| Message ID | 20171106183925.16747-26-marcandre.lureau@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 11/06/2017 01:39 PM, Marc-André Lureau wrote: > 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. Right, so there may be concurrency with the CMD_RESET/GET_TPMESTABLISHED commands. All the other ones shouldn't be affected. It sound like a bug in existing code. > > Add a mutex to protect from concurrent control commands. > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com> > --- > 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)
Hi ----- Original Message ----- > On 11/06/2017 01:39 PM, Marc-André Lureau wrote: > > 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. > > Right, so there may be concurrency with the CMD_RESET/GET_TPMESTABLISHED > commands. All the other ones shouldn't be affected. It sound like a bug > in existing code. > I think so too, I'll rebase on master for 2.11, unless you can trivially cherry-pick it. > > Add a mutex to protect from concurrent control commands. > > > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> > > Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com> > > thanks > > --- > > 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) > > >
On 11/06/2017 05:11 PM, Marc-André Lureau wrote: > Hi > > ----- Original Message ----- >> On 11/06/2017 01:39 PM, Marc-André Lureau wrote: >>> 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. >> Right, so there may be concurrency with the CMD_RESET/GET_TPMESTABLISHED >> commands. All the other ones shouldn't be affected. It sound like a bug >> in existing code. >> > I think so too, I'll rebase on master for 2.11, unless you can trivially cherry-pick it. I could trivially cherry-pick it. Now can I send it as a pull request ? Stefan > >>> Add a mutex to protect from concurrent control commands. >>> >>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> >> Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com> >> >> > thanks > >>> --- >>> 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) >> >>
Hi On Tue, Nov 7, 2017 at 2:11 AM, Stefan Berger <stefanb@linux.vnet.ibm.com> wrote: > On 11/06/2017 05:11 PM, Marc-André Lureau wrote: >> >> Hi >> >> ----- Original Message ----- >>> >>> On 11/06/2017 01:39 PM, Marc-André Lureau wrote: >>>> >>>> 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. >>> >>> Right, so there may be concurrency with the CMD_RESET/GET_TPMESTABLISHED >>> commands. All the other ones shouldn't be affected. It sound like a bug >>> in existing code. >>> >> I think so too, I'll rebase on master for 2.11, unless you can trivially >> cherry-pick it. > > > I could trivially cherry-pick it. Now can I send it as a pull request ? > Sure, thanks! > Stefan > > >> >>>> Add a mutex to protect from concurrent control commands. >>>> >>>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> >>> >>> Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com> >>> >>> >> thanks >> >>>> --- >>>> 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) >>> >>> >>> > >
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)
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 <marcandre.lureau@redhat.com> --- hw/tpm/tpm_emulator.c | 44 ++++++++++++++++++++++++++++---------------- 1 file changed, 28 insertions(+), 16 deletions(-)