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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
commit | 43a123c1ae6613b3efeed291fa552ecd909d3acf (patch) | |
tree | fd92518b7024bc74031f78a1cf9e454b65e73665 /src/cmd/pprof/pprof.go | |
parent | Initial commit. (diff) | |
download | golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.tar.xz golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.zip |
Adding upstream version 1.20.14.upstream/1.20.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/cmd/pprof/pprof.go')
-rw-r--r-- | src/cmd/pprof/pprof.go | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/src/cmd/pprof/pprof.go b/src/cmd/pprof/pprof.go new file mode 100644 index 0000000..bc1a4cf --- /dev/null +++ b/src/cmd/pprof/pprof.go @@ -0,0 +1,378 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// pprof is a tool for visualization of profile.data. It is based on +// the upstream version at github.com/google/pprof, with minor +// modifications specific to the Go distribution. Please consider +// upstreaming any modifications to these packages. + +package main + +import ( + "crypto/tls" + "debug/dwarf" + "fmt" + "io" + "net/http" + "net/url" + "os" + "regexp" + "strconv" + "strings" + "sync" + "time" + + "cmd/internal/objfile" + + "github.com/google/pprof/driver" + "github.com/google/pprof/profile" +) + +func main() { + options := &driver.Options{ + Fetch: new(fetcher), + Obj: new(objTool), + UI: newUI(), + } + if err := driver.PProf(options); err != nil { + fmt.Fprintf(os.Stderr, "%v\n", err) + os.Exit(2) + } +} + +type fetcher struct { +} + +func (f *fetcher) Fetch(src string, duration, timeout time.Duration) (*profile.Profile, string, error) { + sourceURL, timeout := adjustURL(src, duration, timeout) + if sourceURL == "" { + // Could not recognize URL, let regular pprof attempt to fetch the profile (eg. from a file) + return nil, "", nil + } + fmt.Fprintln(os.Stderr, "Fetching profile over HTTP from", sourceURL) + if duration > 0 { + fmt.Fprintf(os.Stderr, "Please wait... (%v)\n", duration) + } + p, err := getProfile(sourceURL, timeout) + return p, sourceURL, err +} + +func getProfile(source string, timeout time.Duration) (*profile.Profile, error) { + url, err := url.Parse(source) + if err != nil { + return nil, err + } + + var tlsConfig *tls.Config + if url.Scheme == "https+insecure" { + tlsConfig = &tls.Config{ + InsecureSkipVerify: true, + } + url.Scheme = "https" + source = url.String() + } + + client := &http.Client{ + Transport: &http.Transport{ + ResponseHeaderTimeout: timeout + 5*time.Second, + Proxy: http.ProxyFromEnvironment, + TLSClientConfig: tlsConfig, + }, + } + resp, err := client.Get(source) + if err != nil { + return nil, err + } + if resp.StatusCode != http.StatusOK { + defer resp.Body.Close() + return nil, statusCodeError(resp) + } + return profile.Parse(resp.Body) +} + +func statusCodeError(resp *http.Response) error { + if resp.Header.Get("X-Go-Pprof") != "" && strings.Contains(resp.Header.Get("Content-Type"), "text/plain") { + // error is from pprof endpoint + if body, err := io.ReadAll(resp.Body); err == nil { + return fmt.Errorf("server response: %s - %s", resp.Status, body) + } + } + return fmt.Errorf("server response: %s", resp.Status) +} + +// cpuProfileHandler is the Go pprof CPU profile handler URL. +const cpuProfileHandler = "/debug/pprof/profile" + +// adjustURL applies the duration/timeout values and Go specific defaults. +func adjustURL(source string, duration, timeout time.Duration) (string, time.Duration) { + u, err := url.Parse(source) + if err != nil || (u.Host == "" && u.Scheme != "" && u.Scheme != "file") { + // Try adding http:// to catch sources of the form hostname:port/path. + // url.Parse treats "hostname" as the scheme. + u, err = url.Parse("http://" + source) + } + if err != nil || u.Host == "" { + return "", 0 + } + + if u.Path == "" || u.Path == "/" { + u.Path = cpuProfileHandler + } + + // Apply duration/timeout overrides to URL. + values := u.Query() + if duration > 0 { + values.Set("seconds", fmt.Sprint(int(duration.Seconds()))) + } else { + if urlSeconds := values.Get("seconds"); urlSeconds != "" { + if us, err := strconv.ParseInt(urlSeconds, 10, 32); err == nil { + duration = time.Duration(us) * time.Second + } + } + } + if timeout <= 0 { + if duration > 0 { + timeout = duration + duration/2 + } else { + timeout = 60 * time.Second + } + } + u.RawQuery = values.Encode() + return u.String(), timeout +} + +// objTool implements driver.ObjTool using Go libraries +// (instead of invoking GNU binutils). +type objTool struct { + mu sync.Mutex + disasmCache map[string]*objfile.Disasm +} + +func (*objTool) Open(name string, start, limit, offset uint64, relocationSymbol string) (driver.ObjFile, error) { + of, err := objfile.Open(name) + if err != nil { + return nil, err + } + f := &file{ + name: name, + file: of, + } + if start != 0 { + if load, err := of.LoadAddress(); err == nil { + f.offset = start - load + } + } + return f, nil +} + +func (*objTool) Demangle(names []string) (map[string]string, error) { + // No C++, nothing to demangle. + return make(map[string]string), nil +} + +func (t *objTool) Disasm(file string, start, end uint64, intelSyntax bool) ([]driver.Inst, error) { + if intelSyntax { + return nil, fmt.Errorf("printing assembly in Intel syntax is not supported") + } + d, err := t.cachedDisasm(file) + if err != nil { + return nil, err + } + var asm []driver.Inst + d.Decode(start, end, nil, false, func(pc, size uint64, file string, line int, text string) { + asm = append(asm, driver.Inst{Addr: pc, File: file, Line: line, Text: text}) + }) + return asm, nil +} + +func (t *objTool) cachedDisasm(file string) (*objfile.Disasm, error) { + t.mu.Lock() + defer t.mu.Unlock() + if t.disasmCache == nil { + t.disasmCache = make(map[string]*objfile.Disasm) + } + d := t.disasmCache[file] + if d != nil { + return d, nil + } + f, err := objfile.Open(file) + if err != nil { + return nil, err + } + d, err = f.Disasm() + f.Close() + if err != nil { + return nil, err + } + t.disasmCache[file] = d + return d, nil +} + +func (*objTool) SetConfig(config string) { + // config is usually used to say what binaries to invoke. + // Ignore entirely. +} + +// file implements driver.ObjFile using Go libraries +// (instead of invoking GNU binutils). +// A file represents a single executable being analyzed. +type file struct { + name string + offset uint64 + sym []objfile.Sym + file *objfile.File + pcln objfile.Liner + + triedDwarf bool + dwarf *dwarf.Data +} + +func (f *file) Name() string { + return f.name +} + +func (f *file) ObjAddr(addr uint64) (uint64, error) { + return addr - f.offset, nil +} + +func (f *file) BuildID() string { + // No support for build ID. + return "" +} + +func (f *file) SourceLine(addr uint64) ([]driver.Frame, error) { + if f.pcln == nil { + pcln, err := f.file.PCLineTable() + if err != nil { + return nil, err + } + f.pcln = pcln + } + addr -= f.offset + file, line, fn := f.pcln.PCToLine(addr) + if fn != nil { + frame := []driver.Frame{ + { + Func: fn.Name, + File: file, + Line: line, + }, + } + return frame, nil + } + + frames := f.dwarfSourceLine(addr) + if frames != nil { + return frames, nil + } + + return nil, fmt.Errorf("no line information for PC=%#x", addr) +} + +// dwarfSourceLine tries to get file/line information using DWARF. +// This is for C functions that appear in the profile. +// Returns nil if there is no information available. +func (f *file) dwarfSourceLine(addr uint64) []driver.Frame { + if f.dwarf == nil && !f.triedDwarf { + // Ignore any error--we don't care exactly why there + // is no DWARF info. + f.dwarf, _ = f.file.DWARF() + f.triedDwarf = true + } + + if f.dwarf != nil { + r := f.dwarf.Reader() + unit, err := r.SeekPC(addr) + if err == nil { + if frames := f.dwarfSourceLineEntry(r, unit, addr); frames != nil { + return frames + } + } + } + + return nil +} + +// dwarfSourceLineEntry tries to get file/line information from a +// DWARF compilation unit. Returns nil if it doesn't find anything. +func (f *file) dwarfSourceLineEntry(r *dwarf.Reader, entry *dwarf.Entry, addr uint64) []driver.Frame { + lines, err := f.dwarf.LineReader(entry) + if err != nil { + return nil + } + var lentry dwarf.LineEntry + if err := lines.SeekPC(addr, &lentry); err != nil { + return nil + } + + // Try to find the function name. + name := "" +FindName: + for entry, err := r.Next(); entry != nil && err == nil; entry, err = r.Next() { + if entry.Tag == dwarf.TagSubprogram { + ranges, err := f.dwarf.Ranges(entry) + if err != nil { + return nil + } + for _, pcs := range ranges { + if pcs[0] <= addr && addr < pcs[1] { + var ok bool + // TODO: AT_linkage_name, AT_MIPS_linkage_name. + name, ok = entry.Val(dwarf.AttrName).(string) + if ok { + break FindName + } + } + } + } + } + + // TODO: Report inlined functions. + + frames := []driver.Frame{ + { + Func: name, + File: lentry.File.Name, + Line: lentry.Line, + }, + } + + return frames +} + +func (f *file) Symbols(r *regexp.Regexp, addr uint64) ([]*driver.Sym, error) { + if f.sym == nil { + sym, err := f.file.Symbols() + if err != nil { + return nil, err + } + f.sym = sym + } + var out []*driver.Sym + for _, s := range f.sym { + // Ignore a symbol with address 0 and size 0. + // An ELF STT_FILE symbol will look like that. + if s.Addr == 0 && s.Size == 0 { + continue + } + if (r == nil || r.MatchString(s.Name)) && (addr == 0 || s.Addr <= addr && addr < s.Addr+uint64(s.Size)) { + out = append(out, &driver.Sym{ + Name: []string{s.Name}, + File: f.name, + Start: s.Addr, + End: s.Addr + uint64(s.Size) - 1, + }) + } + } + return out, nil +} + +func (f *file) Close() error { + f.file.Close() + return nil +} + +// newUI will be set in readlineui.go in some platforms +// for interactive readline functionality. +var newUI = func() driver.UI { return nil } |