From 2bbbd96357ce76cc45ec722c00f654aa7b189112 Mon Sep 17 00:00:00 2001 From: Jan Luebbe Date: Mon, 28 Aug 2017 17:25:16 +0200 Subject: bus: mbus: fix window size calculation for 4GB windows At least the Armada XP SoC supports 4GB on a single DRAM window. Because the size register values contain the actual size - 1, the MSB is set in that case. For example, the SDRAM window's control register's value is 0xffffffe1 for 4GB (bits 31 to 24 contain the size). The MBUS driver reads back each window's size from registers and calculates the actual size as (control_reg | ~DDR_SIZE_MASK) + 1, which overflows for 32 bit values, resulting in other miscalculations further on (a bad RAM window for the CESA crypto engine calculated by mvebu_mbus_setup_cpu_target_nooverlap() in my case). This patch changes the type in 'struct mbus_dram_window' from u32 to u64, which allows us to keep using the same register calculation code in most MBUS-using drivers (which calculate ->size - 1 again). Fixes: fddddb52a6c4 ("bus: introduce an Marvell EBU MBus driver") CC: stable@vger.kernel.org Signed-off-by: Jan Luebbe Signed-off-by: Gregory CLEMENT --- include/linux/mbus.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mbus.h b/include/linux/mbus.h index 0d3f14fd2621..4773145246ed 100644 --- a/include/linux/mbus.h +++ b/include/linux/mbus.h @@ -31,8 +31,8 @@ struct mbus_dram_target_info struct mbus_dram_window { u8 cs_index; u8 mbus_attr; - u32 base; - u32 size; + u64 base; + u64 size; } cs[4]; }; -- cgit v1.2.3 From 30ae9610d275f8f03f5bf7612ce71d8af6fc400b Mon Sep 17 00:00:00 2001 From: Shanker Donthineni Date: Mon, 9 Oct 2017 11:46:55 -0500 Subject: irqchip/gic-v3-its: Add missing changes to support 52bit physical address The current ITS driver works fine as long as normal memory and GICR regions are located within the lower 48bit (>=0 && <2^48) physical address space. Some of the registers GICR_PEND/PROP, GICR_VPEND/VPROP and GITS_CBASER are handled properly but not all when configuring the hardware with 52bit physical address. This patch does the following changes to support 52bit PA. -Handle 52bit PA in GITS_BASERn. -Fix ITT_addr width to 52bits, bits[51:8]. -Fix RDbase width to 52bits, bits[51:16]. -Fix VPT_addr width to 52bits, bits[51:16]. Definition of the GITS_BASERn register when ITS PageSize is 64KB: -Bits[47:16] of the register provide bits[47:16] of the table PA. -Bits[15:12] of the register provide bits[51:48] of the table PA. -Bits[15:00] of the base physical address are 0. Signed-off-by: Shanker Donthineni Signed-off-by: Marc Zyngier --- include/linux/irqchip/arm-gic-v3.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h index 1ea576c8126f..14b74f22d43c 100644 --- a/include/linux/irqchip/arm-gic-v3.h +++ b/include/linux/irqchip/arm-gic-v3.h @@ -372,6 +372,8 @@ #define GITS_BASER_ENTRY_SIZE_SHIFT (48) #define GITS_BASER_ENTRY_SIZE(r) ((((r) >> GITS_BASER_ENTRY_SIZE_SHIFT) & 0x1f) + 1) #define GITS_BASER_ENTRY_SIZE_MASK GENMASK_ULL(52, 48) +#define GITS_BASER_PHYS_52_to_48(phys) \ + (((phys) & GENMASK_ULL(47, 16)) | (((phys) >> 48) & 0xf) << 12) #define GITS_BASER_SHAREABILITY_SHIFT (10) #define GITS_BASER_InnerShareable \ GIC_BASER_SHAREABILITY(GITS_BASER, InnerShareable) -- cgit v1.2.3 From 20608924cc2e6bdeaf6f58ccbe9ddfe12dbfa082 Mon Sep 17 00:00:00 2001 From: Doug Berger Date: Wed, 4 Oct 2017 14:26:26 +0200 Subject: genirq: generic chip: Add irq_gc_mask_disable_and_ack_set() The irq_gc_mask_disable_reg_and_ack() function name implies that it provides the combined functions of irq_gc_mask_disable_reg() and irq_gc_ack(). However, the implementation does not actually do that since it writes the mask instead of the disable register. It also does not maintain the mask cache which makes it inappropriate to use with other masking functions. In addition, commit 659fb32d1b67 ("genirq: replace irq_gc_ack() with {set,clr}_bit variants (fwd)") effectively renamed irq_gc_ack() to irq_gc_ack_set_bit() so this function probably should have also been renamed at that time. The generic chip code currently provides three functions for use with the irq_mask member of the irq_chip structure and two functions for use with the irq_ack member of the irq_chip structure. These functions could be combined into six functions for use with the irq_mask_ack member of the irq_chip structure. However, since only one of the combinations is currently used, only the function irq_gc_mask_disable_and_ack_set() is added by this commit. The '_reg' and '_bit' portions of the base function name were left out of the new combined function name in an attempt to keep the function name length manageable with the 80 character source code line length while still allowing the distinct aspects of each combination to be captured by the name. If other combinations are desired in the future please add them to the irq generic chip library at that time. Signed-off-by: Doug Berger Signed-off-by: Marc Zyngier --- include/linux/irq.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/irq.h b/include/linux/irq.h index d4728bf6a537..494d328f7051 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -1010,6 +1010,7 @@ void irq_gc_unmask_enable_reg(struct irq_data *d); void irq_gc_ack_set_bit(struct irq_data *d); void irq_gc_ack_clr_bit(struct irq_data *d); void irq_gc_mask_disable_reg_and_ack(struct irq_data *d); +void irq_gc_mask_disable_and_ack_set(struct irq_data *d); void irq_gc_eoi(struct irq_data *d); int irq_gc_set_wake(struct irq_data *d, unsigned int on); -- cgit v1.2.3 From 0d08af35f16a0cc418ad2afde3bc5f70ace82705 Mon Sep 17 00:00:00 2001 From: Doug Berger Date: Wed, 4 Oct 2017 14:28:17 +0200 Subject: genirq: generic chip: remove irq_gc_mask_disable_reg_and_ack() Any usage of the irq_gc_mask_disable_reg_and_ack() function has been replaced with the desired functionality. The incorrect and ambiguously named function is removed here to prevent accidental misuse. Signed-off-by: Doug Berger Signed-off-by: Marc Zyngier --- include/linux/irq.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/irq.h b/include/linux/irq.h index 494d328f7051..5ad10948ea95 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -1009,7 +1009,6 @@ void irq_gc_mask_clr_bit(struct irq_data *d); void irq_gc_unmask_enable_reg(struct irq_data *d); void irq_gc_ack_set_bit(struct irq_data *d); void irq_gc_ack_clr_bit(struct irq_data *d); -void irq_gc_mask_disable_reg_and_ack(struct irq_data *d); void irq_gc_mask_disable_and_ack_set(struct irq_data *d); void irq_gc_eoi(struct irq_data *d); int irq_gc_set_wake(struct irq_data *d, unsigned int on); -- cgit v1.2.3 From 0ad646c81b2182f7fa67ec0c8c825e0ee165696d Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Fri, 13 Oct 2017 11:58:53 -0700 Subject: tun: call dev_get_valid_name() before register_netdevice() register_netdevice() could fail early when we have an invalid dev name, in which case ->ndo_uninit() is not called. For tun device, this is a problem because a timer etc. are already initialized and it expects ->ndo_uninit() to clean them up. We could move these initializations into a ->ndo_init() so that register_netdevice() knows better, however this is still complicated due to the logic in tun_detach(). Therefore, I choose to just call dev_get_valid_name() before register_netdevice(), which is quicker and much easier to audit. And for this specific case, it is already enough. Fixes: 96442e42429e ("tuntap: choose the txq based on rxq") Reported-by: Dmitry Alexeev Cc: Jason Wang Cc: "Michael S. Tsirkin" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- include/linux/netdevice.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index f535779d9dc1..2eaac7d75af4 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3694,6 +3694,9 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, unsigned char name_assign_type, void (*setup)(struct net_device *), unsigned int txqs, unsigned int rxqs); +int dev_get_valid_name(struct net *net, struct net_device *dev, + const char *name); + #define alloc_netdev(sizeof_priv, name, name_assign_type, setup) \ alloc_netdev_mqs(sizeof_priv, name, name_assign_type, setup, 1, 1) -- cgit v1.2.3 From 363b02dab09b3226f3bd1420dad9c72b79a42a76 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 4 Oct 2017 16:43:25 +0100 Subject: KEYS: Fix race between updating and finding a negative key Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection error into one field such that: (1) The instantiation state can be modified/read atomically. (2) The error can be accessed atomically with the state. (3) The error isn't stored unioned with the payload pointers. This deals with the problem that the state is spread over three different objects (two bits and a separate variable) and reading or updating them atomically isn't practical, given that not only can uninstantiated keys change into instantiated or rejected keys, but rejected keys can also turn into instantiated keys - and someone accessing the key might not be using any locking. The main side effect of this problem is that what was held in the payload may change, depending on the state. For instance, you might observe the key to be in the rejected state. You then read the cached error, but if the key semaphore wasn't locked, the key might've become instantiated between the two reads - and you might now have something in hand that isn't actually an error code. The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error code if the key is negatively instantiated. The key_is_instantiated() function is replaced with key_is_positive() to avoid confusion as negative keys are also 'instantiated'. Additionally, barriering is included: (1) Order payload-set before state-set during instantiation. (2) Order state-read before payload-read when using the key. Further separate barriering is necessary if RCU is being used to access the payload content after reading the payload pointers. Fixes: 146aa8b1453b ("KEYS: Merge the type-specific data with the payload data") Cc: stable@vger.kernel.org # v4.4+ Reported-by: Eric Biggers Signed-off-by: David Howells Reviewed-by: Eric Biggers --- include/linux/key.h | 47 ++++++++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 17 deletions(-) (limited to 'include/linux') diff --git a/include/linux/key.h b/include/linux/key.h index e315e16b6ff8..8a15cabe928d 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -138,6 +138,11 @@ struct key_restriction { struct key_type *keytype; }; +enum key_state { + KEY_IS_UNINSTANTIATED, + KEY_IS_POSITIVE, /* Positively instantiated */ +}; + /*****************************************************************************/ /* * authentication token / access credential / keyring @@ -169,6 +174,7 @@ struct key { * - may not match RCU dereferenced payload * - payload should contain own length */ + short state; /* Key state (+) or rejection error (-) */ #ifdef KEY_DEBUGGING unsigned magic; @@ -176,18 +182,16 @@ struct key { #endif unsigned long flags; /* status flags (change with bitops) */ -#define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */ -#define KEY_FLAG_DEAD 1 /* set if key type has been deleted */ -#define KEY_FLAG_REVOKED 2 /* set if key had been revoked */ -#define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */ -#define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */ -#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */ -#define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */ -#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */ -#define KEY_FLAG_BUILTIN 8 /* set if key is built in to the kernel */ -#define KEY_FLAG_ROOT_CAN_INVAL 9 /* set if key can be invalidated by root without permission */ -#define KEY_FLAG_KEEP 10 /* set if key should not be removed */ -#define KEY_FLAG_UID_KEYRING 11 /* set if key is a user or user session keyring */ +#define KEY_FLAG_DEAD 0 /* set if key type has been deleted */ +#define KEY_FLAG_REVOKED 1 /* set if key had been revoked */ +#define KEY_FLAG_IN_QUOTA 2 /* set if key consumes quota */ +#define KEY_FLAG_USER_CONSTRUCT 3 /* set if key is being constructed in userspace */ +#define KEY_FLAG_ROOT_CAN_CLEAR 4 /* set if key can be cleared by root without permission */ +#define KEY_FLAG_INVALIDATED 5 /* set if key has been invalidated */ +#define KEY_FLAG_BUILTIN 6 /* set if key is built in to the kernel */ +#define KEY_FLAG_ROOT_CAN_INVAL 7 /* set if key can be invalidated by root without permission */ +#define KEY_FLAG_KEEP 8 /* set if key should not be removed */ +#define KEY_FLAG_UID_KEYRING 9 /* set if key is a user or user session keyring */ /* the key type and key description string * - the desc is used to match a key against search criteria @@ -213,7 +217,6 @@ struct key { struct list_head name_link; struct assoc_array keys; }; - int reject_error; }; /* This is set on a keyring to restrict the addition of a link to a key @@ -353,17 +356,27 @@ extern void key_set_timeout(struct key *, unsigned); #define KEY_NEED_SETATTR 0x20 /* Require permission to change attributes */ #define KEY_NEED_ALL 0x3f /* All the above permissions */ +static inline short key_read_state(const struct key *key) +{ + /* Barrier versus mark_key_instantiated(). */ + return smp_load_acquire(&key->state); +} + /** - * key_is_instantiated - Determine if a key has been positively instantiated + * key_is_positive - Determine if a key has been positively instantiated * @key: The key to check. * * Return true if the specified key has been positively instantiated, false * otherwise. */ -static inline bool key_is_instantiated(const struct key *key) +static inline bool key_is_positive(const struct key *key) +{ + return key_read_state(key) == KEY_IS_POSITIVE; +} + +static inline bool key_is_negative(const struct key *key) { - return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) && - !test_bit(KEY_FLAG_NEGATIVE, &key->flags); + return key_read_state(key) < 0; } #define dereference_key_rcu(KEY) \ -- cgit v1.2.3 From 55dfce873dca46df00304c44a568d7933bffff89 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 9 Oct 2017 11:09:33 -0700 Subject: Input: factor out and export input_device_id matching code Factor out and export input_match_device_id() so that modules may use it. It will be needed by joydev to blacklist accelerometers in composite devices. Tested-by: Roderick Colenbrander Signed-off-by: Dmitry Torokhov --- include/linux/input.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/input.h b/include/linux/input.h index fb5e23c7ed98..2a44650e449d 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -469,6 +469,9 @@ int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke); int input_set_keycode(struct input_dev *dev, const struct input_keymap_entry *ke); +bool input_match_device_id(const struct input_dev *dev, + const struct input_device_id *id); + void input_enable_softrepeat(struct input_dev *dev, int delay, int period); extern struct class input_class; -- cgit v1.2.3 From 8724ecb072293f109a6f5dc93be8a98bf61fe14f Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 9 Oct 2017 12:01:14 -0700 Subject: Input: allow matching device IDs on property bits Let's allow matching input devices on their property bits, both in-kernel and when generating module aliases. Tested-by: Roderick Colenbrander Signed-off-by: Dmitry Torokhov --- include/linux/input.h | 4 ++++ include/linux/mod_devicetable.h | 3 +++ 2 files changed, 7 insertions(+) (limited to 'include/linux') diff --git a/include/linux/input.h b/include/linux/input.h index 2a44650e449d..7c7516eb7d76 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -234,6 +234,10 @@ struct input_dev { #error "SW_MAX and INPUT_DEVICE_ID_SW_MAX do not match" #endif +#if INPUT_PROP_MAX != INPUT_DEVICE_ID_PROP_MAX +#error "INPUT_PROP_MAX and INPUT_DEVICE_ID_PROP_MAX do not match" +#endif + #define INPUT_DEVICE_ID_MATCH_DEVICE \ (INPUT_DEVICE_ID_MATCH_BUS | INPUT_DEVICE_ID_MATCH_VENDOR | INPUT_DEVICE_ID_MATCH_PRODUCT) #define INPUT_DEVICE_ID_MATCH_DEVICE_AND_VERSION \ diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index 3f74ef2281e8..72f0b7f19c59 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -293,6 +293,7 @@ struct pcmcia_device_id { #define INPUT_DEVICE_ID_SND_MAX 0x07 #define INPUT_DEVICE_ID_FF_MAX 0x7f #define INPUT_DEVICE_ID_SW_MAX 0x0f +#define INPUT_DEVICE_ID_PROP_MAX 0x1f #define INPUT_DEVICE_ID_MATCH_BUS 1 #define INPUT_DEVICE_ID_MATCH_VENDOR 2 @@ -308,6 +309,7 @@ struct pcmcia_device_id { #define INPUT_DEVICE_ID_MATCH_SNDBIT 0x0400 #define INPUT_DEVICE_ID_MATCH_FFBIT 0x0800 #define INPUT_DEVICE_ID_MATCH_SWBIT 0x1000 +#define INPUT_DEVICE_ID_MATCH_PROPBIT 0x2000 struct input_device_id { @@ -327,6 +329,7 @@ struct input_device_id { kernel_ulong_t sndbit[INPUT_DEVICE_ID_SND_MAX / BITS_PER_LONG + 1]; kernel_ulong_t ffbit[INPUT_DEVICE_ID_FF_MAX / BITS_PER_LONG + 1]; kernel_ulong_t swbit[INPUT_DEVICE_ID_SW_MAX / BITS_PER_LONG + 1]; + kernel_ulong_t propbit[INPUT_DEVICE_ID_PROP_MAX / BITS_PER_LONG + 1]; kernel_ulong_t driver_info; }; -- cgit v1.2.3 From a961e40917fb14614d368d8bc9782ca4d6a8cd11 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 19 Oct 2017 13:30:15 -0400 Subject: membarrier: Provide register expedited private command This introduces a "register private expedited" membarrier command which allows eventual removal of important memory barrier constraints on the scheduler fast-paths. It changes how the "private expedited" membarrier command (new to 4.14) is used from user-space. This new command allows processes to register their intent to use the private expedited command. This affects how the expedited private command introduced in 4.14-rc is meant to be used, and should be merged before 4.14 final. Processes are now required to register before using MEMBARRIER_CMD_PRIVATE_EXPEDITED, otherwise that command returns EPERM. This fixes a problem that arose when designing requested extensions to sys_membarrier() to allow JITs to efficiently flush old code from instruction caches. Several potential algorithms are much less painful if the user register intent to use this functionality early on, for example, before the process spawns the second thread. Registering at this time removes the need to interrupt each and every thread in that process at the first expedited sys_membarrier() system call. Signed-off-by: Mathieu Desnoyers Acked-by: Paul E. McKenney Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Alexander Viro Signed-off-by: Linus Torvalds --- include/linux/mm_types.h | 3 +++ include/linux/sched/mm.h | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 46f4ecf5479a..1861ea8dba77 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -445,6 +445,9 @@ struct mm_struct { unsigned long flags; /* Must use atomic bitops to access the bits */ struct core_state *core_state; /* coredumping support */ +#ifdef CONFIG_MEMBARRIER + atomic_t membarrier_state; +#endif #ifdef CONFIG_AIO spinlock_t ioctx_lock; struct kioctx_table __rcu *ioctx_table; diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index ae53e413fb13..ab9bf7b73954 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -211,4 +211,20 @@ static inline void memalloc_noreclaim_restore(unsigned int flags) current->flags = (current->flags & ~PF_MEMALLOC) | flags; } +#ifdef CONFIG_MEMBARRIER +enum { + MEMBARRIER_STATE_PRIVATE_EXPEDITED_READY = (1U << 0), + MEMBARRIER_STATE_SWITCH_MM = (1U << 1), +}; + +static inline void membarrier_execve(struct task_struct *t) +{ + atomic_set(&t->mm->membarrier_state, 0); +} +#else +static inline void membarrier_execve(struct task_struct *t) +{ +} +#endif + #endif /* _LINUX_SCHED_MM_H */ -- cgit v1.2.3 From 27fdb35fe99011d86bcc54f62fe84712c53f4d05 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 19 Oct 2017 14:26:21 -0700 Subject: doc: Fix various RCU docbook comment-header problems Because many of RCU's files have not been included into docbook, a number of errors have accumulated. This commit fixes them. Signed-off-by: Paul E. McKenney Signed-off-by: Linus Torvalds --- include/linux/rculist.h | 2 +- include/linux/rcupdate.h | 22 ++++++++++++++-------- include/linux/srcu.h | 1 + 3 files changed, 16 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/include/linux/rculist.h b/include/linux/rculist.h index b1fd8bf85fdc..2bea1d5e9930 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -276,7 +276,7 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, #define list_entry_rcu(ptr, type, member) \ container_of(lockless_dereference(ptr), type, member) -/** +/* * Where are list_empty_rcu() and list_first_entry_rcu()? * * Implementing those functions following their counterparts list_empty() and diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index de50d8a4cf41..1a9f70d44af9 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -523,7 +523,7 @@ static inline void rcu_preempt_sleep_check(void) { } * Return the value of the specified RCU-protected pointer, but omit * both the smp_read_barrier_depends() and the READ_ONCE(). This * is useful in cases where update-side locks prevent the value of the - * pointer from changing. Please note that this primitive does -not- + * pointer from changing. Please note that this primitive does *not* * prevent the compiler from repeating this reference or combining it * with other references, so it should not be used without protection * of appropriate locks. @@ -568,7 +568,7 @@ static inline void rcu_preempt_sleep_check(void) { } * is handed off from RCU to some other synchronization mechanism, for * example, reference counting or locking. In C11, it would map to * kill_dependency(). It could be used as follows: - * + * `` * rcu_read_lock(); * p = rcu_dereference(gp); * long_lived = is_long_lived(p); @@ -579,6 +579,7 @@ static inline void rcu_preempt_sleep_check(void) { } * p = rcu_pointer_handoff(p); * } * rcu_read_unlock(); + *`` */ #define rcu_pointer_handoff(p) (p) @@ -778,18 +779,21 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) /** * RCU_INIT_POINTER() - initialize an RCU protected pointer + * @p: The pointer to be initialized. + * @v: The value to initialized the pointer to. * * Initialize an RCU-protected pointer in special cases where readers * do not need ordering constraints on the CPU or the compiler. These * special cases are: * - * 1. This use of RCU_INIT_POINTER() is NULLing out the pointer -or- + * 1. This use of RCU_INIT_POINTER() is NULLing out the pointer *or* * 2. The caller has taken whatever steps are required to prevent - * RCU readers from concurrently accessing this pointer -or- + * RCU readers from concurrently accessing this pointer *or* * 3. The referenced data structure has already been exposed to - * readers either at compile time or via rcu_assign_pointer() -and- - * a. You have not made -any- reader-visible changes to - * this structure since then -or- + * readers either at compile time or via rcu_assign_pointer() *and* + * + * a. You have not made *any* reader-visible changes to + * this structure since then *or* * b. It is OK for readers accessing this structure from its * new location to see the old state of the structure. (For * example, the changes were to statistical counters or to @@ -805,7 +809,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) * by a single external-to-structure RCU-protected pointer, then you may * use RCU_INIT_POINTER() to initialize the internal RCU-protected * pointers, but you must use rcu_assign_pointer() to initialize the - * external-to-structure pointer -after- you have completely initialized + * external-to-structure pointer *after* you have completely initialized * the reader-accessible portions of the linked structure. * * Note that unlike rcu_assign_pointer(), RCU_INIT_POINTER() provides no @@ -819,6 +823,8 @@ static inline notrace void rcu_read_unlock_sched_notrace(void) /** * RCU_POINTER_INITIALIZER() - statically initialize an RCU protected pointer + * @p: The pointer to be initialized. + * @v: The value to initialized the pointer to. * * GCC-style initialization for an RCU-protected pointer in a structure field. */ diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 39af9bc0f653..62be8966e837 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -78,6 +78,7 @@ void synchronize_srcu(struct srcu_struct *sp); /** * srcu_read_lock_held - might we be in SRCU read-side critical section? + * @sp: The srcu_struct structure to check * * If CONFIG_DEBUG_LOCK_ALLOC is selected, returns nonzero iff in an SRCU * read-side critical section. In absence of CONFIG_DEBUG_LOCK_ALLOC, -- cgit v1.2.3 From 34f79502bbcfab659b8729da68b5e387f96eb4c1 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Wed, 18 Oct 2017 07:10:36 -0700 Subject: bpf: avoid preempt enable/disable in sockmap using tcp_skb_cb region SK_SKB BPF programs are run from the socket/tcp context but early in the stack before much of the TCP metadata is needed in tcp_skb_cb. So we can use some unused fields to place BPF metadata needed for SK_SKB programs when implementing the redirect function. This allows us to drop the preempt disable logic. It does however require an API change so sk_redirect_map() has been updated to additionally provide ctx_ptr to skb. Note, we do however continue to disable/enable preemption around actual BPF program running to account for map updates. Signed-off-by: John Fastabend Acked-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- include/linux/filter.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/filter.h b/include/linux/filter.h index d29e58fde364..818a0b26249e 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -728,7 +728,7 @@ void xdp_do_flush_map(void); void bpf_warn_invalid_xdp_action(u32 act); void bpf_warn_invalid_xdp_redirect(u32 ifindex); -struct sock *do_sk_redirect_map(void); +struct sock *do_sk_redirect_map(struct sk_buff *skb); #ifdef CONFIG_BPF_JIT extern int bpf_jit_enable; -- cgit v1.2.3