Date: Thu, 12 May 2016 09:06:54 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r299526 - in head/sys/compat/linuxkpi/common: include/linux src Message-ID: <201605120906.u4C96sb6035508@repo.freebsd.org>
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Author: hselasky Date: Thu May 12 09:06:54 2016 New Revision: 299526 URL: https://svnweb.freebsd.org/changeset/base/299526 Log: Create a dummy "task_struct" on the stack which is returned by "current" inside all LinuxKPI file operation callbacks. The "current" is frequently used for various debug prints, printing the thread name and thread ID for example. Obtained from: kmacy @ MFC after: 1 week Sponsored by: Mellanox Technologies Modified: head/sys/compat/linuxkpi/common/include/linux/kthread.h head/sys/compat/linuxkpi/common/include/linux/sched.h head/sys/compat/linuxkpi/common/src/linux_compat.c Modified: head/sys/compat/linuxkpi/common/include/linux/kthread.h ============================================================================== --- head/sys/compat/linuxkpi/common/include/linux/kthread.h Thu May 12 08:55:57 2016 (r299525) +++ head/sys/compat/linuxkpi/common/include/linux/kthread.h Thu May 12 09:06:54 2016 (r299526) @@ -2,7 +2,7 @@ * Copyright (c) 2010 Isilon Systems, Inc. * Copyright (c) 2010 iX Systems, Inc. * Copyright (c) 2010 Panasas, Inc. - * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. + * Copyright (c) 2013-2016 Mellanox Technologies, Ltd. * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -45,15 +45,18 @@ static inline void linux_kthread_fn(void *arg) { struct task_struct *task; + struct thread *td = curthread; task = arg; - task_struct_set(curthread, task); + task_struct_fill(td, task); + task_struct_set(td, task); if (task->should_stop == 0) task->task_ret = task->task_fn(task->task_data); - PROC_LOCK(task->task_thread->td_proc); + PROC_LOCK(td->td_proc); task->should_stop = TASK_STOPPED; wakeup(task); - PROC_UNLOCK(task->task_thread->td_proc); + PROC_UNLOCK(td->td_proc); + task_struct_set(td, NULL); kthread_exit(); } Modified: head/sys/compat/linuxkpi/common/include/linux/sched.h ============================================================================== --- head/sys/compat/linuxkpi/common/include/linux/sched.h Thu May 12 08:55:57 2016 (r299525) +++ head/sys/compat/linuxkpi/common/include/linux/sched.h Thu May 12 09:06:54 2016 (r299526) @@ -2,7 +2,7 @@ * Copyright (c) 2010 Isilon Systems, Inc. * Copyright (c) 2010 iX Systems, Inc. * Copyright (c) 2010 Panasas, Inc. - * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. + * Copyright (c) 2013-2016 Mellanox Technologies, Ltd. * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -50,10 +50,12 @@ #define TASK_STOPPED 2 /* - * A task_struct is only provided for those tasks created with kthread. - * Using these routines with threads not started via kthread will cause - * panics because no task_struct is allocated and td_retval[1] is - * overwritten by syscalls which kernel threads will not make use of. + * A task_struct is only provided for threads created by kthread() and + * file operation callbacks. + * + * Using these routines outside the above mentioned contexts will + * cause panics because no task_struct is assigned and td_retval[1] is + * overwritten by syscalls. */ struct task_struct { struct thread *task_thread; @@ -62,10 +64,17 @@ struct task_struct { int task_ret; int state; int should_stop; + pid_t pid; + const char *comm; }; #define current task_struct_get(curthread) #define task_struct_get(x) ((struct task_struct *)(uintptr_t)(x)->td_retval[1]) +#define task_struct_fill(x, y) do { \ + (y)->task_thread = (x); \ + (y)->comm = (x)->td_name; \ + (y)->pid = (x)->td_tid; \ +} while (0) #define task_struct_set(x, y) (x)->td_retval[1] = (uintptr_t)(y) /* ensure the task_struct pointer fits into the td_retval[1] field */ Modified: head/sys/compat/linuxkpi/common/src/linux_compat.c ============================================================================== --- head/sys/compat/linuxkpi/common/src/linux_compat.c Thu May 12 08:55:57 2016 (r299525) +++ head/sys/compat/linuxkpi/common/src/linux_compat.c Thu May 12 09:06:54 2016 (r299526) @@ -374,12 +374,31 @@ kobject_init_and_add(struct kobject *kob } static void +linux_set_current(struct thread *td, struct task_struct *t) +{ + memset(t, 0, sizeof(*t)); + task_struct_fill(td, t); + task_struct_set(td, t); +} + +static void +linux_clear_current(struct thread *td) +{ + task_struct_set(td, NULL); +} + +static void linux_file_dtor(void *cdp) { struct linux_file *filp; + struct task_struct t; + struct thread *td; + td = curthread; filp = cdp; + linux_set_current(td, &t); filp->f_op->release(filp->f_vnode, filp); + linux_clear_current(td); vdrop(filp->f_vnode); kfree(filp); } @@ -389,10 +408,11 @@ linux_dev_open(struct cdev *dev, int ofl { struct linux_cdev *ldev; struct linux_file *filp; + struct task_struct t; struct file *file; int error; - file = curthread->td_fpop; + file = td->td_fpop; ldev = dev->si_drv1; if (ldev == NULL) return (ENODEV); @@ -402,21 +422,22 @@ linux_dev_open(struct cdev *dev, int ofl filp->f_flags = file->f_flag; vhold(file->f_vnode); filp->f_vnode = file->f_vnode; + linux_set_current(td, &t); if (filp->f_op->open) { error = -filp->f_op->open(file->f_vnode, filp); if (error) { kfree(filp); - return (error); + goto done; } } error = devfs_set_cdevpriv(filp, linux_file_dtor); if (error) { filp->f_op->release(file->f_vnode, filp); kfree(filp); - return (error); } - - return 0; +done: + linux_clear_current(td); + return (error); } static int @@ -427,7 +448,7 @@ linux_dev_close(struct cdev *dev, int ff struct file *file; int error; - file = curthread->td_fpop; + file = td->td_fpop; ldev = dev->si_drv1; if (ldev == NULL) return (0); @@ -446,16 +467,18 @@ linux_dev_ioctl(struct cdev *dev, u_long { struct linux_cdev *ldev; struct linux_file *filp; + struct task_struct t; struct file *file; int error; - file = curthread->td_fpop; + file = td->td_fpop; ldev = dev->si_drv1; if (ldev == NULL) return (0); if ((error = devfs_get_cdevpriv((void **)&filp)) != 0) return (error); filp->f_flags = file->f_flag; + linux_set_current(td, &t); /* * Linux does not have a generic ioctl copyin/copyout layer. All * linux ioctls must be converted to void ioctls which pass a @@ -467,6 +490,7 @@ linux_dev_ioctl(struct cdev *dev, u_long error = -filp->f_op->unlocked_ioctl(filp, cmd, (u_long)data); else error = ENOTTY; + linux_clear_current(td); return (error); } @@ -476,11 +500,14 @@ linux_dev_read(struct cdev *dev, struct { struct linux_cdev *ldev; struct linux_file *filp; + struct task_struct t; + struct thread *td; struct file *file; ssize_t bytes; int error; - file = curthread->td_fpop; + td = curthread; + file = td->td_fpop; ldev = dev->si_drv1; if (ldev == NULL) return (0); @@ -490,6 +517,7 @@ linux_dev_read(struct cdev *dev, struct /* XXX no support for I/O vectors currently */ if (uio->uio_iovcnt != 1) return (EOPNOTSUPP); + linux_set_current(td, &t); if (filp->f_op->read) { bytes = filp->f_op->read(filp, uio->uio_iov->iov_base, uio->uio_iov->iov_len, &uio->uio_offset); @@ -502,6 +530,7 @@ linux_dev_read(struct cdev *dev, struct error = -bytes; } else error = ENXIO; + linux_clear_current(td); return (error); } @@ -511,11 +540,14 @@ linux_dev_write(struct cdev *dev, struct { struct linux_cdev *ldev; struct linux_file *filp; + struct task_struct t; + struct thread *td; struct file *file; ssize_t bytes; int error; - file = curthread->td_fpop; + td = curthread; + file = td->td_fpop; ldev = dev->si_drv1; if (ldev == NULL) return (0); @@ -525,6 +557,7 @@ linux_dev_write(struct cdev *dev, struct /* XXX no support for I/O vectors currently */ if (uio->uio_iovcnt != 1) return (EOPNOTSUPP); + linux_set_current(td, &t); if (filp->f_op->write) { bytes = filp->f_op->write(filp, uio->uio_iov->iov_base, uio->uio_iov->iov_len, &uio->uio_offset); @@ -537,6 +570,7 @@ linux_dev_write(struct cdev *dev, struct error = -bytes; } else error = ENXIO; + linux_clear_current(td); return (error); } @@ -546,21 +580,24 @@ linux_dev_poll(struct cdev *dev, int eve { struct linux_cdev *ldev; struct linux_file *filp; + struct task_struct t; struct file *file; int revents; int error; - file = curthread->td_fpop; + file = td->td_fpop; ldev = dev->si_drv1; if (ldev == NULL) return (0); if ((error = devfs_get_cdevpriv((void **)&filp)) != 0) return (error); filp->f_flags = file->f_flag; + linux_set_current(td, &t); if (filp->f_op->poll) revents = filp->f_op->poll(filp, NULL) & events; else revents = 0; + linux_clear_current(td); return (revents); } @@ -571,17 +608,21 @@ linux_dev_mmap_single(struct cdev *dev, { struct linux_cdev *ldev; struct linux_file *filp; + struct thread *td; + struct task_struct t; struct file *file; struct vm_area_struct vma; int error; - file = curthread->td_fpop; + td = curthread; + file = td->td_fpop; ldev = dev->si_drv1; if (ldev == NULL) return (ENODEV); if ((error = devfs_get_cdevpriv((void **)&filp)) != 0) return (error); filp->f_flags = file->f_flag; + linux_set_current(td, &t); vma.vm_start = 0; vma.vm_end = size; vma.vm_pgoff = *offset / PAGE_SIZE; @@ -596,10 +637,11 @@ linux_dev_mmap_single(struct cdev *dev, sglist_append_phys(sg, (vm_paddr_t)vma.vm_pfn << PAGE_SHIFT, vma.vm_len); *object = vm_pager_allocate(OBJT_SG, sg, vma.vm_len, - nprot, 0, curthread->td_ucred); + nprot, 0, td->td_ucred); if (*object == NULL) { sglist_free(sg); - return (EINVAL); + error = EINVAL; + goto done; } *offset = 0; if (vma.vm_page_prot != VM_MEMATTR_DEFAULT) { @@ -611,7 +653,8 @@ linux_dev_mmap_single(struct cdev *dev, } } else error = ENODEV; - +done: + linux_clear_current(td); return (error); } @@ -632,6 +675,7 @@ linux_file_read(struct file *file, struc int flags, struct thread *td) { struct linux_file *filp; + struct task_struct t; ssize_t bytes; int error; @@ -641,6 +685,7 @@ linux_file_read(struct file *file, struc /* XXX no support for I/O vectors currently */ if (uio->uio_iovcnt != 1) return (EOPNOTSUPP); + linux_set_current(td, &t); if (filp->f_op->read) { bytes = filp->f_op->read(filp, uio->uio_iov->iov_base, uio->uio_iov->iov_len, &uio->uio_offset); @@ -653,6 +698,7 @@ linux_file_read(struct file *file, struc error = -bytes; } else error = ENXIO; + linux_clear_current(td); return (error); } @@ -662,14 +708,17 @@ linux_file_poll(struct file *file, int e struct thread *td) { struct linux_file *filp; + struct task_struct t; int revents; filp = (struct linux_file *)file->f_data; filp->f_flags = file->f_flag; + linux_set_current(td, &t); if (filp->f_op->poll) revents = filp->f_op->poll(filp, NULL) & events; else revents = 0; + linux_clear_current(td); return (revents); } @@ -678,11 +727,14 @@ static int linux_file_close(struct file *file, struct thread *td) { struct linux_file *filp; + struct task_struct t; int error; filp = (struct linux_file *)file->f_data; filp->f_flags = file->f_flag; + linux_set_current(td, &t); error = -filp->f_op->release(NULL, filp); + linux_clear_current(td); funsetown(&filp->f_sigio); kfree(filp); @@ -694,12 +746,14 @@ linux_file_ioctl(struct file *fp, u_long struct thread *td) { struct linux_file *filp; + struct task_struct t; int error; filp = (struct linux_file *)fp->f_data; filp->f_flags = fp->f_flag; error = 0; + linux_set_current(td, &t); switch (cmd) { case FIONBIO: break; @@ -721,6 +775,7 @@ linux_file_ioctl(struct file *fp, u_long error = ENOTTY; break; } + linux_clear_current(td); return (error); }
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