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- // Copyright 2019 The Prometheus 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.
-
- //go:build (aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris) && !js
- // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
- // +build !js
-
- package procfs
-
- import (
- "bufio"
- "fmt"
- "os"
- "strconv"
- "strings"
-
- "golang.org/x/sys/unix"
- )
-
- // ProcMapPermissions contains permission settings read from `/proc/[pid]/maps`.
- type ProcMapPermissions struct {
- // mapping has the [R]ead flag set
- Read bool
- // mapping has the [W]rite flag set
- Write bool
- // mapping has the [X]ecutable flag set
- Execute bool
- // mapping has the [S]hared flag set
- Shared bool
- // mapping is marked as [P]rivate (copy on write)
- Private bool
- }
-
- // ProcMap contains the process memory-mappings of the process
- // read from `/proc/[pid]/maps`.
- type ProcMap struct {
- // The start address of current mapping.
- StartAddr uintptr
- // The end address of the current mapping
- EndAddr uintptr
- // The permissions for this mapping
- Perms *ProcMapPermissions
- // The current offset into the file/fd (e.g., shared libs)
- Offset int64
- // Device owner of this mapping (major:minor) in Mkdev format.
- Dev uint64
- // The inode of the device above
- Inode uint64
- // The file or psuedofile (or empty==anonymous)
- Pathname string
- }
-
- // parseDevice parses the device token of a line and converts it to a dev_t
- // (mkdev) like structure.
- func parseDevice(s string) (uint64, error) {
- toks := strings.Split(s, ":")
- if len(toks) < 2 {
- return 0, fmt.Errorf("unexpected number of fields")
- }
-
- major, err := strconv.ParseUint(toks[0], 16, 0)
- if err != nil {
- return 0, err
- }
-
- minor, err := strconv.ParseUint(toks[1], 16, 0)
- if err != nil {
- return 0, err
- }
-
- return unix.Mkdev(uint32(major), uint32(minor)), nil
- }
-
- // parseAddress converts a hex-string to a uintptr.
- func parseAddress(s string) (uintptr, error) {
- a, err := strconv.ParseUint(s, 16, 0)
- if err != nil {
- return 0, err
- }
-
- return uintptr(a), nil
- }
-
- // parseAddresses parses the start-end address.
- func parseAddresses(s string) (uintptr, uintptr, error) {
- toks := strings.Split(s, "-")
- if len(toks) < 2 {
- return 0, 0, fmt.Errorf("invalid address")
- }
-
- saddr, err := parseAddress(toks[0])
- if err != nil {
- return 0, 0, err
- }
-
- eaddr, err := parseAddress(toks[1])
- if err != nil {
- return 0, 0, err
- }
-
- return saddr, eaddr, nil
- }
-
- // parsePermissions parses a token and returns any that are set.
- func parsePermissions(s string) (*ProcMapPermissions, error) {
- if len(s) < 4 {
- return nil, fmt.Errorf("invalid permissions token")
- }
-
- perms := ProcMapPermissions{}
- for _, ch := range s {
- switch ch {
- case 'r':
- perms.Read = true
- case 'w':
- perms.Write = true
- case 'x':
- perms.Execute = true
- case 'p':
- perms.Private = true
- case 's':
- perms.Shared = true
- }
- }
-
- return &perms, nil
- }
-
- // parseProcMap will attempt to parse a single line within a proc/[pid]/maps
- // buffer.
- func parseProcMap(text string) (*ProcMap, error) {
- fields := strings.Fields(text)
- if len(fields) < 5 {
- return nil, fmt.Errorf("truncated procmap entry")
- }
-
- saddr, eaddr, err := parseAddresses(fields[0])
- if err != nil {
- return nil, err
- }
-
- perms, err := parsePermissions(fields[1])
- if err != nil {
- return nil, err
- }
-
- offset, err := strconv.ParseInt(fields[2], 16, 0)
- if err != nil {
- return nil, err
- }
-
- device, err := parseDevice(fields[3])
- if err != nil {
- return nil, err
- }
-
- inode, err := strconv.ParseUint(fields[4], 10, 0)
- if err != nil {
- return nil, err
- }
-
- pathname := ""
-
- if len(fields) >= 5 {
- pathname = strings.Join(fields[5:], " ")
- }
-
- return &ProcMap{
- StartAddr: saddr,
- EndAddr: eaddr,
- Perms: perms,
- Offset: offset,
- Dev: device,
- Inode: inode,
- Pathname: pathname,
- }, nil
- }
-
- // ProcMaps reads from /proc/[pid]/maps to get the memory-mappings of the
- // process.
- func (p Proc) ProcMaps() ([]*ProcMap, error) {
- file, err := os.Open(p.path("maps"))
- if err != nil {
- return nil, err
- }
- defer file.Close()
-
- maps := []*ProcMap{}
- scan := bufio.NewScanner(file)
-
- for scan.Scan() {
- m, err := parseProcMap(scan.Text())
- if err != nil {
- return nil, err
- }
-
- maps = append(maps, m)
- }
-
- return maps, nil
- }
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