cmd/pprof: update vendored github.com/google/pprof

Pull in the latest published version of github.com/google/pprof
that is available at this time in the Go 1.18 development cycle.

Done with:

	go get -d github.com/google/pprof@latest
	go mod tidy
	go mod vendor

For #36905.

Change-Id: Ib25aa38365ec70a0bed2a8a6527e5823ab9f9ded
Reviewed-on: https://go-review.googlesource.com/c/go/+/348410
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>

8 files changed, 131 insertions, 99 deletions

diff --git a/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_llvm.go b/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_llvm.go
index 24c48e649b..844c7a475d 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_llvm.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_llvm.go
@@ -76,7 +76,7 @@ func newLLVMSymbolizer(cmd, file string, base uint64, isData bool) (*llvmSymboli
 	}
 
 	j := &llvmSymbolizerJob{
-		cmd:     exec.Command(cmd, "-inlining", "-demangle=false"),
+		cmd:     exec.Command(cmd, "--inlining", "-demangle=false"),
 		symType: "CODE",
 	}
 	if isData {
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go b/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go
index 5ed8a1f9f1..e920eeb2fa 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go
@@ -525,6 +525,47 @@ type elfMapping struct {
 	stextOffset *uint64
 }
 
+// findProgramHeader returns the program segment that matches the current
+// mapping and the given address, or an error if it cannot find a unique program
+// header.
+func (m *elfMapping) findProgramHeader(ef *elf.File, addr uint64) (*elf.ProgHeader, error) {
+	// For user space executables, we try to find the actual program segment that
+	// is associated with the given mapping. Skip this search if limit <= start.
+	// We cannot use just a check on the start address of the mapping to tell if
+	// it's a kernel / .ko module mapping, because with quipper address remapping
+	// enabled, the address would be in the lower half of the address space.
+
+	if m.stextOffset != nil || m.start >= m.limit || m.limit >= (uint64(1)<<63) {
+		// For the kernel, find the program segment that includes the .text section.
+		return elfexec.FindTextProgHeader(ef), nil
+	}
+
+	// Fetch all the loadable segments.
+	var phdrs []elf.ProgHeader
+	for i := range ef.Progs {
+		if ef.Progs[i].Type == elf.PT_LOAD {
+			phdrs = append(phdrs, ef.Progs[i].ProgHeader)
+		}
+	}
+	// Some ELF files don't contain any loadable program segments, e.g. .ko
+	// kernel modules. It's not an error to have no header in such cases.
+	if len(phdrs) == 0 {
+		return nil, nil
+	}
+	// Get all program headers associated with the mapping.
+	headers := elfexec.ProgramHeadersForMapping(phdrs, m.offset, m.limit-m.start)
+	if len(headers) == 0 {
+		return nil, errors.New("no program header matches mapping info")
+	}
+	if len(headers) == 1 {
+		return headers[0], nil
+	}
+
+	// Use the file offset corresponding to the address to symbolize, to narrow
+	// down the header.
+	return elfexec.HeaderForFileOffset(headers, addr-m.start+m.offset)
+}
+
 // file implements the binutils.ObjFile interface.
 type file struct {
 	b       *binrep
@@ -555,27 +596,9 @@ func (f *file) computeBase(addr uint64) error {
 	}
 	defer ef.Close()
 
-	var ph *elf.ProgHeader
-	// For user space executables, find the actual program segment that is
-	// associated with the given mapping. Skip this search if limit <= start.
-	// We cannot use just a check on the start address of the mapping to tell if
-	// it's a kernel / .ko module mapping, because with quipper address remapping
-	// enabled, the address would be in the lower half of the address space.
-	if f.m.stextOffset == nil && f.m.start < f.m.limit && f.m.limit < (uint64(1)<<63) {
-		// Get all program headers associated with the mapping.
-		headers, hasLoadables := elfexec.ProgramHeadersForMapping(ef, f.m.offset, f.m.limit-f.m.start)
-
-		// Some ELF files don't contain any loadable program segments, e.g. .ko
-		// kernel modules. It's not an error to have no header in such cases.
-		if hasLoadables {
-			ph, err = matchUniqueHeader(headers, addr-f.m.start+f.m.offset)
-			if err != nil {
-				return fmt.Errorf("failed to find program header for file %q, ELF mapping %#v, address %x: %v", f.name, *f.m, addr, err)
-			}
-		}
-	} else {
-		// For the kernel, find the program segment that includes the .text section.
-		ph = elfexec.FindTextProgHeader(ef)
+	ph, err := f.m.findProgramHeader(ef, addr)
+	if err != nil {
+		return fmt.Errorf("failed to find program header for file %q, ELF mapping %#v, address %x: %v", f.name, *f.m, addr, err)
 	}
 
 	base, err := elfexec.GetBase(&ef.FileHeader, ph, f.m.stextOffset, f.m.start, f.m.limit, f.m.offset)
@@ -587,38 +610,6 @@ func (f *file) computeBase(addr uint64) error {
 	return nil
 }
 
-// matchUniqueHeader attempts to identify a unique header from the given list,
-// using the given file offset to disambiguate between multiple segments. It
-// returns an error if the header list is empty or if it cannot identify a
-// unique header.
-func matchUniqueHeader(headers []*elf.ProgHeader, fileOffset uint64) (*elf.ProgHeader, error) {
-	if len(headers) == 0 {
-		return nil, errors.New("no program header matches mapping info")
-	}
-	if len(headers) == 1 {
-		// Don't use the file offset if we already have a single header.
-		return headers[0], nil
-	}
-	// We have multiple input segments. Attempt to identify a unique one
-	// based on the given file offset.
-	var ph *elf.ProgHeader
-	for _, h := range headers {
-		if fileOffset >= h.Off && fileOffset < h.Off+h.Memsz {
-			if ph != nil {
-				// Assuming no other bugs, this can only happen if we have two or
-				// more small program segments that fit on the same page, and a
-				// segment other than the last one includes uninitialized data.
-				return nil, fmt.Errorf("found second program header (%#v) that matches file offset %x, first program header is %#v. Does first program segment contain uninitialized data?", *h, fileOffset, *ph)
-			}
-			ph = h
-		}
-	}
-	if ph == nil {
-		return nil, fmt.Errorf("no program header matches file offset %x", fileOffset)
-	}
-	return ph, nil
-}
-
 func (f *file) Name() string {
 	return f.name
 }
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go
index b8e8b50b94..b9c73271b8 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go
@@ -132,6 +132,10 @@ a {
   align-items: center;
   justify-content: center;
 }
+.menu-name a {
+  text-decoration: none;
+  color: #212121;
+}
 .submenu {
   display: none;
   z-index: 1;
@@ -370,6 +374,12 @@ table tr td {
     </div>
   </div>
 
+  <div id="download" class="menu-item">
+    <div class="menu-name">
+      <a href="./download">Download</a>
+    </div>
+  </div>
+
   <div>
     <input id="search" type="text" placeholder="Search regexp" autocomplete="off" autocapitalize="none" size=40>
   </div>
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go
index 52dc68809c..0f3e8bf93c 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go
@@ -127,6 +127,11 @@ func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, d
 			"/flamegraph":   http.HandlerFunc(ui.flamegraph),
 			"/saveconfig":   http.HandlerFunc(ui.saveConfig),
 			"/deleteconfig": http.HandlerFunc(ui.deleteConfig),
+			"/download": http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+				w.Header().Set("Content-Type", "application/vnd.google.protobuf+gzip")
+				w.Header().Set("Content-Disposition", "attachment;filename=profile.pb.gz")
+				p.Write(w)
+			}),
 		},
 	}
 
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go b/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go
index 2638b2db2d..4f11645185 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go
@@ -284,10 +284,16 @@ func FindTextProgHeader(f *elf.File) *elf.ProgHeader {
 	return nil
 }
 
-// ProgramHeadersForMapping returns the loadable program segment headers that
-// are fully contained in the runtime mapping with file offset pgoff and memory
-// size memsz, and if the binary includes any loadable segments.
-func ProgramHeadersForMapping(f *elf.File, pgoff, memsz uint64) ([]*elf.ProgHeader, bool) {
+// ProgramHeadersForMapping returns the program segment headers that overlap
+// the runtime mapping with file offset mapOff and memory size mapSz. We skip
+// over segments zero file size because their file offset values are unreliable.
+// Even if overlapping, a segment is not selected if its aligned file offset is
+// greater than the mapping file offset, or if the mapping includes the last
+// page of the segment, but not the full segment and the mapping includes
+// additional pages after the segment end.
+// The function returns a slice of pointers to the headers in the input
+// slice, which are valid only while phdrs is not modified or discarded.
+func ProgramHeadersForMapping(phdrs []elf.ProgHeader, mapOff, mapSz uint64) []*elf.ProgHeader {
 	const (
 		// pageSize defines the virtual memory page size used by the loader. This
 		// value is dependent on the memory management unit of the CPU. The page
@@ -298,57 +304,61 @@ func ProgramHeadersForMapping(f *elf.File, pgoff, memsz uint64) ([]*elf.ProgHead
 		// specified in the ELF file header.
 		pageSize       = 4096
 		pageOffsetMask = pageSize - 1
-		pageMask       = ^uint64(pageOffsetMask)
 	)
+	mapLimit := mapOff + mapSz
 	var headers []*elf.ProgHeader
-	hasLoadables := false
-	for _, p := range f.Progs {
-		// The segment must be fully included in the mapping.
-		if p.Type == elf.PT_LOAD && pgoff <= p.Off && p.Off+p.Memsz <= pgoff+memsz {
-			alignedOffset := uint64(0)
+	for i := range phdrs {
+		p := &phdrs[i]
+		// Skip over segments with zero file size. Their file offsets can have
+		// arbitrary values, see b/195427553.
+		if p.Filesz == 0 {
+			continue
+		}
+		segLimit := p.Off + p.Memsz
+		// The segment must overlap the mapping.
+		if p.Type == elf.PT_LOAD && mapOff < segLimit && p.Off < mapLimit {
+			// If the mapping offset is strictly less than the page aligned segment
+			// offset, then this mapping comes from a different segment, fixes
+			// b/179920361.
+			alignedSegOffset := uint64(0)
 			if p.Off > (p.Vaddr & pageOffsetMask) {
-				alignedOffset = p.Off - (p.Vaddr & pageOffsetMask)
+				alignedSegOffset = p.Off - (p.Vaddr & pageOffsetMask)
 			}
-			if alignedOffset <= pgoff {
-				headers = append(headers, &p.ProgHeader)
+			if mapOff < alignedSegOffset {
+				continue
 			}
+			// If the mapping starts in the middle of the segment, it covers less than
+			// one page of the segment, and it extends at least one page past the
+			// segment, then this mapping comes from a different segment.
+			if mapOff > p.Off && (segLimit < mapOff+pageSize) && (mapLimit >= segLimit+pageSize) {
+				continue
+			}
+			headers = append(headers, p)
 		}
-		if p.Type == elf.PT_LOAD {
-			hasLoadables = true
-		}
-	}
-	if len(headers) < 2 {
-		return headers, hasLoadables
-	}
-
-	// If we have more than one matching segments, try a strict check on the
-	// segment memory size. We use a heuristic to compute the minimum mapping size
-	// required for a segment, assuming mappings are page aligned.
-	// The memory size based heuristic makes sense only if the mapping size is a
-	// multiple of page size.
-	if memsz%pageSize != 0 {
-		return headers, hasLoadables
 	}
+	return headers
+}
 
-	// Return all found headers if we cannot narrow the selection to a single
-	// program segment.
+// HeaderForFileOffset attempts to identify a unique program header that
+// includes the given file offset. It returns an error if it cannot identify a
+// unique header.
+func HeaderForFileOffset(headers []*elf.ProgHeader, fileOffset uint64) (*elf.ProgHeader, error) {
 	var ph *elf.ProgHeader
 	for _, h := range headers {
-		wantSize := (h.Vaddr+h.Memsz+pageSize-1)&pageMask - (h.Vaddr & pageMask)
-		if wantSize != memsz {
-			continue
-		}
-		if ph != nil {
-			// Found a second program header matching, so return all previously
-			// identified headers.
-			return headers, hasLoadables
+		if fileOffset >= h.Off && fileOffset < h.Off+h.Memsz {
+			if ph != nil {
+				// Assuming no other bugs, this can only happen if we have two or
+				// more small program segments that fit on the same page, and a
+				// segment other than the last one includes uninitialized data, or
+				// if the debug binary used for symbolization is stripped of some
+				// sections, so segment file sizes are smaller than memory sizes.
+				return nil, fmt.Errorf("found second program header (%#v) that matches file offset %x, first program header is %#v. Is this a stripped binary, or does the first program segment contain uninitialized data?", *h, fileOffset, *ph)
+			}
+			ph = h
 		}
-		ph = h
 	}
 	if ph == nil {
-		// No matching header for the strict check. Return all previously identified
-		// headers.
-		return headers, hasLoadables
+		return nil, fmt.Errorf("no program header matches file offset %x", fileOffset)
 	}
-	return []*elf.ProgHeader{ph}, hasLoadables
+	return ph, nil
 }
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/report.go b/src/cmd/vendor/github.com/google/pprof/internal/report/report.go
index 4a86554880..e2fb00314c 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/report/report.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/report.go
@@ -432,6 +432,10 @@ func PrintAssembly(w io.Writer, rpt *Report, obj plugin.ObjTool, maxFuncs int) e
 		}
 	}
 
+	if len(syms) == 0 {
+		return fmt.Errorf("no matches found for regexp: %s", o.Symbol)
+	}
+
 	// Correlate the symbols from the binary with the profile samples.
 	for _, s := range syms {
 		sns := symNodes[s]
@@ -1054,6 +1058,7 @@ func printTree(w io.Writer, rpt *Report) error {
 	var flatSum int64
 
 	rx := rpt.options.Symbol
+	matched := 0
 	for _, n := range g.Nodes {
 		name, flat, cum := n.Info.PrintableName(), n.FlatValue(), n.CumValue()
 
@@ -1061,6 +1066,7 @@ func printTree(w io.Writer, rpt *Report) error {
 		if rx != nil && !rx.MatchString(name) {
 			continue
 		}
+		matched++
 
 		fmt.Fprintln(w, separator)
 		// Print incoming edges.
@@ -1098,6 +1104,9 @@ func printTree(w io.Writer, rpt *Report) error {
 	if len(g.Nodes) > 0 {
 		fmt.Fprintln(w, separator)
 	}
+	if rx != nil && matched == 0 {
+		return fmt.Errorf("no matches found for regexp: %s", rx)
+	}
 	return nil
 }
 
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/source.go b/src/cmd/vendor/github.com/google/pprof/internal/report/source.go
index 54245e5f9e..33d04c591d 100644
--- a/src/cmd/vendor/github.com/google/pprof/internal/report/source.go
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/source.go
@@ -58,6 +58,10 @@ func printSource(w io.Writer, rpt *Report) error {
 	}
 	functions.Sort(graph.NameOrder)
 
+	if len(functionNodes) == 0 {
+		return fmt.Errorf("no matches found for regexp: %s", o.Symbol)
+	}
+
 	sourcePath := o.SourcePath
 	if sourcePath == "" {
 		wd, err := os.Getwd()
@@ -206,6 +210,9 @@ func PrintWebList(w io.Writer, rpt *Report, obj plugin.ObjTool, maxFiles int) er
 		sourcePath = wd
 	}
 	sp := newSourcePrinter(rpt, obj, sourcePath)
+	if len(sp.interest) == 0 {
+		return fmt.Errorf("no matches found for regexp: %s", rpt.options.Symbol)
+	}
 	sp.print(w, maxFiles, rpt)
 	sp.close()
 	return nil
@@ -299,7 +306,7 @@ func newSourcePrinter(rpt *Report, obj plugin.ObjTool, sourcePath string) *sourc
 				continue
 			}
 
-			// Seach in inlined stack for a match.
+			// Search in inlined stack for a match.
 			matchFile := (loc.Mapping != nil && sp.sym.MatchString(loc.Mapping.File))
 			for j, line := range loc.Line {
 				if (j == 0 && matchFile) || matches(line) {
diff --git a/src/cmd/vendor/modules.txt b/src/cmd/vendor/modules.txt
index 8a6497b5f2..966ba1358e 100644
--- a/src/cmd/vendor/modules.txt
+++ b/src/cmd/vendor/modules.txt
@@ -1,4 +1,4 @@
-# github.com/google/pprof v0.0.0-20210506205249-923b5ab0fc1a
+# github.com/google/pprof v0.0.0-20210827144239-02619b876842
 ## explicit; go 1.14
 github.com/google/pprof/driver
 github.com/google/pprof/internal/binutils