linux/arch/arm64/include/asm
Will Deacon 045afc2412 arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value
Rather embarrassingly, our futex() FUTEX_WAKE_OP implementation doesn't
explicitly set the return value on the non-faulting path and instead
leaves it holding the result of the underlying atomic operation. This
means that any FUTEX_WAKE_OP atomic operation which computes a non-zero
value will be reported as having failed. Regrettably, I wrote the buggy
code back in 2011 and it was upstreamed as part of the initial arm64
support in 2012.

The reasons we appear to get away with this are:

  1. FUTEX_WAKE_OP is rarely used and therefore doesn't appear to get
     exercised by futex() test applications

  2. If the result of the atomic operation is zero, the system call
     behaves correctly

  3. Prior to version 2.25, the only operation used by GLIBC set the
     futex to zero, and therefore worked as expected. From 2.25 onwards,
     FUTEX_WAKE_OP is not used by GLIBC at all.

Fix the implementation by ensuring that the return value is either 0
to indicate that the atomic operation completed successfully, or -EFAULT
if we encountered a fault when accessing the user mapping.

Cc: <stable@kernel.org>
Fixes: 6170a97460 ("arm64: Atomic operations")
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-12 15:04:33 +01:00
..
xen arm64/xen: fix xen-swiotlb cache flushing 2019-01-23 22:14:56 +01:00
acenv.h
acpi.h arm64: KVM/mm: Move SEA handling behind a single 'claim' interface 2019-02-07 23:10:45 +01:00
alternative.h arm64: alternative: Apply alternatives early in boot process 2019-02-06 10:05:20 +00:00
arch_gicv3.h arm64: gic-v3: Implement arch support for priority masking 2019-02-06 10:05:21 +00:00
arch_timer.h First batch of KVM changes for 4.15 2017-11-16 13:00:24 -08:00
arm_dsu_pmu.h perf: ARM DynamIQ Shared Unit PMU support 2018-01-02 16:43:12 +00:00
arm-cci.h
asm-bug.h arm64: asm-bug: Renumber macro local labels to avoid clashes 2017-10-25 15:57:15 +01:00
asm-offsets.h
asm-prototypes.h arm64: asm-prototypes: Fix fat-fingered typo in comment 2019-01-10 11:11:46 +00:00
asm-uaccess.h arm64: Rename get_thread_info() 2019-02-26 16:57:59 +00:00
assembler.h arm64: Add workaround for Fujitsu A64FX erratum 010001 2019-02-28 16:24:25 +00:00
atomic_ll_sc.h Merge branch 'locking/atomics' into locking/core, to pick up WIP commits 2019-02-11 14:27:05 +01:00
atomic_lse.h Merge branch 'locking/atomics' into locking/core, to pick up WIP commits 2019-02-11 14:27:05 +01:00
atomic.h arm64, locking/atomics: Use instrumented atomics 2018-11-01 11:01:40 +01:00
barrier.h arm64: Add support for SB barrier and patch in over DSB; ISB sequences 2018-12-06 16:47:04 +00:00
bitops.h locking/atomics/arm64, arm64/bitops: Include <asm-generic/bitops/ext2-atomic-setbit.h> 2018-06-21 12:52:12 +02:00
bitrev.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
boot.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
brk-imm.h kasan, arm64: add brk handler for inline instrumentation 2018-12-28 12:11:44 -08:00
bug.h arm64: Add ASM_BUG() 2017-08-08 16:28:13 +01:00
cache.h kasan, arm64: remove redundant ARCH_SLAB_MINALIGN define 2019-01-16 12:09:11 +00:00
cacheflush.h arm64: IPI each CPU after invalidating the I-cache for kernel mappings 2018-07-05 17:24:36 +01:00
checksum.h arm64: add missing conversion to __wsum in ip_fast_csum() 2017-06-29 16:32:43 +01:00
clocksource.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cmpxchg.h Merge branch 'locking/atomics' into locking/core, to pick up WIP commits 2019-02-11 14:27:05 +01:00
compat.h Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-25 11:14:36 -07:00
cpu_ops.h
cpu.h arm64/sve: Probe SVE capabilities and usable vector lengths 2017-11-03 15:24:17 +00:00
cpucaps.h arm64: cpufeature: Add cpufeature for IRQ priority masking 2019-02-06 10:05:17 +00:00
cpufeature.h arm64: alternative: Apply alternatives early in boot process 2019-02-06 10:05:20 +00:00
cpuidle.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cputype.h arm64: Add MIDR encoding for HiSilicon Taishan CPUs 2019-03-19 14:55:10 +00:00
current.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
daifflags.h arm64 updates for 5.1: 2019-03-10 10:17:23 -07:00
dcc.h
debug-monitors.h arm64: Add uprobe support 2016-11-07 18:15:21 +00:00
device.h arm64/xen: fix xen-swiotlb cache flushing 2019-01-23 22:14:56 +01:00
dma-mapping.h dma-mapping: add a kconfig symbol for arch_teardown_dma_ops availability 2019-02-13 19:12:50 +01:00
dmi.h
efi.h arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking 2019-02-06 10:05:19 +00:00
elf.h arm64: mm: Allow forcing all userspace addresses to 52-bit 2018-12-10 18:42:18 +00:00
esr.h arm64: add pointer authentication register bits 2018-12-13 16:42:45 +00:00
exception.h arm64: kernel: Prepare for a DISR user 2018-01-16 15:07:12 +00:00
exec.h
extable.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fb.h
fixmap.h firmware: arm_sdei: Add ACPI GHES registration helper 2019-02-11 11:07:49 +01:00
fpsimd.h arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> 2018-07-12 14:40:39 +01:00
fpsimdmacros.h arm64/sve: Write ZCR_EL1 on context switch only if changed 2018-05-17 18:19:53 +01:00
ftrace.h arm64 festive updates for 4.21 2018-12-25 17:41:56 -08:00
futex.h arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value 2019-04-12 15:04:33 +01:00
hardirq.h arm64: Fix HCR.TGE status for NMI contexts 2019-02-06 10:05:16 +00:00
hugetlb.h arm64/mm: enable HugeTLB migration for contiguous bit HugeTLB pages 2019-03-05 21:07:15 -08:00
hw_breakpoint.h perf/hw_breakpoint: Remove default hw_breakpoint_arch_parse() 2018-06-26 09:07:58 +02:00
hwcap.h
hypervisor.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
image.h arm64: add image head flag definitions 2018-12-06 14:38:51 +00:00
insn.h arm64/insn: add support for emitting ADR/ADRP instructions 2018-11-27 18:47:33 +00:00
io.h arm64: io: Hook up __io_par() for inX() ordering 2019-02-28 17:24:27 +00:00
irq_work.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq.h arm64: Use the new GENERIC_IRQ_MULTI_HANDLER 2018-08-03 12:14:09 +02:00
irqflags.h arm64: irqflags: Fix clang build warnings 2019-02-12 11:33:57 +00:00
jump_label.h arm64/kernel: jump_label: Switch to relative references 2018-09-27 17:56:47 +02:00
kasan.h kasan: add tag related helper functions 2018-12-28 12:11:43 -08:00
Kbuild arm64: preempt: Provide our own implementation of asm/preempt.h 2018-12-07 12:35:53 +00:00
kernel-pgtable.h arm64/mm: Separate boot-time page tables from swapper_pg_dir 2018-09-25 15:10:54 +01:00
kexec.h arm64: kexec_file: allow for loading Image-format kernel 2018-12-06 14:38:52 +00:00
kgdb.h
kprobes.h arm64/kprobes: Remove jprobe implementation 2018-06-21 12:33:07 +02:00
kvm_arm.h * ARM: selftests improvements, large PUD support for HugeTLB, 2018-12-26 11:46:28 -08:00
kvm_asm.h arm/arm64: KVM: Add ARM_EXCEPTION_IS_TRAP macro 2018-12-19 17:47:53 +00:00
kvm_coproc.h
kvm_emulate.h arm64: KVM: Describe data or unified caches as having 1 set and 1 way 2019-02-19 21:05:49 +00:00
kvm_host.h ARM: some cleanups, direct physical timer assignment, cache sanitization 2019-03-15 15:00:28 -07:00
kvm_hyp.h KVM: arm/arm64: Factor out VMID into struct kvm_vmid 2019-02-19 21:05:35 +00:00
kvm_mmio.h
kvm_mmu.h KVM: arm/arm64: vgic-its: Take the srcu lock when writing to guest memory 2019-03-19 17:56:56 +00:00
kvm_ras.h arm64: KVM/mm: Move SEA handling behind a single 'claim' interface 2019-02-07 23:10:45 +01:00
linkage.h arm64: relax assembly code alignment from 16 byte to 4 byte 2017-09-18 11:20:19 +01:00
lse.h arm64: lse: Include compiler_types.h and export.h for out-of-line LL/SC 2018-03-27 13:14:49 +01:00
memory.h arm64 updates for 5.1: 2019-03-10 10:17:23 -07:00
mmu_context.h arm64: Kconfig: Re-jig CONFIG options for 52-bit VA 2018-12-10 18:42:18 +00:00
mmu.h arm64: Remove asm/memblock.h 2019-01-21 17:31:15 +00:00
mmzone.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
module.h arm64/ftrace: fix inadvertent BUG() in trampoline check 2019-04-08 16:58:13 +01:00
neon-intrinsics.h arm64/neon: Disable -Wincompatible-pointer-types when building with Clang 2019-02-18 10:54:47 +00:00
neon.h arm64: drop unused kernel_neon_begin_partial() macro 2018-07-31 10:13:50 +01:00
numa.h arm64: numa: separate out updates to percpu nodeid and NUMA node cpumap 2018-07-06 13:18:18 +01:00
page-def.h arm64: factor out PAGE_* and CONT_* definitions 2017-08-15 18:35:00 +01:00
page.h arm64: Kconfig: Remove ARCH_HAS_HOLES_MEMORYMODEL 2018-09-21 12:02:45 +01:00
paravirt.h x86/paravirt: Use a single ops structure 2018-09-03 16:50:35 +02:00
pci.h PCI: remove PCI_DMA_BUS_IS_PHYS 2018-05-07 07:15:41 +02:00
percpu.h arm64: percpu: Fix LSE implementation of value-returning pcpu atomics 2018-12-12 14:43:35 +00:00
perf_event.h arm64: perf: Treat EXCLUDE_EL* bit definitions as unsigned 2018-12-13 15:34:44 +00:00
pgalloc.h mm: treewide: remove unused address argument from pte_alloc functions 2019-01-04 13:13:47 -08:00
pgtable-hwdef.h arm64: Add workaround for Fujitsu A64FX erratum 010001 2019-02-28 16:24:25 +00:00
pgtable-prot.h arm64: kpti: Avoid rewriting early page tables when KASLR is enabled 2019-01-10 17:49:35 +00:00
pgtable-types.h arch, mm: convert all architectures to use 5level-fixup.h 2017-03-09 11:48:47 -08:00
pgtable.h * ARM: selftests improvements, large PUD support for HugeTLB, 2018-12-26 11:46:28 -08:00
pointer_auth.h arm64: ptr auth: Move per-thread keys from thread_info to thread_struct 2018-12-13 16:42:47 +00:00
preempt.h arm64: preempt: Provide our own implementation of asm/preempt.h 2018-12-07 12:35:53 +00:00
probes.h arm64: Remove reference to asm/opcodes.h 2016-12-05 10:42:34 +00:00
proc-fns.h arm64: mm: Move ASID from TTBR0 to TTBR1 2017-12-11 13:40:25 +00:00
processor.h arm64: Make PMR part of task context 2019-02-06 10:05:18 +00:00
ptdump.h arm64: dump: no need to check return value of debugfs_create functions 2019-01-31 17:38:19 +00:00
ptrace.h arm64: Make PMR part of task context 2019-02-06 10:05:18 +00:00
sdei.h arm64: Add stack information to on_accessible_stack 2018-07-26 11:36:07 +01:00
seccomp.h
sections.h arm64: mmu: add the entry trampolines start/end section markers into sections.h 2018-01-14 18:49:50 +00:00
shmparam.h
signal32.h arm64: compat: Remove leftover variable declaration 2017-08-10 18:17:32 +01:00
simd.h arm64: neon: Fix function may_use_simd() return error status 2018-07-11 17:02:02 +01:00
smp_plat.h
smp.h arm64: smp: Fix compilation error 2019-01-03 15:14:32 +00:00
sparsemem.h arm64: add kconfig symbol to configure physical address size 2017-12-22 17:30:33 +00:00
spinlock_types.h arm64: locking: Replace ticket lock implementation with qspinlock 2018-07-05 10:05:06 +01:00
spinlock.h arm64: locking: Replace ticket lock implementation with qspinlock 2018-07-05 10:05:06 +01:00
stack_pointer.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
stackprotector.h arm64: enable per-task stack canaries 2018-12-12 18:45:31 +00:00
stacktrace.h arm64: Add stack information to on_accessible_stack 2018-07-26 11:36:07 +01:00
stage2_pgtable.h KVM: arm64: Clarify explanation of STAGE2_PGTABLE_LEVELS 2018-12-18 15:14:50 +00:00
stat.h y2038: globally rename compat_time to old_time32 2018-08-27 14:48:48 +02:00
string.h arm64: lib: use C string functions with KASAN enabled 2018-10-26 16:25:18 -07:00
suspend.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sync_bitops.h arm64, locking/atomics: Use instrumented atomics 2018-11-01 11:01:40 +01:00
syscall_wrapper.h arm64: implement syscall wrappers 2018-07-12 14:49:48 +01:00
syscall.h syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
sysreg.h arm64: KVM: Expose sanitised cache type register to guest 2019-02-19 21:05:48 +00:00
system_misc.h KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing 2019-02-07 23:10:45 +01:00
thread_info.h arm64: Remove documentation about TIF_USEDFPU 2019-02-26 16:41:10 +00:00
timex.h arm64: Use physical counter for in-kernel reads when booted in EL2 2017-11-06 16:23:09 +01:00
tlb.h arm64: tlb: Avoid synchronous TLBIs when freeing page tables 2018-09-11 16:49:12 +01:00
tlbflush.h arm64 festive updates for 4.21 2018-12-25 17:41:56 -08:00
topology.h sched/topology, arch/arm64: Rebuild the sched_domain hierarchy when the CPU capacity changes 2018-09-10 11:05:47 +02:00
traps.h signal/arm64: Add and use arm64_force_sig_ptrace_errno_trap 2018-09-27 21:55:15 +02:00
uaccess.h arm64 updates for 5.1: 2019-03-10 10:17:23 -07:00
unistd32.h y2038: add 64-bit time_t syscalls to all 32-bit architectures 2019-02-07 00:13:28 +01:00
unistd.h y2038: add 64-bit time_t syscalls to all 32-bit architectures 2019-02-07 00:13:28 +01:00
uprobes.h arm64: Add uprobe support 2016-11-07 18:15:21 +00:00
vdso_datapage.h
vdso.h
virt.h arm64: capabilities: Change scope of VHE to Boot CPU feature 2018-03-26 18:01:41 +01:00
vmap_stack.h arm64: Add vmap_stack header file 2018-01-13 10:45:03 +00:00
word-at-a-time.h Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
xor.h arm64: crypto: add NEON accelerated XOR implementation 2018-12-06 16:47:06 +00:00