Format getcwd path

PiperOrigin-RevId: 205440332
Change-Id: I2a838f363e079164c83da88e1b0b8769844fe79b

pkg/sentry/strace/linux64.go

@@ -96,7 +96,7 @@ var linuxAMD64 = SyscallMap{
 	76:  makeSyscallInfo("truncate", Path, Hex),
 	77:  makeSyscallInfo("ftruncate", Hex, Hex),
 	78:  makeSyscallInfo("getdents", Hex, Hex, Hex),
-	79:  makeSyscallInfo("getcwd", Hex, Hex),
+	79:  makeSyscallInfo("getcwd", PostPath, Hex),
 	80:  makeSyscallInfo("chdir", Path),
 	81:  makeSyscallInfo("fchdir", Hex),
 	82:  makeSyscallInfo("rename", Path, Path),

pkg/sentry/strace/strace.go

@@ -346,6 +346,8 @@ func (i *SyscallInfo) post(t *kernel.Task, args arch.SyscallArguments, rval uint
 			output[arg] = msghdr(t, args[arg].Pointer(), false /* content */, uint64(maximumBlobSize))
 		case RecvMsgHdr:
 			output[arg] = msghdr(t, args[arg].Pointer(), true /* content */, uint64(maximumBlobSize))
+		case PostPath:
+			output[arg] = path(t, args[arg].Pointer())
 		case PipeFDs:
 			output[arg] = fdpair(t, args[arg].Pointer())
 		case Uname:

pkg/sentry/strace/syscalls.go

@@ -75,6 +75,10 @@ const (
 	// Path is a pointer to a char* path.
 	Path
 
+	// PostPath is a pointer to a char* path, formatted after syscall
+	// execution.
+	PostPath
+
 	// ExecveStringVector is a NULL-terminated array of strings. Enforces
 	// the maximum execve array length.
 	ExecveStringVector