* [PATCH v2] ocxl: fix pci device refcount leak when calling get_function_0()
@ 2022-11-21 15:43 Yang Yingliang
2022-11-22 0:47 ` Andrew Donnellan
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Yang Yingliang @ 2022-11-21 15:43 UTC (permalink / raw)
To: fbarrat, ajd, arnd, gregkh, mpe; +Cc: linuxppc-dev, yangyingliang
get_function_0() calls pci_get_domain_bus_and_slot(), as comment
says, it returns a pci device with refcount increment, so after
using it, pci_dev_put() needs be called.
Get the device reference when get_function_0() is not called, so
pci_dev_put() can be called in the error path and callers
unconditionally. And add comment above get_dvsec_vendor0() to tell
callers to call pci_dev_put().
Fixes: 87db7579ebd5 ("ocxl: control via sysfs whether the FPGA is reloaded on a link reset")
Suggested-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
v1 -> v2:
Add comment above get_dvsec_vendor0().
Get reference where dev is function 0, and call pci_dev_put()
unconditionally in callers.
---
drivers/misc/ocxl/config.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
index e401a51596b9..92ab49705f64 100644
--- a/drivers/misc/ocxl/config.c
+++ b/drivers/misc/ocxl/config.c
@@ -193,6 +193,18 @@ static int read_dvsec_vendor(struct pci_dev *dev)
return 0;
}
+/**
+ * get_dvsec_vendor0() - Find a related PCI device (function 0)
+ * @dev: PCI device to match
+ * @dev0: The PCI device (function 0) found
+ * @out_pos: The position of PCI device (function 0)
+ *
+ * Returns 0 on success, negative on failure.
+ *
+ * NOTE: If it's successful, the reference of dev0 is increased,
+ * so after using it, the callers must call pci_dev_put() to give
+ * up the reference.
+ */
static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0,
int *out_pos)
{
@@ -202,10 +214,14 @@ static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0,
dev = get_function_0(dev);
if (!dev)
return -1;
+ } else {
+ dev = pci_dev_get(dev);
}
pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID);
- if (!pos)
+ if (!pos) {
+ pci_dev_put(dev);
return -1;
+ }
*dev0 = dev;
*out_pos = pos;
return 0;
@@ -222,6 +238,7 @@ int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val)
pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,
&reset_reload);
+ pci_dev_put(dev0);
*val = !!(reset_reload & BIT(0));
return 0;
}
@@ -243,6 +260,7 @@ int ocxl_config_set_reset_reload(struct pci_dev *dev, int val)
reset_reload &= ~BIT(0);
pci_write_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,
reset_reload);
+ pci_dev_put(dev0);
return 0;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2] ocxl: fix pci device refcount leak when calling get_function_0()
2022-11-21 15:43 [PATCH v2] ocxl: fix pci device refcount leak when calling get_function_0() Yang Yingliang
@ 2022-11-22 0:47 ` Andrew Donnellan
2022-11-24 8:10 ` Frederic Barrat
2022-11-30 9:24 ` Michael Ellerman
2 siblings, 0 replies; 4+ messages in thread
From: Andrew Donnellan @ 2022-11-22 0:47 UTC (permalink / raw)
To: Yang Yingliang, fbarrat, arnd, gregkh, mpe; +Cc: linuxppc-dev
On Mon, 2022-11-21 at 23:43 +0800, Yang Yingliang wrote:
> get_function_0() calls pci_get_domain_bus_and_slot(), as comment
> says, it returns a pci device with refcount increment, so after
> using it, pci_dev_put() needs be called.
>
> Get the device reference when get_function_0() is not called, so
> pci_dev_put() can be called in the error path and callers
> unconditionally. And add comment above get_dvsec_vendor0() to tell
> callers to call pci_dev_put().
>
> Fixes: 87db7579ebd5 ("ocxl: control via sysfs whether the FPGA is
> reloaded on a link reset")
> Suggested-by: Andrew Donnellan <ajd@linux.ibm.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Looks good!
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
> ---
> v1 -> v2:
> Add comment above get_dvsec_vendor0().
> Get reference where dev is function 0, and call pci_dev_put()
> unconditionally in callers.
> ---
> drivers/misc/ocxl/config.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
> index e401a51596b9..92ab49705f64 100644
> --- a/drivers/misc/ocxl/config.c
> +++ b/drivers/misc/ocxl/config.c
> @@ -193,6 +193,18 @@ static int read_dvsec_vendor(struct pci_dev
> *dev)
> return 0;
> }
>
> +/**
> + * get_dvsec_vendor0() - Find a related PCI device (function 0)
> + * @dev: PCI device to match
> + * @dev0: The PCI device (function 0) found
> + * @out_pos: The position of PCI device (function 0)
> + *
> + * Returns 0 on success, negative on failure.
> + *
> + * NOTE: If it's successful, the reference of dev0 is increased,
> + * so after using it, the callers must call pci_dev_put() to give
> + * up the reference.
> + */
> static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev
> **dev0,
> int *out_pos)
> {
> @@ -202,10 +214,14 @@ static int get_dvsec_vendor0(struct pci_dev
> *dev, struct pci_dev **dev0,
> dev = get_function_0(dev);
> if (!dev)
> return -1;
> + } else {
> + dev = pci_dev_get(dev);
> }
> pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID);
> - if (!pos)
> + if (!pos) {
> + pci_dev_put(dev);
> return -1;
> + }
> *dev0 = dev;
> *out_pos = pos;
> return 0;
> @@ -222,6 +238,7 @@ int ocxl_config_get_reset_reload(struct pci_dev
> *dev, int *val)
>
> pci_read_config_dword(dev0, pos +
> OCXL_DVSEC_VENDOR_RESET_RELOAD,
> &reset_reload);
> + pci_dev_put(dev0);
> *val = !!(reset_reload & BIT(0));
> return 0;
> }
> @@ -243,6 +260,7 @@ int ocxl_config_set_reset_reload(struct pci_dev
> *dev, int val)
> reset_reload &= ~BIT(0);
> pci_write_config_dword(dev0, pos +
> OCXL_DVSEC_VENDOR_RESET_RELOAD,
> reset_reload);
> + pci_dev_put(dev0);
> return 0;
> }
>
--
Andrew Donnellan OzLabs, ADL Canberra
ajd@linux.ibm.com IBM Australia Limited
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2] ocxl: fix pci device refcount leak when calling get_function_0()
2022-11-21 15:43 [PATCH v2] ocxl: fix pci device refcount leak when calling get_function_0() Yang Yingliang
2022-11-22 0:47 ` Andrew Donnellan
@ 2022-11-24 8:10 ` Frederic Barrat
2022-11-30 9:24 ` Michael Ellerman
2 siblings, 0 replies; 4+ messages in thread
From: Frederic Barrat @ 2022-11-24 8:10 UTC (permalink / raw)
To: Yang Yingliang, ajd, arnd, gregkh, mpe; +Cc: linuxppc-dev
On 21/11/2022 16:43, Yang Yingliang wrote:
> get_function_0() calls pci_get_domain_bus_and_slot(), as comment
> says, it returns a pci device with refcount increment, so after
> using it, pci_dev_put() needs be called.
>
> Get the device reference when get_function_0() is not called, so
> pci_dev_put() can be called in the error path and callers
> unconditionally. And add comment above get_dvsec_vendor0() to tell
> callers to call pci_dev_put().
>
> Fixes: 87db7579ebd5 ("ocxl: control via sysfs whether the FPGA is reloaded on a link reset")
> Suggested-by: Andrew Donnellan <ajd@linux.ibm.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
Thanks for fixing it!
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Fred
> v1 -> v2:
> Add comment above get_dvsec_vendor0().
> Get reference where dev is function 0, and call pci_dev_put()
> unconditionally in callers.
> ---
> drivers/misc/ocxl/config.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
> index e401a51596b9..92ab49705f64 100644
> --- a/drivers/misc/ocxl/config.c
> +++ b/drivers/misc/ocxl/config.c
> @@ -193,6 +193,18 @@ static int read_dvsec_vendor(struct pci_dev *dev)
> return 0;
> }
>
> +/**
> + * get_dvsec_vendor0() - Find a related PCI device (function 0)
> + * @dev: PCI device to match
> + * @dev0: The PCI device (function 0) found
> + * @out_pos: The position of PCI device (function 0)
> + *
> + * Returns 0 on success, negative on failure.
> + *
> + * NOTE: If it's successful, the reference of dev0 is increased,
> + * so after using it, the callers must call pci_dev_put() to give
> + * up the reference.
> + */
> static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0,
> int *out_pos)
> {
> @@ -202,10 +214,14 @@ static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0,
> dev = get_function_0(dev);
> if (!dev)
> return -1;
> + } else {
> + dev = pci_dev_get(dev);
> }
> pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID);
> - if (!pos)
> + if (!pos) {
> + pci_dev_put(dev);
> return -1;
> + }
> *dev0 = dev;
> *out_pos = pos;
> return 0;
> @@ -222,6 +238,7 @@ int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val)
>
> pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,
> &reset_reload);
> + pci_dev_put(dev0);
> *val = !!(reset_reload & BIT(0));
> return 0;
> }
> @@ -243,6 +260,7 @@ int ocxl_config_set_reset_reload(struct pci_dev *dev, int val)
> reset_reload &= ~BIT(0);
> pci_write_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD,
> reset_reload);
> + pci_dev_put(dev0);
> return 0;
> }
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2] ocxl: fix pci device refcount leak when calling get_function_0()
2022-11-21 15:43 [PATCH v2] ocxl: fix pci device refcount leak when calling get_function_0() Yang Yingliang
2022-11-22 0:47 ` Andrew Donnellan
2022-11-24 8:10 ` Frederic Barrat
@ 2022-11-30 9:24 ` Michael Ellerman
2 siblings, 0 replies; 4+ messages in thread
From: Michael Ellerman @ 2022-11-30 9:24 UTC (permalink / raw)
To: fbarrat, ajd, gregkh, Yang Yingliang, mpe, arnd; +Cc: linuxppc-dev
On Mon, 21 Nov 2022 23:43:39 +0800, Yang Yingliang wrote:
> get_function_0() calls pci_get_domain_bus_and_slot(), as comment
> says, it returns a pci device with refcount increment, so after
> using it, pci_dev_put() needs be called.
>
> Get the device reference when get_function_0() is not called, so
> pci_dev_put() can be called in the error path and callers
> unconditionally. And add comment above get_dvsec_vendor0() to tell
> callers to call pci_dev_put().
>
> [...]
Applied to powerpc/next.
[1/1] ocxl: fix pci device refcount leak when calling get_function_0()
https://git.kernel.org/powerpc/c/5f58cad1e4c65bebee34292696c6d2105eeb2027
cheers
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-11-22 0:47 ` Andrew Donnellan
2022-11-24 8:10 ` Frederic Barrat
2022-11-30 9:24 ` Michael Ellerman
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