From 6878e7de6af726de47f9f3bec649c3f49e786586 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 13 Sep 2017 16:29:48 -0700 Subject: [PATCH 1/5] driver core: suppress sending MODALIAS in UNBIND uevents The current udev rules cause modules to be loaded on all device events save for "remove". With the introduction of KOBJ_BIND/KOBJ_UNBIND this causes issues, as driver modules that have devices bound to their drivers get immediately reloaded, and it appears to the user that module unloading doe snot work. The standard udev matching rule is foillowing: ENV{MODALIAS}=="?*", RUN{builtin}+="kmod load $env{MODALIAS}" Given that MODALIAS data is not terribly useful for UNBIND event, let's zap it from the generated uevent environment until we get userspace updated with the correct udev rule that only loads modules on "add" event. Reported-by: Jakub Kicinski Tested-by: Jakub Kicinski Fixes: 1455cf8dbfd0 ("driver core: emit uevents when device is bound ...") Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman --- lib/kobject_uevent.c | 49 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 41 insertions(+), 8 deletions(-) diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index e590523ea476..f237a09a5862 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -294,6 +294,26 @@ static void cleanup_uevent_env(struct subprocess_info *info) } #endif +static void zap_modalias_env(struct kobj_uevent_env *env) +{ + static const char modalias_prefix[] = "MODALIAS="; + int i; + + for (i = 0; i < env->envp_idx;) { + if (strncmp(env->envp[i], modalias_prefix, + sizeof(modalias_prefix) - 1)) { + i++; + continue; + } + + if (i != env->envp_idx - 1) + memmove(&env->envp[i], &env->envp[i + 1], + sizeof(env->envp[i]) * env->envp_idx - 1); + + env->envp_idx--; + } +} + /** * kobject_uevent_env - send an uevent with environmental data * @@ -409,16 +429,29 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, } } - /* - * Mark "add" and "remove" events in the object to ensure proper - * events to userspace during automatic cleanup. If the object did - * send an "add" event, "remove" will automatically generated by - * the core, if not already done by the caller. - */ - if (action == KOBJ_ADD) + switch (action) { + case KOBJ_ADD: + /* + * Mark "add" event so we can make sure we deliver "remove" + * event to userspace during automatic cleanup. If + * the object did send an "add" event, "remove" will + * automatically generated by the core, if not already done + * by the caller. + */ kobj->state_add_uevent_sent = 1; - else if (action == KOBJ_REMOVE) + break; + + case KOBJ_REMOVE: kobj->state_remove_uevent_sent = 1; + break; + + case KOBJ_UNBIND: + zap_modalias_env(env); + break; + + default: + break; + } mutex_lock(&uevent_sock_mutex); /* we will send an event, so request a new sequence number */ From 452562abb5b76c14449dead2a7113f641893e8bc Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Thu, 7 Sep 2017 15:16:05 +0100 Subject: [PATCH 2/5] base: arch_topology: fix section mismatch build warnings Commit 2ef7a2953c81 ("arm, arm64: factorize common cpu capacity default code") introduced init_cpu_capacity_callback and init_cpu_capacity_notifier which are referenced from initcall and are missing __init{,data} annotations resulting the below section mismatch build warnings. "WARNING: vmlinux.o(.text+0xbab790): Section mismatch in reference from the function init_cpu_capacity_callback() to the variable .init.text:$x The function init_cpu_capacity_callback() references the variable __init $x. This is often because init_cpu_capacity_callback lacks a __init annotation or the annotation of $x is wrong." This patch fixes the above build warnings by adding the required annotations. Fixes: 2ef7a2953c81 ("arm, arm64: factorize common cpu capacity default code") Cc: Juri Lelli Cc: stable Signed-off-by: Sudeep Holla Signed-off-by: Greg Kroah-Hartman --- drivers/base/arch_topology.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 41be9ff7d70a..6df7d6676a48 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -166,11 +166,11 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) } #ifdef CONFIG_CPU_FREQ -static cpumask_var_t cpus_to_visit; -static void parsing_done_workfn(struct work_struct *work); -static DECLARE_WORK(parsing_done_work, parsing_done_workfn); +static cpumask_var_t cpus_to_visit __initdata; +static void __init parsing_done_workfn(struct work_struct *work); +static __initdata DECLARE_WORK(parsing_done_work, parsing_done_workfn); -static int +static int __init init_cpu_capacity_callback(struct notifier_block *nb, unsigned long val, void *data) @@ -206,7 +206,7 @@ init_cpu_capacity_callback(struct notifier_block *nb, return 0; } -static struct notifier_block init_cpu_capacity_notifier = { +static struct notifier_block init_cpu_capacity_notifier __initdata = { .notifier_call = init_cpu_capacity_callback, }; @@ -232,7 +232,7 @@ static int __init register_cpufreq_notifier(void) } core_initcall(register_cpufreq_notifier); -static void parsing_done_workfn(struct work_struct *work) +static void __init parsing_done_workfn(struct work_struct *work) { cpufreq_unregister_notifier(&init_cpu_capacity_notifier, CPUFREQ_POLICY_NOTIFIER); From bf563b01c2895a4bfd1a29cc5abc67fe706ecffd Mon Sep 17 00:00:00 2001 From: Nicolai Stange Date: Mon, 11 Sep 2017 09:45:42 +0200 Subject: [PATCH 3/5] driver core: platform: Don't read past the end of "driver_override" buffer When printing the driver_override parameter when it is 4095 and 4094 bytes long, the printing code would access invalid memory because we need count+1 bytes for printing. Reject driver_override values of these lengths in driver_override_store(). This is in close analogy to commit 4efe874aace5 ("PCI: Don't read past the end of sysfs "driver_override" buffer") from Sasha Levin. Fixes: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") Cc: stable@vger.kernel.org # v3.17+ Signed-off-by: Nicolai Stange Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index d1bd99271066..9045c5f3734e 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -868,7 +868,8 @@ static ssize_t driver_override_store(struct device *dev, struct platform_device *pdev = to_platform_device(dev); char *driver_override, *old, *cp; - if (count > PATH_MAX) + /* We need to keep extra room for a newline */ + if (count >= (PAGE_SIZE - 1)) return -EINVAL; driver_override = kstrndup(buf, count, GFP_KERNEL); From 55e001aabb826c96f09e0a440bdcbce620189dbc Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 18 Sep 2017 12:17:36 +0200 Subject: [PATCH 4/5] fpga: altera-cvp: remove DRIVER_ATTR() usage It's better to be explicit and use the DRIVER_ATTR_RW() macro when defining a driver's sysfs file. This is part of a series to drop DRIVER_ATTR() from the tree entirely. Cc: linux-fpga@vger.kernel.org Reviewed-by: Moritz Fischer Acked-by: Alan Tull Signed-off-by: Greg Kroah-Hartman --- drivers/fpga/altera-cvp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c index 08629ee69d11..00e73d28077c 100644 --- a/drivers/fpga/altera-cvp.c +++ b/drivers/fpga/altera-cvp.c @@ -361,12 +361,12 @@ static const struct fpga_manager_ops altera_cvp_ops = { .write_complete = altera_cvp_write_complete, }; -static ssize_t show_chkcfg(struct device_driver *dev, char *buf) +static ssize_t chkcfg_show(struct device_driver *dev, char *buf) { return snprintf(buf, 3, "%d\n", altera_cvp_chkcfg); } -static ssize_t store_chkcfg(struct device_driver *drv, const char *buf, +static ssize_t chkcfg_store(struct device_driver *drv, const char *buf, size_t count) { int ret; @@ -378,7 +378,7 @@ static ssize_t store_chkcfg(struct device_driver *drv, const char *buf, return count; } -static DRIVER_ATTR(chkcfg, 0600, show_chkcfg, store_chkcfg); +static DRIVER_ATTR_RW(chkcfg); static int altera_cvp_probe(struct pci_dev *pdev, const struct pci_device_id *dev_id); From 850fdec8d2fd1eebfa003fea39bec08cd69b6155 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 18 Sep 2017 12:17:57 +0200 Subject: [PATCH 5/5] driver core: remove DRIVER_ATTR DRIVER_ATTR is no longer in use, and driver authors should be using DRIVER_ATTR_RW() or DRIVER_ATTR_RO() or DRIVER_ATTR_WO() instead in order to always get the permissions correct. So remove it so that no one can use it anymore. Acked-by: Alan Tull Reviewed-by: Moritz Fischer Signed-off-by: Greg Kroah-Hartman --- Documentation/driver-model/driver.txt | 7 ++++--- Documentation/filesystems/sysfs.txt | 3 ++- include/linux/device.h | 2 -- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/Documentation/driver-model/driver.txt b/Documentation/driver-model/driver.txt index 4421135826a2..d661e6f7e6a0 100644 --- a/Documentation/driver-model/driver.txt +++ b/Documentation/driver-model/driver.txt @@ -196,12 +196,13 @@ struct driver_attribute { }; Device drivers can export attributes via their sysfs directories. -Drivers can declare attributes using a DRIVER_ATTR macro that works -identically to the DEVICE_ATTR macro. +Drivers can declare attributes using a DRIVER_ATTR_RW and DRIVER_ATTR_RO +macro that works identically to the DEVICE_ATTR_RW and DEVICE_ATTR_RO +macros. Example: -DRIVER_ATTR(debug,0644,show_debug,store_debug); +DRIVER_ATTR_RW(debug); This is equivalent to declaring: diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt index 24da7b32c489..9a3658cc399e 100644 --- a/Documentation/filesystems/sysfs.txt +++ b/Documentation/filesystems/sysfs.txt @@ -366,7 +366,8 @@ struct driver_attribute { Declaring: -DRIVER_ATTR(_name, _mode, _show, _store) +DRIVER_ATTR_RO(_name) +DRIVER_ATTR_RW(_name) Creation/Removal: diff --git a/include/linux/device.h b/include/linux/device.h index c6f27207dbe8..2bc70ddda09b 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -307,8 +307,6 @@ struct driver_attribute { size_t count); }; -#define DRIVER_ATTR(_name, _mode, _show, _store) \ - struct driver_attribute driver_attr_##_name = __ATTR(_name, _mode, _show, _store) #define DRIVER_ATTR_RW(_name) \ struct driver_attribute driver_attr_##_name = __ATTR_RW(_name) #define DRIVER_ATTR_RO(_name) \