internal/xcoff: use unsigned integers in file structs to avoid negative values

Fixes #58137
Updates #54584

Change-Id: Ifeee1be22051b842e0707d1907dbfa58bfeb336b
GitHub-Last-Rev: 9768e7c4a4954824fa1a2c41c0ad72e496408f91
GitHub-Pull-Request: golang/go#58164
Reviewed-on: https://go-review.googlesource.com/c/go/+/464336
Reviewed-by: Ayappan Perumal <ayappanec@gmail.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>

2 files changed, 32 insertions, 38 deletions

diff --git a/src/internal/xcoff/file.go b/src/internal/xcoff/file.go
index e859de932a..536bd74c30 100644
--- a/src/internal/xcoff/file.go
+++ b/src/internal/xcoff/file.go
@@ -173,7 +173,7 @@ func NewFile(r io.ReaderAt) (*File, error) {
 	}
 	var nscns uint16
 	var symptr uint64
-	var nsyms int32
+	var nsyms uint32
 	var opthdr uint16
 	var hdrsz int
 	switch f.TargetMachine {
@@ -283,9 +283,6 @@ func NewFile(r io.ReaderAt) (*File, error) {
 				return nil, err
 			}
 			numaux = int(se.Nnumaux)
-			if numaux < 0 {
-				return nil, fmt.Errorf("malformed symbol table, invalid number of aux symbols")
-			}
 			sym.SectionNumber = int(se.Nscnum)
 			sym.StorageClass = int(se.Nsclass)
 			sym.Value = uint64(se.Nvalue)
@@ -306,9 +303,6 @@ func NewFile(r io.ReaderAt) (*File, error) {
 				return nil, err
 			}
 			numaux = int(se.Nnumaux)
-			if numaux < 0 {
-				return nil, fmt.Errorf("malformed symbol table, invalid number of aux symbols")
-			}
 			sym.SectionNumber = int(se.Nscnum)
 			sym.StorageClass = int(se.Nsclass)
 			sym.Value = se.Nvalue
@@ -517,7 +511,7 @@ func (f *File) readImportIDs(s *Section) ([]string, error) {
 		return nil, err
 	}
 	var istlen uint32
-	var nimpid int32
+	var nimpid uint32
 	var impoff uint64
 	switch f.TargetMachine {
 	case U802TOCMAGIC:
@@ -587,7 +581,7 @@ func (f *File) ImportedSymbols() ([]ImportedSymbol, error) {
 	}
 	var stlen uint32
 	var stoff uint64
-	var nsyms int32
+	var nsyms uint32
 	var symoff uint64
 	switch f.TargetMachine {
 	case U802TOCMAGIC:
@@ -632,7 +626,7 @@ func (f *File) ImportedSymbols() ([]ImportedSymbol, error) {
 	all := make([]ImportedSymbol, 0)
 	for i := 0; i < int(nsyms); i++ {
 		var name string
-		var ifile int32
+		var ifile uint32
 		var ok bool
 		switch f.TargetMachine {
 		case U802TOCMAGIC:
diff --git a/src/internal/xcoff/xcoff.go b/src/internal/xcoff/xcoff.go
index f8465d7289..db81542ed3 100644
--- a/src/internal/xcoff/xcoff.go
+++ b/src/internal/xcoff/xcoff.go
@@ -8,9 +8,9 @@ package xcoff
 type FileHeader32 struct {
 	Fmagic   uint16 // Target machine
 	Fnscns   uint16 // Number of sections
-	Ftimedat int32  // Time and date of file creation
+	Ftimedat uint32 // Time and date of file creation
 	Fsymptr  uint32 // Byte offset to symbol table start
-	Fnsyms   int32  // Number of entries in symbol table
+	Fnsyms   uint32 // Number of entries in symbol table
 	Fopthdr  uint16 // Number of bytes in optional header
 	Fflags   uint16 // Flags
 }
@@ -18,11 +18,11 @@ type FileHeader32 struct {
 type FileHeader64 struct {
 	Fmagic   uint16 // Target machine
 	Fnscns   uint16 // Number of sections
-	Ftimedat int32  // Time and date of file creation
+	Ftimedat uint32 // Time and date of file creation
 	Fsymptr  uint64 // Byte offset to symbol table start
 	Fopthdr  uint16 // Number of bytes in optional header
 	Fflags   uint16 // Flags
-	Fnsyms   int32  // Number of entries in symbol table
+	Fnsyms   uint32 // Number of entries in symbol table
 }
 
 const (
@@ -109,19 +109,19 @@ const (
 type SymEnt32 struct {
 	Nname   [8]byte // Symbol name
 	Nvalue  uint32  // Symbol value
-	Nscnum  int16   // Section number of symbol
+	Nscnum  uint16  // Section number of symbol
 	Ntype   uint16  // Basic and derived type specification
-	Nsclass int8    // Storage class of symbol
-	Nnumaux int8    // Number of auxiliary entries
+	Nsclass uint8   // Storage class of symbol
+	Nnumaux uint8   // Number of auxiliary entries
 }
 
 type SymEnt64 struct {
 	Nvalue  uint64 // Symbol value
 	Noffset uint32 // Offset of the name in string table or .debug section
-	Nscnum  int16  // Section number of symbol
+	Nscnum  uint16 // Section number of symbol
 	Ntype   uint16 // Basic and derived type specification
-	Nsclass int8   // Storage class of symbol
-	Nnumaux int8   // Number of auxiliary entries
+	Nsclass uint8  // Storage class of symbol
+	Nnumaux uint8  // Number of auxiliary entries
 }
 
 const SYMESZ = 18
@@ -203,7 +203,7 @@ type AuxSect64 struct {
 
 // csect Auxiliary Entry.
 type AuxCSect32 struct {
-	Xscnlen   int32  // Length or symbol table index
+	Xscnlen   uint32 // Length or symbol table index
 	Xparmhash uint32 // Offset of parameter type-check string
 	Xsnhash   uint16 // .typchk section number
 	Xsmtyp    uint8  // Symbol alignment and type
@@ -218,7 +218,7 @@ type AuxCSect64 struct {
 	Xsnhash   uint16 // .typchk section number
 	Xsmtyp    uint8  // Symbol alignment and type
 	Xsmclas   uint8  // Storage-mapping class
-	Xscnlenhi int32  // Upper 4 bytes of length or symbol table index
+	Xscnlenhi uint32 // Upper 4 bytes of length or symbol table index
 	Xpad      uint8  // Unused
 	Xauxtype  uint8  // Type of auxiliary entry
 }
@@ -274,22 +274,22 @@ const (
 
 // Loader Header.
 type LoaderHeader32 struct {
-	Lversion int32  // Loader section version number
-	Lnsyms   int32  // Number of symbol table entries
-	Lnreloc  int32  // Number of relocation table entries
+	Lversion uint32 // Loader section version number
+	Lnsyms   uint32 // Number of symbol table entries
+	Lnreloc  uint32 // Number of relocation table entries
 	Listlen  uint32 // Length of import file ID string table
-	Lnimpid  int32  // Number of import file IDs
+	Lnimpid  uint32 // Number of import file IDs
 	Limpoff  uint32 // Offset to start of import file IDs
 	Lstlen   uint32 // Length of string table
 	Lstoff   uint32 // Offset to start of string table
 }
 
 type LoaderHeader64 struct {
-	Lversion int32  // Loader section version number
-	Lnsyms   int32  // Number of symbol table entries
-	Lnreloc  int32  // Number of relocation table entries
+	Lversion uint32 // Loader section version number
+	Lnsyms   uint32 // Number of symbol table entries
+	Lnreloc  uint32 // Number of relocation table entries
 	Listlen  uint32 // Length of import file ID string table
-	Lnimpid  int32  // Number of import file IDs
+	Lnimpid  uint32 // Number of import file IDs
 	Lstlen   uint32 // Length of string table
 	Limpoff  uint64 // Offset to start of import file IDs
 	Lstoff   uint64 // Offset to start of string table
@@ -306,20 +306,20 @@ const (
 type LoaderSymbol32 struct {
 	Lname   [8]byte // Symbol name or byte offset into string table
 	Lvalue  uint32  // Address field
-	Lscnum  int16   // Section number containing symbol
-	Lsmtype int8    // Symbol type, export, import flags
-	Lsmclas int8    // Symbol storage class
-	Lifile  int32   // Import file ID; ordinal of import file IDs
+	Lscnum  uint16  // Section number containing symbol
+	Lsmtype uint8   // Symbol type, export, import flags
+	Lsmclas uint8   // Symbol storage class
+	Lifile  uint32  // Import file ID; ordinal of import file IDs
 	Lparm   uint32  // Parameter type-check field
 }
 
 type LoaderSymbol64 struct {
 	Lvalue  uint64 // Address field
 	Loffset uint32 // Byte offset into string table of symbol name
-	Lscnum  int16  // Section number containing symbol
-	Lsmtype int8   // Symbol type, export, import flags
-	Lsmclas int8   // Symbol storage class
-	Lifile  int32  // Import file ID; ordinal of import file IDs
+	Lscnum  uint16 // Section number containing symbol
+	Lsmtype uint8  // Symbol type, export, import flags
+	Lsmclas uint8  // Symbol storage class
+	Lifile  uint32 // Import file ID; ordinal of import file IDs
 	Lparm   uint32 // Parameter type-check field
 }