| Message ID | 20220403183758.192236-13-krzysztof.kozlowski@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix broken usage of driver_override (and kfree of static memory) | expand |
Hi Krzysztof Kozlowski, Thanks for the patch. > Subject: [PATCH v6 12/12] rpmsg: Fix kfree() of static memory on setting > driver_override > > The driver_override field from platform driver should not be initialized > from static memory (string literal) because the core later kfree() it, for > example when driver_override is set via sysfs. > > Use dedicated helper to set driver_override properly. > > Fixes: 950a7388f02b ("rpmsg: Turn name service into a stand alone driver") > Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface") > Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> > --- > drivers/rpmsg/rpmsg_internal.h | 13 +++++++++++-- > drivers/rpmsg/rpmsg_ns.c | 14 ++++++++++++-- > include/linux/rpmsg.h | 6 ++++-- > 3 files changed, 27 insertions(+), 6 deletions(-) > > diff --git a/drivers/rpmsg/rpmsg_internal.h > b/drivers/rpmsg/rpmsg_internal.h index d4b23fd019a8..1a2fb8edf5d3 100644 > --- a/drivers/rpmsg/rpmsg_internal.h > +++ b/drivers/rpmsg/rpmsg_internal.h > @@ -94,10 +94,19 @@ int rpmsg_release_channel(struct rpmsg_device *rpdev, > */ > static inline int rpmsg_ctrldev_register_device(struct rpmsg_device > *rpdev) { > + int ret; > + > strcpy(rpdev->id.name, "rpmsg_ctrl"); > - rpdev->driver_override = "rpmsg_ctrl"; > + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, > + "rpmsg_ctrl", strlen("rpmsg_ctrl")); Is it not possible to use rpdev->id.name instead of "rpmsg_ctrl" ? rpdev->id.name has "rpmsg_ctrl" from strcpy(rpdev->id.name, "rpmsg_ctrl"); Same for "rpmsg_ns" as well Cheers, Biju > + if (ret) > + return ret; > + > + ret = rpmsg_register_device(rpdev); > + if (ret) > + kfree(rpdev->driver_override); > > - return rpmsg_register_device(rpdev); > + return ret; > } > > #endif > diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c index > 762ff1ae279f..95a51543f5ad 100644 > --- a/drivers/rpmsg/rpmsg_ns.c > +++ b/drivers/rpmsg/rpmsg_ns.c > @@ -20,12 +20,22 @@ > */ > int rpmsg_ns_register_device(struct rpmsg_device *rpdev) { > + int ret; > + > strcpy(rpdev->id.name, "rpmsg_ns"); > - rpdev->driver_override = "rpmsg_ns"; > + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, > + "rpmsg_ns", strlen("rpmsg_ns")); > + if (ret) > + return ret; > + > rpdev->src = RPMSG_NS_ADDR; > rpdev->dst = RPMSG_NS_ADDR; > > - return rpmsg_register_device(rpdev); > + ret = rpmsg_register_device(rpdev); > + if (ret) > + kfree(rpdev->driver_override); > + > + return ret; > } > EXPORT_SYMBOL(rpmsg_ns_register_device); > > diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h index > 02fa9116cd60..20c8cd1cde21 100644 > --- a/include/linux/rpmsg.h > +++ b/include/linux/rpmsg.h > @@ -41,7 +41,9 @@ struct rpmsg_channel_info { > * rpmsg_device - device that belong to the rpmsg bus > * @dev: the device struct > * @id: device id (used to match between rpmsg drivers and devices) > - * @driver_override: driver name to force a match > + * @driver_override: driver name to force a match; do not set directly, > + * because core frees it; use driver_set_override() to > + * set or clear it. > * @src: local address > * @dst: destination address > * @ept: the rpmsg endpoint of this channel @@ -51,7 +53,7 @@ struct > rpmsg_channel_info { struct rpmsg_device { > struct device dev; > struct rpmsg_device_id id; > - char *driver_override; > + const char *driver_override; > u32 src; > u32 dst; > struct rpmsg_endpoint *ept; > -- > 2.32.0 > > > _______________________________________________
On 12/04/2022 16:10, Biju Das wrote: > Hi Krzysztof Kozlowski, > > Thanks for the patch. > >> Subject: [PATCH v6 12/12] rpmsg: Fix kfree() of static memory on setting >> driver_override >> >> The driver_override field from platform driver should not be initialized >> from static memory (string literal) because the core later kfree() it, for >> example when driver_override is set via sysfs. >> >> Use dedicated helper to set driver_override properly. >> >> Fixes: 950a7388f02b ("rpmsg: Turn name service into a stand alone driver") >> Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface") >> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> >> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> >> --- >> drivers/rpmsg/rpmsg_internal.h | 13 +++++++++++-- >> drivers/rpmsg/rpmsg_ns.c | 14 ++++++++++++-- >> include/linux/rpmsg.h | 6 ++++-- >> 3 files changed, 27 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/rpmsg/rpmsg_internal.h >> b/drivers/rpmsg/rpmsg_internal.h index d4b23fd019a8..1a2fb8edf5d3 100644 >> --- a/drivers/rpmsg/rpmsg_internal.h >> +++ b/drivers/rpmsg/rpmsg_internal.h >> @@ -94,10 +94,19 @@ int rpmsg_release_channel(struct rpmsg_device *rpdev, >> */ >> static inline int rpmsg_ctrldev_register_device(struct rpmsg_device >> *rpdev) { >> + int ret; >> + >> strcpy(rpdev->id.name, "rpmsg_ctrl"); >> - rpdev->driver_override = "rpmsg_ctrl"; >> + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, >> + "rpmsg_ctrl", strlen("rpmsg_ctrl")); > > Is it not possible to use rpdev->id.name instead of "rpmsg_ctrl" ? > rpdev->id.name has "rpmsg_ctrl" from strcpy(rpdev->id.name, "rpmsg_ctrl"); > > Same for "rpmsg_ns" as well It's possible. I kept the pattern of duplicating the string literal because original code had it, but I don't mind to change it. In the output assembler that might be additional instruction - need to dereference the rpdev pointer - but that does not matter much. Best regards, Krzysztof
Hi Krzysztof Kozlowski, > Subject: Re: [PATCH v6 12/12] rpmsg: Fix kfree() of static memory on > setting driver_override > > On 12/04/2022 16:10, Biju Das wrote: > > Hi Krzysztof Kozlowski, > > > > Thanks for the patch. > > > >> Subject: [PATCH v6 12/12] rpmsg: Fix kfree() of static memory on > >> setting driver_override > >> > >> The driver_override field from platform driver should not be > >> initialized from static memory (string literal) because the core > >> later kfree() it, for example when driver_override is set via sysfs. > >> > >> Use dedicated helper to set driver_override properly. > >> > >> Fixes: 950a7388f02b ("rpmsg: Turn name service into a stand alone > >> driver") > >> Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint > >> interface") > >> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > >> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> > >> --- > >> drivers/rpmsg/rpmsg_internal.h | 13 +++++++++++-- > >> drivers/rpmsg/rpmsg_ns.c | 14 ++++++++++++-- > >> include/linux/rpmsg.h | 6 ++++-- > >> 3 files changed, 27 insertions(+), 6 deletions(-) > >> > >> diff --git a/drivers/rpmsg/rpmsg_internal.h > >> b/drivers/rpmsg/rpmsg_internal.h index d4b23fd019a8..1a2fb8edf5d3 > >> 100644 > >> --- a/drivers/rpmsg/rpmsg_internal.h > >> +++ b/drivers/rpmsg/rpmsg_internal.h > >> @@ -94,10 +94,19 @@ int rpmsg_release_channel(struct rpmsg_device > *rpdev, > >> */ > >> static inline int rpmsg_ctrldev_register_device(struct rpmsg_device > >> *rpdev) { > >> + int ret; > >> + > >> strcpy(rpdev->id.name, "rpmsg_ctrl"); > >> - rpdev->driver_override = "rpmsg_ctrl"; > >> + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, > >> + "rpmsg_ctrl", strlen("rpmsg_ctrl")); > > > > Is it not possible to use rpdev->id.name instead of "rpmsg_ctrl" ? > > rpdev->id.name has "rpmsg_ctrl" from strcpy(rpdev->id.name, > > rpdev->"rpmsg_ctrl"); > > > > Same for "rpmsg_ns" as well > > It's possible. I kept the pattern of duplicating the string literal > because original code had it, but I don't mind to change it. In the output > assembler that might be additional instruction - need to dereference the > rpdev pointer - but that does not matter much. > OK, it's a suggestion as same string constant duplicated thrice, Any change in this string constant in future will need changes in 3 places , by using "rpdev->id.name", the change is limited to 1 place. Cheers, Biju
diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h index d4b23fd019a8..1a2fb8edf5d3 100644 --- a/drivers/rpmsg/rpmsg_internal.h +++ b/drivers/rpmsg/rpmsg_internal.h @@ -94,10 +94,19 @@ int rpmsg_release_channel(struct rpmsg_device *rpdev, */ static inline int rpmsg_ctrldev_register_device(struct rpmsg_device *rpdev) { + int ret; + strcpy(rpdev->id.name, "rpmsg_ctrl"); - rpdev->driver_override = "rpmsg_ctrl"; + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, + "rpmsg_ctrl", strlen("rpmsg_ctrl")); + if (ret) + return ret; + + ret = rpmsg_register_device(rpdev); + if (ret) + kfree(rpdev->driver_override); - return rpmsg_register_device(rpdev); + return ret; } #endif diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c index 762ff1ae279f..95a51543f5ad 100644 --- a/drivers/rpmsg/rpmsg_ns.c +++ b/drivers/rpmsg/rpmsg_ns.c @@ -20,12 +20,22 @@ */ int rpmsg_ns_register_device(struct rpmsg_device *rpdev) { + int ret; + strcpy(rpdev->id.name, "rpmsg_ns"); - rpdev->driver_override = "rpmsg_ns"; + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, + "rpmsg_ns", strlen("rpmsg_ns")); + if (ret) + return ret; + rpdev->src = RPMSG_NS_ADDR; rpdev->dst = RPMSG_NS_ADDR; - return rpmsg_register_device(rpdev); + ret = rpmsg_register_device(rpdev); + if (ret) + kfree(rpdev->driver_override); + + return ret; } EXPORT_SYMBOL(rpmsg_ns_register_device); diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h index 02fa9116cd60..20c8cd1cde21 100644 --- a/include/linux/rpmsg.h +++ b/include/linux/rpmsg.h @@ -41,7 +41,9 @@ struct rpmsg_channel_info { * rpmsg_device - device that belong to the rpmsg bus * @dev: the device struct * @id: device id (used to match between rpmsg drivers and devices) - * @driver_override: driver name to force a match + * @driver_override: driver name to force a match; do not set directly, + * because core frees it; use driver_set_override() to + * set or clear it. * @src: local address * @dst: destination address * @ept: the rpmsg endpoint of this channel @@ -51,7 +53,7 @@ struct rpmsg_channel_info { struct rpmsg_device { struct device dev; struct rpmsg_device_id id; - char *driver_override; + const char *driver_override; u32 src; u32 dst; struct rpmsg_endpoint *ept;
The driver_override field from platform driver should not be initialized from static memory (string literal) because the core later kfree() it, for example when driver_override is set via sysfs. Use dedicated helper to set driver_override properly. Fixes: 950a7388f02b ("rpmsg: Turn name service into a stand alone driver") Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface") Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> --- drivers/rpmsg/rpmsg_internal.h | 13 +++++++++++-- drivers/rpmsg/rpmsg_ns.c | 14 ++++++++++++-- include/linux/rpmsg.h | 6 ++++-- 3 files changed, 27 insertions(+), 6 deletions(-)