend *dev = &tpm->ctrl_chr;
uint32_t cmd_no = cpu_to_be32(cmd);
ssize_t n = sizeof(uint32_t) + msg_len_in;
uint8_t *buf = NULL;
+ int ret = -1;
+
+ qemu_mutex_lock(&tpm->mutex);
buf = g_alloca(n);
memcpy(buf, &cmd_no, sizeof(cmd_no));
@@ -87,17 +93,21 @@ static int tpm_emulator_ctrlcmd(CharBackend *dev, unsigned
long cmd, void *msg,
n = qemu_chr_fe_write_all(dev, buf, n);
if (n <= 0) {
- return -1;
+ goto end;
}
if (msg_len_out != 0) {
n = qemu_chr_fe_read_all(dev, msg, msg_len_out);
if (n <= 0) {
- return -1;
+ goto end;
}
}
- return 0;
+ ret = 0;
+
+end:
+ qemu_mutex_unlock(&tpm->mutex);
+ return ret;
}
static int tpm_emulator_unix_tx_bufs(TPMEmulator *tpm_emu,
@@ -154,7 +164,7 @@ static int tpm_emulator_set_locality(TPMEmulator *tpm_emu,
uint8_t locty_number,
DPRINTF("setting locality : 0x%x", locty_number);
loc.u.req.loc = locty_number;
- if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_SET_LOCALITY, &loc,
+ if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_LOCALITY, &loc,
sizeof(loc), sizeof(loc)) < 0) {
error_setg(errp, "tpm-emulator: could not set locality : %s",
strerror(errno));
@@ -200,8 +210,8 @@ error:
static int tpm_emulator_probe_caps(TPMEmulator *tpm_emu)
{
DPRINTF("%s", __func__);
- if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_GET_CAPABILITY,
- &tpm_emu->caps, 0, sizeof(tpm_emu->caps)) < 0) {
+ if (tpm_emulator_ctrlcmd(tpm_emu, CMD_GET_CAPABILITY,
+ &tpm_emu->caps, 0, sizeof(tpm_emu->caps)) < 0) {
error_report("tpm-emulator: probing failed : %s", strerror(errno));
return -1;
}
@@ -252,8 +262,8 @@ static int tpm_emulator_startup_tpm(TPMBackend *tb)
ptm_res res;
DPRINTF("%s", __func__);
- if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_INIT, &init, sizeof(init),
- sizeof(init)) < 0) {
+ if (tpm_emulator_ctrlcmd(tpm_emu, CMD_INIT, &init, sizeof(init),
+ sizeof(init)) < 0) {
error_report("tpm-emulator: could not send INIT: %s",
strerror(errno));
goto err_exit;
@@ -276,7 +286,7 @@ static bool
tpm_emulator_get_tpm_established_flag(TPMBackend *tb)
ptm_est est;
DPRINTF("%s", __func__);
- if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_GET_TPMESTABLISHED, &est,
+ if (tpm_emulator_ctrlcmd(tpm_emu, CMD_GET_TPMESTABLISHED, &est,
0, sizeof(est)) < 0) {
error_report("tpm-emulator: Could not get the TPM established flag:
%s",
strerror(errno));
@@ -300,7 +310,7 @@ static int
tpm_emulator_reset_tpm_established_flag(TPMBackend *tb,
}
reset_est.u.req.loc = tpm_emu->cur_locty_number;
- if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_RESET_TPMESTABLISHED,
+ if (tpm_emulator_ctrlcmd(tpm_emu, CMD_RESET_TPMESTABLISHED,
&reset_est, sizeof(reset_est),
sizeof(reset_est)) < 0) {
error_report("tpm-emulator: Could not reset the establishment bit: %s",
@@ -329,7 +339,7 @@ static void tpm_emulator_cancel_cmd(TPMBackend *tb)
}
/* FIXME: make the function non-blocking, or it may block a VCPU */
- if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_CANCEL_TPM_CMD, &res, 0,
+ if (tpm_emulator_ctrlcmd(tpm_emu, CMD_CANCEL_TPM_CMD, &res, 0,
sizeof(res)) < 0) {
error_report("tpm-emulator: Could not cancel command: %s",
strerror(errno));
@@ -377,8 +387,8 @@ static int tpm_emulator_prepare_data_fd(TPMEmulator
*tpm_emu)
qemu_chr_fe_set_msgfds(&tpm_emu->ctrl_chr, fds + 1, 1);
- if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_SET_DATAFD, &res, 0,
- sizeof(res)) || res != 0) {
+ if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SET_DATAFD, &res, 0,
+ sizeof(res)) < 0 || res != 0) {
error_report("tpm-emulator: Failed to send CMD_SET_DATAFD: %s",
strerror(errno));
goto err_exit;
@@ -494,6 +504,7 @@ static void tpm_emulator_inst_init(Object *obj)
DPRINTF("%s", __func__);
tpm_emu->options = g_new0(TPMEmulatorOptions, 1);
tpm_emu->cur_locty_number = ~0;
+ qemu_mutex_init(&tpm_emu->mutex);
}
/*
@@ -503,8 +514,7 @@ static void tpm_emulator_shutdown(TPMEmulator *tpm_emu)
{
ptm_res res;
- if (tpm_emulator_ctrlcmd(&tpm_emu->ctrl_chr, CMD_SHUTDOWN, &res, 0,
- sizeof(res)) < 0) {
+ if (tpm_emulator_ctrlcmd(tpm_emu, CMD_SHUTDOWN, &res, 0, sizeof(res)) < 0)
{
error_report("tpm-emulator: Could not cleanly shutdown the TPM: %s",
strerror(errno));
} else if (res != 0) {
@@ -529,6 +539,8 @@ static void tpm_emulator_inst_finalize(Object *obj)
migrate_del_blocker(tpm_emu->migration_blocker);
error_free(tpm_emu->migration_blocker);
}
+
+ qemu_mutex_destroy(&tpm_emu->mutex);
}
static void tpm_emulator_class_init(ObjectClass *klass, void *data)
--
2.15.0.rc0.40.gaefcc5f6f
- [Qemu-devel] [PATCH v2 17/28] tpm: rename qemu_find_tpm() -> qemu_find_tpm_be(), (continued)
- [Qemu-devel] [PATCH v2 17/28] tpm: rename qemu_find_tpm() -> qemu_find_tpm_be(), Marc-André Lureau, 2017/11/06
- [Qemu-devel] [PATCH v2 18/28] tpm: lookup the the TPM interface instead of TIS device, Marc-André Lureau, 2017/11/06
- [Qemu-devel] [PATCH v2 19/28] tpm: add TPM interface to lookup TPM version, Marc-André Lureau, 2017/11/06
- [Qemu-devel] [PATCH v2 20/28] tpm: add tpm_cmd_get_size() to tpm_util, Marc-André Lureau, 2017/11/06
- [Qemu-devel] [PATCH v2 21/28] acpi: change TPM TIS data conditions, Marc-André Lureau, 2017/11/06
- [Qemu-devel] [PATCH v2 22/28] tpm-emulator: add a FIXME comment about blocking cancel, Marc-André Lureau, 2017/11/06
- [Qemu-devel] [PATCH v2 23/28] tpm-tis: remove redundant 'tpm_tis:' in error messages, Marc-André Lureau, 2017/11/06
- [Qemu-devel] [PATCH v2 24/28] tpm-tis: check that at most one TPM device exists, Marc-André Lureau, 2017/11/06
- [Qemu-devel] [PATCH v2 25/28] tpm-emulator: protect concurrent ctrl_chr access,
Marc-André Lureau <=
[Qemu-devel] [PATCH v2 26/28] qdev: add DEFINE_PROP_TPMBE, Marc-André Lureau, 2017/11/06
[Qemu-devel] [PATCH v2 27/28] tpm-tis: use DEFINE_PROP_TPMBE, Marc-André Lureau, 2017/11/06
[Qemu-devel] [PATCH v2 28/28] tpm: remove tpm_register_model(), Marc-André Lureau, 2017/11/06