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authorJamie Liu <jamieliu@google.com>2019-06-06 16:27:09 -0700
committerShentubot <shentubot@google.com>2019-06-06 16:29:46 -0700
commitb3f104507d7a04c0ca058cbcacc5ff78d853f4ba (patch)
treefb45110e8c9329b16165a92e67edb2c184de0dd6 /pkg
parenta26043ee53a2f38b81c9eaa098d115025e87f4c3 (diff)
"Implement" mbind(2).
We still only advertise a single NUMA node, and ignore mempolicy accordingly, but mbind() at least now succeeds and has effects reflected by get_mempolicy(). Also fix handling of nodemasks: round sizes to unsigned long (as documented and done by Linux), and zero trailing bits when copying them out. PiperOrigin-RevId: 251950859
Diffstat (limited to 'pkg')
-rw-r--r--pkg/abi/linux/mm.go9
-rw-r--r--pkg/sentry/kernel/task.go7
-rw-r--r--pkg/sentry/kernel/task_sched.go4
-rw-r--r--pkg/sentry/mm/mm.go6
-rw-r--r--pkg/sentry/mm/syscalls.go53
-rw-r--r--pkg/sentry/mm/vma.go3
-rw-r--r--pkg/sentry/syscalls/linux/BUILD1
-rw-r--r--pkg/sentry/syscalls/linux/linux64.go3
-rw-r--r--pkg/sentry/syscalls/linux/sys_mempolicy.go312
-rw-r--r--pkg/sentry/syscalls/linux/sys_mmap.go145
10 files changed, 391 insertions, 152 deletions
diff --git a/pkg/abi/linux/mm.go b/pkg/abi/linux/mm.go
index 0b02f938a..cd043dac3 100644
--- a/pkg/abi/linux/mm.go
+++ b/pkg/abi/linux/mm.go
@@ -114,3 +114,12 @@ const (
MPOL_MODE_FLAGS = (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES)
)
+
+// Flags for mbind(2).
+const (
+ MPOL_MF_STRICT = 1 << 0
+ MPOL_MF_MOVE = 1 << 1
+ MPOL_MF_MOVE_ALL = 1 << 2
+
+ MPOL_MF_VALID = MPOL_MF_STRICT | MPOL_MF_MOVE | MPOL_MF_MOVE_ALL
+)
diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go
index f9378c2de..4d889422f 100644
--- a/pkg/sentry/kernel/task.go
+++ b/pkg/sentry/kernel/task.go
@@ -455,12 +455,13 @@ type Task struct {
// single numa node, all policies are no-ops. We only track this information
// so that we can return reasonable values if the application calls
// get_mempolicy(2) after setting a non-default policy. Note that in the
- // real syscall, nodemask can be longer than 4 bytes, but we always report a
- // single node so never need to save more than a single bit.
+ // real syscall, nodemask can be longer than a single unsigned long, but we
+ // always report a single node so never need to save more than a single
+ // bit.
//
// numaPolicy and numaNodeMask are protected by mu.
numaPolicy int32
- numaNodeMask uint32
+ numaNodeMask uint64
// If netns is true, the task is in a non-root network namespace. Network
// namespaces aren't currently implemented in full; being in a network
diff --git a/pkg/sentry/kernel/task_sched.go b/pkg/sentry/kernel/task_sched.go
index 5455f6ea9..1c94ab11b 100644
--- a/pkg/sentry/kernel/task_sched.go
+++ b/pkg/sentry/kernel/task_sched.go
@@ -622,14 +622,14 @@ func (t *Task) SetNiceness(n int) {
}
// NumaPolicy returns t's current numa policy.
-func (t *Task) NumaPolicy() (policy int32, nodeMask uint32) {
+func (t *Task) NumaPolicy() (policy int32, nodeMask uint64) {
t.mu.Lock()
defer t.mu.Unlock()
return t.numaPolicy, t.numaNodeMask
}
// SetNumaPolicy sets t's numa policy.
-func (t *Task) SetNumaPolicy(policy int32, nodeMask uint32) {
+func (t *Task) SetNumaPolicy(policy int32, nodeMask uint64) {
t.mu.Lock()
defer t.mu.Unlock()
t.numaPolicy = policy
diff --git a/pkg/sentry/mm/mm.go b/pkg/sentry/mm/mm.go
index 0a026ff8c..604866d04 100644
--- a/pkg/sentry/mm/mm.go
+++ b/pkg/sentry/mm/mm.go
@@ -276,6 +276,12 @@ type vma struct {
mlockMode memmap.MLockMode
+ // numaPolicy is the NUMA policy for this vma set by mbind().
+ numaPolicy int32
+
+ // numaNodemask is the NUMA nodemask for this vma set by mbind().
+ numaNodemask uint64
+
// If id is not nil, it controls the lifecycle of mappable and provides vma
// metadata shown in /proc/[pid]/maps, and the vma holds a reference.
id memmap.MappingIdentity
diff --git a/pkg/sentry/mm/syscalls.go b/pkg/sentry/mm/syscalls.go
index af1e53f5d..9cf136532 100644
--- a/pkg/sentry/mm/syscalls.go
+++ b/pkg/sentry/mm/syscalls.go
@@ -973,6 +973,59 @@ func (mm *MemoryManager) MLockAll(ctx context.Context, opts MLockAllOpts) error
return nil
}
+// NumaPolicy implements the semantics of Linux's get_mempolicy(MPOL_F_ADDR).
+func (mm *MemoryManager) NumaPolicy(addr usermem.Addr) (int32, uint64, error) {
+ mm.mappingMu.RLock()
+ defer mm.mappingMu.RUnlock()
+ vseg := mm.vmas.FindSegment(addr)
+ if !vseg.Ok() {
+ return 0, 0, syserror.EFAULT
+ }
+ vma := vseg.ValuePtr()
+ return vma.numaPolicy, vma.numaNodemask, nil
+}
+
+// SetNumaPolicy implements the semantics of Linux's mbind().
+func (mm *MemoryManager) SetNumaPolicy(addr usermem.Addr, length uint64, policy int32, nodemask uint64) error {
+ if !addr.IsPageAligned() {
+ return syserror.EINVAL
+ }
+ // Linux allows this to overflow.
+ la, _ := usermem.Addr(length).RoundUp()
+ ar, ok := addr.ToRange(uint64(la))
+ if !ok {
+ return syserror.EINVAL
+ }
+ if ar.Length() == 0 {
+ return nil
+ }
+
+ mm.mappingMu.Lock()
+ defer mm.mappingMu.Unlock()
+ defer func() {
+ mm.vmas.MergeRange(ar)
+ mm.vmas.MergeAdjacent(ar)
+ }()
+ vseg := mm.vmas.LowerBoundSegment(ar.Start)
+ lastEnd := ar.Start
+ for {
+ if !vseg.Ok() || lastEnd < vseg.Start() {
+ // "EFAULT: ... there was an unmapped hole in the specified memory
+ // range specified [sic] by addr and len." - mbind(2)
+ return syserror.EFAULT
+ }
+ vseg = mm.vmas.Isolate(vseg, ar)
+ vma := vseg.ValuePtr()
+ vma.numaPolicy = policy
+ vma.numaNodemask = nodemask
+ lastEnd = vseg.End()
+ if ar.End <= lastEnd {
+ return nil
+ }
+ vseg, _ = vseg.NextNonEmpty()
+ }
+}
+
// Decommit implements the semantics of Linux's madvise(MADV_DONTNEED).
func (mm *MemoryManager) Decommit(addr usermem.Addr, length uint64) error {
ar, ok := addr.ToRange(length)
diff --git a/pkg/sentry/mm/vma.go b/pkg/sentry/mm/vma.go
index 02203f79f..0af8de5b0 100644
--- a/pkg/sentry/mm/vma.go
+++ b/pkg/sentry/mm/vma.go
@@ -107,6 +107,7 @@ func (mm *MemoryManager) createVMALocked(ctx context.Context, opts memmap.MMapOp
private: opts.Private,
growsDown: opts.GrowsDown,
mlockMode: opts.MLockMode,
+ numaPolicy: linux.MPOL_DEFAULT,
id: opts.MappingIdentity,
hint: opts.Hint,
}
@@ -436,6 +437,8 @@ func (vmaSetFunctions) Merge(ar1 usermem.AddrRange, vma1 vma, ar2 usermem.AddrRa
vma1.private != vma2.private ||
vma1.growsDown != vma2.growsDown ||
vma1.mlockMode != vma2.mlockMode ||
+ vma1.numaPolicy != vma2.numaPolicy ||
+ vma1.numaNodemask != vma2.numaNodemask ||
vma1.id != vma2.id ||
vma1.hint != vma2.hint {
return vma{}, false
diff --git a/pkg/sentry/syscalls/linux/BUILD b/pkg/sentry/syscalls/linux/BUILD
index f76989ae2..1c057526b 100644
--- a/pkg/sentry/syscalls/linux/BUILD
+++ b/pkg/sentry/syscalls/linux/BUILD
@@ -19,6 +19,7 @@ go_library(
"sys_identity.go",
"sys_inotify.go",
"sys_lseek.go",
+ "sys_mempolicy.go",
"sys_mmap.go",
"sys_mount.go",
"sys_pipe.go",
diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index 3e4d312af..ad88b1391 100644
--- a/pkg/sentry/syscalls/linux/linux64.go
+++ b/pkg/sentry/syscalls/linux/linux64.go
@@ -360,8 +360,7 @@ var AMD64 = &kernel.SyscallTable{
235: Utimes,
// @Syscall(Vserver, note:Not implemented by Linux)
236: syscalls.Error(syscall.ENOSYS), // Vserver, not implemented by Linux
- // @Syscall(Mbind, returns:EPERM or ENOSYS, note:Returns EPERM if the process does not have cap_sys_nice; ENOSYS otherwise), TODO(b/117792295)
- 237: syscalls.CapError(linux.CAP_SYS_NICE), // may require cap_sys_nice
+ 237: Mbind,
238: SetMempolicy,
239: GetMempolicy,
// 240: @Syscall(MqOpen), TODO(b/29354921)
diff --git a/pkg/sentry/syscalls/linux/sys_mempolicy.go b/pkg/sentry/syscalls/linux/sys_mempolicy.go
new file mode 100644
index 000000000..652b2c206
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/sys_mempolicy.go
@@ -0,0 +1,312 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package linux
+
+import (
+ "fmt"
+
+ "gvisor.googlesource.com/gvisor/pkg/abi/linux"
+ "gvisor.googlesource.com/gvisor/pkg/sentry/arch"
+ "gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
+ "gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+ "gvisor.googlesource.com/gvisor/pkg/syserror"
+)
+
+// We unconditionally report a single NUMA node. This also means that our
+// "nodemask_t" is a single unsigned long (uint64).
+const (
+ maxNodes = 1
+ allowedNodemask = (1 << maxNodes) - 1
+)
+
+func copyInNodemask(t *kernel.Task, addr usermem.Addr, maxnode uint32) (uint64, error) {
+ // "nodemask points to a bit mask of node IDs that contains up to maxnode
+ // bits. The bit mask size is rounded to the next multiple of
+ // sizeof(unsigned long), but the kernel will use bits only up to maxnode.
+ // A NULL value of nodemask or a maxnode value of zero specifies the empty
+ // set of nodes. If the value of maxnode is zero, the nodemask argument is
+ // ignored." - set_mempolicy(2). Unfortunately, most of this is inaccurate
+ // because of what appears to be a bug: mm/mempolicy.c:get_nodes() uses
+ // maxnode-1, not maxnode, as the number of bits.
+ bits := maxnode - 1
+ if bits > usermem.PageSize*8 { // also handles overflow from maxnode == 0
+ return 0, syserror.EINVAL
+ }
+ if bits == 0 {
+ return 0, nil
+ }
+ // Copy in the whole nodemask.
+ numUint64 := (bits + 63) / 64
+ buf := t.CopyScratchBuffer(int(numUint64) * 8)
+ if _, err := t.CopyInBytes(addr, buf); err != nil {
+ return 0, err
+ }
+ val := usermem.ByteOrder.Uint64(buf)
+ // Check that only allowed bits in the first unsigned long in the nodemask
+ // are set.
+ if val&^allowedNodemask != 0 {
+ return 0, syserror.EINVAL
+ }
+ // Check that all remaining bits in the nodemask are 0.
+ for i := 8; i < len(buf); i++ {
+ if buf[i] != 0 {
+ return 0, syserror.EINVAL
+ }
+ }
+ return val, nil
+}
+
+func copyOutNodemask(t *kernel.Task, addr usermem.Addr, maxnode uint32, val uint64) error {
+ // mm/mempolicy.c:copy_nodes_to_user() also uses maxnode-1 as the number of
+ // bits.
+ bits := maxnode - 1
+ if bits > usermem.PageSize*8 { // also handles overflow from maxnode == 0
+ return syserror.EINVAL
+ }
+ if bits == 0 {
+ return nil
+ }
+ // Copy out the first unsigned long in the nodemask.
+ buf := t.CopyScratchBuffer(8)
+ usermem.ByteOrder.PutUint64(buf, val)
+ if _, err := t.CopyOutBytes(addr, buf); err != nil {
+ return err
+ }
+ // Zero out remaining unsigned longs in the nodemask.
+ if bits > 64 {
+ remAddr, ok := addr.AddLength(8)
+ if !ok {
+ return syserror.EFAULT
+ }
+ remUint64 := (bits - 1) / 64
+ if _, err := t.MemoryManager().ZeroOut(t, remAddr, int64(remUint64)*8, usermem.IOOpts{
+ AddressSpaceActive: true,
+ }); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+// GetMempolicy implements the syscall get_mempolicy(2).
+func GetMempolicy(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ mode := args[0].Pointer()
+ nodemask := args[1].Pointer()
+ maxnode := args[2].Uint()
+ addr := args[3].Pointer()
+ flags := args[4].Uint()
+
+ if flags&^(linux.MPOL_F_NODE|linux.MPOL_F_ADDR|linux.MPOL_F_MEMS_ALLOWED) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+ nodeFlag := flags&linux.MPOL_F_NODE != 0
+ addrFlag := flags&linux.MPOL_F_ADDR != 0
+ memsAllowed := flags&linux.MPOL_F_MEMS_ALLOWED != 0
+
+ // "EINVAL: The value specified by maxnode is less than the number of node
+ // IDs supported by the system." - get_mempolicy(2)
+ if nodemask != 0 && maxnode < maxNodes {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // "If flags specifies MPOL_F_MEMS_ALLOWED [...], the mode argument is
+ // ignored and the set of nodes (memories) that the thread is allowed to
+ // specify in subsequent calls to mbind(2) or set_mempolicy(2) (in the
+ // absence of any mode flags) is returned in nodemask."
+ if memsAllowed {
+ // "It is not permitted to combine MPOL_F_MEMS_ALLOWED with either
+ // MPOL_F_ADDR or MPOL_F_NODE."
+ if nodeFlag || addrFlag {
+ return 0, nil, syserror.EINVAL
+ }
+ if err := copyOutNodemask(t, nodemask, maxnode, allowedNodemask); err != nil {
+ return 0, nil, err
+ }
+ return 0, nil, nil
+ }
+
+ // "If flags specifies MPOL_F_ADDR, then information is returned about the
+ // policy governing the memory address given in addr. ... If the mode
+ // argument is not NULL, then get_mempolicy() will store the policy mode
+ // and any optional mode flags of the requested NUMA policy in the location
+ // pointed to by this argument. If nodemask is not NULL, then the nodemask
+ // associated with the policy will be stored in the location pointed to by
+ // this argument."
+ if addrFlag {
+ policy, nodemaskVal, err := t.MemoryManager().NumaPolicy(addr)
+ if err != nil {
+ return 0, nil, err
+ }
+ if nodeFlag {
+ // "If flags specifies both MPOL_F_NODE and MPOL_F_ADDR,
+ // get_mempolicy() will return the node ID of the node on which the
+ // address addr is allocated into the location pointed to by mode.
+ // If no page has yet been allocated for the specified address,
+ // get_mempolicy() will allocate a page as if the thread had
+ // performed a read (load) access to that address, and return the
+ // ID of the node where that page was allocated."
+ buf := t.CopyScratchBuffer(1)
+ _, err := t.CopyInBytes(addr, buf)
+ if err != nil {
+ return 0, nil, err
+ }
+ policy = 0 // maxNodes == 1
+ }
+ if mode != 0 {
+ if _, err := t.CopyOut(mode, policy); err != nil {
+ return 0, nil, err
+ }
+ }
+ if nodemask != 0 {
+ if err := copyOutNodemask(t, nodemask, maxnode, nodemaskVal); err != nil {
+ return 0, nil, err
+ }
+ }
+ return 0, nil, nil
+ }
+
+ // "EINVAL: ... flags specified MPOL_F_ADDR and addr is NULL, or flags did
+ // not specify MPOL_F_ADDR and addr is not NULL." This is partially
+ // inaccurate: if flags specifies MPOL_F_ADDR,
+ // mm/mempolicy.c:do_get_mempolicy() doesn't special-case NULL; it will
+ // just (usually) fail to find a VMA at address 0 and return EFAULT.
+ if addr != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // "If flags is specified as 0, then information about the calling thread's
+ // default policy (as set by set_mempolicy(2)) is returned, in the buffers
+ // pointed to by mode and nodemask. ... If flags specifies MPOL_F_NODE, but
+ // not MPOL_F_ADDR, and the thread's current policy is MPOL_INTERLEAVE,
+ // then get_mempolicy() will return in the location pointed to by a
+ // non-NULL mode argument, the node ID of the next node that will be used
+ // for interleaving of internal kernel pages allocated on behalf of the
+ // thread."
+ policy, nodemaskVal := t.NumaPolicy()
+ if nodeFlag {
+ if policy&^linux.MPOL_MODE_FLAGS != linux.MPOL_INTERLEAVE {
+ return 0, nil, syserror.EINVAL
+ }
+ policy = 0 // maxNodes == 1
+ }
+ if mode != 0 {
+ if _, err := t.CopyOut(mode, policy); err != nil {
+ return 0, nil, err
+ }
+ }
+ if nodemask != 0 {
+ if err := copyOutNodemask(t, nodemask, maxnode, nodemaskVal); err != nil {
+ return 0, nil, err
+ }
+ }
+ return 0, nil, nil
+}
+
+// SetMempolicy implements the syscall set_mempolicy(2).
+func SetMempolicy(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ modeWithFlags := args[0].Int()
+ nodemask := args[1].Pointer()
+ maxnode := args[2].Uint()
+
+ modeWithFlags, nodemaskVal, err := copyInMempolicyNodemask(t, modeWithFlags, nodemask, maxnode)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ t.SetNumaPolicy(modeWithFlags, nodemaskVal)
+ return 0, nil, nil
+}
+
+// Mbind implements the syscall mbind(2).
+func Mbind(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+ length := args[1].Uint64()
+ mode := args[2].Int()
+ nodemask := args[3].Pointer()
+ maxnode := args[4].Uint()
+ flags := args[5].Uint()
+
+ if flags&^linux.MPOL_MF_VALID != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+ // "If MPOL_MF_MOVE_ALL is passed in flags ... [the] calling thread must be
+ // privileged (CAP_SYS_NICE) to use this flag." - mbind(2)
+ if flags&linux.MPOL_MF_MOVE_ALL != 0 && !t.HasCapability(linux.CAP_SYS_NICE) {
+ return 0, nil, syserror.EPERM
+ }
+
+ mode, nodemaskVal, err := copyInMempolicyNodemask(t, mode, nodemask, maxnode)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ // Since we claim to have only a single node, all flags can be ignored
+ // (since all pages must already be on that single node).
+ err = t.MemoryManager().SetNumaPolicy(addr, length, mode, nodemaskVal)
+ return 0, nil, err
+}
+
+func copyInMempolicyNodemask(t *kernel.Task, modeWithFlags int32, nodemask usermem.Addr, maxnode uint32) (int32, uint64, error) {
+ flags := modeWithFlags & linux.MPOL_MODE_FLAGS
+ mode := modeWithFlags &^ linux.MPOL_MODE_FLAGS
+ if flags == linux.MPOL_MODE_FLAGS {
+ // Can't specify both mode flags simultaneously.
+ return 0, 0, syserror.EINVAL
+ }
+ if mode < 0 || mode >= linux.MPOL_MAX {
+ // Must specify a valid mode.
+ return 0, 0, syserror.EINVAL
+ }
+
+ var nodemaskVal uint64
+ if nodemask != 0 {
+ var err error
+ nodemaskVal, err = copyInNodemask(t, nodemask, maxnode)
+ if err != nil {
+ return 0, 0, err
+ }
+ }
+
+ switch mode {
+ case linux.MPOL_DEFAULT:
+ // "nodemask must be specified as NULL." - set_mempolicy(2). This is inaccurate;
+ // Linux allows a nodemask to be specified, as long as it is empty.
+ if nodemaskVal != 0 {
+ return 0, 0, syserror.EINVAL
+ }
+ case linux.MPOL_BIND, linux.MPOL_INTERLEAVE:
+ // These require a non-empty nodemask.
+ if nodemaskVal == 0 {
+ return 0, 0, syserror.EINVAL
+ }
+ case linux.MPOL_PREFERRED:
+ // This permits an empty nodemask, as long as no flags are set.
+ if nodemaskVal == 0 && flags != 0 {
+ return 0, 0, syserror.EINVAL
+ }
+ case linux.MPOL_LOCAL:
+ // This requires an empty nodemask and no flags set ...
+ if nodemaskVal != 0 || flags != 0 {
+ return 0, 0, syserror.EINVAL
+ }
+ // ... and is implemented as MPOL_PREFERRED.
+ mode = linux.MPOL_PREFERRED
+ default:
+ // Unknown mode, which we should have rejected above.
+ panic(fmt.Sprintf("unknown mode: %v", mode))
+ }
+
+ return mode | flags, nodemaskVal, nil
+}
diff --git a/pkg/sentry/syscalls/linux/sys_mmap.go b/pkg/sentry/syscalls/linux/sys_mmap.go
index 64a6e639c..9926f0ac5 100644
--- a/pkg/sentry/syscalls/linux/sys_mmap.go
+++ b/pkg/sentry/syscalls/linux/sys_mmap.go
@@ -204,151 +204,6 @@ func Madvise(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca
}
}
-func copyOutIfNotNull(t *kernel.Task, ptr usermem.Addr, val interface{}) (int, error) {
- if ptr != 0 {
- return t.CopyOut(ptr, val)
- }
- return 0, nil
-}
-
-// GetMempolicy implements the syscall get_mempolicy(2).
-func GetMempolicy(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
- mode := args[0].Pointer()
- nodemask := args[1].Pointer()
- maxnode := args[2].Uint()
- addr := args[3].Pointer()
- flags := args[4].Uint()
-
- memsAllowed := flags&linux.MPOL_F_MEMS_ALLOWED != 0
- nodeFlag := flags&linux.MPOL_F_NODE != 0
- addrFlag := flags&linux.MPOL_F_ADDR != 0
-
- // TODO(rahat): Once sysfs is implemented, report a single numa node in
- // /sys/devices/system/node.
- if nodemask != 0 && maxnode < 1 {
- return 0, nil, syserror.EINVAL
- }
-
- // 'addr' provided iff 'addrFlag' set.
- if addrFlag == (addr == 0) {
- return 0, nil, syserror.EINVAL
- }
-
- // Default policy for the thread.
- if flags == 0 {
- policy, nodemaskVal := t.NumaPolicy()
- if _, err := copyOutIfNotNull(t, mode, policy); err != nil {
- return 0, nil, syserror.EFAULT
- }
- if _, err := copyOutIfNotNull(t, nodemask, nodemaskVal); err != nil {
- return 0, nil, syserror.EFAULT
- }
- return 0, nil, nil
- }
-
- // Report all nodes available to caller.
- if memsAllowed {
- // MPOL_F_NODE and MPOL_F_ADDR not allowed with MPOL_F_MEMS_ALLOWED.
- if nodeFlag || addrFlag {
- return 0, nil, syserror.EINVAL
- }
-
- // Report a single numa node.
- if _, err := copyOutIfNotNull(t, nodemask, uint32(0x1)); err != nil {
- return 0, nil, syserror.EFAULT
- }
- return 0, nil, nil
- }
-
- if addrFlag {
- if nodeFlag {
- // Return the id for the node where 'addr' resides, via 'mode'.
- //
- // The real get_mempolicy(2) allocates the page referenced by 'addr'
- // by simulating a read, if it is unallocated before the call. It
- // then returns the node the page is allocated on through the mode
- // pointer.
- b := t.CopyScratchBuffer(1)
- _, err := t.CopyInBytes(addr, b)
- if err != nil {
- return 0, nil, syserror.EFAULT
- }
- if _, err := copyOutIfNotNull(t, mode, int32(0)); err != nil {
- return 0, nil, syserror.EFAULT
- }
- } else {
- storedPolicy, _ := t.NumaPolicy()
- // Return the policy governing the memory referenced by 'addr'.
- if _, err := copyOutIfNotNull(t, mode, int32(storedPolicy)); err != nil {
- return 0, nil, syserror.EFAULT
- }
- }
- return 0, nil, nil
- }
-
- storedPolicy, _ := t.NumaPolicy()
- if nodeFlag && (storedPolicy&^linux.MPOL_MODE_FLAGS == linux.MPOL_INTERLEAVE) {
- // Policy for current thread is to interleave memory between
- // nodes. Return the next node we'll allocate on. Since we only have a
- // single node, this is always node 0.
- if _, err := copyOutIfNotNull(t, mode, int32(0)); err != nil {
- return 0, nil, syserror.EFAULT
- }
- return 0, nil, nil
- }
-
- return 0, nil, syserror.EINVAL
-}
-
-func allowedNodesMask() uint32 {
- const maxNodes = 1
- return ^uint32((1 << maxNodes) - 1)
-}
-
-// SetMempolicy implements the syscall set_mempolicy(2).
-func SetMempolicy(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
- modeWithFlags := args[0].Int()
- nodemask := args[1].Pointer()
- maxnode := args[2].Uint()
-
- if nodemask != 0 && maxnode < 1 {
- return 0, nil, syserror.EINVAL
- }
-
- if modeWithFlags&linux.MPOL_MODE_FLAGS == linux.MPOL_MODE_FLAGS {
- // Can't specify multiple modes simultaneously.
- return 0, nil, syserror.EINVAL
- }
-
- mode := modeWithFlags &^ linux.MPOL_MODE_FLAGS
- if mode < 0 || mode >= linux.MPOL_MAX {
- // Must specify a valid mode.
- return 0, nil, syserror.EINVAL
- }
-
- var nodemaskVal uint32
- // Nodemask may be empty for some policy modes.
- if nodemask != 0 && maxnode > 0 {
- if _, err := t.CopyIn(nodemask, &nodemaskVal); err != nil {
- return 0, nil, syserror.EFAULT
- }
- }
-
- if (mode == linux.MPOL_INTERLEAVE || mode == linux.MPOL_BIND) && nodemaskVal == 0 {
- // Mode requires a non-empty nodemask, but got an empty nodemask.
- return 0, nil, syserror.EINVAL
- }
-
- if nodemaskVal&allowedNodesMask() != 0 {
- // Invalid node specified.
- return 0, nil, syserror.EINVAL
- }
-
- t.SetNumaPolicy(int32(modeWithFlags), nodemaskVal)
-
- return 0, nil, nil
-}
-
// Mincore implements the syscall mincore(2).
func Mincore(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
addr := args[0].Pointer()