search for: _safe

...if (!node) schedule(); node = llist_reverse_order(node); ... process works ... To me this looks a bit confusing. Shouldn't we do if (!node) { schedule(); continue; } just to make the code a bit more clear? If node == NULL then llist_reverse_order() and llist_for_each_entry_safe() will do nothing. But this is minor. /* make sure flag is seen after deletion */ smp_wmb(); llist_for_each_entry_safe(work, work_next, node, node) { clear_bit(VHOST_WORK_QUEUED, &work->flags); I am not sure about smp_wmb + clear_bit. Once we clear VHOST_WORK_QUEUED, vhost_work_...

...gt; > > On 05/31, Jason Wang wrote: > > > > > > ? 2023/5/23 20:15, Oleg Nesterov ??: > > > > > > > > /* make sure flag is seen after deletion */ > > > > smp_wmb(); > > > > llist_for_each_entry_safe(work, work_next, node, node) { > > > > clear_bit(VHOST_WORK_QUEUED, &work->flags); > > > > > > > >I am not sure about smp_wmb + clear_bit. Once we clear VHOST_WORK_QUEUED, > > > >vhost_work_queue() can add this work again an...

On Tue, Jun 23, 2020 at 04:59:14PM +0200, Joerg Roedel wrote: > On Tue, Jun 23, 2020 at 04:53:44PM +0200, Peter Zijlstra wrote: > > +noinstr void idtentry_validate_ist(struct pt_regs *regs) > > +{ > > + if ((regs->sp & ~(EXCEPTION_STKSZ-1)) == > > + (_RET_IP_ & ~(EXCEPTION_STKSZ-1))) > > + die("IST stack recursion", regs, 0); > > +}

...this is a start, it doesn't cover the case where the NMI stack is >> in-between, so I think you need to walk down regs->sp too. > That shouldn't be possible with the current code, I think. NMI; #MC; Anything which IRET but isn't fatal - #DB, or #BP from patching, #GP from *_safe(), etc; NMI Sure its a corner case, but did you hear that IST is evil? ~Andrew P.S. did you also hear that with Rowhammer, userspace has a nonzero quantity of control over generating #MC, depending on how ECC is configured on the platform.

...n't cover the case where the NMI stack is > >> in-between, so I think you need to walk down regs->sp too. > > That shouldn't be possible with the current code, I think. > > NMI; #MC; Anything which IRET but isn't fatal - #DB, or #BP from > patching, #GP from *_safe(), etc; NMI > > Sure its a corner case, but did you hear that IST is evil? Isn't current #MC unconditionally fatal from kernel? But yes, I was sorta aware people want that changed. And yes, NMI can recurse, mostly on #BP and #PF. Like I wrote, its broken vs #MC. But Joerg was talking...

Hello Roger Pau Monne, The patch 4d4f270f1880: "xen-blkback: move free persistent grants code" from Nov 16, 2012, leads to the following warning: drivers/block/xen-blkback/blkback.c:238 free_persistent_gnts() warn: 'persistent_gnt' was already freed. drivers/block/xen-blkback/blkback.c 232 pages[segs_to_unmap] = persistent_gnt->page; 233

Hello Roger Pau Monne, The patch 4d4f270f1880: "xen-blkback: move free persistent grants code" from Nov 16, 2012, leads to the following warning: drivers/block/xen-blkback/blkback.c:238 free_persistent_gnts() warn: 'persistent_gnt' was already freed. drivers/block/xen-blkback/blkback.c 232 pages[segs_to_unmap] = persistent_gnt->page; 233

On 05/22, Mike Christie wrote: > > On 5/22/23 7:30 AM, Oleg Nesterov wrote: > >> + /* > >> + * When we get a SIGKILL our release function will > >> + * be called. That will stop new IOs from being queued > >> + * and check for outstanding cmd responses. It will then > >> + * call vhost_task_stop to tell us to return and exit. >

...order(node); > ... process works ... > > To me this looks a bit confusing. Shouldn't we do > > if (!node) { > schedule(); > continue; > } > > just to make the code a bit more clear? If node == NULL then > llist_reverse_order() and llist_for_each_entry_safe() will do nothing. > But this is minor. > > > > /* make sure flag is seen after deletion */ > smp_wmb(); > llist_for_each_entry_safe(work, work_next, node, node) { > clear_bit(VHOST_WORK_QUEUED, &work->flags); > > I am not sure about smp_wmb + clear_bit...

I have just starting auditing the NMI path and found that the oprofile code calls into a fair amount of common code. So far, down the first leg of the call graph, I have found several ASSERT()s, a BUG() and many {rd,wr}msr()s. Given that these are common code, and sensible in their places, removing them for the sake of being on the NMI path seems silly. As an alternative, I suggest that we make

...Wang wrote: > > > > > > > > ? 2023/5/23 20:15, Oleg Nesterov ??: > > > > > > > > > > /* make sure flag is seen after deletion */ > > > > > smp_wmb(); > > > > > llist_for_each_entry_safe(work, work_next, node, node) { > > > > > clear_bit(VHOST_WORK_QUEUED, &work->flags); > > > > > > > > > >I am not sure about smp_wmb + clear_bit. Once we clear VHOST_WORK_QUEUED, > > > > >vhost_work_queue() can ad...

Basic x86 support [1] for running Linux as secondary Jailhouse [2] guest is currently pending in the tip tree. This builds on top and enhances the PCI support for x86 and also ARM guests (ARM[64] does not require platform patches and works already). Key elements of this series are: - detection of Jailhouse via device tree hypervisor node - function-level PCI scan if Jailhouse is detected -