[PATCH AUTOSEL 4.20 022/105] soc/fsl/qe: fix err handling of ucc_of_parse_tdm

Sasha Levin
2019-02-13T03:05:09Z

From: Wen Yang <wen.yang99@zte.com.cn>

[ Upstream commit 8d68100ab4ad92560a16a68b72e068613ac4d573 ]

Currently there are some issues with the ucc_of_parse_tdm function:
1, a possible null pointer dereference in ucc_of_parse_tdm,
detected by the semantic patch deref_null.cocci,
with the following warning:
drivers/soc/fsl/qe/qe_tdm.c:177:21-24: ERROR: pdev is NULL but dereferenced.
2, dev gets modified, so in any case that devm_iounmap() will fail
even when the new pdev is valid, because the iomap was done with a
different pdev.
3, there is no driver bind with the "fsl,t1040-qe-si" or
"fsl,t1040-qe-siram" device. So allocating resources using devm_*()
with these devices won't provide a cleanup path for these resources
when the caller fails.

This patch fixes them.

Suggested-by: Li Yang <leoyang.li@nxp.com>
Suggested-by: Christophe LEROY <christophe.leroy@c-s.fr>
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Reviewed-by: Peng Hao <peng.hao2@zte.com.cn>
CC: Julia Lawall <julia.lawall@lip6.fr>
CC: Zhao Qiang <qiang.zhao@nxp.com>
CC: David S. Miller <davem@davemloft.net>
CC: netdev@vger.kernel.org
CC: linuxppc-dev@lists.ozlabs.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wan/fsl_ucc_hdlc.c | 62 +++++++++++++++++++++++++++++++++-
drivers/soc/fsl/qe/qe_tdm.c | 55 ------------------------------
2 files changed, 61 insertions(+), 56 deletions(-)

diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index 4d6409605207..af13d8cf94ad 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -1049,6 +1049,54 @@ static const struct net_device_ops uhdlc_ops = {
.ndo_tx_timeout = uhdlc_tx_timeout,
};

+static int hdlc_map_iomem(char *name, int init_flag, void __iomem **ptr)
+{
+ struct device_node *np;
+ struct platform_device *pdev;
+ struct resource *res;
+ static int siram_init_flag;
+ int ret = 0;
+
+ np = of_find_compatible_node(NULL, NULL, name);
+ if (!np)
+ return -EINVAL;
+
+ pdev = of_find_device_by_node(np);
+ if (!pdev) {
+ pr_err("%pOFn: failed to lookup pdev\n", np);
+ of_node_put(np);
+ return -EINVAL;
+ }
+
+ of_node_put(np);
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ ret = -EINVAL;
+ goto error_put_device;
+ }
+ *ptr = ioremap(res->start, resource_size(res));
+ if (!*ptr) {
+ ret = -ENOMEM;
+ goto error_put_device;
+ }
+
+ /* We've remapped the addresses, and we don't need the device any
+ * more, so we should release it.
+ */
+ put_device(&pdev->dev);
+
+ if (init_flag && siram_init_flag == 0) {
+ memset_io(*ptr, 0, resource_size(res));
+ siram_init_flag = 1;
+ }
+ return 0;
+
+error_put_device:
+ put_device(&pdev->dev);
+
+ return ret;
+}
+
static int ucc_hdlc_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
@@ -1143,6 +1191,15 @@ static int ucc_hdlc_probe(struct platform_device *pdev)
ret = ucc_of_parse_tdm(np, utdm, ut_info);
if (ret)
goto free_utdm;
+
+ ret = hdlc_map_iomem("fsl,t1040-qe-si", 0,
+ (void __iomem **)&utdm->si_regs);
+ if (ret)
+ goto free_utdm;
+ ret = hdlc_map_iomem("fsl,t1040-qe-siram", 1,
+ (void __iomem **)&utdm->siram);
+ if (ret)
+ goto unmap_si_regs;
}

if (of_property_read_u16(np, "fsl,hmask", &uhdlc_priv->hmask))
@@ -1151,7 +1208,7 @@ static int ucc_hdlc_probe(struct platform_device *pdev)
ret = uhdlc_init(uhdlc_priv);
if (ret) {
dev_err(&pdev->dev, "Failed to init uhdlc\n");
- goto free_utdm;
+ goto undo_uhdlc_init;
}

dev = alloc_hdlcdev(uhdlc_priv);
@@ -1181,6 +1238,9 @@ static int ucc_hdlc_probe(struct platform_device *pdev)
free_dev:
free_netdev(dev);
undo_uhdlc_init:
+ iounmap(utdm->siram);
+unmap_si_regs:
+ iounmap(utdm->si_regs);
free_utdm:
if (uhdlc_priv->tsa)
kfree(utdm);
diff --git a/drivers/soc/fsl/qe/qe_tdm.c b/drivers/soc/fsl/qe/qe_tdm.c
index f78c34647ca2..76480df195a8 100644
--- a/drivers/soc/fsl/qe/qe_tdm.c
+++ b/drivers/soc/fsl/qe/qe_tdm.c
@@ -44,10 +44,6 @@ int ucc_of_parse_tdm(struct device_node *np, struct ucc_tdm *utdm,
const char *sprop;
int ret = 0;
u32 val;
- struct resource *res;
- struct device_node *np2;
- static int siram_init_flag;
- struct platform_device *pdev;

sprop = of_get_property(np, "fsl,rx-sync-clock", NULL);
if (sprop) {
@@ -124,57 +120,6 @@ int ucc_of_parse_tdm(struct device_node *np, struct ucc_tdm *utdm,
utdm->siram_entry_id = val;

set_si_param(utdm, ut_info);
-
- np2 = of_find_compatible_node(NULL, NULL, "fsl,t1040-qe-si");
- if (!np2)
- return -EINVAL;
-
- pdev = of_find_device_by_node(np2);
- if (!pdev) {
- pr_err("%pOFn: failed to lookup pdev\n", np2);
- of_node_put(np2);
- return -EINVAL;
- }
-
- of_node_put(np2);
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- utdm->si_regs = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(utdm->si_regs)) {
- ret = PTR_ERR(utdm->si_regs);
- goto err_miss_siram_property;
- }
-
- np2 = of_find_compatible_node(NULL, NULL, "fsl,t1040-qe-siram");
- if (!np2) {
- ret = -EINVAL;
- goto err_miss_siram_property;
- }
-
- pdev = of_find_device_by_node(np2);
- if (!pdev) {
- ret = -EINVAL;
- pr_err("%pOFn: failed to lookup pdev\n", np2);
- of_node_put(np2);
- goto err_miss_siram_property;
- }
-
- of_node_put(np2);
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- utdm->siram = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(utdm->siram)) {
- ret = PTR_ERR(utdm->siram);
- goto err_miss_siram_property;
- }
-
- if (siram_init_flag == 0) {
- memset_io(utdm->siram, 0, resource_size(res));
- siram_init_flag = 1;
- }
-
- return ret;
-
-err_miss_siram_property:
- devm_iounmap(&pdev->dev, utdm->si_regs);
return ret;
}
EXPORT_SYMBOL(ucc_of_parse_tdm);
--
2.19.1