[RESEND PATCH v5] soc/fsl/qe: fix err handling of ucc_of_parse_tdm
Peng Hao
peng.hao2 at zte.com.cn
Thu Jan 3 04:09:53 AEDT 2019
From: Wen Yang <wen.yang99 at zte.com.cn>
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 at nxp.com>
Suggested-by: Christophe LEROY <christophe.leroy at c-s.fr>
Signed-off-by: Wen Yang <wen.yang99 at zte.com.cn>
Reviewed-by: Peng Hao <peng.hao2 at zte.com.cn>
CC: Julia Lawall <julia.lawall at lip6.fr>
CC: Zhao Qiang <qiang.zhao at nxp.com>
CC: David S. Miller <davem at davemloft.net>
CC: netdev at vger.kernel.org
CC: linuxppc-dev at lists.ozlabs.org
CC: linux-kernel at vger.kernel.org
---
v5->v4:
- "of_find_device_by_node()" takes a reference to the underlying device structure,
we should release it.
v4->v3:
- This assignment to 'res' doesn't do what you think it does. The caller never
sees the value you compute.
v3->v2:
- 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.
v2->v1:
- 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.
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 839fa77..f30a040 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -1057,6 +1057,54 @@ 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;
@@ -1151,6 +1199,15 @@ 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))
@@ -1159,7 +1216,7 @@ 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);
@@ -1188,6 +1245,9 @@ 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 f78c346..76480df 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);
--
2.9.5
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