user/sven/linux.git/kernel/padata.c, branch v4.9.38

padata: free correct variable

2017-05-20T12:28:40Z

commit 07a77929ba672d93642a56dc2255dd21e6e2290b upstream. The author meant to free the variable that was just allocated, instead of the one that failed to be allocated, but made a simple typo. This patch rectifies that. Signed-off-by: Jason A. Donenfeld Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

padata: avoid race in reordering

2017-04-08T07:30:36Z

commit de5540d088fe97ad583cc7d396586437b32149a5 upstream. Under extremely heavy uses of padata, crashes occur, and with list debugging turned on, this happens instead: [87487.298728] WARNING: CPU: 1 PID: 882 at lib/list_debug.c:33 __list_add+0xae/0x130 [87487.301868] list_add corruption. prev->next should be next (ffffb17abfc043d0), but was ffff8dba70872c80. (prev=ffff8dba70872b00). [87487.339011] [] dump_stack+0x68/0xa3 [87487.342198] [] ? console_unlock+0x281/0x6d0 [87487.345364] [] __warn+0xff/0x140 [87487.348513] [] warn_slowpath_fmt+0x4a/0x50 [87487.351659] [] __list_add+0xae/0x130 [87487.354772] [] ? _raw_spin_lock+0x64/0x70 [87487.357915] [] padata_reorder+0x1e6/0x420 [87487.361084] [] padata_do_serial+0xa5/0x120 padata_reorder calls list_add_tail with the list to which its adding locked, which seems correct: spin_lock(&squeue->serial.lock); list_add_tail(&padata->list, &squeue->serial.list); spin_unlock(&squeue->serial.lock); This therefore leaves only place where such inconsistency could occur: if padata->list is added at the same time on two different threads. This pdata pointer comes from the function call to padata_get_next(pd), which has in it the following block: next_queue = per_cpu_ptr(pd->pqueue, cpu); padata = NULL; reorder = &next_queue->reorder; if (!list_empty(&reorder->list)) { padata = list_entry(reorder->list.next, struct padata_priv, list); spin_lock(&reorder->lock); list_del_init(&padata->list); atomic_dec(&pd->reorder_objects); spin_unlock(&reorder->lock); pd->processed++; goto out; } out: return padata; I strongly suspect that the problem here is that two threads can race on reorder list. Even though the deletion is locked, call to list_entry is not locked, which means it's feasible that two threads pick up the same padata object and subsequently call list_add_tail on them at the same time. The fix is thus be hoist that lock outside of that block. Signed-off-by: Jason A. Donenfeld Acked-by: Steffen Klassert Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

padata: Convert to hotplug state machine

2016-09-19T19:44:30Z

Install the callbacks via the state machine. CPU-hotplug multinstance support is used with the nocalls() version. Maybe parts of padata_alloc() could be moved into the online callback so that we could invoke ->startup callback for instance and drop get_online_cpus(). Signed-off-by: Sebastian Andrzej Siewior Cc: Steffen Klassert Cc: Peter Zijlstra Cc: linux-crypto@vger.kernel.org Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160906170457.32393-14-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner

kernel/padata.c: hide unused functions

2016-05-20T02:12:14Z

A recent cleanup removed some exported functions that were not used anywhere, which in turn exposed the fact that some other functions in the same file are only used in some configurations. We now get a warning about them when CONFIG_HOTPLUG_CPU is disabled: kernel/padata.c:670:12: error: '__padata_remove_cpu' defined but not used [-Werror=unused-function] static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) ^~~~~~~~~~~~~~~~~~~ kernel/padata.c:650:12: error: '__padata_add_cpu' defined but not used [-Werror=unused-function] static int __padata_add_cpu(struct padata_instance *pinst, int cpu) This rearranges the code so the __padata_remove_cpu/__padata_add_cpu functions are within the #ifdef that protects the code that calls them. [akpm@linux-foundation.org: coding-style fixes] Fixes: 4ba6d78c671e ("kernel/padata.c: removed unused code") Signed-off-by: Arnd Bergmann Cc: Richard Cochran Cc: Steffen Klassert Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel/padata.c: removed unused code

2016-05-20T02:12:14Z

By accident I stumbled across code that has never been used. This driver has EXPORT_SYMBOL functions, and the only user of the code is pcrypt.c, but this only uses a subset of the exported symbols. According to 'git log -G', the functions, padata_set_cpumasks, padata_add_cpu, and padata_remove_cpu have never been used since they were first introduced. This patch removes the unused code. On one 64 bit build, with CRYPTO_PCRYPT built in, the text is more than 4k smaller. kbuild_hp> size $KBUILD_OUTPUT/vmlinux text data bss dec hex filename 10566658 4678360 1122304 16367322 f9beda vmlinux 10561984 4678360 1122304 16362648 f9ac98 vmlinux On another config, 32 bit, the saving is about 0.5k bytes. kbuild_hp-x86> size $KBUILD_OUTPUT/vmlinux 6012005 2409513 2785280 11206798 ab008e vmlinux 6011491 2409513 2785280 11206284 aafe8c vmlinux Signed-off-by: Richard Cochran Cc: Steffen Klassert Cc: Herbert Xu Cc: "David S. Miller" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks

2015-02-14T05:21:38Z

printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by: Tejun Heo Cc: Steffen Klassert Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

padata: Fix wrong usage of rcu_dereference()

2013-12-05T13:28:42Z

A kernel with enabled lockdep complains about the wrong usage of rcu_dereference() under a rcu_read_lock_bh() protected region. =============================== [ INFO: suspicious RCU usage. ] 3.13.0-rc1+ #126 Not tainted ------------------------------- linux/kernel/padata.c:115 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 1 lock held by cryptomgr_test/153: #0: (rcu_read_lock_bh){.+....}, at: [] padata_do_parallel+0x5/0x270 Fix that by using rcu_dereference_bh() instead. Signed-off-by: Mathias Krause Acked-by: Steffen Klassert Signed-off-by: Herbert Xu

padata: make the sequence counter an atomic_t

2013-10-30T04:02:58Z

Using a spinlock to atomically increase a counter sounds wrong -- we've atomic_t for this! Also move 'seq_nr' to a different cache line than 'lock' to reduce cache line trashing. This has the nice side effect of decreasing the size of struct parallel_data from 192 to 128 bytes for a x86-64 build, e.g. occupying only two instead of three cache lines. Those changes results in a 5% performance increase on an IPsec test run using pcrypt. Btw. the seq_lock spinlock was never explicitly initialized -- one more reason to get rid of it. Signed-off-by: Mathias Krause Acked-by: Steffen Klassert Signed-off-by: Herbert Xu

padata - Register hotcpu notifier after initialization

2013-08-29T04:37:59Z

padata_cpu_callback() takes pinst->lock, to avoid taking an uninitialized lock, register the notifier after it's initialization. Signed-off-by: Richard Weinberger Acked-by: Steffen Klassert Signed-off-by: Herbert Xu

padata - share code between CPU_ONLINE and CPU_DOWN_FAILED, same to CPU_DOWN_PREPARE and CPU_UP_CANCELED

2013-08-29T04:37:59Z

Share code between CPU_ONLINE and CPU_DOWN_FAILED, same to CPU_DOWN_PREPARE and CPU_UP_CANCELED. It will fix 2 bugs: "not check the return value of __padata_remove_cpu() and __padata_add_cpu()". "need add 'break' between CPU_UP_CANCELED and CPU_DOWN_FAILED". Signed-off-by: Chen Gang Acked-by: Steffen Klassert Signed-off-by: Herbert Xu