summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2021-11-24KVM: PPC: Book3S HV P9: Move TB updatesNicholas Piggin
Move the TB updates between saving and loading guest and host SPRs, to improve scheduling by keeping issue-NTC operations together as much as possible. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-24-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: Change dec_expires to be relative to guest timebaseNicholas Piggin
Change dec_expires to be relative to the guest timebase, and allow it to be moved into low level P9 guest entry functions, to improve SPR access scheduling. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-23-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Add kvmppc_stop_thread to match kvmppc_start_threadNicholas Piggin
Small cleanup makes it a bit easier to match up entry and exit operations. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-22-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Improve mtmsrd scheduling by delaying MSR[EE] disableNicholas Piggin
Moving the mtmsrd after the host SPRs are saved and before the guest SPRs start to be loaded can prevent an SPR scoreboard stall (because the mtmsrd is L=1 type which does not cause context synchronisation. This is also now more convenient to combined with the mtmsrd L=0 instruction to enable facilities just below, but that is not done yet. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-21-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Reduce mtmsrd instructions required to save host SPRsNicholas Piggin
This reduces the number of mtmsrd required to enable facility bits when saving/restoring registers, by having the KVM code set all bits up front rather than using individual facility functions that set their particular MSR bits. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-20-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Move SPRG restore to restore_p9_host_os_sprsNicholas Piggin
Move the SPR update into its relevant helper function. This will help with SPR scheduling improvements in later changes. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-19-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: CTRL SPR does not require read-modify-writeNicholas Piggin
Processors that support KVM HV do not require read-modify-write of the CTRL SPR to set/clear their thread's runlatch. Just write 1 or 0 to it. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-18-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Factor out yield_count incrementNicholas Piggin
Factor duplicated code into a helper function. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-17-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Demand fault PMU SPRs when marked not inuseNicholas Piggin
The pmcregs_in_use field in the guest VPA can not be trusted to reflect what the guest is doing with PMU SPRs, so the PMU must always be managed (stopped) when exiting the guest, and SPR values set when entering the guest to ensure it can't cause a covert channel or otherwise cause other guests or the host to misbehave. So prevent guest access to the PMU with HFSCR[PM] if pmcregs_in_use is clear, and avoid the PMU SPR access on every partition switch. Guests that set pmcregs_in_use incorrectly or when first setting it and using the PMU will take a hypervisor facility unavailable interrupt that will bring in the PMU SPRs. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-16-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Factor PMU save/load into context switch functionsNicholas Piggin
Rather than guest/host save/retsore functions, implement context switch functions that take care of details like the VPA update for nested. The reason to split these kind of helpers into explicit save/load functions is mainly to schedule SPR access nicely, but PMU is a special case where the load requires mtSPR (to stop counters) and other difficulties, so there's less possibility to schedule those nicely. The SPR accesses also have side-effects if the PMU is running, and in later changes we keep the host PMU running as long as possible so this code can be better profiled, which also complicates scheduling. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-15-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Implement PMU save/restore in CNicholas Piggin
Implement the P9 path PMU save/restore code in C, and remove the POWER9/10 code from the P7/8 path assembly. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-14-npiggin@gmail.com
2021-11-24powerpc/64s: Implement PMU override command line optionNicholas Piggin
It can be useful in simulators (with very constrained environments) to allow some PMCs to run from boot so they can be sampled directly by a test harness, rather than having to run perf. A previous change freezes counters at boot by default, so provide a boot time option to un-freeze (plus a bit more flexibility). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-13-npiggin@gmail.com
2021-11-24powerpc/64s: Always set PMU control registers to frozen/disabled when not in useNicholas Piggin
KVM PMU management code looks for particular frozen/disabled bits in the PMU registers so it knows whether it must clear them when coming out of a guest or not. Setting this up helps KVM make these optimisations without getting confused. Longer term the better approach might be to move guest/host PMU switching to the perf subsystem. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-12-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: Don't always save PMU for guest capable of nestingNicholas Piggin
Provide a config option that controls the workaround added by commit 63279eeb7f93 ("KVM: PPC: Book3S HV: Always save guest pmu for guest capable of nesting"). The option defaults to y for now, but is expected to go away within a few releases. Nested capable guests running with the earlier commit 178266389794 ("KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest SPRs are live") will now indicate the PMU in-use status of their guests, which means the parent does not need to unconditionally save the PMU for nested capable guests. After this latest round of performance optimisations, this option costs about 540 cycles or 10% entry/exit performance on a POWER9 nested-capable guest. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> References: 178266389794 ("KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest SPRs are live") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-11-npiggin@gmail.com
2021-11-24powerpc/64s: Keep AMOR SPR a constant ~0 at runtimeNicholas Piggin
This register controls supervisor SPR modifications, and as such is only relevant for KVM. KVM always sets AMOR to ~0 on guest entry, and never restores it coming back out to the host, so it can be kept constant and avoid the mtSPR in KVM guest entry. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-10-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: POWER10 enable HAIL when running radix guestsNicholas Piggin
HV interrupts may be taken with the MMU enabled when radix guests are running. Enable LPCR[HAIL] on ISA v3.1 processors for radix guests. Make this depend on the host LPCR[HAIL] being enabled. Currently that is always enabled, but having this test means any issue that might require LPCR[HAIL] to be disabled in the host will not have to be duplicated in KVM. This optimisation takes 1380 cycles off a NULL hcall entry+exit micro benchmark on a POWER10. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-9-npiggin@gmail.com
2021-11-24powerpc/time: add API for KVM to re-arm the host timer/decrementerNicholas Piggin
Rather than have KVM look up the host timer and fiddle with the irq-work internal details, have the powerpc/time.c code provide a function for KVM to re-arm the Linux timer code when exiting a guest. This is implementation has an improvement over existing code of marking a decrementer interrupt as soft-pending if a timer has expired, rather than setting DEC to a -ve value, which tended to cause host timers to take two interrupts (first hdec to exit the guest, then the immediate dec). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-8-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exitNicholas Piggin
mftb is serialising (dispatch next-to-complete) so it is heavy weight for a mfspr. Avoid reading it multiple times in the entry or exit paths. A small number of cycles delay to timers is tolerable. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-7-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Use large decrementer for HDECNicholas Piggin
On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0, this could help reduce needless guest exits due to leftover exceptions on entering the guest. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-6-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer readNicholas Piggin
There is no need to save away the host DEC value, as it is derived from the host timer subsystem which maintains the next timer time, so it can be restored from there. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-5-npiggin@gmail.com
2021-11-24KMV: PPC: Book3S HV P9: Use set_dec to set decrementer to hostNicholas Piggin
The host Linux timer code arms the decrementer with the value 'decrementers_next_tb - current_tb' using set_dec(), which stores val - 1 on Book3S-64, which is not quite the same as what KVM does to re-arm the host decrementer when exiting the guest. This shouldn't be a significant change, but it makes the logic match and avoids this small extra change being brought into the next patch. Suggested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-4-npiggin@gmail.com
2021-11-24powerpc/64s: guard optional TIDR SPR with CPU ftr testNicholas Piggin
The TIDR SPR only exists on POWER9. Avoid accessing it when the feature bit for it is not set. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-3-npiggin@gmail.com
2021-11-24powerpc/64s: Remove WORT SPR from POWER9/10 (take 2)Nicholas Piggin
This removes a missed remnant of the WORT SPR. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-2-npiggin@gmail.com
2021-11-24KVM: PPC: Book3S HV: Prevent POWER7/8 TLB flush flushing SLBNicholas Piggin
The POWER9 ERAT flush instruction is a SLBIA with IH=7, which is a reserved value on POWER7/8. On POWER8 this invalidates the SLB entries above index 0, similarly to SLBIA IH=0. If the SLB entries are invalidated, and then the guest is bypassed, the host SLB does not get re-loaded, so the bolted entries above 0 will be lost. This can result in kernel stack access causing a SLB fault. Kernel stack access causing a SLB fault was responsible for the infamous mega bug (search "Fix SLB reload bug"). Although since commit 48e7b7695745 ("powerpc/64s/hash: Convert SLB miss handlers to C") that starts using the kernel stack in the SLB miss handler, it might only result in an infinite loop of SLB faults. In any case it's a bug. Fix this by only executing the instruction on >= POWER9 where IH=7 is defined not to invalidate the SLB. POWER7/8 don't require this ERAT flush. Fixes: 500871125920 ("KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211119031627.577853-1-npiggin@gmail.com
2021-11-21Linux 5.16-rc2v5.16-rc2Linus Torvalds
2021-11-21Merge tag 'x86-urgent-2021-11-21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: - Move the command line preparation and the early command line parsing earlier so that the command line parameters which affect early_reserve_memory(), e.g. efi=nosftreserve, are taken into account. This was broken when the invocation of early_reserve_memory() was moved recently. - Use an atomic type for the SGX page accounting, which is read and written locklessly, to plug various race conditions related to it. * tag 'x86-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sgx: Fix free page accounting x86/boot: Pull up cmdline preparation and early param parsing
2021-11-21Merge tag 'perf-urgent-2021-11-21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 perf fixes from Thomas Gleixner: - Remove unneded PEBS disabling when taking LBR snapshots to prevent an unchecked MSR access error. - Fix IIO event constraints for Snowridge and Skylake server chips. * tag 'perf-urgent-2021-11-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/perf: Fix snapshot_branch_stack warning in VM perf/x86/intel/uncore: Fix IIO event constraints for Snowridge perf/x86/intel/uncore: Fix IIO event constraints for Skylake Server perf/x86/intel/uncore: Fix filter_tid mask for CHA events on Skylake Server
2021-11-21Merge tag 'powerpc-5.16-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull more powerpc fixes from Michael Ellerman: - Fix a bug in copying of sigset_t for 32-bit systems, which caused X to not start. - Fix handling of shared LSIs (rare) with the xive interrupt controller (Power9/10). - Fix missing TOC setup in some KVM code, which could result in oopses depending on kernel data layout. - Fix DMA mapping when we have persistent memory and only one DMA window available. - Fix further problems with STRICT_KERNEL_RWX on 8xx, exposed by a recent fix. - A couple of other minor fixes. Thanks to Alexey Kardashevskiy, Aneesh Kumar K.V, Cédric Le Goater, Christian Zigotzky, Christophe Leroy, Daniel Axtens, Finn Thain, Greg Kurz, Masahiro Yamada, Nicholas Piggin, and Uwe Kleine-König. * tag 'powerpc-5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/xive: Change IRQ domain to a tree domain powerpc/8xx: Fix pinned TLBs with CONFIG_STRICT_KERNEL_RWX powerpc/signal32: Fix sigset_t copy powerpc/book3e: Fix TLBCAM preset at boot powerpc/pseries/ddw: Do not try direct mapping with persistent memory and one window powerpc/pseries/ddw: simplify enable_ddw() powerpc/pseries/ddw: Revert "Extend upper limit for huge DMA window for persistent memory" powerpc/pseries: Fix numa FORM2 parsing fallback code powerpc/pseries: rename numa_dist_table to form2_distances powerpc: clean vdso32 and vdso64 directories powerpc/83xx/mpc8349emitx: Drop unused variable KVM: PPC: Book3S HV: Use GLOBAL_TOC for kvmppc_h_set_dabr/xdabr()
2021-11-21pstore/blk: Use "%lu" to format unsigned longGeert Uytterhoeven
On 32-bit: fs/pstore/blk.c: In function ‘__best_effort_init’: include/linux/kern_levels.h:5:18: warning: format ‘%zu’ expects argument of type ‘size_t’, but argument 3 has type ‘long unsigned int’ [-Wformat=] 5 | #define KERN_SOH "\001" /* ASCII Start Of Header */ | ^~~~~~ include/linux/kern_levels.h:14:19: note: in expansion of macro ‘KERN_SOH’ 14 | #define KERN_INFO KERN_SOH "6" /* informational */ | ^~~~~~~~ include/linux/printk.h:373:9: note: in expansion of macro ‘KERN_INFO’ 373 | printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~ fs/pstore/blk.c:314:3: note: in expansion of macro ‘pr_info’ 314 | pr_info("attached %s (%zu) (no dedicated panic_write!)\n", | ^~~~~~~ Cc: stable@vger.kernel.org Fixes: 7bb9557b48fcabaa ("pstore/blk: Use the normal block device I/O path") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210629103700.1935012-1-geert@linux-m68k.org Cc: Jens Axboe <axboe@kernel.dk> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "15 patches. Subsystems affected by this patch series: ipc, hexagon, mm (swap, slab-generic, kmemleak, hugetlb, kasan, damon, and highmem), and proc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: proc/vmcore: fix clearing user buffer by properly using clear_user() kmap_local: don't assume kmap PTEs are linear arrays in memory mm/damon/dbgfs: fix missed use of damon_dbgfs_lock mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocation kasan: test: silence intentional read overflow warnings hugetlb, userfaultfd: fix reservation restore on userfaultfd error hugetlb: fix hugetlb cgroup refcounting during mremap mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flag hexagon: ignore vmlinux.lds hexagon: clean up timer-regs.h hexagon: export raw I/O routines for modules mm: emit the "free" trace report before freeing memory in kmem_cache_free() shm: extend forced shm destroy to support objects from several IPC nses ipc: WARN if trying to remove ipc object which is absent mm/swap.c:put_pages_list(): reinitialise the page list
2021-11-20Merge tag 'block-5.16-2021-11-19' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - Flip a cap check to avoid a selinux error (Alistair) - Fix for a regression this merge window where we can miss a queue ref put (me) - Un-mark pstore-blk as broken, as the condition that triggered that change has been rectified (Kees) - Queue quiesce and sync fixes (Ming) - FUA insertion fix (Ming) - blk-cgroup error path put fix (Yu) * tag 'block-5.16-2021-11-19' of git://git.kernel.dk/linux-block: blk-mq: don't insert FUA request with data into scheduler queue blk-cgroup: fix missing put device in error path from blkg_conf_pref() block: avoid to quiesce queue in elevator_init_mq Revert "mark pstore-blk as broken" blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release() block: fix missing queue put in error path block: Check ADMIN before NICE for IOPRIO_CLASS_RT
2021-11-20Merge tag 'pinctrl-v5.16-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl Pull pin control fixes from Linus Walleij: "There is an ACPI stubs fix which is ACKed by the ACPI maintainer for merging through my tree. One item stand out and that is that I delete the <linux/sdb.h> header that is used by nothing. I deleted this subsystem (through the GPIO tree) a while back so I feel responsible for tidying up the floor. Other than that it is the usual mistakes, a bit noisy around build issue and Kconfig then driver fixes. Specifics: - Fix some stubs causing compile issues for ACPI. - Fix some wakeups on AMD IRQs shared between GPIO and SCI. - Fix a build warning in the Tegra driver. - Fix a Kconfig issue in the Qualcomm driver. - Add a missing include the RALink driver. - Return a valid type for the Apple pinctrl IRQs. - Implement some Qualcomm SDM845 dual-edge errata. - Remove the unused <linux/sdb.h> header. (The subsystem was once deleted by the pinctrl maintainer...) - Fix a duplicate initialized in the Tegra driver. - Fix register offsets for UFS and SDC in the Qualcomm SM8350 driver" * tag 'pinctrl-v5.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: pinctrl: qcom: sm8350: Correct UFS and SDC offsets pinctrl: tegra194: remove duplicate initializer again Remove unused header <linux/sdb.h> pinctrl: qcom: sdm845: Enable dual edge errata pinctrl: apple: Always return valid type in apple_gpio_irq_type pinctrl: ralink: include 'ralink_regs.h' in 'pinctrl-mt7620.c' pinctrl: qcom: fix unmet dependencies on GPIOLIB for GPIOLIB_IRQCHIP pinctrl: tegra: Return const pointer from tegra_pinctrl_get_group() pinctrl: amd: Fix wakeups when IRQ is shared with SCI ACPI: Add stubs for wakeup handler functions
2021-11-20Merge tag 's390-5.16-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Add missing Kconfig option for ftrace direct multi sample, so it can be compiled again, and also add s390 support for this sample. - Update Christian Borntraeger's email address. - Various fixes for memory layout setup. Besides other this makes it possible to load shared DCSS segments again. - Fix copy to user space of swapped kdump oldmem. - Remove -mstack-guard and -mstack-size compile options when building vdso binaries. This can happen when CONFIG_VMAP_STACK is disabled and results in broken vdso code which causes more or less random exceptions. Also remove the not needed -nostdlib option. - Fix memory leak on cpu hotplug and return code handling in kexec code. - Wire up futex_waitv system call. - Replace snprintf with sysfs_emit where appropriate. * tag 's390-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: ftrace/samples: add s390 support for ftrace direct multi sample ftrace/samples: add missing Kconfig option for ftrace direct multi sample MAINTAINERS: update email address of Christian Borntraeger s390/kexec: fix memory leak of ipl report buffer s390/kexec: fix return code handling s390/dump: fix copying to user-space of swapped kdump oldmem s390: wire up sys_futex_waitv system call s390/vdso: filter out -mstack-guard and -mstack-size s390/vdso: remove -nostdlib compiler flag s390: replace snprintf in show functions with sysfs_emit s390/boot: simplify and fix kernel memory layout setup s390/setup: re-arrange memblock setup s390/setup: avoid using memblock_enforce_memory_limit s390/setup: avoid reserving memory above identity mapping
2021-11-20Merge tag '5.16-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull cifs fixes from Steve French: "Three small cifs/smb3 fixes: two to address minor coverity issues and one cleanup" * tag '5.16-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: introduce cifs_ses_mark_for_reconnect() helper cifs: protect srv_count with cifs_tcp_ses_lock cifs: move debug print out of spinlock
2021-11-20proc/vmcore: fix clearing user buffer by properly using clear_user()David Hildenbrand
To clear a user buffer we cannot simply use memset, we have to use clear_user(). With a virtio-mem device that registers a vmcore_cb and has some logically unplugged memory inside an added Linux memory block, I can easily trigger a BUG by copying the vmcore via "cp": systemd[1]: Starting Kdump Vmcore Save Service... kdump[420]: Kdump is using the default log level(3). kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/ kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/ kdump[465]: saving vmcore-dmesg.txt complete kdump[467]: saving vmcore BUG: unable to handle page fault for address: 00007f2374e01000 #PF: supervisor write access in kernel mode #PF: error_code(0x0003) - permissions violation PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867 Oops: 0003 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 468 Comm: cp Not tainted 5.15.0+ #6 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_from_oldmem.part.0.cold+0x1d/0x86 Code: ff ff ff e8 05 ff fe ff e9 b9 e9 7f ff 48 89 de 48 c7 c7 38 3b 60 82 e8 f1 fe fe ff 83 fd 08 72 3c 49 8d 7d 08 4c 89 e9 89 e8 <49> c7 45 00 00 00 00 00 49 c7 44 05 f8 00 00 00 00 48 83 e7 f81 RSP: 0018:ffffc9000073be08 EFLAGS: 00010212 RAX: 0000000000001000 RBX: 00000000002fd000 RCX: 00007f2374e01000 RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00007f2374e01008 RBP: 0000000000001000 R08: 0000000000000000 R09: ffffc9000073bc50 R10: ffffc9000073bc48 R11: ffffffff829461a8 R12: 000000000000f000 R13: 00007f2374e01000 R14: 0000000000000000 R15: ffff88807bd421e8 FS: 00007f2374e12140(0000) GS:ffff88807f000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2374e01000 CR3: 000000007a4aa000 CR4: 0000000000350eb0 Call Trace: read_vmcore+0x236/0x2c0 proc_reg_read+0x55/0xa0 vfs_read+0x95/0x190 ksys_read+0x4f/0xc0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access Prevention (SMAP)", which is used to detect wrong access from the kernel to user buffers like this: SMAP triggers a permissions violation on wrong access. In the x86-64 variant of clear_user(), SMAP is properly handled via clac()+stac(). To fix, properly use clear_user() when we're dealing with a user buffer. Link: https://lkml.kernel.org/r/20211112092750.6921-1-david@redhat.com Fixes: 997c136f518c ("fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages") Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Philipp Rudo <prudo@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20kmap_local: don't assume kmap PTEs are linear arrays in memoryArd Biesheuvel
The kmap_local conversion broke the ARM architecture, because the new code assumes that all PTEs used for creating kmaps form a linear array in memory, and uses array indexing to look up the kmap PTE belonging to a certain kmap index. On ARM, this cannot work, not only because the PTE pages may be non-adjacent in memory, but also because ARM/!LPAE interleaves hardware entries and extended entries (carrying software-only bits) in a way that is not compatible with array indexing. Fortunately, this only seems to affect configurations with more than 8 CPUs, due to the way the per-CPU kmap slots are organized in memory. Work around this by permitting an architecture to set a Kconfig symbol that signifies that the kmap PTEs do not form a lineary array in memory, and so the only way to locate the appropriate one is to walk the page tables. Link: https://lore.kernel.org/linux-arm-kernel/20211026131249.3731275-1-ardb@kernel.org/ Link: https://lkml.kernel.org/r/20211116094737.7391-1-ardb@kernel.org Fixes: 2a15ba82fa6c ("ARM: highmem: Switch to generic kmap atomic") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reported-by: Quanyang Wang <quanyang.wang@windriver.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20mm/damon/dbgfs: fix missed use of damon_dbgfs_lockSeongJae Park
DAMON debugfs is supposed to protect dbgfs_ctxs, dbgfs_nr_ctxs, and dbgfs_dirs using damon_dbgfs_lock. However, some of the code is accessing the variables without the protection. This fixes it by protecting all such accesses. Link: https://lkml.kernel.org/r/20211110145758.16558-3-sj@kernel.org Fixes: 75c1c2b53c78 ("mm/damon/dbgfs: support multiple contexts") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20mm/damon/dbgfs: use '__GFP_NOWARN' for user-specified size buffer allocationSeongJae Park
Patch series "DAMON fixes". This patch (of 2): DAMON users can trigger below warning in '__alloc_pages()' by invoking write() to some DAMON debugfs files with arbitrarily high count argument, because DAMON debugfs interface allocates some buffers based on the user-specified 'count'. if (unlikely(order >= MAX_ORDER)) { WARN_ON_ONCE(!(gfp & __GFP_NOWARN)); return NULL; } Because the DAMON debugfs interface code checks failure of the 'kmalloc()', this commit simply suppresses the warnings by adding '__GFP_NOWARN' flag. Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@kernel.org Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@kernel.org Fixes: 4bc05954d007 ("mm/damon: implement a debugfs-based user space interface") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20kasan: test: silence intentional read overflow warningsKees Cook
As done in commit d73dad4eb5ad ("kasan: test: bypass __alloc_size checks") for __write_overflow warnings, also silence some more cases that trip the __read_overflow warnings seen in 5.16-rc1[1]: In file included from include/linux/string.h:253, from include/linux/bitmap.h:10, from include/linux/cpumask.h:12, from include/linux/mm_types_task.h:14, from include/linux/mm_types.h:5, from include/linux/page-flags.h:13, from arch/arm64/include/asm/mte.h:14, from arch/arm64/include/asm/pgtable.h:12, from include/linux/pgtable.h:6, from include/linux/kasan.h:29, from lib/test_kasan.c:10: In function 'memcmp', inlined from 'kasan_memcmp' at lib/test_kasan.c:897:2: include/linux/fortify-string.h:263:25: error: call to '__read_overflow' declared with attribute error: detected read beyond size of object (1st parameter) 263 | __read_overflow(); | ^~~~~~~~~~~~~~~~~ In function 'memchr', inlined from 'kasan_memchr' at lib/test_kasan.c:872:2: include/linux/fortify-string.h:277:17: error: call to '__read_overflow' declared with attribute error: detected read beyond size of object (1st parameter) 277 | __read_overflow(); | ^~~~~~~~~~~~~~~~~ [1] http://kisskb.ellerman.id.au/kisskb/buildresult/14660585/log/ Link: https://lkml.kernel.org/r/20211116004111.3171781-1-keescook@chromium.org Fixes: d73dad4eb5ad ("kasan: test: bypass __alloc_size checks") Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Acked-by: Marco Elver <elver@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20hugetlb, userfaultfd: fix reservation restore on userfaultfd errorMina Almasry
Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we bail out using "goto out_release_unlock;" in the cases where idx >= size, or !huge_pte_none(), the code will detect that new_pagecache_page == false, and so call restore_reserve_on_error(). In this case I see restore_reserve_on_error() delete the reservation, and the following call to remove_inode_hugepages() will increment h->resv_hugepages causing a 100% reproducible leak. We should treat the is_continue case similar to adding a page into the pagecache and set new_pagecache_page to true, to indicate that there is no reservation to restore on the error path, and we need not call restore_reserve_on_error(). Rename new_pagecache_page to page_in_pagecache to make that clear. Link: https://lkml.kernel.org/r/20211117193825.378528-1-almasrymina@google.com Fixes: c7b1850dfb41 ("hugetlb: don't pass page cache pages to restore_reserve_on_error") Signed-off-by: Mina Almasry <almasrymina@google.com> Reported-by: James Houghton <jthoughton@google.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Wei Xu <weixugc@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20hugetlb: fix hugetlb cgroup refcounting during mremapBui Quang Minh
When hugetlb_vm_op_open() is called during copy_vma(), we may take the reference to resv_map->css. Later, when clearing the reservation pointer of old_vma after transferring it to new_vma, we forget to drop the reference to resv_map->css. This leads to a reference leak of css. Fixes this by adding a check to drop reservation css reference in clear_vma_resv_huge_pages() Link: https://lkml.kernel.org/r/20211113154412.91134-1-minhquangbui99@gmail.com Fixes: 550a7d60bd5e35 ("mm, hugepages: add mremap() support for hugepage backed vma") Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flagRustam Kovhaev
When kmemleak is enabled for SLOB, system does not boot and does not print anything to the console. At the very early stage in the boot process we hit infinite recursion from kmemleak_init() and eventually kernel crashes. kmemleak_init() specifies SLAB_NOLEAKTRACE for KMEM_CACHE(), but kmem_cache_create_usercopy() removes it because CACHE_CREATE_MASK is not valid for SLOB. Let's fix CACHE_CREATE_MASK and make kmemleak work with SLOB Link: https://lkml.kernel.org/r/20211115020850.3154366-1-rkovhaev@gmail.com Fixes: d8843922fba4 ("slab: Ignore internal flags in cache creation") Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Glauber Costa <glommer@parallels.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20hexagon: ignore vmlinux.ldsNathan Chancellor
After building allmodconfig, there is an untracked vmlinux.lds file in arch/hexagon/kernel: $ git ls-files . --exclude-standard --others arch/hexagon/kernel/vmlinux.lds Ignore it as all other architectures have. Link: https://lkml.kernel.org/r/20211115174250.1994179-4-nathan@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20hexagon: clean up timer-regs.hNathan Chancellor
When building allmodconfig, there is a warning about TIMER_ENABLE being redefined: drivers/clocksource/timer-oxnas-rps.c:39:9: error: 'TIMER_ENABLE' macro redefined [-Werror,-Wmacro-redefined] #define TIMER_ENABLE BIT(7) ^ arch/hexagon/include/asm/timer-regs.h:13:9: note: previous definition is here #define TIMER_ENABLE 0 ^ 1 error generated. The values in this header are only used in one file each, if they are used at all. Remove the header and sink all of the constants into their respective files. TCX0_CLK_RATE is only used in arch/hexagon/include/asm/timex.h TIMER_ENABLE, RTOS_TIMER_INT, RTOS_TIMER_REGS_ADDR are only used in arch/hexagon/kernel/time.c. SLEEP_CLK_RATE and TIMER_CLR_ON_MATCH have both been unused since the file's introduction in commit 71e4a47f32f4 ("Hexagon: Add time and timer functions"). TIMER_ENABLE is redefined as BIT(0) so the shift is moved into the definition, rather than its use. Link: https://lkml.kernel.org/r/20211115174250.1994179-3-nathan@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Brian Cain <bcain@codeaurora.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20hexagon: export raw I/O routines for modulesNathan Chancellor
Patch series "Fixes for ARCH=hexagon allmodconfig", v2. This series fixes some issues noticed with ARCH=hexagon allmodconfig. This patch (of 3): When building ARCH=hexagon allmodconfig, the following errors occur: ERROR: modpost: "__raw_readsl" [drivers/i3c/master/svc-i3c-master.ko] undefined! ERROR: modpost: "__raw_writesl" [drivers/i3c/master/dw-i3c-master.ko] undefined! ERROR: modpost: "__raw_readsl" [drivers/i3c/master/dw-i3c-master.ko] undefined! ERROR: modpost: "__raw_writesl" [drivers/i3c/master/i3c-master-cdns.ko] undefined! ERROR: modpost: "__raw_readsl" [drivers/i3c/master/i3c-master-cdns.ko] undefined! Export these symbols so that modules can use them without any errors. Link: https://lkml.kernel.org/r/20211115174250.1994179-1-nathan@kernel.org Link: https://lkml.kernel.org/r/20211115174250.1994179-2-nathan@kernel.org Fixes: 013bf24c3829 ("Hexagon: Provide basic implementation and/or stubs for I/O routines.") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Brian Cain <bcain@codeaurora.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20mm: emit the "free" trace report before freeing memory in kmem_cache_free()Yunfeng Ye
After the memory is freed, it can be immediately allocated by other CPUs, before the "free" trace report has been emitted. This causes inaccurate traces. For example, if the following sequence of events occurs: CPU 0 CPU 1 (1) alloc xxxxxx (2) free xxxxxx (3) alloc xxxxxx (4) free xxxxxx Then they will be inaccurately reported via tracing, so that they appear to have happened in this order: CPU 0 CPU 1 (1) alloc xxxxxx (2) alloc xxxxxx (3) free xxxxxx (4) free xxxxxx This makes it look like CPU 1 somehow managed to allocate memory that CPU 0 still had allocated for itself. In order to avoid this, emit the "free xxxxxx" tracing report just before the actual call to free the memory, instead of just after it. Link: https://lkml.kernel.org/r/374eb75d-7404-8721-4e1e-65b0e5b17279@huawei.com Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20shm: extend forced shm destroy to support objects from several IPC nsesAlexander Mikhalitsyn
Currently, the exit_shm() function not designed to work properly when task->sysvshm.shm_clist holds shm objects from different IPC namespaces. This is a real pain when sysctl kernel.shm_rmid_forced = 1, because it leads to use-after-free (reproducer exists). This is an attempt to fix the problem by extending exit_shm mechanism to handle shm's destroy from several IPC ns'es. To achieve that we do several things: 1. add a namespace (non-refcounted) pointer to the struct shmid_kernel 2. during new shm object creation (newseg()/shmget syscall) we initialize this pointer by current task IPC ns 3. exit_shm() fully reworked such that it traverses over all shp's in task->sysvshm.shm_clist and gets IPC namespace not from current task as it was before but from shp's object itself, then call shm_destroy(shp, ns). Note: We need to be really careful here, because as it was said before (1), our pointer to IPC ns non-refcnt'ed. To be on the safe side we using special helper get_ipc_ns_not_zero() which allows to get IPC ns refcounter only if IPC ns not in the "state of destruction". Q/A Q: Why can we access shp->ns memory using non-refcounted pointer? A: Because shp object lifetime is always shorther than IPC namespace lifetime, so, if we get shp object from the task->sysvshm.shm_clist while holding task_lock(task) nobody can steal our namespace. Q: Does this patch change semantics of unshare/setns/clone syscalls? A: No. It's just fixes non-covered case when process may leave IPC namespace without getting task->sysvshm.shm_clist list cleaned up. Link: https://lkml.kernel.org/r/67bb03e5-f79c-1815-e2bf-949c67047418@colorfullife.com Link: https://lkml.kernel.org/r/20211109151501.4921-1-manfred@colorfullife.com Fixes: ab602f79915 ("shm: make exit_shm work proportional to task activity") Co-developed-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Cc: Vasily Averin <vvs@virtuozzo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20ipc: WARN if trying to remove ipc object which is absentAlexander Mikhalitsyn
Patch series "shm: shm_rmid_forced feature fixes". Some time ago I met kernel crash after CRIU restore procedure, fortunately, it was CRIU restore, so, I had dump files and could do restore many times and crash reproduced easily. After some investigation I've constructed the minimal reproducer. It was found that it's use-after-free and it happens only if sysctl kernel.shm_rmid_forced = 1. The key of the problem is that the exit_shm() function not handles shp's object destroy when task->sysvshm.shm_clist contains items from different IPC namespaces. In most cases this list will contain only items from one IPC namespace. How can this list contain object from different namespaces? The exit_shm() function is designed to clean up this list always when process leaves IPC namespace. But we made a mistake a long time ago and did not add a exit_shm() call into the setns() syscall procedures. The first idea was just to add this call to setns() syscall but it obviously changes semantics of setns() syscall and that's userspace-visible change. So, I gave up on this idea. The first real attempt to address the issue was just to omit forced destroy if we meet shp object not from current task IPC namespace [1]. But that was not the best idea because task->sysvshm.shm_clist was protected by rwsem which belongs to current task IPC namespace. It means that list corruption may occur. Second approach is just extend exit_shm() to properly handle shp's from different IPC namespaces [2]. This is really non-trivial thing, I've put a lot of effort into that but not believed that it's possible to make it fully safe, clean and clear. Thanks to the efforts of Manfred Spraul working an elegant solution was designed. Thanks a lot, Manfred! Eric also suggested the way to address the issue in ("[RFC][PATCH] shm: In shm_exit destroy all created and never attached segments") Eric's idea was to maintain a list of shm_clists one per IPC namespace, use lock-less lists. But there is some extra memory consumption-related concerns. An alternative solution which was suggested by me was implemented in ("shm: reset shm_clist on setns but omit forced shm destroy"). The idea is pretty simple, we add exit_shm() syscall to setns() but DO NOT destroy shm segments even if sysctl kernel.shm_rmid_forced = 1, we just clean up the task->sysvshm.shm_clist list. This chages semantics of setns() syscall a little bit but in comparision to the "naive" solution when we just add exit_shm() without any special exclusions this looks like a safer option. [1] https://lkml.org/lkml/2021/7/6/1108 [2] https://lkml.org/lkml/2021/7/14/736 This patch (of 2): Let's produce a warning if we trying to remove non-existing IPC object from IPC namespace kht/idr structures. This allows us to catch possible bugs when the ipc_rmid() function was called with inconsistent struct ipc_ids*, struct kern_ipc_perm* arguments. Link: https://lkml.kernel.org/r/20211027224348.611025-1-alexander.mikhalitsyn@virtuozzo.com Link: https://lkml.kernel.org/r/20211027224348.611025-2-alexander.mikhalitsyn@virtuozzo.com Co-developed-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Cc: Vasily Averin <vvs@virtuozzo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-20mm/swap.c:put_pages_list(): reinitialise the page listMatthew Wilcox
While free_unref_page_list() puts pages onto the CPU local LRU list, it does not remove them from the list they were passed in on. That makes the list_head appear to be non-empty, and would lead to various corruption problems if we didn't have an assertion that the list was empty. Reinitialise the list after calling free_unref_page_list() to avoid this problem. Link: https://lkml.kernel.org/r/YYp40A2lNrxaZji8@casper.infradead.org Fixes: 988c69f1bc23 ("mm: optimise put_pages_list()") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Steve French <stfrench@microsoft.com> Reported-by: Namjae Jeon <linkinjeon@kernel.org> Tested-by: Steve French <stfrench@microsoft.com> Tested-by: Namjae Jeon <linkinjeon@kernel.org> Cc: Steve French <smfrench@gmail.com> Cc: Hyeoncheol Lee <hyc.lee@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-19Merge tag 'libata-5.16-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata Pull libata fixes from Damien Le Moal: - Prevent accesses to unsupported log pages as that causes device scan failures with LLDDs using libsas (from me). - A couple of fixes for AMD AHCI adapters handling of low power modes and resume (from Mario). - Fix a compilation warning (from me). * tag 'libata-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata: ata: libata-sata: Declare ata_ncq_sdev_attrs static ata: libahci: Adjust behavior when StorageD3Enable _DSD is set ata: ahci: Add Green Sardine vendor ID as board_ahci_mobile ata: libata: add missing ata_identify_page_supported() calls ata: libata: improve ata_read_log_page() error message
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-07-31 14:00:41 +0000