user/sven/linux.git, branch v4.4.234

Linux 4.4.234

2020-08-26T08:27:10Z

Tested-by: Jon Hunter Tested-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

KVM: arm/arm64: Don't reschedule in unmap_stage2_range()

2020-08-26T08:27:10Z

Upstream commits fdfe7cbd5880 ("KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()") and b5331379bc62 ("KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set") fix a "sleeping from invalid context" BUG caused by unmap_stage2_range() attempting to reschedule when called on the OOM path. Unfortunately, these patches rely on the MMU notifier callback being passed knowledge about whether or not blocking is permitted, which was introduced in 4.19. Rather than backport this considerable amount of infrastructure just for KVM on arm, instead just remove the conditional reschedule. Cc: # v4.4 only Cc: Marc Zyngier Cc: Suzuki K Poulose Cc: James Morse Signed-off-by: Will Deacon Acked-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

omapfb: dss: Fix max fclk divider for omap36xx

2020-08-26T08:27:10Z

There appears to be a timing issue where using a divider of 32 breaks the DSS for OMAP36xx despite the TRM stating 32 is a valid number. Through experimentation, it appears that 31 works. This same fix was issued for kernels 4.5+. However, between kernels 4.4 and 4.5, the directory structure was changed when the dss directory was moved inside the omapfb directory. That broke the patch on kernels older than 4.5, because it didn't permit the patch to apply cleanly for 4.4 and older. A similar patch was applied to the 3.16 kernel already, but not to 4.4. Commit 4b911101a5cd ("drm/omap: fix max fclk divider for omap36xx") is on the 3.16 stable branch with notes from Ben about the path change. Since this was applied for 3.16 already, this patch is for kernels 3.17 through 4.4 only. Fixes: f7018c213502 ("video: move fbdev to drivers/video/fbdev") Cc: #3.17 - 4.4 CC: Signed-off-by: Adam Ford Signed-off-by: Greg Kroah-Hartman

xen: don't reschedule in preemption off sections

2020-08-26T08:27:10Z

For support of long running hypercalls xen_maybe_preempt_hcall() is calling cond_resched() in case a hypercall marked as preemptible has been interrupted. Normally this is no problem, as only hypercalls done via some ioctl()s are marked to be preemptible. In rare cases when during such a preemptible hypercall an interrupt occurs and any softirq action is started from irq_exit(), a further hypercall issued by the softirq handler will be regarded to be preemptible, too. This might lead to rescheduling in spite of the softirq handler potentially having set preempt_disable(), leading to splats like: BUG: sleeping function called from invalid context at drivers/xen/preempt.c:37 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 20775, name: xl INFO: lockdep is turned off. CPU: 1 PID: 20775 Comm: xl Tainted: G D W 5.4.46-1_prgmr_debug.el7.x86_64 #1 Call Trace: dump_stack+0x8f/0xd0 ___might_sleep.cold.76+0xb2/0x103 xen_maybe_preempt_hcall+0x48/0x70 xen_do_hypervisor_callback+0x37/0x40 RIP: e030:xen_hypercall_xen_version+0xa/0x20 Code: ... RSP: e02b:ffffc900400dcc30 EFLAGS: 00000246 RAX: 000000000004000d RBX: 0000000000000200 RCX: ffffffff8100122a RDX: ffff88812e788000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff83ee3ad0 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: ffff8881824aa0b0 R13: 0000000865496000 R14: 0000000865496000 R15: ffff88815d040000 ? xen_hypercall_xen_version+0xa/0x20 ? xen_force_evtchn_callback+0x9/0x10 ? check_events+0x12/0x20 ? xen_restore_fl_direct+0x1f/0x20 ? _raw_spin_unlock_irqrestore+0x53/0x60 ? debug_dma_sync_single_for_cpu+0x91/0xc0 ? _raw_spin_unlock_irqrestore+0x53/0x60 ? xen_swiotlb_sync_single_for_cpu+0x3d/0x140 ? mlx4_en_process_rx_cq+0x6b6/0x1110 [mlx4_en] ? mlx4_en_poll_rx_cq+0x64/0x100 [mlx4_en] ? net_rx_action+0x151/0x4a0 ? __do_softirq+0xed/0x55b ? irq_exit+0xea/0x100 ? xen_evtchn_do_upcall+0x2c/0x40 ? xen_do_hypervisor_callback+0x29/0x40 ? xen_hypercall_domctl+0xa/0x20 ? xen_hypercall_domctl+0x8/0x20 ? privcmd_ioctl+0x221/0x990 [xen_privcmd] ? do_vfs_ioctl+0xa5/0x6f0 ? ksys_ioctl+0x60/0x90 ? trace_hardirqs_off_thunk+0x1a/0x20 ? __x64_sys_ioctl+0x16/0x20 ? do_syscall_64+0x62/0x250 ? entry_SYSCALL_64_after_hwframe+0x49/0xbe Fix that by testing preempt_count() before calling cond_resched(). In kernel 5.8 this can't happen any more due to the entry code rework (more than 100 patches, so not a candidate for backporting). The issue was introduced in kernel 4.3, so this patch should go into all stable kernels in [4.3 ... 5.7]. Reported-by: Sarah Newman Fixes: 0fa2f5cb2b0ecd8 ("sched/preempt, xen: Use need_resched() instead of should_resched()") Cc: Sarah Newman Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross Tested-by: Chris Brannon Signed-off-by: Greg Kroah-Hartman

mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible

2020-08-26T08:27:10Z

commit 75802ca66354a39ab8e35822747cd08b3384a99a upstream. This is found by code observation only. Firstly, the worst case scenario should assume the whole range was covered by pmd sharing. The old algorithm might not work as expected for ranges like (1g-2m, 1g+2m), where the adjusted range should be (0, 1g+2m) but the expected range should be (0, 2g). Since at it, remove the loop since it should not be required. With that, the new code should be faster too when the invalidating range is huge. Mike said: : With range (1g-2m, 1g+2m) within a vma (0, 2g) the existing code will only : adjust to (0, 1g+2m) which is incorrect. : : We should cc stable. The original reason for adjusting the range was to : prevent data corruption (getting wrong page). Since the range is not : always adjusted correctly, the potential for corruption still exists. : : However, I am fairly confident that adjust_range_if_pmd_sharing_possible : is only gong to be called in two cases: : : 1) for a single page : 2) for range == entire vma : : In those cases, the current code should produce the correct results. : : To be safe, let's just cc stable. Fixes: 017b1660df89 ("mm: migration: fix migration of huge PMD shared pages") Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Reviewed-by: Mike Kravetz Cc: Andrea Arcangeli Cc: Matthew Wilcox Cc: Link: http://lkml.kernel.org/r/20200730201636.74778-1-peterx@redhat.com Signed-off-by: Linus Torvalds Signed-off-by: Mike Kravetz Signed-off-by: Greg Kroah-Hartman

do_epoll_ctl(): clean the failure exits up a bit

2020-08-26T08:27:10Z

commit 52c479697c9b73f628140dcdfcd39ea302d05482 upstream. Signed-off-by: Al Viro Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

epoll: Keep a reference on files added to the check list

2020-08-26T08:27:10Z

commit a9ed4a6560b8562b7e2e2bed9527e88001f7b682 upstream. When adding a new fd to an epoll, and that this new fd is an epoll fd itself, we recursively scan the fds attached to it to detect cycles, and add non-epool files to a "check list" that gets subsequently parsed. However, this check list isn't completely safe when deletions can happen concurrently. To sidestep the issue, make sure that a struct file placed on the check list sees its f_count increased, ensuring that a concurrent deletion won't result in the file disapearing from under our feet. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier Signed-off-by: Al Viro Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

powerpc: Allow 4224 bytes of stack expansion for the signal frame

2020-08-26T08:27:09Z

commit 63dee5df43a31f3844efabc58972f0a206ca4534 upstream. We have powerpc specific logic in our page fault handling to decide if an access to an unmapped address below the stack pointer should expand the stack VMA. The code was originally added in 2004 "ported from 2.4". The rough logic is that the stack is allowed to grow to 1MB with no extra checking. Over 1MB the access must be within 2048 bytes of the stack pointer, or be from a user instruction that updates the stack pointer. The 2048 byte allowance below the stack pointer is there to cover the 288 byte "red zone" as well as the "about 1.5kB" needed by the signal delivery code. Unfortunately since then the signal frame has expanded, and is now 4224 bytes on 64-bit kernels with transactional memory enabled. This means if a process has consumed more than 1MB of stack, and its stack pointer lies less than 4224 bytes from the next page boundary, signal delivery will fault when trying to expand the stack and the process will see a SEGV. The total size of the signal frame is the size of struct rt_sigframe (which includes the red zone) plus __SIGNAL_FRAMESIZE (128 bytes on 64-bit). The 2048 byte allowance was correct until 2008 as the signal frame was: struct rt_sigframe { struct ucontext uc; /* 0 1440 */ /* --- cacheline 11 boundary (1408 bytes) was 32 bytes ago --- */ long unsigned int _unused[2]; /* 1440 16 */ unsigned int tramp[6]; /* 1456 24 */ struct siginfo * pinfo; /* 1480 8 */ void * puc; /* 1488 8 */ struct siginfo info; /* 1496 128 */ /* --- cacheline 12 boundary (1536 bytes) was 88 bytes ago --- */ char abigap[288]; /* 1624 288 */ /* size: 1920, cachelines: 15, members: 7 */ /* padding: 8 */ }; 1920 + 128 = 2048 Then in commit ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support") (Jul 2008) the signal frame expanded to 2304 bytes: struct rt_sigframe { struct ucontext uc; /* 0 1696 */ <-- /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ long unsigned int _unused[2]; /* 1696 16 */ unsigned int tramp[6]; /* 1712 24 */ struct siginfo * pinfo; /* 1736 8 */ void * puc; /* 1744 8 */ struct siginfo info; /* 1752 128 */ /* --- cacheline 14 boundary (1792 bytes) was 88 bytes ago --- */ char abigap[288]; /* 1880 288 */ /* size: 2176, cachelines: 17, members: 7 */ /* padding: 8 */ }; 2176 + 128 = 2304 At this point we should have been exposed to the bug, though as far as I know it was never reported. I no longer have a system old enough to easily test on. Then in 2010 commit 320b2b8de126 ("mm: keep a guard page below a grow-down stack segment") caused our stack expansion code to never trigger, as there was always a VMA found for a write up to PAGE_SIZE below r1. That meant the bug was hidden as we continued to expand the signal frame in commit 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context") (Feb 2013): struct rt_sigframe { struct ucontext uc; /* 0 1696 */ /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ struct ucontext uc_transact; /* 1696 1696 */ <-- /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */ long unsigned int _unused[2]; /* 3392 16 */ unsigned int tramp[6]; /* 3408 24 */ struct siginfo * pinfo; /* 3432 8 */ void * puc; /* 3440 8 */ struct siginfo info; /* 3448 128 */ /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */ char abigap[288]; /* 3576 288 */ /* size: 3872, cachelines: 31, members: 8 */ /* padding: 8 */ /* last cacheline: 32 bytes */ }; 3872 + 128 = 4000 And commit 573ebfa6601f ("powerpc: Increase stack redzone for 64-bit userspace to 512 bytes") (Feb 2014): struct rt_sigframe { struct ucontext uc; /* 0 1696 */ /* --- cacheline 13 boundary (1664 bytes) was 32 bytes ago --- */ struct ucontext uc_transact; /* 1696 1696 */ /* --- cacheline 26 boundary (3328 bytes) was 64 bytes ago --- */ long unsigned int _unused[2]; /* 3392 16 */ unsigned int tramp[6]; /* 3408 24 */ struct siginfo * pinfo; /* 3432 8 */ void * puc; /* 3440 8 */ struct siginfo info; /* 3448 128 */ /* --- cacheline 27 boundary (3456 bytes) was 120 bytes ago --- */ char abigap[512]; /* 3576 512 */ <-- /* size: 4096, cachelines: 32, members: 8 */ /* padding: 8 */ }; 4096 + 128 = 4224 Then finally in 2017, commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") exposed us to the existing bug, because it changed the stack VMA to be the correct/real size, meaning our stack expansion code is now triggered. Fix it by increasing the allowance to 4224 bytes. Hard-coding 4224 is obviously unsafe against future expansions of the signal frame in the same way as the existing code. We can't easily use sizeof() because the signal frame structure is not in a header. We will either fix that, or rip out all the custom stack expansion checking logic entirely. Fixes: ce48b2100785 ("powerpc: Add VSX context save/restore, ptrace and signal support") Cc: stable@vger.kernel.org # v2.6.27+ Reported-by: Tom Lane Tested-by: Daniel Axtens Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200724092528.1578671-2-mpe@ellerman.id.au Signed-off-by: Daniel Axtens Signed-off-by: Greg Kroah-Hartman

ASoC: intel: Fix memleak in sst_media_open

2020-08-26T08:27:09Z

[ Upstream commit 062fa09f44f4fb3776a23184d5d296b0c8872eb9 ] When power_up_sst() fails, stream needs to be freed just like when try_module_get() fails. However, current code is returning directly and ends up leaking memory. Fixes: 0121327c1a68b ("ASoC: Intel: mfld-pcm: add control for powering up/down dsp") Signed-off-by: Dinghao Liu Acked-by: Pierre-Louis Bossart Link: https://lore.kernel.org/r/20200813084112.26205-1-dinghao.liu@zju.edu.cn Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

ext4: fix potential negative array index in do_split()

2020-08-26T08:27:09Z

[ Upstream commit 5872331b3d91820e14716632ebb56b1399b34fe1 ] If for any reason a directory passed to do_split() does not have enough active entries to exceed half the size of the block, we can end up iterating over all "count" entries without finding a split point. In this case, count == move, and split will be zero, and we will attempt a negative index into map[]. Guard against this by detecting this case, and falling back to split-to-half-of-count instead; in this case we will still have plenty of space (> half blocksize) in each split block. Fixes: ef2b02d3e617 ("ext34: ensure do_split leaves enough free space in both blocks") Signed-off-by: Eric Sandeen Reviewed-by: Andreas Dilger Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/f53e246b-647c-64bb-16ec-135383c70ad7@redhat.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin