search for: set_fs

...tion/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -824,13 +824,9 @@ static void ffs_user_copy_worker(struct work_struct *work) bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; if (io_data->read && ret > 0) { - mm_segment_t oldfs = get_fs(); - - set_fs(USER_DS); kthread_use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); kthread_unuse_mm(io_data->mm); - set_fs(oldfs); } io_data->kiocb->ki_complete(io_data->kiocb, ret, ret); diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhos...

...tion/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -824,13 +824,9 @@ static void ffs_user_copy_worker(struct work_struct *work) bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; if (io_data->read && ret > 0) { - mm_segment_t oldfs = get_fs(); - - set_fs(USER_DS); kthread_use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); kthread_unuse_mm(io_data->mm); - set_fs(oldfs); } io_data->kiocb->ki_complete(io_data->kiocb, ret, ret); diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhos...

Hi all, this series improves the use_mm / unuse_mm interface by better documenting the assumptions, and my taking the set_fs manipulations spread over the callers into the core API. Changes since v1: - drop a few patches - fix a comment typo - cover the newly merged use_mm/unuse_mm caller in vfio

Hi all, this series improves the use_mm / unuse_mm interface by better documenting the assumptions, and my taking the set_fs manipulations spread over the callers into the core API. Changes since v1: - drop a few patches - fix a comment typo - cover the newly merged use_mm/unuse_mm caller in vfio

Hi all, this series improves the use_mm / unuse_mm interface by better documenting the assumptions, and my taking the set_fs manipulations spread over the callers into the core API.

Hi all, this series improves the use_mm / unuse_mm interface by better documenting the assumptions, and my taking the set_fs manipulations spread over the callers into the core API.

...gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index c57b1b2507c6..d9e48bd7c692 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -827,9 +827,9 @@ static void ffs_user_copy_worker(struct work_struct *work) mm_segment_t oldfs = get_fs(); set_fs(USER_DS); - use_mm(io_data->mm); + kthread_use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); - unuse_mm(io_data->mm); + kthread_unuse_mm(io_data->mm); set_fs(oldfs); } diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadg...

...mits. Oooh. *Just* as I sent this, I realized that "use_mm()" doesn't update the thread addr_limit. That actually looks like a bug to me - although one that you've apparently been aware of and worked around. Wouldn't it be nicer to just make "use_mm()" do set_fs(USER_DS); instead? And undo it on unuse_mm()? And, in fact, maybe we should default kernel threads to have a zero address limit, so that they can't do any user accesses at all without doing this? Adding Al to the cc, because I think he's been looking at set_fs() in general....

...gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index c57b1b2507c6..d9e48bd7c692 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -827,9 +827,9 @@ static void ffs_user_copy_worker(struct work_struct *work) mm_segment_t oldfs = get_fs(); set_fs(USER_DS); - use_mm(io_data->mm); + kthread_use_mm(io_data->mm); ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); - unuse_mm(io_data->mm); + kthread_unuse_mm(io_data->mm); set_fs(oldfs); } diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadg...

On Thu, Apr 16, 2020 at 07:31:55AM +0200, Christoph Hellwig wrote: > this series improves the use_mm / unuse_mm interface by better > documenting the assumptions, and my taking the set_fs manipulations > spread over the callers into the core API. I appreciate all the work you're doing here. Do you have plans to introduce a better-named API than set_fs() / get_fs()? Also, having set_fs() return the previous value of 'fs' would simplify a lot of the callers.

...spin_unlock_irqrestore(&dev->work_lock, flags); wake_up_process(dev->worker); } else { @@ -310,7 +306,6 @@ static int vhost_worker(void *data) { struct vhost_dev *dev = data; struct vhost_work *work = NULL; - unsigned uninitialized_var(seq); mm_segment_t oldfs = get_fs(); set_fs(USER_DS); @@ -321,11 +316,6 @@ static int vhost_worker(void *data) set_current_state(TASK_INTERRUPTIBLE); spin_lock_irq(&dev->work_lock); - if (work) { - work->done_seq = seq; - if (work->flushing) - wake_up_all(&work->done); - } if (kthread_should_stop())...

...spin_unlock_irqrestore(&dev->work_lock, flags); wake_up_process(dev->worker); } else { @@ -310,7 +306,6 @@ static int vhost_worker(void *data) { struct vhost_dev *dev = data; struct vhost_work *work = NULL; - unsigned uninitialized_var(seq); mm_segment_t oldfs = get_fs(); set_fs(USER_DS); @@ -321,11 +316,6 @@ static int vhost_worker(void *data) set_current_state(TASK_INTERRUPTIBLE); spin_lock_irq(&dev->work_lock); - if (work) { - work->done_seq = seq; - if (work->flushing) - wake_up_all(&work->done); - } if (kthread_should_stop())...

This patch removes the __init modifier from an extern function declaration in acpi.h. Besides not being strictly needed, it requires the inclusion of linux/init.h, which is usually not even included directly, increasing header mess by a lot. Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> --- include/asm-x86/acpi.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)

This patch removes the __init modifier from an extern function declaration in acpi.h. Besides not being strictly needed, it requires the inclusion of linux/init.h, which is usually not even included directly, increasing header mess by a lot. Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> --- include/asm-x86/acpi.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)

...("The old fs is [%lu]\n",old_fs.seg) ; printk("The neww fs is [%lu]\n ",new_fs.seg) ; /* I found the old_fs and new_fs is in the same address * But in other module is different ,why,can you tell me */ int fd = 0; char pathname[50] ="/test/log/8.mail" ; set_fs(new_fs) ; fd = sys_open(pathname,O_WRONLY|O_CREAT,S_IRUSR|S_IWUSR); printk("fd is [%d]",fd); sys_write(fd,"Mail has develope sucesses , ",20) ; sys_close(fd); set_fs(old_fs) ; return NF_ACCEPT; } static struct nf_hook_ops iplimitfilter= { {NULL,NULL}, myfirewa...

...\ + .ss1 = __KERNEL_CS, \ + .io_bitmap_base = INVALID_IO_BITMAP_OFFSET, \ + }, \ + .io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 }, \ +} + +#define start_thread(regs, new_eip, new_esp) do { \ + __asm__("movl %0,%%gs": :"r" (0)); \ + regs->fs = 0; \ + set_fs(USER_DS); \ + regs->ds = __USER_DS; \ + regs->es = __USER_DS; \ + regs->ss = __USER_DS; \ + regs->cs = __USER_CS; \ + regs->ip = new_eip; \ + regs->sp = new_esp; \ +} while (0) + + +extern unsigned long thread_saved_pc(struct task_struct *tsk); + +#defi...

...\ + .ss1 = __KERNEL_CS, \ + .io_bitmap_base = INVALID_IO_BITMAP_OFFSET, \ + }, \ + .io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 }, \ +} + +#define start_thread(regs, new_eip, new_esp) do { \ + __asm__("movl %0,%%gs": :"r" (0)); \ + regs->fs = 0; \ + set_fs(USER_DS); \ + regs->ds = __USER_DS; \ + regs->es = __USER_DS; \ + regs->ss = __USER_DS; \ + regs->cs = __USER_CS; \ + regs->ip = new_eip; \ + regs->sp = new_esp; \ +} while (0) + + +extern unsigned long thread_saved_pc(struct task_struct *tsk); + +#defi...

...L(vhost_has_work); @@ -305,7 +306,8 @@ static void vhost_vq_reset(struct vhost_dev *dev, static int vhost_worker(void *data) { struct vhost_dev *dev = data; - struct vhost_work *work = NULL; + struct vhost_work *work, *work_next; + struct llist_node *node; mm_segment_t oldfs = get_fs(); set_fs(USER_DS); @@ -315,29 +317,25 @@ static int vhost_worker(void *data) /* mb paired w/ kthread_stop */ set_current_state(TASK_INTERRUPTIBLE); - spin_lock_irq(&dev->work_lock); - if (kthread_should_stop()) { - spin_unlock_irq(&dev->work_lock); __set_current_state(TASK_RU...

On Fri, Nov 02, 2018 at 09:14:51AM -0700, Linus Torvalds wrote: > On Fri, Nov 2, 2018 at 6:04 AM Michael S. Tsirkin <mst at redhat.com> wrote: > > > > I've tried making access_ok mask the parameter it gets. > > PLEASE don't do this. Okay. > Just use "copy_to/from_user()". Just for completeness I'd like to point out for vhost the copies are

Currently, vhost-net is the only consumer of vhost infrastructure. So vhost infrastructure and vhost-net driver are in a single module. Separating this as a vhost.ko module and a vhost-net.ko module makes it is easier to share code with other vhost drivers, e.g. vhost-blk.ko, tcm-vhost.ko. Signed-off-by: Asias He <asias at redhat.com> --- drivers/vhost/Kconfig | 10 +++++++++-