- 22 Jun, 2017 7 commits
-
-
git://git.samba.org/sfrench/cifs-2.6Linus Torvalds authored
Pull cifs fixes from Steve French: "Various small fixes for stable" * 'for-next' of git://git.samba.org/sfrench/cifs-2.6: CIFS: Fix some return values in case of error in 'crypt_message' cifs: remove redundant return in cifs_creation_time_get CIFS: Improve readdir verbosity CIFS: check if pages is null rather than bv for a failed allocation CIFS: Set ->should_dirty in cifs_user_readv()
-
git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull KVM fixes from Radim Krčmář: "MIPS: - Fix build with KVM, DYNAMIC_DEBUG and JUMP_LABEL. PPC: - Fix host crashes/hangs on POWER9. - Properly restore userspace state after KVM_RUN ioctl. s390: - Fix address translation in odd-ball cases (real-space designation ASCEs). x86: - Fix privilege escalation in 64-bit Windows guests All patches are for stable and the x86 also has a CVE" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: fix singlestepping over syscall KVM: s390: gaccess: fix real-space designation asce handling for gmap shadows KVM: MIPS: Fix maybe-uninitialized build failure KVM: PPC: Book3S HV: Ignore timebase offset on POWER9 DD1 KVM: PPC: Book3S HV: Save/restore host values of debug registers KVM: PPC: Book3S HV: Preserve userspace HTM state properly KVM: PPC: Book3S HV: Restore critical SPRs to host values on guest exit KVM: PPC: Book3S HV: Context-switch EBB registers properly KVM: PPC: Book3S HV: Cope with host using large decrementer mode
-
git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfdLinus Torvalds authored
Pull MFD fixes from Lee Jones: - arizona: use address passed in, rather than hard coded value - correct STM32 clock-names value in DT binding documentation * tag 'mfd-fixes-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: dt-bindings: mfd: Update STM32 timers clock names mfd: arizona: Fix typo using hard-coded register
-
Paolo Bonzini authored
TF is handled a bit differently for syscall and sysret, compared to the other instructions: TF is checked after the instruction completes, so that the OS can disable #DB at a syscall by adding TF to FMASK. When the sysret is executed the #DB is taken "as if" the syscall insn just completed. KVM emulates syscall so that it can trap 32-bit syscall on Intel processors. Fix the behavior, otherwise you could get #DB on a user stack which is not nice. This does not affect Linux guests, as they use an IST or task gate for #DB. This fixes CVE-2017-7518. Cc: stable@vger.kernel.org Reported-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
-
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linuxRadim Krčmář authored
KVM: s390: fix shadow table handling for nested guests Some odd-ball cases (real-space designation ASCEs) are handled wrong for the shadow page tables. Fix it.
-
Heiko Carstens authored
For real-space designation asces the asce origin part is only a token. The asce token origin must not be used to generate an effective address for storage references. This however is erroneously done within kvm_s390_shadow_tables(). Furthermore within the same function the wrong parts of virtual addresses are used to generate a corresponding real address (e.g. the region second index is used as region first index). Both of the above can result in incorrect address translations. Only for real space designations with a token origin of zero and addresses below one megabyte the translation was correct. Furthermore replace a "!asce.r" statement with a "!*fake" statement to make it more obvious that a specific condition has nothing to do with the architecture, but with the fake handling of real space designations. Fixes: 3218f709 ("s390/mm: support real-space for gmap shadows") Cc: David Hildenbrand <david@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
-
git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull block fixes from Jens Axboe: "This contains a set of fixes for xen-blkback by way of Konrad, and a performance regression fix for blk-mq for shared tags. The latter could account for as much as a 50x reduction in performance, with the test case from the user with 500 name spaces. A more realistic setup on my end with 32 drives showed a 3.5x drop. The fix has been thoroughly tested before being committed" * 'for-linus' of git://git.kernel.dk/linux-block: blk-mq: fix performance regression with shared tags xen-blkback: don't leak stack data via response ring xen/blkback: don't use xen_blkif_get() in xen-blkback kthread xen/blkback: don't free be structure too early xen/blkback: fix disconnect while I/Os in flight
-
- 21 Jun, 2017 12 commits
-
-
git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds authored
Pull networking fixes from David Miller: 1) Fix refcounting wrt timers which hold onto inet6 address objects, from Xin Long. 2) Fix an ancient bug in wireless wext ioctls, from Johannes Berg. 3) Firmware handling fixes in brcm80211 driver, from Arend Van Spriel. 4) Several mlx5 driver fixes (firmware readiness, timestamp cap reporting, devlink command validity checking, tc offloading, etc.) From Eli Cohen, Maor Dickman, Chris Mi, and Or Gerlitz. 5) Fix dst leak in IP/IP6 tunnels, from Haishuang Yan. 6) Fix dst refcount bug in decnet, from Wei Wang. 7) Netdev can be double freed in register_vlan_device(). Fix from Gao Feng. 8) Don't allow object to be destroyed while it is being dumped in SCTP, from Xin Long. 9) Fix dpaa_eth build when modular, from Madalin Bucur. 10) Fix throw route leaks, from Serhey Popovych. 11) IFLA_GROUP missing from if_nlmsg_size() and ifla_policy[] table, also from Serhey Popovych. 12) Fix premature TX SKB free in stmmac, from Niklas Cassel. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (36 commits) igmp: add a missing spin_lock_init() net: stmmac: free an skb first when there are no longer any descriptors using it sfc: remove duplicate up_write on VF filter_sem rtnetlink: add IFLA_GROUP to ifla_policy ipv6: Do not leak throw route references dt-bindings: net: sms911x: Add missing optional VDD regulators dpaa_eth: reuse the dma_ops provided by the FMan MAC device fsl/fman: propagate dma_ops net/core: remove explicit do_softirq() from busy_poll_stop() fib_rules: Resolve goto rules target on delete sctp: ensure ep is not destroyed before doing the dump net/hns:bugfix of ethtool -t phy self_test net: 8021q: Fix one possible panic caused by BUG_ON in free_netdev cxgb4: notify uP to route ctrlq compl to rdma rspq ip6_tunnel: Correct tos value in collect_md mode decnet: always not take dst->__refcnt when inserting dst into hash table ip6_tunnel: fix potential issue in __ip6_tnl_rcv ip_tunnel: fix potential issue in ip_tunnel_rcv brcmfmac: fix uninitialized warning in brcmf_usb_probe_phase2() net/mlx5e: Avoid doing a cleanup call if the profile doesn't have it ...
-
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlLinus Torvalds authored
Pull more pin control fixes from Linus Walleij: "Some late arriving fixes. I should have sent earlier, just swamped with work as usual. Thomas patch makes AMD systems usable despite firmware bugs so it is fairly important. - Make the AMD driver use a regular interrupt rather than a chained one, so the system does not lock up. - Fix a function call error deep inside the STM32 driver" * tag 'pinctrl-v4.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: pinctrl: stm32: Fix bad function call pinctrl/amd: Use regular interrupt instead of chained
-
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hidLinus Torvalds authored
Pull HID fixes from Jiri Kosina: - revert of a commit to magicmouse driver that regressess certain devices, from Daniel Stone - quirk for a specific Dell mouse, from Sebastian Parschauer * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: Revert "HID: magicmouse: Set multi-touch keybits for Magic Mouse" HID: Add quirk for Dell PIXART OEM mouse
-
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatchingLinus Torvalds authored
Pull livepatching fix from Jiri Kosina: "Fix the way how livepatches are being stacked with respect to RCU, from Petr Mladek" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: Fix stacking of patches with respect to RCU
-
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds authored
Pull more ufs fixes from Al Viro: "More UFS fixes, unfortunately including build regression fix for the 64-bit s_dsize commit. Fixed in this pile: - trivial bug in signedness of 32bit timestamps on ufs1 - ESTALE instead of ufs_error() when doing open-by-fhandle on something deleted - build regression on 32bit in ufs_new_fragments() - calculating that many percents of u64 pulls libgcc stuff on some of those. Mea culpa. - fix hysteresis loop broken by typo in 2.4.14.7 (right next to the location of previous bug). - fix the insane limits of said hysteresis loop on filesystems with very low percentage of reserved blocks. If it's 5% or less, just use the OPTSPACE policy. - calculate those limits once and mount time. This tree does pass xfstests clean (both ufs1 and ufs2) and it _does_ survive cross-builds. Again, my apologies for missing that, especially since I have noticed a related percentage-of-64bit issue in earlier patches (when dealing with amount of reserved blocks). Self-LART applied..." * 'ufs-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ufs: fix the logics for tail relocation ufs_iget(): fail with -ESTALE on deleted inode fix signedness of timestamps on ufs1
-
Helge Deller authored
Fix expand_upwards() on architectures with an upward-growing stack (parisc, metag and partly IA-64) to allow the stack to reliably grow exactly up to the address space limit given by TASK_SIZE. Signed-off-by: Helge Deller <deller@gmx.de> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Hugh Dickins authored
Trinity gets kernel BUG at mm/mmap.c:1963! in about 3 minutes of mmap testing. That's the VM_BUG_ON(gap_end < gap_start) at the end of unmapped_area_topdown(). Linus points out how MAP_FIXED (which does not have to respect our stack guard gap intentions) could result in gap_end below gap_start there. Fix that, and the similar case in its alternative, unmapped_area(). Cc: stable@vger.kernel.org Fixes: 1be7107f ("mm: larger stack guard gap, between vmas") Reported-by: Dave Jones <davej@codemonkey.org.uk> Debugged-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Jens Axboe authored
If we have shared tags enabled, then every IO completion will trigger a full loop of every queue belonging to a tag set, and every hardware queue for each of those queues, even if nothing needs to be done. This causes a massive performance regression if you have a lot of shared devices. Instead of doing this huge full scan on every IO, add an atomic counter to the main queue that tracks how many hardware queues have been marked as needing a restart. With that, we can avoid looking for restartable queues, if we don't have to. Max reports that this restores performance. Before this patch, 4K IOPS was limited to 22-23K IOPS. With the patch, we are running at 950-970K IOPS. Fixes: 6d8c6c0f ("blk-mq: Restart a single queue if tag sets are shared") Reported-by: Max Gurtovoy <maxg@mellanox.com> Tested-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-
Christophe Jaillet authored
'rc' is known to be 0 at this point. So if 'init_sg' or 'kzalloc' fails, we should return -ENOMEM instead. Also remove a useless 'rc' in a debug message as it is meaningless here. Fixes: 026e93dc ("CIFS: Encrypt SMB3 requests before sending") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <smfrench@gmail.com> CC: Stable <stable@vger.kernel.org>
-
Colin Ian King authored
There is a redundant return in function cifs_creation_time_get that appears to be old vestigial code than can be removed. So remove it. Detected by CoverityScan, CID#1361924 ("Structurally dead code") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steve French <smfrench@gmail.com>
-
Pavel Shilovsky authored
Downgrade the loglevel for SMB2 to prevent filling the log with messages if e.g. readdir was interrupted. Also make SMB2 and SMB1 codepaths do the same logging during readdir. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com> CC: Stable <stable@vger.kernel.org>
-
Colin Ian King authored
pages is being allocated however a null check on bv is being used to see if the allocation failed. Fix this by checking if pages is null. Detected by CoverityScan, CID#1432974 ("Logically dead code") Fixes: ccf7f408 ("CIFS: Add asynchronous context to support kernel AIO") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com>
-
- 20 Jun, 2017 21 commits
-
-
Dan Carpenter authored
The current code causes a static checker warning because ITER_IOVEC is zero so the condition is never true. Fixes: 6685c5e2 ("CIFS: Add asynchronous read support through kernel AIO") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <smfrench@gmail.com>
-
WANG Cong authored
Andrey reported a lockdep warning on non-initialized spinlock: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 4099 Comm: a.out Not tainted 4.12.0-rc6+ #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 register_lock_class+0x717/0x1aa0 kernel/locking/lockdep.c:755 ? 0xffffffffa0000000 __lock_acquire+0x269/0x3690 kernel/locking/lockdep.c:3255 lock_acquire+0x22d/0x560 kernel/locking/lockdep.c:3855 __raw_spin_lock_bh ./include/linux/spinlock_api_smp.h:135 _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:175 spin_lock_bh ./include/linux/spinlock.h:304 ip_mc_clear_src+0x27/0x1e0 net/ipv4/igmp.c:2076 igmpv3_clear_delrec+0xee/0x4f0 net/ipv4/igmp.c:1194 ip_mc_destroy_dev+0x4e/0x190 net/ipv4/igmp.c:1736 We miss a spin_lock_init() in igmpv3_add_delrec(), probably because previously we never use it on this code path. Since we already unlink it from the global mc_tomb list, it is probably safe not to acquire this spinlock here. It does not harm to have it although, to avoid conditional locking. Fixes: c38b7d32 ("igmp: acquire pmc lock for ip_mc_clear_src()") Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-
David S. Miller authored
Merge tag 'wireless-drivers-for-davem-2017-06-20' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers Kalle Valo says: ==================== wireless-drivers fixes for 4.12 Two important fixes for brcmfmac. The rest of the brcmfmac patches are either code preparation and fixing a new build warning. brcmfmac * fix a NULL pointer dereference during resume * fix a NULL pointer dereference with USB devices, a regression from v4.12-rc1 ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-
Niklas Cassel authored
When having the skb pointer in the first descriptor, stmmac_tx_clean can get called at a moment where the IP has only cleared the own bit of the first descriptor, thus freeing the skb, even though there can be several descriptors whose buffers point into the same skb. By simply moving the skb pointer from the first descriptor to the last descriptor, a skb will get freed only when the IP has cleared the own bit of all the descriptors that are using that skb. Signed-off-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-
Edward Cree authored
Somehow two copies of the line 'up_write(&vf->efx->filter_sem);' got into efx_ef10_sriov_set_vf_vlan(). This would put the mutex in a bad state and cause all subsequent down attempts to hang. Fixes: 671b53ee ("sfc: Ensure down_write(&filter_sem) and up_write() are matched before calling efx_net_open()") Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-
Serhey Popovych authored
Network interface groups support added while ago, however there is no IFLA_GROUP attribute description in policy and netlink message size calculations until now. Add IFLA_GROUP attribute to the policy. Fixes: cbda10fa ("net_device: add support for network device groups") Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-
Serhey Popovych authored
While commit 73ba57bf ("ipv6: fix backtracking for throw routes") does good job on error propagation to the fib_rules_lookup() in fib rules core framework that also corrects throw routes handling, it does not solve route reference leakage problem happened when we return -EAGAIN to the fib_rules_lookup() and leave routing table entry referenced in arg->result. If rule with matched throw route isn't last matched in the list we overwrite arg->result losing reference on throw route stored previously forever. We also partially revert commit ab997ad4 ("ipv6: fix the incorrect return value of throw route") since we never return routing table entry with dst.error == -EAGAIN when CONFIG_IPV6_MULTIPLE_TABLES is on. Also there is no point to check for RTF_REJECT flag since it is always set throw route. Fixes: 73ba57bf ("ipv6: fix backtracking for throw routes") Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-
Krzysztof Kozlowski authored
The lan911x family of devices require supplying from 3.3 V power supplies (connected to VDD_IO, VDD_A and VREG_3.3 pins). The existing driver however obtains only VDD_IO and VDD_A regulators in an optional way so document this in bindings. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-
David S. Miller authored
Madalin Bucur says: ==================== net: fix loadable module for DPAA Ethernet The DPAA Ethernet makes use of a symbol that is not exported. Address the issue by propagating the dma_ops rather than calling arch_setup_dma_ops(). ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-
Madalin Bucur authored
Remove the use of arch_setup_dma_ops() that was not exported and was breaking loadable module compilation. Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-
Madalin Bucur authored
Make sure dma_ops are set, to be later used by the Ethernet driver. Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-
Sebastian Siewior authored
Since commit 217f6974 ("net: busy-poll: allow preemption in sk_busy_loop()") there is an explicit do_softirq() invocation after local_bh_enable() has been invoked. I don't understand why we need this because local_bh_enable() will invoke do_softirq() once the softirq counter reached zero and we have softirq-related work pending. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
-
Serhey Popovych authored
We should avoid marking goto rules unresolved when their target is actually reachable after rule deletion. Consolder following sample scenario: # ip -4 ru sh 0: from all lookup local 32000: from all goto 32100 32100: from all lookup main 32100: from all lookup default 32766: from all lookup main 32767: from all lookup default # ip -4 ru del pref 32100 table main # ip -4 ru sh 0: from all lookup local 32000: from all goto 32100 [unresolved] 32100: from all lookup default 32766: from all lookup main 32767: from all lookup default After removal of first rule with preference 32100 we mark all goto rules as unreachable, even when rule with same preference as removed one still present. Check if next rule with same preference is available and make all rules with goto action pointing to it. Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-
Fabrice Gasnier authored
Clock name has been updated during driver/DT binding review: https://lkml.org/lkml/2016/12/13/718 Update DT binding doc to reflect this. Fixes: 8f9359c6 (dt-bindings: mfd: Add bindings for STM32 Timers driver) Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
-
James Cowgill authored
This commit fixes a "maybe-uninitialized" build failure in arch/mips/kvm/tlb.c when KVM, DYNAMIC_DEBUG and JUMP_LABEL are all enabled. The failure is: In file included from ./include/linux/printk.h:329:0, from ./include/linux/kernel.h:13, from ./include/asm-generic/bug.h:15, from ./arch/mips/include/asm/bug.h:41, from ./include/linux/bug.h:4, from ./include/linux/thread_info.h:11, from ./include/asm-generic/current.h:4, from ./arch/mips/include/generated/asm/current.h:1, from ./include/linux/sched.h:11, from arch/mips/kvm/tlb.c:13: arch/mips/kvm/tlb.c: In function ‘kvm_mips_host_tlb_inv’: ./include/linux/dynamic_debug.h:126:3: error: ‘idx_kernel’ may be used uninitialized in this function [-Werror=maybe-uninitialized] __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \ ^~~~~~~~~~~~~~~~~~ arch/mips/kvm/tlb.c:169:16: note: ‘idx_kernel’ was declared here int idx_user, idx_kernel; ^~~~~~~~~~ There is a similar error relating to "idx_user". Both errors were observed with GCC 6. As far as I can tell, it is impossible for either idx_user or idx_kernel to be uninitialized when they are later read in the calls to kvm_debug, but to satisfy the compiler, add zero initializers to both variables. Signed-off-by: James Cowgill <James.Cowgill@imgtec.com> Fixes: 57e3869c ("KVM: MIPS/TLB: Generalise host TLB invalidate to kernel ASID") Cc: <stable@vger.kernel.org> # 4.11+ Acked-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
-
Jens Axboe authored
Merge branch 'stable/for-jens-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus Pull xen-blkback fixes from Konrad: "Security and memory leak fixes in xen block driver."
-
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpcRadim Krčmář authored
* fix problems that could cause hangs or crashes in the host on POWER9 * fix problems that could allow guests to potentially affect or disrupt the execution of the controlling userspace
-
Jiri Kosina authored
-
Petr Mladek authored
rcu_read_(un)lock(), list_*_rcu(), and synchronize_rcu() are used for a secure access and manipulation of the list of patches that modify the same function. In particular, it is the variable func_stack that is accessible from the ftrace handler via struct ftrace_ops and klp_ops. Of course, it synchronizes also some states of the patch on the top of the stack, e.g. func->transition in klp_ftrace_handler. At the same time, this mechanism guards also the manipulation of task->patch_state. It is modified according to the state of the transition and the state of the process. Now, all this works well as long as RCU works well. Sadly livepatching might get into some corner cases when this is not true. For example, RCU is not watching when rcu_read_lock() is taken in idle threads. It is because they might sleep and prevent reaching the grace period for too long. There are ways how to make RCU watching even in idle threads, see rcu_irq_enter(). But there is a small location inside RCU infrastructure when even this does not work. This small problematic location can be detected either before calling rcu_irq_enter() by rcu_irq_enter_disabled() or later by rcu_is_watching(). Sadly, there is no safe way how to handle it. Once we detect that RCU was not watching, we might see inconsistent state of the function stack and the related variables in klp_ftrace_handler(). Then we could do a wrong decision, use an incompatible implementation of the function and break the consistency of the system. We could warn but we could not avoid the damage. Fortunately, ftrace has similar problems and they seem to be solved well there. It uses a heavy weight implementation of some RCU operations. In particular, it replaces: + rcu_read_lock() with preempt_disable_notrace() + rcu_read_unlock() with preempt_enable_notrace() + synchronize_rcu() with schedule_on_each_cpu(sync_work) My understanding is that this is RCU implementation from a stone age. It meets the core RCU requirements but it is rather ineffective. Especially, it does not allow to batch or speed up the synchronize calls. On the other hand, it is very trivial. It allows to safely trace and/or livepatch even the RCU core infrastructure. And the effectiveness is a not a big issue because using ftrace or livepatches on productive systems is a rare operation. The safety is much more important than a negligible extra load. Note that the alternative implementation follows the RCU principles. Therefore, we could and actually must use list_*_rcu() variants when manipulating the func_stack. These functions allow to access the pointers in the right order and with the right barriers. But they do not use any other information that would be set only by rcu_read_lock(). Also note that there are actually two problems solved in ftrace: First, it cares about the consistency of RCU read sections. It is being solved the way as described and used in this patch. Second, ftrace needs to make sure that nobody is inside the dynamic trampoline when it is being freed. For this, it also calls synchronize_rcu_tasks() in preemptive kernel in ftrace_shutdown(). Livepatch has similar problem but it is solved by ftrace for free. klp_ftrace_handler() is a good guy and never sleeps. In addition, it is registered with FTRACE_OPS_FL_DYNAMIC. It causes that unregister_ftrace_function() calls: * schedule_on_each_cpu(ftrace_sync) - always * synchronize_rcu_tasks() - in preemptive kernel The effect is that nobody is neither inside the dynamic trampoline nor inside the ftrace handler after unregister_ftrace_function() returns. [jkosina@suse.cz: reformat changelog, fix comment] Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-
Daniel Stone authored
Setting these bits causes libinput to fail to initialize the device; setting BTN_TOUCH and BTN_TOOL_FINGER causes it to treat the mouse as a touchpad, and it then refuses to continue when it discovers ABS_X is not set. This breaks all known Wayland compositors, as well as Xorg when the libinput driver is being used. This reverts commit f4b65b95. Signed-off-by: Daniel Stone <daniels@collabora.com> Cc: Che-Liang Chiou <clchiou@chromium.org> Cc: Thierry Escande <thierry.escande@collabora.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-
git://git.kernel.org/pub/scm/linux/kernel/git/clk/linuxLinus Torvalds authored
Pull clk fixes from Stephen Boyd: "One build fix for an Amlogic clk driver and a handful of Allwinner clk driver fixes for some DT bindings and a randconfig build error that all came in this merge window" * tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: clk: sunxi-ng: a64: Export PLL_PERIPH0 clock for the PRCM clk: sunxi-ng: h3: Export PLL_PERIPH0 clock for the PRCM dt-bindings: clock: sunxi-ccu: Add pll-periph to PRCM's needed clocks clk: sunxi-ng: sun5i: Fix ahb_bist_clk definition clk: sunxi-ng: enable SUNXI_CCU_MP for PRCM clk: meson: gxbb: fix build error without RESET_CONTROLLER clk: sunxi-ng: v3s: Fix usb otg device reset bit clk: sunxi-ng: a31: Correct lcd1-ch1 clock register offset
-