proper license on Microsoft-related files #7

Holek · 2011-09-05T18:46:20Z

No description provided.

torvalds · 2011-09-05T19:05:40Z

Is there some way to just turn off github pull requests? They're all jokes.

shuhaowu · 2011-09-05T19:08:33Z

You could ask [email protected] or whatever their help email is.
Though that means legitimate pull request won't get through, though.

Holek · 2011-09-05T19:21:57Z

don't do that, by tomorrow people will lose the urge to troll ;)

senfo · 2011-09-05T20:38:01Z

Are you considering use Github as the standard public repository? Pull requests generally work out well for open source projects, but I'd be curious how it works out for a project the size of Linux.

Spaceghost · 2011-09-05T21:36:30Z

@torvalds you could just report the user. You might have to go to their profile page and click the gear to get to the reporting page.

CruzBishop · 2011-09-05T21:46:56Z

Reported @Holek, you guys all should too as @Spaceghost said :P

Spaceghost · 2011-09-06T07:40:56Z

@diegoviola called @Holek's mommy.

CruzBishop · 2011-09-06T07:48:20Z

I would laugh if @Holek is some millionaire troll :P

craigbarnes · 2011-09-06T08:05:41Z

@Holek I see you contribute to wikipedia.pl quite a lot. I would have thought that someone who probably deals with a lot of spam himself would have had more sense than this.

Holek · 2011-09-06T09:01:49Z

Hello, everybody!

First of all, I apologize about that crappy prank: that should not have happened. And I'm not saying that, because people are mad, but because I should have known better before doing that.

I have a huge respect towards Linux, and people doing their job on this project, and me making them waste time on such pull requests was irresponsible.

I sincerely apologize for my childish behaviour, and wish you the best of code!

CruzBishop · 2011-09-06T09:38:37Z

Good job for coming around, Holek! :)

commit 1780f2d upstream. Affected kernels 2.6.36 - 3.0 AppArmor may do a GFP_KERNEL memory allocation with task_lock(tsk->group_leader); held when called from security_task_setrlimit. This will only occur when the task's current policy has been replaced, and the task's creds have not been updated before entering the LSM security_task_setrlimit() hook. BUG: sleeping function called from invalid context at mm/slub.c:847 in_atomic(): 1, irqs_disabled(): 0, pid: 1583, name: cupsd 2 locks held by cupsd/1583: #0: (tasklist_lock){.+.+.+}, at: [<ffffffff8104dafa>] do_prlimit+0x61/0x189 #1: (&(&p->alloc_lock)->rlock){+.+.+.}, at: [<ffffffff8104db2d>] do_prlimit+0x94/0x189 Pid: 1583, comm: cupsd Not tainted 3.0.0-rc2-git1 #7 Call Trace: [<ffffffff8102ebf2>] __might_sleep+0x10d/0x112 [<ffffffff810e6f46>] slab_pre_alloc_hook.isra.49+0x2d/0x33 [<ffffffff810e7bc4>] kmem_cache_alloc+0x22/0x132 [<ffffffff8105b6e6>] prepare_creds+0x35/0xe4 [<ffffffff811c0675>] aa_replace_current_profile+0x35/0xb2 [<ffffffff811c4d2d>] aa_current_profile+0x45/0x4c [<ffffffff811c4d4d>] apparmor_task_setrlimit+0x19/0x3a [<ffffffff811beaa5>] security_task_setrlimit+0x11/0x13 [<ffffffff8104db6b>] do_prlimit+0xd2/0x189 [<ffffffff8104dea9>] sys_setrlimit+0x3b/0x48 [<ffffffff814062bb>] system_call_fastpath+0x16/0x1b Signed-off-by: John Johansen <[email protected]> Reported-by: Miles Lane <[email protected]> Signed-off-by: James Morris <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

This patch updates 'kvm run' to boot to host filesystem via 9p '/bin/sh' by default: $ ./kvm run # kvm run -k ../../arch/x86/boot/bzImage -m 320 -c 2 --name guest-3462 [ 0.000000] Linux version 3.1.0-rc1+ (penberg@tiger) (gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5) ) torvalds#7 SMP PREEMPT Tue Aug 9 16:39:20 EEST 2011 [ 0.000000] Command line: notsc noapic noacpi pci=conf1 reboot=k panic=1 console=ttyS0 earlyprintk=serial init=/bin/sh root=/dev/vda rw root=/dev/root rootflags=rw,trans=virtio,version=9p2000.u rootfstype=9p [snip] [ 1.803261] VFS: Mounted root (9p filesystem) on device 0:13. [ 1.805153] devtmpfs: mounted [ 1.808353] Freeing unused kernel memory: 924k freed [ 1.810592] Write protecting the kernel read-only data: 12288k [ 1.816268] Freeing unused kernel memory: 632k freed [ 1.826030] Freeing unused kernel memory: 1448k freed sh: cannot set terminal process group (-1): Inappropriate ioctl for device sh: no job control in this shell sh-4.1# Cc: Linus Torvalds <[email protected]> Cc: Asias He <[email protected]> Cc: Cyrill Gorcunov <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Prasad Joshi <[email protected]> Cc: Sasha Levin <[email protected]> Signed-off-by: Pekka Enberg <[email protected]>

This patch validates sdev pointer in scsi_dh_activate before proceeding further. Without this check we might see the panic as below. I have seen this panic multiple times.. Call trace: #0 [ffff88007d647b50] machine_kexec at ffffffff81020902 #1 [ffff88007d647ba0] crash_kexec at ffffffff810875b0 #2 [ffff88007d647c70] oops_end at ffffffff8139c650 #3 [ffff88007d647c90] __bad_area_nosemaphore at ffffffff8102dd15 #4 [ffff88007d647d50] page_fault at ffffffff8139b8cf [exception RIP: scsi_dh_activate+0x82] RIP: ffffffffa0041922 RSP: ffff88007d647e00 RFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000093c5 RDX: 00000000000093c5 RSI: ffffffffa02e6640 RDI: ffff88007cc88988 RBP: 000000000000000f R8: ffff88007d646000 R9: 0000000000000000 R10: ffff880082293790 R11: 00000000ffffffff R12: ffff88007cc88988 R13: 0000000000000000 R14: 0000000000000286 R15: ffff880037b845e0 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000 #5 [ffff88007d647e38] run_workqueue at ffffffff81060268 torvalds#6 [ffff88007d647e78] worker_thread at ffffffff81060386 torvalds#7 [ffff88007d647ee8] kthread at ffffffff81064436 torvalds#8 [ffff88007d647f48] kernel_thread at ffffffff81003fba Signed-off-by: Babu Moger <[email protected]> Cc: [email protected] Signed-off-by: James Bottomley <[email protected]>

commit a18a920 upstream. This patch validates sdev pointer in scsi_dh_activate before proceeding further. Without this check we might see the panic as below. I have seen this panic multiple times.. Call trace: #0 [ffff88007d647b50] machine_kexec at ffffffff81020902 #1 [ffff88007d647ba0] crash_kexec at ffffffff810875b0 #2 [ffff88007d647c70] oops_end at ffffffff8139c650 #3 [ffff88007d647c90] __bad_area_nosemaphore at ffffffff8102dd15 #4 [ffff88007d647d50] page_fault at ffffffff8139b8cf [exception RIP: scsi_dh_activate+0x82] RIP: ffffffffa0041922 RSP: ffff88007d647e00 RFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000093c5 RDX: 00000000000093c5 RSI: ffffffffa02e6640 RDI: ffff88007cc88988 RBP: 000000000000000f R8: ffff88007d646000 R9: 0000000000000000 R10: ffff880082293790 R11: 00000000ffffffff R12: ffff88007cc88988 R13: 0000000000000000 R14: 0000000000000286 R15: ffff880037b845e0 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000 #5 [ffff88007d647e38] run_workqueue at ffffffff81060268 torvalds#6 [ffff88007d647e78] worker_thread at ffffffff81060386 torvalds#7 [ffff88007d647ee8] kthread at ffffffff81064436 torvalds#8 [ffff88007d647f48] kernel_thread at ffffffff81003fba Signed-off-by: Babu Moger <[email protected]> Signed-off-by: James Bottomley <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

If the pte mapping in generic_perform_write() is unmapped between iov_iter_fault_in_readable() and iov_iter_copy_from_user_atomic(), the "copied" parameter to ->end_write can be zero. ext4 couldn't cope with it with delayed allocations enabled. This skips the i_disksize enlargement logic if copied is zero and no new data was appeneded to the inode. gdb> bt #0 0xffffffff811afe80 in ext4_da_should_update_i_disksize (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x1\ 08000, len=0x1000, copied=0x0, page=0xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2467 #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 #2 0xffffffff810d97f1 in generic_perform_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value o\ ptimized out>, pos=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2440 #3 generic_file_buffered_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value optimized out>, p\ os=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2482 #4 0xffffffff810db5d1 in __generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, ppos=0\ xffff88001e26be40) at mm/filemap.c:2600 #5 0xffffffff810db853 in generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=<value optimi\ zed out>, pos=<value optimized out>) at mm/filemap.c:2632 #6 0xffffffff811a71aa in ext4_file_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, pos=0x108000) a\ t fs/ext4/file.c:136 #7 0xffffffff811375aa in do_sync_write (filp=0xffff88003f606a80, buf=<value optimized out>, len=<value optimized out>, \ ppos=0xffff88001e26bf48) at fs/read_write.c:406 #8 0xffffffff81137e56 in vfs_write (file=0xffff88003f606a80, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x4\ 000, pos=0xffff88001e26bf48) at fs/read_write.c:435 #9 0xffffffff8113816c in sys_write (fd=<value optimized out>, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x\ 4000) at fs/read_write.c:487 #10 <signal handler called> #11 0x00007f120077a390 in __brk_reservation_fn_dmi_alloc__ () #12 0x0000000000000000 in ?? () gdb> print offset $22 = 0xffffffffffffffff gdb> print idx $23 = 0xffffffff gdb> print inode->i_blkbits $24 = 0xc gdb> up #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 2512 if (ext4_da_should_update_i_disksize(page, end)) { gdb> print start $25 = 0x0 gdb> print end $26 = 0xffffffffffffffff gdb> print pos $27 = 0x108000 gdb> print new_i_size $28 = 0x108000 gdb> print ((struct ext4_inode_info *)((char *)inode-((int)(&((struct ext4_inode_info *)0)->vfs_inode))))->i_disksize $29 = 0xd9000 gdb> down 2467 for (i = 0; i < idx; i++) gdb> print i $30 = 0xd44acbee This is 100% reproducible with some autonuma development code tuned in a very aggressive manner (not normal way even for knumad) which does "exotic" changes to the ptes. It wouldn't normally trigger but I don't see why it can't happen normally if the page is added to swap cache in between the two faults leading to "copied" being zero (which then hangs in ext4). So it should be fixed. Especially possible with lumpy reclaim (albeit disabled if compaction is enabled) as that would ignore the young bits in the ptes. Signed-off-by: Andrea Arcangeli <[email protected]> Signed-off-by: "Theodore Ts'o" <[email protected]> Cc: [email protected]

The current selection of the GPTIMER on was result of a hardware issue in early versions of the Beagleboards (Ax and B1 thru B4). [1] [2] Its been long since the hardware issue has been fixed. This patch uses GPTIMER 1 for all newer board revisions incl. Beagleboard XM. [1] http://thread.gmane.org/gmane.comp.hardware.beagleboard.general/91 [2] Errata torvalds#7 at http://elinux.org/BeagleBoard#Errata Signed-off-by: Sanjeev Premi <[email protected]> Cc: Paul Walmsley <[email protected]> Reviewed-by: Paul Walmsley <[email protected]>

$ wget "http://pkgs.fedoraproject.org/gitweb/?p=kernel.git;a=blob_plain;f=mac80211_offchannel_rework_revert.patch;h=859799714cd85a58450ecde4a1dabc5adffd5100;hb=refs/heads/f16" -O mac80211_offchannel_rework_revert.patch $ patch -p1 --dry-run < mac80211_offchannel_rework_revert.patch patching file net/mac80211/ieee80211_i.h Hunk #1 succeeded at 702 (offset 8 lines). Hunk #2 succeeded at 712 (offset 8 lines). Hunk #3 succeeded at 1143 (offset -57 lines). patching file net/mac80211/main.c patching file net/mac80211/offchannel.c Hunk #1 succeeded at 18 (offset 1 line). Hunk #2 succeeded at 42 (offset 1 line). Hunk #3 succeeded at 78 (offset 1 line). Hunk #4 succeeded at 96 (offset 1 line). Hunk #5 succeeded at 162 (offset 1 line). Hunk torvalds#6 succeeded at 182 (offset 1 line). patching file net/mac80211/rx.c Hunk #1 succeeded at 421 (offset 4 lines). Hunk #2 succeeded at 2864 (offset 87 lines). patching file net/mac80211/scan.c Hunk #1 succeeded at 213 (offset 1 line). Hunk #2 succeeded at 256 (offset 2 lines). Hunk #3 succeeded at 288 (offset 2 lines). Hunk #4 succeeded at 333 (offset 2 lines). Hunk #5 succeeded at 482 (offset 2 lines). Hunk torvalds#6 succeeded at 498 (offset 2 lines). Hunk torvalds#7 succeeded at 516 (offset 2 lines). Hunk torvalds#8 succeeded at 530 (offset 2 lines). Hunk torvalds#9 succeeded at 555 (offset 2 lines). patching file net/mac80211/tx.c Hunk #1 succeeded at 259 (offset 1 line). patching file net/mac80211/work.c Hunk #1 succeeded at 899 (offset -2 lines). Hunk #2 succeeded at 949 (offset -2 lines). Hunk #3 succeeded at 1046 (offset -2 lines). Hunk #4 succeeded at 1054 (offset -2 lines).

If the netdev is already in NETREG_UNREGISTERING/_UNREGISTERED state, do not update the real num tx queues. netdev_queue_update_kobjects() is already called via remove_queue_kobjects() at NETREG_UNREGISTERING time. So, when upper layer driver, e.g., FCoE protocol stack is monitoring the netdev event of NETDEV_UNREGISTER and calls back to LLD ndo_fcoe_disable() to remove extra queues allocated for FCoE, the associated txq sysfs kobjects are already removed, and trying to update the real num queues would cause something like below: ... PID: 25138 TASK: ffff88021e64c440 CPU: 3 COMMAND: "kworker/3:3" #0 [ffff88021f007760] machine_kexec at ffffffff810226d9 #1 [ffff88021f0077d0] crash_kexec at ffffffff81089d2d #2 [ffff88021f0078a0] oops_end at ffffffff813bca78 #3 [ffff88021f0078d0] no_context at ffffffff81029e72 #4 [ffff88021f007920] __bad_area_nosemaphore at ffffffff8102a155 #5 [ffff88021f0079f0] bad_area_nosemaphore at ffffffff8102a23e torvalds#6 [ffff88021f007a00] do_page_fault at ffffffff813bf32e torvalds#7 [ffff88021f007b10] page_fault at ffffffff813bc045 [exception RIP: sysfs_find_dirent+17] RIP: ffffffff81178611 RSP: ffff88021f007bc0 RFLAGS: 00010246 RAX: ffff88021e64c440 RBX: ffffffff8156cc63 RCX: 0000000000000004 RDX: ffffffff8156cc63 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88021f007be0 R8: 0000000000000004 R9: 0000000000000008 R10: ffffffff816fed00 R11: 0000000000000004 R12: 0000000000000000 R13: ffffffff8156cc63 R14: 0000000000000000 R15: ffff8802222a0000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#8 [ffff88021f007be8] sysfs_get_dirent at ffffffff81178c07 torvalds#9 [ffff88021f007c18] sysfs_remove_group at ffffffff8117ac27 torvalds#10 [ffff88021f007c48] netdev_queue_update_kobjects at ffffffff813178f9 torvalds#11 [ffff88021f007c88] netif_set_real_num_tx_queues at ffffffff81303e38 torvalds#12 [ffff88021f007cc8] ixgbe_set_num_queues at ffffffffa0249763 [ixgbe] torvalds#13 [ffff88021f007cf8] ixgbe_init_interrupt_scheme at ffffffffa024ea89 [ixgbe] torvalds#14 [ffff88021f007d48] ixgbe_fcoe_disable at ffffffffa0267113 [ixgbe] torvalds#15 [ffff88021f007d68] vlan_dev_fcoe_disable at ffffffffa014fef5 [8021q] torvalds#16 [ffff88021f007d78] fcoe_interface_cleanup at ffffffffa02b7dfd [fcoe] torvalds#17 [ffff88021f007df8] fcoe_destroy_work at ffffffffa02b7f08 [fcoe] torvalds#18 [ffff88021f007e18] process_one_work at ffffffff8105d7ca torvalds#19 [ffff88021f007e68] worker_thread at ffffffff81060513 torvalds#20 [ffff88021f007ee8] kthread at ffffffff810648b6 torvalds#21 [ffff88021f007f48] kernel_thread_helper at ffffffff813c40f4 Signed-off-by: Yi Zou <[email protected]> Tested-by: Ross Brattain <[email protected]> Tested-by: Stephen Ko <[email protected]> Signed-off-by: Jeff Kirsher <[email protected]>

…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 torvalds#6 [d72d3cb4] isolate_migratepages at c030b15a torvalds#7 [d72d3d14] zone_watermark_ok at c02d26cb torvalds#8 [d72d3d2c] compact_zone at c030b8d torvalds#9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <[email protected]> Tested-by: Herbert van den Bergh <[email protected]> Signed-off-by: Mel Gorman <[email protected]> Acked-by: Michal Nazarewicz <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

…S block during isolation for migration commit 0bf380b upstream. When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72e #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8d #9 [d72d3d68] compact_zone_order at c030bba1 torvalds#10 [d72d3db4] try_to_compact_pages at c030bc84 torvalds#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 torvalds#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 torvalds#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 torvalds#14 [d72d3eb8] alloc_pages_vma at c030a845 torvalds#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb torvalds#16 [d72d3f00] handle_mm_fault at c02f36c6 torvalds#17 [d72d3f30] do_page_fault at c05c70ed torvalds#18 [d72d3fb] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <[email protected]> Tested-by: Herbert van den Bergh <[email protected]> Signed-off-by: Mel Gorman <[email protected]> Acked-by: Michal Nazarewicz <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>

As guest_irq is coming from KVM_IRQFD API call, it may trigger crash in svm_update_pi_irte() due to out-of-bounds: crash> bt PID: 22218 TASK: ffff951a6ad74980 CPU: 73 COMMAND: "vcpu8" #0 [ffffb1ba6707fa40] machine_kexec at ffffffff8565b397 #1 [ffffb1ba6707fa90] __crash_kexec at ffffffff85788a6d #2 [ffffb1ba6707fb58] crash_kexec at ffffffff8578995d #3 [ffffb1ba6707fb70] oops_end at ffffffff85623c0d #4 [ffffb1ba6707fb90] no_context at ffffffff856692c9 #5 [ffffb1ba6707fbf8] exc_page_fault at ffffffff85f95b51 torvalds#6 [ffffb1ba6707fc50] asm_exc_page_fault at ffffffff86000ace [exception RIP: svm_update_pi_irte+227] RIP: ffffffffc0761b53 RSP: ffffb1ba6707fd08 RFLAGS: 00010086 RAX: ffffb1ba6707fd78 RBX: ffffb1ba66d91000 RCX: 0000000000000001 RDX: 00003c803f63f1c0 RSI: 000000000000019a RDI: ffffb1ba66db2ab8 RBP: 000000000000019a R8: 0000000000000040 R9: ffff94ca41b82200 R10: ffffffffffffffcf R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffffffffffcf R15: 000000000000005f ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 torvalds#7 [ffffb1ba6707fdb8] kvm_irq_routing_update at ffffffffc09f19a1 [kvm] torvalds#8 [ffffb1ba6707fde0] kvm_set_irq_routing at ffffffffc09f2133 [kvm] torvalds#9 [ffffb1ba6707fe18] kvm_vm_ioctl at ffffffffc09ef544 [kvm] RIP: 00007f143c36488b RSP: 00007f143a4e04b8 RFLAGS: 00000246 RAX: ffffffffffffffda RBX: 00007f05780041d0 RCX: 00007f143c36488b RDX: 00007f05780041d0 RSI: 000000004008ae6a RDI: 0000000000000020 RBP: 00000000000004e8 R8: 0000000000000008 R9: 00007f05780041e0 R10: 00007f0578004560 R11: 0000000000000246 R12: 00000000000004e0 R13: 000000000000001a R14: 00007f1424001c60 R15: 00007f0578003bc0 ORIG_RAX: 0000000000000010 CS: 0033 SS: 002b Vmx have been fix this in commit 96560e7 (KVM: VMX: Do not BUG() on out-of-bounds guest IRQ), so we can just copy source from that to fix this. Co-developed-by: Yi Liu <[email protected]> Signed-off-by: Yi Liu <[email protected]> Signed-off-by: Yi Wang <[email protected]> Message-Id: <[email protected]> Cc: [email protected] Signed-off-by: Paolo Bonzini <[email protected]>

It should release the maps at the end. $ perf test -v 71 71: Convert perf time to TSC : --- start --- test child forked, pid 178744 mmap size 528384B 1st event perf time 59207256505278 tsc 13187166645142 rdtsc time 59207256542151 tsc 13187166723020 2nd event perf time 59207256543749 tsc 13187166726393 ================================================================= ==178744==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7faf601f9e8f in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145 #1 0x55b620cfc00a in cpu_map__trim_new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:79 #2 0x55b620cfca2f in perf_cpu_map__read /home/namhyung/project/linux/tools/lib/perf/cpumap.c:149 #3 0x55b620cfd1ef in cpu_map__read_all_cpu_map /home/namhyung/project/linux/tools/lib/perf/cpumap.c:166 #4 0x55b620cfd1ef in perf_cpu_map__new /home/namhyung/project/linux/tools/lib/perf/cpumap.c:181 #5 0x55b6209ef1b2 in test__perf_time_to_tsc tests/perf-time-to-tsc.c:73 torvalds#6 0x55b6209828fb in run_test tests/builtin-test.c:428 torvalds#7 0x55b6209828fb in test_and_print tests/builtin-test.c:458 torvalds#8 0x55b620984a53 in __cmd_test tests/builtin-test.c:679 torvalds#9 0x55b620984a53 in cmd_test tests/builtin-test.c:825 torvalds#10 0x55b6209f0cd4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 torvalds#11 0x55b62087aa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 torvalds#12 0x55b62087aa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 torvalds#13 0x55b62087aa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 torvalds#14 0x7faf5fd2fd09 in __libc_start_main ../csu/libc-start.c:308 SUMMARY: AddressSanitizer: 72 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Convert perf time to TSC: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

I got a segfault when using -r option with event groups. The option makes it run the workload multiple times and it will reuse the evlist and evsel for each run. While most of resources are allocated and freed properly, the id hash in the evlist was not and it resulted in the bug. You can see it with the address sanitizer like below: $ perf stat -r 100 -e '{cycles,instructions}' true ================================================================= ==693052==ERROR: AddressSanitizer: heap-use-after-free on address 0x6080000003d0 at pc 0x558c57732835 bp 0x7fff1526adb0 sp 0x7fff1526ada8 WRITE of size 8 at 0x6080000003d0 thread T0 #0 0x558c57732834 in hlist_add_head /home/namhyung/project/linux/tools/include/linux/list.h:644 #1 0x558c57732834 in perf_evlist__id_hash /home/namhyung/project/linux/tools/lib/perf/evlist.c:237 #2 0x558c57732834 in perf_evlist__id_add /home/namhyung/project/linux/tools/lib/perf/evlist.c:244 #3 0x558c57732834 in perf_evlist__id_add_fd /home/namhyung/project/linux/tools/lib/perf/evlist.c:285 #4 0x558c5747733e in store_evsel_ids util/evsel.c:2765 #5 0x558c5747733e in evsel__store_ids util/evsel.c:2782 torvalds#6 0x558c5730b717 in __run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:895 torvalds#7 0x558c5730b717 in run_perf_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:1014 torvalds#8 0x558c5730b717 in cmd_stat /home/namhyung/project/linux/tools/perf/builtin-stat.c:2446 torvalds#9 0x558c57427c24 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 torvalds#10 0x558c572b1a48 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 torvalds#11 0x558c572b1a48 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 torvalds#12 0x558c572b1a48 in main /home/namhyung/project/linux/tools/perf/perf.c:539 torvalds#13 0x7fcadb9f7d09 in __libc_start_main ../csu/libc-start.c:308 torvalds#14 0x558c572b60f9 in _start (/home/namhyung/project/linux/tools/perf/perf+0x45d0f9) Actually the nodes in the hash table are struct perf_stream_id and they were freed in the previous run. Fix it by resetting the hash. Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

If something was written to the buffer just before destruction, it may be possible (maybe not in a real system, but it did happen in ARCH=um with time-travel) to destroy the ringbuffer before the IRQ work ran, leading this KASAN report (or a crash without KASAN): BUG: KASAN: slab-use-after-free in irq_work_run_list+0x11a/0x13a Read of size 8 at addr 000000006d640a48 by task swapper/0 CPU: 0 PID: 0 Comm: swapper Tainted: G W O 6.3.0-rc1 torvalds#7 Stack: 60c4f20 0c203d48 41b58ab3 60f224fc 600477fa 60f35687 60c4f20 601273dd 00000008 6101eb00 6101eab0 615be548 Call Trace: [<60047a58>] show_stack+0x25e/0x282 [<60c609e0>] dump_stack_lvl+0x96/0xfd [<60c50d4c>] print_report+0x1a7/0x5a8 [<603078d3>] kasan_report+0xc1/0xe9 [<60308950>] __asan_report_load8_noabort+0x1b/0x1d [<60232844>] irq_work_run_list+0x11a/0x13a [<602328b4>] irq_work_tick+0x24/0x34 [<6017f9dc>] update_process_times+0x162/0x196 [<6019f335>] tick_sched_handle+0x1a4/0x1c3 [<6019fd9e>] tick_sched_timer+0x79/0x10c [<601812b9>] __hrtimer_run_queues.constprop.0+0x425/0x695 [<60182913>] hrtimer_interrupt+0x16c/0x2c4 [<600486a3>] um_timer+0x164/0x183 [...] Allocated by task 411: save_stack_trace+0x99/0xb5 stack_trace_save+0x81/0x9b kasan_save_stack+0x2d/0x54 kasan_set_track+0x34/0x3e kasan_save_alloc_info+0x25/0x28 ____kasan_kmalloc+0x8b/0x97 __kasan_kmalloc+0x10/0x12 __kmalloc+0xb2/0xe8 load_elf_phdrs+0xee/0x182 [...] The buggy address belongs to the object at 000000006d640800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 584 bytes inside of freed 1024-byte region [000000006d640800, 000000006d640c00) Add the appropriate irq_work_sync() so the work finishes before the buffers are destroyed. Prior to the commit in the Fixes tag below, there was only a single global IRQ work, so this issue didn't exist. Link: https://lore.kernel.org/linux-trace-kernel/20230427175920.a76159263122.I8295e405c44362a86c995e9c2c37e3e03810aa56@changeid Cc: [email protected] Cc: Masami Hiramatsu <[email protected]> Fixes: e11d4b2 ("tracing/ring-buffer: Move poll wake ups into ring buffer code") Signed-off-by: Johannes Berg <[email protected]> Signed-off-by: Steven Rostedt (Google) <[email protected]>

Sai Krishna says: ==================== octeontx2: Miscellaneous fixes This patchset includes following fixes. Patch #1 Fix for the race condition while updating APR table Patch #2 Fix end bit position in NPC scan config Patch #3 Fix depth of CAM, MEM table entries Patch #4 Fix in increase the size of DMAC filter flows Patch #5 Fix driver crash resulting from invalid interface type information retrieved from firmware Patch torvalds#6 Fix incorrect mask used while installing filters involving fragmented packets Patch torvalds#7 Fixes for NPC field hash extract w.r.t IPV6 hash reduction, IPV6 filed hash configuration. Patch torvalds#8 Fix for NPC hardware parser configuration destination address hash, IPV6 endianness issues. Patch torvalds#9 Fix for skipping mbox initialization for PFs disabled by firmware. Patch torvalds#10 Fix disabling packet I/O in case of mailbox timeout. Patch torvalds#11 Fix detaching LF resources in case of VF probe fail. ==================== Signed-off-by: David S. Miller <[email protected]>

This fixes the following hard lockup in isolate_lru_folios() during memory reclaim. If the LRU mostly contains ineligible folios this may trigger watchdog. watchdog: Watchdog detected hard LOCKUP on cpu 173 RIP: 0010:native_queued_spin_lock_slowpath+0x255/0x2a0 Call Trace: _raw_spin_lock_irqsave+0x31/0x40 folio_lruvec_lock_irqsave+0x5f/0x90 folio_batch_move_lru+0x91/0x150 lru_add_drain_per_cpu+0x1c/0x40 process_one_work+0x17d/0x350 worker_thread+0x27b/0x3a0 kthread+0xe8/0x120 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1b/0x30 lruvec->lru_lock owner： PID: 2865 TASK: ffff888139214d40 CPU: 40 COMMAND: "kswapd0" #0 [fffffe0000945e60] crash_nmi_callback at ffffffffa567a555 #1 [fffffe0000945e68] nmi_handle at ffffffffa563b171 #2 [fffffe0000945eb0] default_do_nmi at ffffffffa6575920 #3 [fffffe0000945ed0] exc_nmi at ffffffffa6575af4 #4 [fffffe0000945ef0] end_repeat_nmi at ffffffffa6601dde [exception RIP: isolate_lru_folios+403] RIP: ffffffffa597df53 RSP: ffffc90006fb7c28 RFLAGS: 00000002 RAX: 0000000000000001 RBX: ffffc90006fb7c60 RCX: ffffea04a2196f88 RDX: ffffc90006fb7c60 RSI: ffffc90006fb7c60 RDI: ffffea04a2197048 RBP: ffff88812cbd3010 R8: ffffea04a2197008 R9: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffffea04a2197008 R13: ffffea04a2197048 R14: ffffc90006fb7de8 R15: 0000000003e3e937 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 <NMI exception stack> #5 [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53 torvalds#6 [ffffc90006fb7cf8] shrink_active_list at ffffffffa597f788 torvalds#7 [ffffc90006fb7da8] balance_pgdat at ffffffffa5986db0 torvalds#8 [ffffc90006fb7ec0] kswapd at ffffffffa5987354 torvalds#9 [ffffc90006fb7ef8] kthread at ffffffffa5748238 crash> Scenario: User processe are requesting a large amount of memory and keep page active. Then a module continuously requests memory from ZONE_DMA32 area. Memory reclaim will be triggered due to ZONE_DMA32 watermark alarm reached. However pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area. Reproduce: Terminal 1: Construct to continuously increase pages active(anon). mkdir /tmp/memory mount -t tmpfs -o size=1024000M tmpfs /tmp/memory dd if=/dev/zero of=/tmp/memory/block bs=4M tail /tmp/memory/block Terminal 2: vmstat -a 1 active will increase. procs ---memory--- ---swap-- ---io---- -system-- ---cpu--- ... r b swpd free inact active si so bi bo 1 0 0 1445623076 45898836 83646008 0 0 0 1 0 0 1445623076 43450228 86094616 0 0 0 1 0 0 1445623076 41003480 88541364 0 0 0 1 0 0 1445623076 38557088 90987756 0 0 0 1 0 0 1445623076 36109688 93435156 0 0 0 1 0 0 1445619552 33663256 95881632 0 0 0 1 0 0 1445619804 31217140 98327792 0 0 0 1 0 0 1445619804 28769988 100774944 0 0 0 1 0 0 1445619804 26322348 103222584 0 0 0 1 0 0 1445619804 23875592 105669340 0 0 0 cat /proc/meminfo | head Active(anon) increase. MemTotal: 1579941036 kB MemFree: 1445618500 kB MemAvailable: 1453013224 kB Buffers: 6516 kB Cached: 128653956 kB SwapCached: 0 kB Active: 118110812 kB Inactive: 11436620 kB Active(anon): 115345744 kB Inactive(anon): 945292 kB When the Active(anon) is 115345744 kB, insmod module triggers the ZONE_DMA32 watermark. perf record -e vmscan:mm_vmscan_lru_isolate -aR perf script isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=2 nr_skipped=2 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=0 nr_skipped=0 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=28835844 nr_skipped=28835844 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=28835844 nr_skipped=28835844 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=29 nr_skipped=29 nr_taken=0 lru=active_anon isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=0 nr_skipped=0 nr_taken=0 lru=active_anon See nr_scanned=28835844. 28835844 * 4k = 115343376KB approximately equal to 115345744 kB. If increase Active(anon) to 1000G then insmod module triggers the ZONE_DMA32 watermark. hard lockup will occur. In my device nr_scanned = 0000000003e3e937 when hard lockup. Convert to memory size 0x0000000003e3e937 * 4KB = 261072092 KB. [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53 ffffc90006fb7c30: 0000000000000020 0000000000000000 ffffc90006fb7c40: ffffc90006fb7d40 ffff88812cbd3000 ffffc90006fb7c50: ffffc90006fb7d30 0000000106fb7de8 ffffc90006fb7c60: ffffea04a2197008 ffffea0006ed4a48 ffffc90006fb7c70: 0000000000000000 0000000000000000 ffffc90006fb7c80: 0000000000000000 0000000000000000 ffffc90006fb7c90: 0000000000000000 0000000000000000 ffffc90006fb7ca0: 0000000000000000 0000000003e3e937 ffffc90006fb7cb0: 0000000000000000 0000000000000000 ffffc90006fb7cc0: 8d7c0b56b7874b00 ffff88812cbd3000 About the Fixes: Why did it take eight years to be discovered? The problem requires the following conditions to occur: 1. The device memory should be large enough. 2. Pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area. 3. The memory in ZONE_DMA32 needs to reach the watermark. If the memory is not large enough, or if the usage design of ZONE_DMA32 area memory is reasonable, this problem is difficult to detect. notes: The problem is most likely to occur in ZONE_DMA32 and ZONE_NORMAL, but other suitable scenarios may also trigger the problem. Link: https://lkml.kernel.org/r/[email protected] Fixes: 0c17553 ("mm, vmscan: begin reclaiming pages on a per-node basis") Signed-off-by: liuye <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Yang Shi <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

devm_platform_profile_register() expects a pointer to the private driver data but instead an address of the pointer variable is passed due to a typo. This leads to the crashes later: BUG: unable to handle page fault for address: 00000000fe0d0044 PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 6 UID: 0 PID: 1284 Comm: tuned Tainted: G W 6.13.0+ torvalds#7 Tainted: [W]=WARN Hardware name: LENOVO 21D0/LNVNB161216, BIOS J6CN45WW 03/17/2023 RIP: 0010:__mutex_lock.constprop.0+0x6bf/0x7f0 Call Trace: <TASK> dytc_profile_set+0x4a/0x140 [ideapad_laptop] _store_and_notify+0x13/0x40 [platform_profile] class_for_each_device+0x145/0x180 platform_profile_store+0xc0/0x130 [platform_profile] kernfs_fop_write_iter+0x13e/0x1f0 vfs_write+0x290/0x450 ksys_write+0x6c/0xe0 do_syscall_64+0x82/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Found by Linux Verification Center (linuxtesting.org). Fixes: acfdf53 ("ACPI: platform_profile: Let drivers set drvdata to the class device") Signed-off-by: Fedor Pchelkin <[email protected]> Reviewed-by: Kurt Borja <[email protected]> Link: https://lore.kernel.org/r/[email protected] Reviewed-by: Ilpo Järvinen <[email protected]> Signed-off-by: Ilpo Järvinen <[email protected]>

We have several places across the kernel where we want to access another task's syscall arguments, such as ptrace(2), seccomp(2), etc., by making a call to syscall_get_arguments(). This works for register arguments right away by accessing the task's `regs' member of `struct pt_regs', however for stack arguments seen with 32-bit/o32 kernels things are more complicated. Technically they ought to be obtained from the user stack with calls to an access_remote_vm(), but we have an easier way available already. So as to be able to access syscall stack arguments as regular function arguments following the MIPS calling convention we copy them over from the user stack to the kernel stack in arch/mips/kernel/scall32-o32.S, in handle_sys(), to the current stack frame's outgoing argument space at the top of the stack, which is where the handler called expects to see its incoming arguments. This area is also pointed at by the `pt_regs' pointer obtained by task_pt_regs(). Make the o32 stack argument space a proper member of `struct pt_regs' then, by renaming the existing member from `pad0' to `args' and using generated offsets to access the space. No functional change though. With the change in place the o32 kernel stack frame layout at the entry to a syscall handler invoked by handle_sys() is therefore as follows: $sp + 68 -> | ... | <- pt_regs.regs[9] +---------------------+ $sp + 64 -> | $t0 | <- pt_regs.regs[8] +---------------------+ $sp + 60 -> | $a3/argument #4 | <- pt_regs.regs[7] +---------------------+ $sp + 56 -> | $a2/argument #3 | <- pt_regs.regs[6] +---------------------+ $sp + 52 -> | $a1/argument #2 | <- pt_regs.regs[5] +---------------------+ $sp + 48 -> | $a0/argument #1 | <- pt_regs.regs[4] +---------------------+ $sp + 44 -> | $v1 | <- pt_regs.regs[3] +---------------------+ $sp + 40 -> | $v0 | <- pt_regs.regs[2] +---------------------+ $sp + 36 -> | $at | <- pt_regs.regs[1] +---------------------+ $sp + 32 -> | $zero | <- pt_regs.regs[0] +---------------------+ $sp + 28 -> | stack argument torvalds#8 | <- pt_regs.args[7] +---------------------+ $sp + 24 -> | stack argument torvalds#7 | <- pt_regs.args[6] +---------------------+ $sp + 20 -> | stack argument torvalds#6 | <- pt_regs.args[5] +---------------------+ $sp + 16 -> | stack argument #5 | <- pt_regs.args[4] +---------------------+ $sp + 12 -> | psABI space for $a3 | <- pt_regs.args[3] +---------------------+ $sp + 8 -> | psABI space for $a2 | <- pt_regs.args[2] +---------------------+ $sp + 4 -> | psABI space for $a1 | <- pt_regs.args[1] +---------------------+ $sp + 0 -> | psABI space for $a0 | <- pt_regs.args[0] +---------------------+ holding user data received and with the first 4 frame slots reserved by the psABI for the compiler to spill the incoming arguments from $a0-$a3 registers (which it sometimes does according to its needs) and the next 4 frame slots designated by the psABI for any stack function arguments that follow. This data is also available for other tasks to peek/poke at as reqired and where permitted. Signed-off-by: Maciej W. Rozycki <[email protected]> Signed-off-by: Thomas Bogendoerfer <[email protected]>

This makes ptrace/get_syscall_info selftest pass on mips o32 and mips64 o32 by fixing the following two test assertions: 1. get_syscall_info test assertion on mips o32: # get_syscall_info.c:218:get_syscall_info:Expected exp_args[5] (3134521044) == info.entry.args[4] (4911432) # get_syscall_info.c:219:get_syscall_info:wait #1: entry stop mismatch 2. get_syscall_info test assertion on mips64 o32: # get_syscall_info.c:209:get_syscall_info:Expected exp_args[2] (3134324433) == info.entry.args[1] (18446744072548908753) # get_syscall_info.c:210:get_syscall_info:wait #1: entry stop mismatch The first assertion happens due to mips_get_syscall_arg() trying to access another task's context but failing to do it properly because get_user() it calls just peeks at the current task's context. It usually does not crash because the default user stack always gets assigned the same VMA, but it is pure luck which mips_get_syscall_arg() wouldn't have if e.g. the stack was switched (via setcontext(3) or however) or a non-default process's thread peeked at, and in any case irrelevant data is obtained just as observed with the test case. mips_get_syscall_arg() ought to be using access_remote_vm() instead to retrieve the other task's stack contents, but given that the data has been already obtained and saved in `struct pt_regs' it would be an overkill. The first assertion is fixed for mips o32 by using struct pt_regs.args instead of get_user() to obtain syscall arguments. This approach works due to this piece in arch/mips/kernel/scall32-o32.S: /* * Ok, copy the args from the luser stack to the kernel stack. */ .set push .set noreorder .set nomacro load_a4: user_lw(t5, 16(t0)) # argument #5 from usp load_a5: user_lw(t6, 20(t0)) # argument torvalds#6 from usp load_a6: user_lw(t7, 24(t0)) # argument torvalds#7 from usp load_a7: user_lw(t8, 28(t0)) # argument torvalds#8 from usp loads_done: sw t5, PT_ARG4(sp) # argument #5 to ksp sw t6, PT_ARG5(sp) # argument torvalds#6 to ksp sw t7, PT_ARG6(sp) # argument torvalds#7 to ksp sw t8, PT_ARG7(sp) # argument torvalds#8 to ksp .set pop .section __ex_table,"a" PTR_WD load_a4, bad_stack_a4 PTR_WD load_a5, bad_stack_a5 PTR_WD load_a6, bad_stack_a6 PTR_WD load_a7, bad_stack_a7 .previous arch/mips/kernel/scall64-o32.S has analogous code for mips64 o32 that allows fixing the issue by obtaining syscall arguments from struct pt_regs.regs[4..11] instead of the erroneous use of get_user(). The second assertion is fixed by truncating 64-bit values to 32-bit syscall arguments. Fixes: ab30749 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.") Signed-off-by: Dmitry V. Levin <[email protected]> Signed-off-by: Thomas Bogendoerfer <[email protected]>

- treat tailcall count as 32-bit for access and update - change out_offset scope from file to function - minor format/structure changes for consistency Testing: (skipping fentry, fexit, freplace) ======== root@qemu-armhf:/usr/libexec/kselftests-bpf# modprobe test_bpf test_suite=test_tail_calls test_bpf: #0 Tail call leaf jited:1 967 PASS test_bpf: #1 Tail call 2 jited:1 1427 PASS test_bpf: #2 Tail call 3 jited:1 2373 PASS test_bpf: #3 Tail call 4 jited:1 2304 PASS test_bpf: #4 Tail call load/store leaf jited:1 1684 PASS test_bpf: #5 Tail call load/store jited:1 2249 PASS test_bpf: torvalds#6 Tail call error path, max count reached jited:1 22538 PASS test_bpf: torvalds#7 Tail call count preserved across function calls jited:1 1055668 PASS test_bpf: torvalds#8 Tail call error path, NULL target jited:1 513 PASS test_bpf: torvalds#9 Tail call error path, index out of range jited:1 392 PASS test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed] root@qemu-armhf:/usr/libexec/kselftests-bpf# ./test_progs -n 397/1-12,17-18,23-24,27-31 397/1 tailcalls/tailcall_1:OK 397/2 tailcalls/tailcall_2:OK 397/3 tailcalls/tailcall_3:OK 397/4 tailcalls/tailcall_4:OK 397/5 tailcalls/tailcall_5:OK 397/6 tailcalls/tailcall_6:OK 397/7 tailcalls/tailcall_bpf2bpf_1:OK 397/8 tailcalls/tailcall_bpf2bpf_2:OK 397/9 tailcalls/tailcall_bpf2bpf_3:OK 397/10 tailcalls/tailcall_bpf2bpf_4:OK 397/11 tailcalls/tailcall_bpf2bpf_5:OK 397/12 tailcalls/tailcall_bpf2bpf_6:OK 397/17 tailcalls/tailcall_poke:OK 397/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK 397/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK 397/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK 397/27 tailcalls/tailcall_failure:OK 397/28 tailcalls/reject_tail_call_spin_lock:OK 397/29 tailcalls/reject_tail_call_rcu_lock:OK 397/30 tailcalls/reject_tail_call_preempt_lock:OK 397/31 tailcalls/reject_tail_call_ref:OK 397 tailcalls:OK Summary: 1/21 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Tony Ambardar <[email protected]>

Load (and put) FPU state in kvm_arch_vcpu_ioctl_get_mpstate() if KVM (and the host) supports CET, as kvm_apic_accept_events() can trigger emulation of INIT, which in turn can lead to putting FPU state. E.g. on a host with CET but not MPX, syzkaller+KASAN generates: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 211 UID: 0 PID: 20451 Comm: syz.9.26 Tainted: G S 6.18.0-smp-DEV torvalds#7 NONE Tainted: [S]=CPU_OUT_OF_SPEC Hardware name: Google Izumi/izumi, BIOS 0.20250729.1-0 07/29/2025 RIP: 0010:fpu_swap_kvm_fpstate+0x3ce/0x610 ../arch/x86/kernel/fpu/core.c:377 RSP: 0018:ff1100410c167cc0 EFLAGS: 00010202 RAX: 0000000000000004 RBX: 0000000000000020 RCX: 00000000000001aa RDX: 00000000000001ab RSI: ffffffff817bb960 RDI: 0000000022600000 RBP: dffffc0000000000 R08: ff110040d23c8007 R09: 1fe220081a479000 R10: dffffc0000000000 R11: ffe21c081a479001 R12: ff110040d23c8d98 R13: 00000000fffdc578 R14: 0000000000000000 R15: ff110040d23c8d90 FS: 00007f86dd1876c0(0000) GS:ff11007fc969b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86dd186fa8 CR3: 00000040d1dfa003 CR4: 0000000000f73ef0 PKRU: 80000000 Call Trace: <TASK> kvm_vcpu_reset+0x80d/0x12c0 ../arch/x86/kvm/x86.c:11818 kvm_apic_accept_events+0x1cb/0x500 ../arch/x86/kvm/lapic.c:3489 kvm_arch_vcpu_ioctl_get_mpstate+0xd0/0x4e0 ../arch/x86/kvm/x86.c:12145 kvm_vcpu_ioctl+0x5e2/0xed0 ../virt/kvm/kvm_main.c:4539 __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:51 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6e/0x940 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f86de71d9c9 </TASK> with a very simple reproducer: r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x80b00, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) ioctl$KVM_CREATE_IRQCHIP(r1, 0xae60) r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) ioctl$KVM_SET_IRQCHIP(r1, 0x8208ae63, ...) ioctl$KVM_GET_MP_STATE(r2, 0x8004ae98, &(0x7f00000000c0)) For now, defer a more robust/pretty fix and address the immediate issue in the same way as commit f958bd2 ("KVM: x86: Fix potential put_fpu() w/o load_fpu() on MPX platform") in order to minimize the change in functionality. Commit f958bd2's justification for its hackery of "MPX is being removed from the kernel" obviously doesn't apply to CET, but providing a cleaner solution isn't an urgent concern. Reported-by: Alexander Potapenko <[email protected]> Fixes: 69cc3e8 ("KVM: x86: Add XSS support for CET_KERNEL and CET_USER") Signed-off-by: Sean Christopherson <[email protected]>

- treat tailcall count as 32-bit for access and update - change out_offset scope from file to function - minor format/structure changes for consistency Testing: (skipping fentry, fexit, freplace) ======== root@qemu-armhf:/usr/libexec/kselftests-bpf# modprobe test_bpf test_suite=test_tail_calls test_bpf: #0 Tail call leaf jited:1 967 PASS test_bpf: #1 Tail call 2 jited:1 1427 PASS test_bpf: #2 Tail call 3 jited:1 2373 PASS test_bpf: #3 Tail call 4 jited:1 2304 PASS test_bpf: #4 Tail call load/store leaf jited:1 1684 PASS test_bpf: #5 Tail call load/store jited:1 2249 PASS test_bpf: torvalds#6 Tail call error path, max count reached jited:1 22538 PASS test_bpf: torvalds#7 Tail call count preserved across function calls jited:1 1055668 PASS test_bpf: torvalds#8 Tail call error path, NULL target jited:1 513 PASS test_bpf: torvalds#9 Tail call error path, index out of range jited:1 392 PASS test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed] root@qemu-armhf:/usr/libexec/kselftests-bpf# ./test_progs -n 397/1-12,17-18,23-24,27-31 397/1 tailcalls/tailcall_1:OK 397/2 tailcalls/tailcall_2:OK 397/3 tailcalls/tailcall_3:OK 397/4 tailcalls/tailcall_4:OK 397/5 tailcalls/tailcall_5:OK 397/6 tailcalls/tailcall_6:OK 397/7 tailcalls/tailcall_bpf2bpf_1:OK 397/8 tailcalls/tailcall_bpf2bpf_2:OK 397/9 tailcalls/tailcall_bpf2bpf_3:OK 397/10 tailcalls/tailcall_bpf2bpf_4:OK 397/11 tailcalls/tailcall_bpf2bpf_5:OK 397/12 tailcalls/tailcall_bpf2bpf_6:OK 397/17 tailcalls/tailcall_poke:OK 397/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK 397/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK 397/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK 397/27 tailcalls/tailcall_failure:OK 397/28 tailcalls/reject_tail_call_spin_lock:OK 397/29 tailcalls/reject_tail_call_rcu_lock:OK 397/30 tailcalls/reject_tail_call_preempt_lock:OK 397/31 tailcalls/reject_tail_call_ref:OK 397 tailcalls:OK Summary: 1/21 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Tony Ambardar <[email protected]>

Replace the hack added by commit f958bd2 ("KVM: x86: Fix potential put_fpu() w/o load_fpu() on MPX platform") with a more robust approach of unloading+reloading guest FPU state based on whether or not the vCPU's FPU is currently in-use, i.e. currently loaded. This fixes a bug on hosts that support CET but not MPX, where kvm_arch_vcpu_ioctl_get_mpstate() neglects to load FPU state (it only checks for MPX support) and leads to KVM attempting to put FPU state due to kvm_apic_accept_events() triggering INIT emulation. E.g. on a host with CET but not MPX, syzkaller+KASAN generates: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 211 UID: 0 PID: 20451 Comm: syz.9.26 Tainted: G S 6.18.0-smp-DEV torvalds#7 NONE Tainted: [S]=CPU_OUT_OF_SPEC Hardware name: Google Izumi/izumi, BIOS 0.20250729.1-0 07/29/2025 RIP: 0010:fpu_swap_kvm_fpstate+0x3ce/0x610 ../arch/x86/kernel/fpu/core.c:377 RSP: 0018:ff1100410c167cc0 EFLAGS: 00010202 RAX: 0000000000000004 RBX: 0000000000000020 RCX: 00000000000001aa RDX: 00000000000001ab RSI: ffffffff817bb960 RDI: 0000000022600000 RBP: dffffc0000000000 R08: ff110040d23c8007 R09: 1fe220081a479000 R10: dffffc0000000000 R11: ffe21c081a479001 R12: ff110040d23c8d98 R13: 00000000fffdc578 R14: 0000000000000000 R15: ff110040d23c8d90 FS: 00007f86dd1876c0(0000) GS:ff11007fc969b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86dd186fa8 CR3: 00000040d1dfa003 CR4: 0000000000f73ef0 PKRU: 80000000 Call Trace: <TASK> kvm_vcpu_reset+0x80d/0x12c0 ../arch/x86/kvm/x86.c:11818 kvm_apic_accept_events+0x1cb/0x500 ../arch/x86/kvm/lapic.c:3489 kvm_arch_vcpu_ioctl_get_mpstate+0xd0/0x4e0 ../arch/x86/kvm/x86.c:12145 kvm_vcpu_ioctl+0x5e2/0xed0 ../virt/kvm/kvm_main.c:4539 __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:51 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6e/0x940 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f86de71d9c9 </TASK> with a very simple reproducer: r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x80b00, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) ioctl$KVM_CREATE_IRQCHIP(r1, 0xae60) r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) ioctl$KVM_SET_IRQCHIP(r1, 0x8208ae63, ...) ioctl$KVM_GET_MP_STATE(r2, 0x8004ae98, &(0x7f00000000c0)) Alternatively, the MPX hack in GET_MP_STATE could be extended to cover CET, but from a "don't break existing functionality" perspective, that isn't any less risky than peeking at the state of in_use, and it's far less robust for a long term solution (as evidenced by this bug). Reported-by: Alexander Potapenko <[email protected]> Fixes: 69cc3e8 ("KVM: x86: Add XSS support for CET_KERNEL and CET_USER") Signed-off-by: Sean Christopherson <[email protected]>

commit 0570327 upstream. Before disabling SR-IOV via config space accesses to the parent PF, sriov_disable() first removes the PCI devices representing the VFs. Since commit 9d16947 ("PCI: Add global pci_lock_rescan_remove()") such removal operations are serialized against concurrent remove and rescan using the pci_rescan_remove_lock. No such locking was ever added in sriov_disable() however. In particular when commit 18f9e9d ("PCI/IOV: Factor out sriov_add_vfs()") factored out the PCI device removal into sriov_del_vfs() there was still no locking around the pci_iov_remove_virtfn() calls. On s390 the lack of serialization in sriov_disable() may cause double remove and list corruption with the below (amended) trace being observed: PSW: 0704c00180000000 0000000c914e4b38 (klist_put+56) GPRS: 000003800313fb48 0000000000000000 0000000100000001 0000000000000001 00000000f9b520a8 0000000000000000 0000000000002fbd 00000000f4cc9480 0000000000000001 0000000000000000 0000000000000000 0000000180692828 00000000818e8000 000003800313fe2c 000003800313fb20 000003800313fad8 #0 [3800313fb20] device_del at c9158ad5c #1 [3800313fb88] pci_remove_bus_device at c915105ba #2 [3800313fbd0] pci_iov_remove_virtfn at c9152f198 #3 [3800313fc28] zpci_iov_remove_virtfn at c90fb67c0 #4 [3800313fc60] zpci_bus_remove_device at c90fb6104 #5 [3800313fca0] __zpci_event_availability at c90fb3dca torvalds#6 [3800313fd08] chsc_process_sei_nt0 at c918fe4a2 torvalds#7 [3800313fd60] crw_collect_info at c91905822 torvalds#8 [3800313fe10] kthread at c90feb390 torvalds#9 [3800313fe68] __ret_from_fork at c90f6aa64 torvalds#10 [3800313fe98] ret_from_fork at c9194f3f2. This is because in addition to sriov_disable() removing the VFs, the platform also generates hot-unplug events for the VFs. This being the reverse operation to the hotplug events generated by sriov_enable() and handled via pdev->no_vf_scan. And while the event processing takes pci_rescan_remove_lock and checks whether the struct pci_dev still exists, the lack of synchronization makes this checking racy. Other races may also be possible of course though given that this lack of locking persisted so long observable races seem very rare. Even on s390 the list corruption was only observed with certain devices since the platform events are only triggered by config accesses after the removal, so as long as the removal finished synchronously they would not race. Either way the locking is missing so fix this by adding it to the sriov_del_vfs() helper. Just like PCI rescan-remove, locking is also missing in sriov_add_vfs() including for the error case where pci_stop_and_remove_bus_device() is called without the PCI rescan-remove lock being held. Even in the non-error case, adding new PCI devices and buses should be serialized via the PCI rescan-remove lock. Add the necessary locking. Fixes: 18f9e9d ("PCI/IOV: Factor out sriov_add_vfs()") Signed-off-by: Niklas Schnelle <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Reviewed-by: Benjamin Block <[email protected]> Reviewed-by: Farhan Ali <[email protected]> Reviewed-by: Julian Ruess <[email protected]> Cc: [email protected] Link: https://patch.msgid.link/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>

Replace the hack added by commit f958bd2 ("KVM: x86: Fix potential put_fpu() w/o load_fpu() on MPX platform") with a more robust approach of unloading+reloading guest FPU state based on whether or not the vCPU's FPU is currently in-use, i.e. currently loaded. This fixes a bug on hosts that support CET but not MPX, where kvm_arch_vcpu_ioctl_get_mpstate() neglects to load FPU state (it only checks for MPX support) and leads to KVM attempting to put FPU state due to kvm_apic_accept_events() triggering INIT emulation. E.g. on a host with CET but not MPX, syzkaller+KASAN generates: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 211 UID: 0 PID: 20451 Comm: syz.9.26 Tainted: G S 6.18.0-smp-DEV torvalds#7 NONE Tainted: [S]=CPU_OUT_OF_SPEC Hardware name: Google Izumi/izumi, BIOS 0.20250729.1-0 07/29/2025 RIP: 0010:fpu_swap_kvm_fpstate+0x3ce/0x610 ../arch/x86/kernel/fpu/core.c:377 RSP: 0018:ff1100410c167cc0 EFLAGS: 00010202 RAX: 0000000000000004 RBX: 0000000000000020 RCX: 00000000000001aa RDX: 00000000000001ab RSI: ffffffff817bb960 RDI: 0000000022600000 RBP: dffffc0000000000 R08: ff110040d23c8007 R09: 1fe220081a479000 R10: dffffc0000000000 R11: ffe21c081a479001 R12: ff110040d23c8d98 R13: 00000000fffdc578 R14: 0000000000000000 R15: ff110040d23c8d90 FS: 00007f86dd1876c0(0000) GS:ff11007fc969b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86dd186fa8 CR3: 00000040d1dfa003 CR4: 0000000000f73ef0 PKRU: 80000000 Call Trace: <TASK> kvm_vcpu_reset+0x80d/0x12c0 ../arch/x86/kvm/x86.c:11818 kvm_apic_accept_events+0x1cb/0x500 ../arch/x86/kvm/lapic.c:3489 kvm_arch_vcpu_ioctl_get_mpstate+0xd0/0x4e0 ../arch/x86/kvm/x86.c:12145 kvm_vcpu_ioctl+0x5e2/0xed0 ../virt/kvm/kvm_main.c:4539 __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:51 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6e/0x940 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f86de71d9c9 </TASK> with a very simple reproducer: r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x80b00, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) ioctl$KVM_CREATE_IRQCHIP(r1, 0xae60) r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) ioctl$KVM_SET_IRQCHIP(r1, 0x8208ae63, ...) ioctl$KVM_GET_MP_STATE(r2, 0x8004ae98, &(0x7f00000000c0)) Alternatively, the MPX hack in GET_MP_STATE could be extended to cover CET, but from a "don't break existing functionality" perspective, that isn't any less risky than peeking at the state of in_use, and it's far less robust for a long term solution (as evidenced by this bug). Reported-by: Alexander Potapenko <[email protected]> Fixes: 69cc3e8 ("KVM: x86: Add XSS support for CET_KERNEL and CET_USER") Signed-off-by: Sean Christopherson <[email protected]>

- treat tailcall count as 32-bit for access and update - change out_offset scope from file to function - minor format/structure changes for consistency Testing: (skipping fentry, fexit, freplace) ======== root@qemu-armhf:/usr/libexec/kselftests-bpf# modprobe test_bpf test_suite=test_tail_calls test_bpf: #0 Tail call leaf jited:1 967 PASS test_bpf: #1 Tail call 2 jited:1 1427 PASS test_bpf: #2 Tail call 3 jited:1 2373 PASS test_bpf: #3 Tail call 4 jited:1 2304 PASS test_bpf: #4 Tail call load/store leaf jited:1 1684 PASS test_bpf: #5 Tail call load/store jited:1 2249 PASS test_bpf: torvalds#6 Tail call error path, max count reached jited:1 22538 PASS test_bpf: torvalds#7 Tail call count preserved across function calls jited:1 1055668 PASS test_bpf: torvalds#8 Tail call error path, NULL target jited:1 513 PASS test_bpf: torvalds#9 Tail call error path, index out of range jited:1 392 PASS test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed] root@qemu-armhf:/usr/libexec/kselftests-bpf# ./test_progs -n 397/1-12,17-18,23-24,27-31 397/1 tailcalls/tailcall_1:OK 397/2 tailcalls/tailcall_2:OK 397/3 tailcalls/tailcall_3:OK 397/4 tailcalls/tailcall_4:OK 397/5 tailcalls/tailcall_5:OK 397/6 tailcalls/tailcall_6:OK 397/7 tailcalls/tailcall_bpf2bpf_1:OK 397/8 tailcalls/tailcall_bpf2bpf_2:OK 397/9 tailcalls/tailcall_bpf2bpf_3:OK 397/10 tailcalls/tailcall_bpf2bpf_4:OK 397/11 tailcalls/tailcall_bpf2bpf_5:OK 397/12 tailcalls/tailcall_bpf2bpf_6:OK 397/17 tailcalls/tailcall_poke:OK 397/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK 397/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK 397/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK 397/27 tailcalls/tailcall_failure:OK 397/28 tailcalls/reject_tail_call_spin_lock:OK 397/29 tailcalls/reject_tail_call_rcu_lock:OK 397/30 tailcalls/reject_tail_call_preempt_lock:OK 397/31 tailcalls/reject_tail_call_ref:OK 397 tailcalls:OK Summary: 1/21 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Tony Ambardar <[email protected]>

Replace the hack added by commit f958bd2 ("KVM: x86: Fix potential put_fpu() w/o load_fpu() on MPX platform") with a more robust approach of unloading+reloading guest FPU state based on whether or not the vCPU's FPU is currently in-use, i.e. currently loaded. This fixes a bug on hosts that support CET but not MPX, where kvm_arch_vcpu_ioctl_get_mpstate() neglects to load FPU state (it only checks for MPX support) and leads to KVM attempting to put FPU state due to kvm_apic_accept_events() triggering INIT emulation. E.g. on a host with CET but not MPX, syzkaller+KASAN generates: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 211 UID: 0 PID: 20451 Comm: syz.9.26 Tainted: G S 6.18.0-smp-DEV torvalds#7 NONE Tainted: [S]=CPU_OUT_OF_SPEC Hardware name: Google Izumi/izumi, BIOS 0.20250729.1-0 07/29/2025 RIP: 0010:fpu_swap_kvm_fpstate+0x3ce/0x610 ../arch/x86/kernel/fpu/core.c:377 RSP: 0018:ff1100410c167cc0 EFLAGS: 00010202 RAX: 0000000000000004 RBX: 0000000000000020 RCX: 00000000000001aa RDX: 00000000000001ab RSI: ffffffff817bb960 RDI: 0000000022600000 RBP: dffffc0000000000 R08: ff110040d23c8007 R09: 1fe220081a479000 R10: dffffc0000000000 R11: ffe21c081a479001 R12: ff110040d23c8d98 R13: 00000000fffdc578 R14: 0000000000000000 R15: ff110040d23c8d90 FS: 00007f86dd1876c0(0000) GS:ff11007fc969b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86dd186fa8 CR3: 00000040d1dfa003 CR4: 0000000000f73ef0 PKRU: 80000000 Call Trace: <TASK> kvm_vcpu_reset+0x80d/0x12c0 ../arch/x86/kvm/x86.c:11818 kvm_apic_accept_events+0x1cb/0x500 ../arch/x86/kvm/lapic.c:3489 kvm_arch_vcpu_ioctl_get_mpstate+0xd0/0x4e0 ../arch/x86/kvm/x86.c:12145 kvm_vcpu_ioctl+0x5e2/0xed0 ../virt/kvm/kvm_main.c:4539 __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:51 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6e/0x940 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f86de71d9c9 </TASK> with a very simple reproducer: r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x80b00, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) ioctl$KVM_CREATE_IRQCHIP(r1, 0xae60) r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) ioctl$KVM_SET_IRQCHIP(r1, 0x8208ae63, ...) ioctl$KVM_GET_MP_STATE(r2, 0x8004ae98, &(0x7f00000000c0)) Alternatively, the MPX hack in GET_MP_STATE could be extended to cover CET, but from a "don't break existing functionality" perspective, that isn't any less risky than peeking at the state of in_use, and it's far less robust for a long term solution (as evidenced by this bug). Reported-by: Alexander Potapenko <[email protected]> Fixes: 69cc3e8 ("KVM: x86: Add XSS support for CET_KERNEL and CET_USER") Signed-off-by: Sean Christopherson <[email protected]>

- treat tailcall count as 32-bit for access and update - change out_offset scope from file to function - minor format/structure changes for consistency Testing: (skipping fentry, fexit, freplace) ======== root@qemu-armhf:/usr/libexec/kselftests-bpf# modprobe test_bpf test_suite=test_tail_calls test_bpf: #0 Tail call leaf jited:1 967 PASS test_bpf: #1 Tail call 2 jited:1 1427 PASS test_bpf: #2 Tail call 3 jited:1 2373 PASS test_bpf: #3 Tail call 4 jited:1 2304 PASS test_bpf: #4 Tail call load/store leaf jited:1 1684 PASS test_bpf: #5 Tail call load/store jited:1 2249 PASS test_bpf: torvalds#6 Tail call error path, max count reached jited:1 22538 PASS test_bpf: torvalds#7 Tail call count preserved across function calls jited:1 1055668 PASS test_bpf: torvalds#8 Tail call error path, NULL target jited:1 513 PASS test_bpf: torvalds#9 Tail call error path, index out of range jited:1 392 PASS test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed] root@qemu-armhf:/usr/libexec/kselftests-bpf# ./test_progs -n 397/1-12,17-18,23-24,27-31 397/1 tailcalls/tailcall_1:OK 397/2 tailcalls/tailcall_2:OK 397/3 tailcalls/tailcall_3:OK 397/4 tailcalls/tailcall_4:OK 397/5 tailcalls/tailcall_5:OK 397/6 tailcalls/tailcall_6:OK 397/7 tailcalls/tailcall_bpf2bpf_1:OK 397/8 tailcalls/tailcall_bpf2bpf_2:OK 397/9 tailcalls/tailcall_bpf2bpf_3:OK 397/10 tailcalls/tailcall_bpf2bpf_4:OK 397/11 tailcalls/tailcall_bpf2bpf_5:OK 397/12 tailcalls/tailcall_bpf2bpf_6:OK 397/17 tailcalls/tailcall_poke:OK 397/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK 397/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK 397/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK 397/27 tailcalls/tailcall_failure:OK 397/28 tailcalls/reject_tail_call_spin_lock:OK 397/29 tailcalls/reject_tail_call_rcu_lock:OK 397/30 tailcalls/reject_tail_call_preempt_lock:OK 397/31 tailcalls/reject_tail_call_ref:OK 397 tailcalls:OK Summary: 1/21 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Tony Ambardar <[email protected]>

Fix a kernel NULL pointer dereference in pick_next_task_fair() caused by EEVDF scheduler arithmetic overflows when cfs_rq->avg_vruntime approaches the s64 low. The issue occurs when: 1. cfs_rq->avg_vruntime is driven downward by dynamic reweight operations on se->vruntime combined with frequent enqueue/dequeue of another sched_entity with large se->vlag values. Note that the presence of only one other sched_entity (besides the current one) is critical because having more would average out the effect and prevent the continuous and rapid decrease of cfs_rq->avg_vruntime. 2. These factors `reweight` and `frequent enqueue/dequeue` persistently suppress cfs_rq->min_vruntime, causing cfs_rq->avg_vruntime to decrease rapidly toward S64_MIN. 3. In vruntime_eligible(), the calculation (int64_t)(vruntime - cfs_rq->min_vruntime) * load may overflow downward, becoming a large positive value. 4. This causes vruntime_eligible() to incorrectly judge all tasks as ineligible, leading to NULL pointer dereference in pick_next_task_fair(). The fix addresses this by adjusting the current sched_entity's vruntime during reweight operations when: - The entity is cfs_rq->curr and the only running task - The entity is on the runqueue - Its vruntime is below min_vruntime The most straightforward fix would be to adjust the vruntime during dequeue, but that would require checking and possibly modifying the curr's vruntime on every dequeue, which has a broader impact and concurrency concerns. Therefore, we choose to apply the fix in the reweight path, which is one of the necessary conditions for the problem to occur. BUG: kernel NULL pointer dereference, address: 00000000000000a0 RIP: 0010:pick_next_task_fair+0x39b/0xab03 KERNEL: vmlinux [TAINTED] DUMPFILE: 127.0.0.1-2025-10-30-13:52:24/vmcore [PARTIAL DUMP] CPUS: 4 DATE: Thu Oct 30 05:52:18 UTC 2025 UPTIME: 02:02:50 LOAD AVERAGE: 15.00, 15.00, 15.00 TASKS: 151 NODENAME: SangforOS.localdomain RELEASE: 6.6.0+ VERSION: #4 SMP Thu Oct 30 11:25:11 CST 2025 MACHINE: x86_64 (2194 Mhz) MEMORY: 4 GB PANIC: "Oops: 0000 [#1] SMP PTI" (check log for details) PID: 4702 COMMAND: "test_sched_2/-1" TASK: ffff8881362dcf80 [THREAD_INFO: ffff8881362dcf80] CPU: 1 STATE: TASK_UNINTERRUPTIBLE (PANIC) crash> bt PID: 4702 TASK: ffff8881362dcf80 CPU: 1 COMMAND: "test_sched_2/-1" #0 [ffffc90000fffab0] machine_kexec at ffffffffb567e767 #1 [ffffc90000fffb10] __crash_kexec at ffffffffb580474a #2 [ffffc90000fffbd0] crash_kexec at ffffffffb5805768 #3 [ffffc90000fffbd8] oops_end at ffffffffb5639599 #4 [ffffc90000fffbf8] page_fault_oops at ffffffffb56954a8 #5 [ffffc90000fffc50] exc_page_fault at ffffffffb63424a9 torvalds#6 [ffffc90000fffcb0] asm_exc_page_fault at ffffffffb6400c12 [exception RIP: pick_next_task_fair+923] RIP: ffffffffb576f22b RSP: ffffc90000fffd60 RFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff8881340b4d80 RCX: 82a3cdbe7f1c7aed RDX: 01721730951583fc RSI: 0000000000015f5f RDI: 00105468401dc9e3 RBP: ffffc90000fffe18 R8: 00000000000003fa R9: 0000000000000002 R10: 0000000000000002 R11: 0000000000000064 R12: ffff8881362dcf80 R13: ffffc90000fffdc0 R14: ffff8881340b4e00 R15: ffff8881340b4e00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000 torvalds#7 [ffffc90000fffdb0] __schedule at ffffffffb6348cc8 torvalds#8 [ffffc90000fffe20] schedule at ffffffffb63493ab torvalds#9 [ffffc90000fffe38] schedule_timeout at ffffffffb634eeaf crash> crash> crash> p runqueues PER-CPU DATA TYPE: struct rq runqueues; PER-CPU ADDRESSES: [0]: ffff888134034d80 [1]: ffff8881340b4d80 [2]: ffff888134134d80 [3]: ffff8881341b4d80 crash> crash> struct -o rq.cfs ffff8881340b4d80 struct rq { [ffff8881340b4e00] struct cfs_rq cfs; } crash> struct cfs_rq.nr_running,curr,next,tasks_timeline,min_vruntime,avg_vruntime,avg_load,load,exec_clock ffff8881340b4e00 nr_running = 3, curr = 0xffff888139b57c00, next = 0xffff888139b57c00, tasks_timeline = { rb_root = { rb_node = 0xffff8881362d80d0 }, rb_leftmost = 0xffff8881362d9b50 }, min_vruntime = 4596406356396515, avg_vruntime = -9137321448325056783, avg_load = 88933, load = { weight = 92109859, inv_weight = 0 }, exec_clock = 0, crash> struct sched_entity.on_rq,deadline,min_vruntime,vruntime,load,vlag,slice,exec_start,sum_exec_runtime,prev_sum_exec_runtime,my_q,run_node 0xffff888139b57c00 on_rq = 1, deadline = 4705706610399852, min_vruntime = 4493662477571149, vruntime = 4698735667604793, load = { weight = 1042467, inv_weight = 0 }, vlag = 4493662483537817, slice = 2250000, exec_start = 7308537586004, sum_exec_runtime = 7196457582967, prev_sum_exec_runtime = 7196456203065, my_q = 0xffff888139b55000, run_node = { __rb_parent_color = 1, rb_right = 0xffff8881362d80d0, rb_left = 0x0 }, crash> struct sched_entity.deadline,min_vruntime,vruntime,load,vlag,slice,exec_start,sum_exec_runtime,prev_sum_exec_runtime,my_q,run_node -l sched_entity.run_node 0xffff8881362d80d0 deadline = 4493662533339551, min_vruntime = 4493662476669436, vruntime = 4493662519944203, load = { weight = 176128, inv_weight = 24970740 }, vlag = 4493662519002535, slice = 2250000, exec_start = 7308527703195, sum_exec_runtime = 4759831, prev_sum_exec_runtime = 2351660, my_q = 0x0, run_node = { __rb_parent_color = 1, rb_right = 0x0, rb_left = 0xffff8881362d9b50 }, crash> struct sched_entity.deadline,min_vruntime,vruntime,load,vlag,slice,exec_start,sum_exec_runtime,prev_sum_exec_runtime,my_q,run_node -l sched_entity.run_node 0xffff8881362d9b50 deadline = 4493662476695393, min_vruntime = 4493662476669436, vruntime = 4493662476669436, load = { weight = 90891264, inv_weight = 48388 }, vlag = 51914, slice = 2250000, exec_start = 7308536206102, sum_exec_runtime = 2102797408, prev_sum_exec_runtime = 2102198648, my_q = 0x0, run_node = { __rb_parent_color = 18446612687273951440, rb_right = 0x0, rb_left = 0x0 }, crash> In vruntime_eligible(): for sched_entity curr [0xffff888139b57c00]: avg [-9033150209515029779], (int64_t)(vruntime - cfs_rq->min_vruntime) * load [9204623872495814378], so return false for sched_entity root [0xffff8881362d80d0]: avg [-9033150209515029779], (int64_t)(vruntime - cfs_rq->min_vruntime) * load [9204833240987634904], so return false for sched_entity leftmost [0xffff8881362d9b50]: avg [-9033150209515029779], (int64_t)(vruntime - cfs_rq->min_vruntime) * load [9204829348379068487], so return false Therefore, all sched_entities on this cfs_rq have no eligibility to run to cause the NULL pointer dereference in pick_next_task_fair(). Fixes: 147f3ef ("sched/fair: Implement an EEVDF-like scheduling policy") Signed-off-by: Zicheng Qu <[email protected]> Signed-off-by: wulibin163 <[email protected]>

When using perf record with the `--overwrite` option, a segmentation fault occurs if an event fails to open. For example: perf record -e cycles-ct -F 1000 -a --overwrite Error: cycles-ct:H: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat' perf: Segmentation fault #0 0x6466b6 in dump_stack debug.c:366 #1 0x646729 in sighandler_dump_stack debug.c:378 #2 0x453fd1 in sigsegv_handler builtin-record.c:722 #3 0x7f8454e65090 in __restore_rt libc-2.32.so[54090] #4 0x6c5671 in __perf_event__synthesize_id_index synthetic-events.c:1862 #5 0x6c5ac0 in perf_event__synthesize_id_index synthetic-events.c:1943 torvalds#6 0x458090 in record__synthesize builtin-record.c:2075 torvalds#7 0x45a85a in __cmd_record builtin-record.c:2888 torvalds#8 0x45deb6 in cmd_record builtin-record.c:4374 torvalds#9 0x4e5e33 in run_builtin perf.c:349 torvalds#10 0x4e60bf in handle_internal_command perf.c:401 torvalds#11 0x4e6215 in run_argv perf.c:448 torvalds#12 0x4e653a in main perf.c:555 torvalds#13 0x7f8454e4fa72 in __libc_start_main libc-2.32.so[3ea72] torvalds#14 0x43a3ee in _start ??:0 The --overwrite option implies --tail-synthesize, which collects non-sample events reflecting the system status when recording finishes. However, when evsel opening fails (e.g., unsupported event 'cycles-ct'), session->evlist is not initialized and remains NULL. The code unconditionally calls record__synthesize() in the error path, which iterates through the NULL evlist pointer and causes a segfault. To fix it, move the record__synthesize() call inside the error check block, so it's only called when there was no error during recording, ensuring that evlist is properly initialized. Fixes: 4ea648a ("perf record: Add --tail-synthesize option") Signed-off-by: Shuai Xue <[email protected]> Signed-off-by: Namhyung Kim <[email protected]>

Replace the hack added by commit f958bd2 ("KVM: x86: Fix potential put_fpu() w/o load_fpu() on MPX platform") with a more robust approach of unloading+reloading guest FPU state based on whether or not the vCPU's FPU is currently in-use, i.e. currently loaded. This fixes a bug on hosts that support CET but not MPX, where kvm_arch_vcpu_ioctl_get_mpstate() neglects to load FPU state (it only checks for MPX support) and leads to KVM attempting to put FPU state due to kvm_apic_accept_events() triggering INIT emulation. E.g. on a host with CET but not MPX, syzkaller+KASAN generates: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 211 UID: 0 PID: 20451 Comm: syz.9.26 Tainted: G S 6.18.0-smp-DEV torvalds#7 NONE Tainted: [S]=CPU_OUT_OF_SPEC Hardware name: Google Izumi/izumi, BIOS 0.20250729.1-0 07/29/2025 RIP: 0010:fpu_swap_kvm_fpstate+0x3ce/0x610 ../arch/x86/kernel/fpu/core.c:377 RSP: 0018:ff1100410c167cc0 EFLAGS: 00010202 RAX: 0000000000000004 RBX: 0000000000000020 RCX: 00000000000001aa RDX: 00000000000001ab RSI: ffffffff817bb960 RDI: 0000000022600000 RBP: dffffc0000000000 R08: ff110040d23c8007 R09: 1fe220081a479000 R10: dffffc0000000000 R11: ffe21c081a479001 R12: ff110040d23c8d98 R13: 00000000fffdc578 R14: 0000000000000000 R15: ff110040d23c8d90 FS: 00007f86dd1876c0(0000) GS:ff11007fc969b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86dd186fa8 CR3: 00000040d1dfa003 CR4: 0000000000f73ef0 PKRU: 80000000 Call Trace: <TASK> kvm_vcpu_reset+0x80d/0x12c0 ../arch/x86/kvm/x86.c:11818 kvm_apic_accept_events+0x1cb/0x500 ../arch/x86/kvm/lapic.c:3489 kvm_arch_vcpu_ioctl_get_mpstate+0xd0/0x4e0 ../arch/x86/kvm/x86.c:12145 kvm_vcpu_ioctl+0x5e2/0xed0 ../virt/kvm/kvm_main.c:4539 __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:51 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6e/0x940 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f86de71d9c9 </TASK> with a very simple reproducer: r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x80b00, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) ioctl$KVM_CREATE_IRQCHIP(r1, 0xae60) r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) ioctl$KVM_SET_IRQCHIP(r1, 0x8208ae63, ...) ioctl$KVM_GET_MP_STATE(r2, 0x8004ae98, &(0x7f00000000c0)) Alternatively, the MPX hack in GET_MP_STATE could be extended to cover CET, but from a "don't break existing functionality" perspective, that isn't any less risky than peeking at the state of in_use, and it's far less robust for a long term solution (as evidenced by this bug). Reported-by: Alexander Potapenko <[email protected]> Fixes: 69cc3e8 ("KVM: x86: Add XSS support for CET_KERNEL and CET_USER") Reviewed-by: Yao Yuan <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Sean Christopherson <[email protected]>

Fixes the following lockdep splat on PREEMPT_RT: <3> BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 <3> in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1373, name: xe_module_load <3> preempt_count: 1, expected: 0 <3> RCU nest depth: 0, expected: 0 <4> 11 locks held by xe_module_load/1373: <4> #0: ffff888107b691a0 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x104/0x220 <4> #1: ffff88813cd30280 (&dev->clientlist_mutex){+.+.}-{3:3}, at: drm_client_register+0x32/0xe0 <4> #2: ffffffff837f88f8 (registration_lock){+.+.}-{3:3}, at: register_framebuffer+0x1b/0x50 <4> #3: ffffffff835985e0 (console_lock){+.+.}-{0:0}, at: fbcon_fb_registered+0x6f/0x90 <4> #4: ffff88812589e6a0 (&helper->lock){+.+.}-{3:3}, at: __drm_fb_helper_restore_fbdev_mode_unlocked+0x7b/0x110 <4> #5: ffff88813cd30158 (&dev->master_mutex){+.+.}-{3:3}, at: drm_master_internal_acquire+0x20/0x50 <4> torvalds#6: ffff88812589e488 (&client->modeset_mutex){+.+.}-{3:3}, at: drm_client_modeset_commit_locked+0x2a/0x1b0 <4> torvalds#7: ffffc9000031eef0 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_client_modeset_commit_atomic+0x4c/0x2b0 <4> torvalds#8: ffffc9000031ef18 (crtc_ww_class_mutex){+.+.}-{3:3}, at: drm_client_modeset_commit_atomic+0x4c/0x2b0 <4> torvalds#9: ffff888114f7b8b8 (&intel_dp->psr.lock){+.+.}-{3:3}, at: intel_psr_lock+0xc5/0xf0 [xe] <4> torvalds#10: ffff88812a0cbbc0 (&wl->lock){+.+.}-{2:2}, at: intel_dmc_wl_get+0x3c/0x140 [xe] This splat will happen otherwise on all tracepoints too, for similar reasons. Signed-off-by: Maarten Lankhorst <[email protected]>

Replace the hack added by commit f958bd2 ("KVM: x86: Fix potential put_fpu() w/o load_fpu() on MPX platform") with a more robust approach of unloading+reloading guest FPU state based on whether or not the vCPU's FPU is currently in-use, i.e. currently loaded. This fixes a bug on hosts that support CET but not MPX, where kvm_arch_vcpu_ioctl_get_mpstate() neglects to load FPU state (it only checks for MPX support) and leads to KVM attempting to put FPU state due to kvm_apic_accept_events() triggering INIT emulation. E.g. on a host with CET but not MPX, syzkaller+KASAN generates: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 211 UID: 0 PID: 20451 Comm: syz.9.26 Tainted: G S 6.18.0-smp-DEV torvalds#7 NONE Tainted: [S]=CPU_OUT_OF_SPEC Hardware name: Google Izumi/izumi, BIOS 0.20250729.1-0 07/29/2025 RIP: 0010:fpu_swap_kvm_fpstate+0x3ce/0x610 ../arch/x86/kernel/fpu/core.c:377 RSP: 0018:ff1100410c167cc0 EFLAGS: 00010202 RAX: 0000000000000004 RBX: 0000000000000020 RCX: 00000000000001aa RDX: 00000000000001ab RSI: ffffffff817bb960 RDI: 0000000022600000 RBP: dffffc0000000000 R08: ff110040d23c8007 R09: 1fe220081a479000 R10: dffffc0000000000 R11: ffe21c081a479001 R12: ff110040d23c8d98 R13: 00000000fffdc578 R14: 0000000000000000 R15: ff110040d23c8d90 FS: 00007f86dd1876c0(0000) GS:ff11007fc969b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86dd186fa8 CR3: 00000040d1dfa003 CR4: 0000000000f73ef0 PKRU: 80000000 Call Trace: <TASK> kvm_vcpu_reset+0x80d/0x12c0 ../arch/x86/kvm/x86.c:11818 kvm_apic_accept_events+0x1cb/0x500 ../arch/x86/kvm/lapic.c:3489 kvm_arch_vcpu_ioctl_get_mpstate+0xd0/0x4e0 ../arch/x86/kvm/x86.c:12145 kvm_vcpu_ioctl+0x5e2/0xed0 ../virt/kvm/kvm_main.c:4539 __se_sys_ioctl+0x11d/0x1b0 ../fs/ioctl.c:51 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6e/0x940 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f86de71d9c9 </TASK> with a very simple reproducer: r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x80b00, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) ioctl$KVM_CREATE_IRQCHIP(r1, 0xae60) r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) ioctl$KVM_SET_IRQCHIP(r1, 0x8208ae63, ...) ioctl$KVM_GET_MP_STATE(r2, 0x8004ae98, &(0x7f00000000c0)) Alternatively, the MPX hack in GET_MP_STATE could be extended to cover CET, but from a "don't break existing functionality" perspective, that isn't any less risky than peeking at the state of in_use, and it's far less robust for a long term solution (as evidenced by this bug). Reported-by: Alexander Potapenko <[email protected]> Fixes: 69cc3e8 ("KVM: x86: Add XSS support for CET_KERNEL and CET_USER") Reviewed-by: Yao Yuan <[email protected]> Reviewed-by: Chao Gao <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Sean Christopherson <[email protected]>

- treat tailcall count as 32-bit for access and update - change out_offset scope from file to function - minor format/structure changes for consistency Testing: (skipping fentry, fexit, freplace) ======== root@qemu-armhf:/usr/libexec/kselftests-bpf# modprobe test_bpf test_suite=test_tail_calls test_bpf: #0 Tail call leaf jited:1 967 PASS test_bpf: #1 Tail call 2 jited:1 1427 PASS test_bpf: #2 Tail call 3 jited:1 2373 PASS test_bpf: #3 Tail call 4 jited:1 2304 PASS test_bpf: #4 Tail call load/store leaf jited:1 1684 PASS test_bpf: #5 Tail call load/store jited:1 2249 PASS test_bpf: torvalds#6 Tail call error path, max count reached jited:1 22538 PASS test_bpf: torvalds#7 Tail call count preserved across function calls jited:1 1055668 PASS test_bpf: torvalds#8 Tail call error path, NULL target jited:1 513 PASS test_bpf: torvalds#9 Tail call error path, index out of range jited:1 392 PASS test_bpf: test_tail_calls: Summary: 10 PASSED, 0 FAILED, [10/10 JIT'ed] root@qemu-armhf:/usr/libexec/kselftests-bpf# ./test_progs -n 397/1-12,17-18,23-24,27-31 397/1 tailcalls/tailcall_1:OK 397/2 tailcalls/tailcall_2:OK 397/3 tailcalls/tailcall_3:OK 397/4 tailcalls/tailcall_4:OK 397/5 tailcalls/tailcall_5:OK 397/6 tailcalls/tailcall_6:OK 397/7 tailcalls/tailcall_bpf2bpf_1:OK 397/8 tailcalls/tailcall_bpf2bpf_2:OK 397/9 tailcalls/tailcall_bpf2bpf_3:OK 397/10 tailcalls/tailcall_bpf2bpf_4:OK 397/11 tailcalls/tailcall_bpf2bpf_5:OK 397/12 tailcalls/tailcall_bpf2bpf_6:OK 397/17 tailcalls/tailcall_poke:OK 397/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK 397/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK 397/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK 397/27 tailcalls/tailcall_failure:OK 397/28 tailcalls/reject_tail_call_spin_lock:OK 397/29 tailcalls/reject_tail_call_rcu_lock:OK 397/30 tailcalls/reject_tail_call_preempt_lock:OK 397/31 tailcalls/reject_tail_call_ref:OK 397 tailcalls:OK Summary: 1/21 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Tony Ambardar <[email protected]>

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