github.com/nicocha30/gvisor-ligolo@v0.0.0-20230726075806-989fa2c0a413/pkg/sentry/syscalls/linux/sys_sched.go (about)

     1  // Copyright 2018 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package linux
    16  
    17  import (
    18  	"github.com/nicocha30/gvisor-ligolo/pkg/abi/linux"
    19  	"github.com/nicocha30/gvisor-ligolo/pkg/errors/linuxerr"
    20  	"github.com/nicocha30/gvisor-ligolo/pkg/sentry/arch"
    21  	"github.com/nicocha30/gvisor-ligolo/pkg/sentry/kernel"
    22  )
    23  
    24  const (
    25  	onlyScheduler = linux.SCHED_NORMAL
    26  	onlyPriority  = 0
    27  )
    28  
    29  // SchedParam replicates struct sched_param in sched.h.
    30  //
    31  // +marshal
    32  type SchedParam struct {
    33  	schedPriority int32
    34  }
    35  
    36  // SchedGetparam implements linux syscall sched_getparam(2).
    37  func SchedGetparam(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
    38  	pid := args[0].Int()
    39  	param := args[1].Pointer()
    40  	if param == 0 {
    41  		return 0, nil, linuxerr.EINVAL
    42  	}
    43  	if pid < 0 {
    44  		return 0, nil, linuxerr.EINVAL
    45  	}
    46  	if pid != 0 && t.PIDNamespace().TaskWithID(kernel.ThreadID(pid)) == nil {
    47  		return 0, nil, linuxerr.ESRCH
    48  	}
    49  	r := SchedParam{schedPriority: onlyPriority}
    50  	if _, err := r.CopyOut(t, param); err != nil {
    51  		return 0, nil, err
    52  	}
    53  
    54  	return 0, nil, nil
    55  }
    56  
    57  // SchedGetscheduler implements linux syscall sched_getscheduler(2).
    58  func SchedGetscheduler(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
    59  	pid := args[0].Int()
    60  	if pid < 0 {
    61  		return 0, nil, linuxerr.EINVAL
    62  	}
    63  	if pid != 0 && t.PIDNamespace().TaskWithID(kernel.ThreadID(pid)) == nil {
    64  		return 0, nil, linuxerr.ESRCH
    65  	}
    66  	return onlyScheduler, nil, nil
    67  }
    68  
    69  // SchedSetscheduler implements linux syscall sched_setscheduler(2).
    70  func SchedSetscheduler(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
    71  	pid := args[0].Int()
    72  	policy := args[1].Int()
    73  	param := args[2].Pointer()
    74  	if pid < 0 {
    75  		return 0, nil, linuxerr.EINVAL
    76  	}
    77  	if policy != onlyScheduler {
    78  		return 0, nil, linuxerr.EINVAL
    79  	}
    80  	if pid != 0 && t.PIDNamespace().TaskWithID(kernel.ThreadID(pid)) == nil {
    81  		return 0, nil, linuxerr.ESRCH
    82  	}
    83  	var r SchedParam
    84  	if _, err := r.CopyIn(t, param); err != nil {
    85  		return 0, nil, linuxerr.EINVAL
    86  	}
    87  	if r.schedPriority != onlyPriority {
    88  		return 0, nil, linuxerr.EINVAL
    89  	}
    90  	return 0, nil, nil
    91  }
    92  
    93  // SchedGetPriorityMax implements linux syscall sched_get_priority_max(2).
    94  func SchedGetPriorityMax(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
    95  	return onlyPriority, nil, nil
    96  }
    97  
    98  // SchedGetPriorityMin implements linux syscall sched_get_priority_min(2).
    99  func SchedGetPriorityMin(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
   100  	return onlyPriority, nil, nil
   101  }