1 files changed, 57 insertions, 1 deletions

diff --git a/src/cmd/link/internal/ld/elf_test.go b/src/cmd/link/internal/ld/elf_test.go
index 16bf4039b1..b48cf66038 100644
--- a/src/cmd/link/internal/ld/elf_test.go
+++ b/src/cmd/link/internal/ld/elf_test.go
@@ -198,6 +198,7 @@ func TestElfBindNow(t *testing.T) {
 		name                 string
 		args                 []string
 		prog                 string
+		wantSecsRO           []string
 		mustHaveBuildModePIE bool
 		mustHaveCGO          bool
 		mustInternalLink     bool
@@ -213,6 +214,7 @@ func TestElfBindNow(t *testing.T) {
 			mustHaveBuildModePIE: true,
 			mustInternalLink:     true,
 			wantDf1Pie:           true,
+			wantSecsRO:           []string{".dynamic", ".got"},
 		},
 		{
 			name:             "bindnow-linkmode-internal",
@@ -232,6 +234,7 @@ func TestElfBindNow(t *testing.T) {
 			wantDfBindNow:        true,
 			wantDf1Now:           true,
 			wantDf1Pie:           true,
+			wantSecsRO:           []string{".dynamic", ".got", ".got.plt"},
 		},
 		{
 			name:                 "bindnow-pie-linkmode-external",
@@ -242,6 +245,8 @@ func TestElfBindNow(t *testing.T) {
 			wantDfBindNow:        true,
 			wantDf1Now:           true,
 			wantDf1Pie:           true,
+			// NB: external linker produces .plt.got, not .got.plt
+			wantSecsRO: []string{".dynamic", ".got"},
 		},
 	}
 
@@ -251,10 +256,14 @@ func TestElfBindNow(t *testing.T) {
 				return true
 			}
 		}
-
 		return false
 	}
 
+	segContainsSec := func(p *elf.Prog, s *elf.Section) bool {
+		return s.Addr >= p.Vaddr &&
+			s.Addr+s.FileSize <= p.Vaddr+p.Filesz
+	}
+
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			if test.mustInternalLink {
@@ -329,6 +338,53 @@ func TestElfBindNow(t *testing.T) {
 			if gotDf1Pie := gotDynFlag(flags1, uint64(elf.DF_1_PIE)); gotDf1Pie != test.wantDf1Pie {
 				t.Fatalf("DT_FLAGS_1 DF_1_PIE got: %v, want: %v", gotDf1Pie, test.wantDf1Pie)
 			}
+
+			for _, wsroname := range test.wantSecsRO {
+				// Locate section of interest.
+				var wsro *elf.Section
+				for _, s := range elfFile.Sections {
+					if s.Name == wsroname {
+						wsro = s
+						break
+					}
+				}
+				if wsro == nil {
+					t.Fatalf("test %s: can't locate %q section",
+						test.name, wsroname)
+				}
+
+				// Now walk the program headers. Section should be part of
+				// some segment that is readonly.
+				foundRO := false
+				foundSegs := []*elf.Prog{}
+				for _, p := range elfFile.Progs {
+					if segContainsSec(p, wsro) {
+						foundSegs = append(foundSegs, p)
+						if p.Flags == elf.PF_R {
+							foundRO = true
+						}
+					}
+				}
+				if !foundRO {
+					// Things went off the rails. Write out some
+					// useful information for a human looking at the
+					// test failure.
+					t.Logf("test %s: %q section not in readonly segment",
+						wsro.Name, test.name)
+					t.Logf("section %s location: st=0x%x en=0x%x\n",
+						wsro.Name, wsro.Addr, wsro.Addr+wsro.FileSize)
+					t.Logf("sec %s found in these segments: ", wsro.Name)
+					for _, p := range foundSegs {
+						t.Logf(" %q", p.Type)
+					}
+					t.Logf("\nall segments: \n")
+					for k, p := range elfFile.Progs {
+						t.Logf("%d t=%s fl=%s st=0x%x en=0x%x\n",
+							k, p.Type, p.Flags, p.Vaddr, p.Vaddr+p.Filesz)
+					}
+					t.Fatalf("test %s failed", test.name)
+				}
+			}
 		})
 	}
 }