[PATCH 4.19 079/190] crypto: ccree - fix resume race condition on init

Greg Kroah-Hartman
2019-09-13T13:14:45Z

[ Upstream commit 1358c13a48c43f5e4de0c1835291837a27b9720c ]

We were enabling autosuspend, which is using data set by the
hash module, prior to the hash module being inited, casuing
a crash on resume as part of the startup sequence if the race
was lost.

This was never a real problem because the PM infra was using low
res timers so we were always winning the race, until commit 8234f6734c5d
("PM-runtime: Switch autosuspend over to using hrtimers") changed that :-)

Fix this by seperating the PM setup and enablement and doing the
latter only at the end of the init sequence.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: stable@kernel.org # v4.20
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/crypto/ccree/cc_driver.c | 7 ++++---
drivers/crypto/ccree/cc_pm.c | 13 ++++++-------
drivers/crypto/ccree/cc_pm.h | 3 +++
3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/ccree/cc_driver.c b/drivers/crypto/ccree/cc_driver.c
index 1ff229c2aeab1..186a2536fb8b9 100644
--- a/drivers/crypto/ccree/cc_driver.c
+++ b/drivers/crypto/ccree/cc_driver.c
@@ -364,7 +364,7 @@ static int init_cc_resources(struct platform_device *plat_dev)
rc = cc_ivgen_init(new_drvdata);
if (rc) {
dev_err(dev, "cc_ivgen_init failed\n");
- goto post_power_mgr_err;
+ goto post_buf_mgr_err;
}

/* Allocate crypto algs */
@@ -387,6 +387,9 @@ static int init_cc_resources(struct platform_device *plat_dev)
goto post_hash_err;
}

+ /* All set, we can allow autosuspend */
+ cc_pm_go(new_drvdata);
+
/* If we got here and FIPS mode is enabled
* it means all FIPS test passed, so let TEE
* know we're good.
@@ -401,8 +404,6 @@ post_cipher_err:
cc_cipher_free(new_drvdata);
post_ivgen_err:
cc_ivgen_fini(new_drvdata);
-post_power_mgr_err:
- cc_pm_fini(new_drvdata);
post_buf_mgr_err:
cc_buffer_mgr_fini(new_drvdata);
post_req_mgr_err:
diff --git a/drivers/crypto/ccree/cc_pm.c b/drivers/crypto/ccree/cc_pm.c
index 79fc0a37ba6e4..638082dff183a 100644
--- a/drivers/crypto/ccree/cc_pm.c
+++ b/drivers/crypto/ccree/cc_pm.c
@@ -103,20 +103,19 @@ int cc_pm_put_suspend(struct device *dev)

int cc_pm_init(struct cc_drvdata *drvdata)
{
- int rc = 0;
struct device *dev = drvdata_to_dev(drvdata);

/* must be before the enabling to avoid resdundent suspending */
pm_runtime_set_autosuspend_delay(dev, CC_SUSPEND_TIMEOUT);
pm_runtime_use_autosuspend(dev);
/* activate the PM module */
- rc = pm_runtime_set_active(dev);
- if (rc)
- return rc;
- /* enable the PM module*/
- pm_runtime_enable(dev);
+ return pm_runtime_set_active(dev);
+}

- return rc;
+/* enable the PM module*/
+void cc_pm_go(struct cc_drvdata *drvdata)
+{
+ pm_runtime_enable(drvdata_to_dev(drvdata));
}

void cc_pm_fini(struct cc_drvdata *drvdata)
diff --git a/drivers/crypto/ccree/cc_pm.h b/drivers/crypto/ccree/cc_pm.h
index 020a5403c58ba..f626243570209 100644
--- a/drivers/crypto/ccree/cc_pm.h
+++ b/drivers/crypto/ccree/cc_pm.h
@@ -16,6 +16,7 @@
extern const struct dev_pm_ops ccree_pm;

int cc_pm_init(struct cc_drvdata *drvdata);
+void cc_pm_go(struct cc_drvdata *drvdata);
void cc_pm_fini(struct cc_drvdata *drvdata);
int cc_pm_suspend(struct device *dev);
int cc_pm_resume(struct device *dev);
@@ -29,6 +30,8 @@ static inline int cc_pm_init(struct cc_drvdata *drvdata)
return 0;
}

+static void cc_pm_go(struct cc_drvdata *drvdata) {}
+
static inline void cc_pm_fini(struct cc_drvdata *drvdata) {}

static inline int cc_pm_suspend(struct device *dev)
--
2.20.1