github.com/ttpreport/gvisor-ligolo@v0.0.0-20240123134145-a858404967ba/pkg/sentry/syscalls/linux/sys_afs_syscall.go (about)

     1  // Copyright 2023 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/ttpreport/gvisor-ligolo/pkg/atomicbitops"
    19  	"github.com/ttpreport/gvisor-ligolo/pkg/errors/linuxerr"
    20  	"github.com/ttpreport/gvisor-ligolo/pkg/log"
    21  	"github.com/ttpreport/gvisor-ligolo/pkg/sentry/arch"
    22  	"github.com/ttpreport/gvisor-ligolo/pkg/sentry/kernel"
    23  )
    24  
    25  var afsSyscallPanic = atomicbitops.Bool{}
    26  
    27  // SetAFSSyscallPanic sets the panic behaviour of afs_syscall.
    28  // Should only be called based on the config value of TESTONLY-afs-syscall-panic.
    29  func SetAFSSyscallPanic(v bool) {
    30  	if v {
    31  		log.Warningf("AFSSyscallPanic is set. User workloads may trigger sentry panics.")
    32  	}
    33  	afsSyscallPanic.Store(v)
    34  }
    35  
    36  // AFSSyscall is a gVisor specific implementation of afs_syscall:
    37  // - if TESTONLY-afs-syscall-panic flag is set it triggers a panic.
    38  func AFSSyscall(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
    39  	if afsSyscallPanic.Load() {
    40  		panic("User workload triggered a panic via afs_syscall. This panic is intentional.")
    41  	}
    42  
    43  	return 0, nil, linuxerr.ENOSYS
    44  }