add x32 ABI support

lss/linux_syscall_support.h

 /* Copyright (c) 2005-2011, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 85 matching lines @@
  * multiple nested 'extern "C"' blocks, just add another one here.
  */
 extern "C" {
 #endif
 
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdarg.h>
 #include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 #include <sys/ptrace.h>
 #include <sys/resource.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 #include <linux/unistd.h>
 #include <endian.h>
 
@@ skipping 285 matching lines @@
   unsigned           st_atime_nsec_;
   unsigned           st_mtime_;
   unsigned           st_mtime_nsec_;
   unsigned           st_ctime_;
   unsigned           st_ctime_nsec_;
   unsigned           __unused4;
   unsigned           __unused5;
 };
 #elif defined(__x86_64__)
 struct kernel_stat {
-  unsigned long      st_dev;
-  unsigned long      st_ino;
-  unsigned long      st_nlink;
+  uint64_t           st_dev;
+  uint64_t           st_ino;
+  uint64_t           st_nlink;
   unsigned           st_mode;
   unsigned           st_uid;
   unsigned           st_gid;
   unsigned           __pad0;
-  unsigned long      st_rdev;
-  long               st_size;
-  long               st_blksize;
-  long               st_blocks;
-  unsigned long      st_atime_;
-  unsigned long      st_atime_nsec_;
-  unsigned long      st_mtime_;
-  unsigned long      st_mtime_nsec_;
-  unsigned long      st_ctime_;
-  unsigned long      st_ctime_nsec_;
-  long               __unused[3];
+  uint64_t           st_rdev;
+  int64_t            st_size;
+  int64_t            st_blksize;
+  int64_t            st_blocks;
+  uint64_t           st_atime_;
+  uint64_t           st_atime_nsec_;
+  uint64_t           st_mtime_;
+  uint64_t           st_mtime_nsec_;
+  uint64_t           st_ctime_;
+  uint64_t           st_ctime_nsec_;
+  int64_t            __unused[3];
 };
 #elif defined(__PPC__)
 struct kernel_stat {
   unsigned           st_dev;
   unsigned long      st_ino;      // ino_t
   unsigned long      st_mode;     // mode_t
   unsigned short     st_nlink;    // nlink_t
   unsigned           st_uid;      // uid_t
   unsigned           st_gid;      // gid_t
   unsigned           st_rdev;
@@ skipping 76 matching lines @@
   long               f_frsize;
   long               f_blocks;
   long               f_bfree;
   long               f_files;
   long               f_ffree;
   long               f_bavail;
   struct { int val[2]; } f_fsid;
   long               f_namelen;
   long               f_spare[6];
 };
-#else
+#elif defined(__x86_64__)
 struct kernel_statfs {
   /* x86_64 actually defines all these fields as signed, whereas all other  */
   /* platforms define them as unsigned. Leaving them at unsigned should not */
-  /* cause any problems.                                                    */
+  /* cause any problems. Make sure these are 64-bit even on x32.            */
+  uint64_t           f_type;
+  uint64_t           f_bsize;
+  uint64_t           f_blocks;
+  uint64_t           f_bfree;
+  uint64_t           f_bavail;
+  uint64_t           f_files;
+  uint64_t           f_ffree;
+  struct { int val[2]; } f_fsid;
+  uint64_t           f_namelen;
+  uint64_t           f_frsize;
+  uint64_t           f_spare[5];
+};
+#else
+struct kernel_statfs {
   unsigned long      f_type;
   unsigned long      f_bsize;
   unsigned long      f_blocks;
   unsigned long      f_bfree;
   unsigned long      f_bavail;
   unsigned long      f_files;
   unsigned long      f_ffree;
   struct { int val[2]; } f_fsid;
   unsigned long      f_namelen;
   unsigned long      f_frsize;
@@ skipping 1243 matching lines @@
               "test %%rcx, %%rcx\n"                                           \
               "jz   10001f\n"                                                 \
               "call *%%rcx\n"                                                 \
               "jmp  10002f\n"                                                 \
         "10001:syscall\n"                                                     \
         "10002:\n"
 
     #else
     #define LSS_ENTRYPOINT "syscall\n"
     #endif
+
+    /* The x32 ABI has 32 bit longs, but the syscall interface is 64 bit.
+     * We need to explicitly cast to an unsigned 64 bit type to avoid implicit
+     * sign extension.  We can't cast pointers directly because those are
+     * 32 bits, and gcc will dump ugly warnings about casting from a pointer
+     * to an integer of a different size.
+     */
+    #undef  LSS_SYSCALL_ARG
+    #define LSS_SYSCALL_ARG(a) ((uint64_t)(uintptr_t)(a))
+    #undef  _LSS_RETURN
+    #define _LSS_RETURN(type, res, cast)                                      \
+      do {                                                                    \
+        if ((uint64_t)(res) >= (uint64_t)(-4095)) {                           \
+          LSS_ERRNO = -(res);                                                 \
+          res = -1;                                                           \
+        }                                                                     \
+        return (type)(cast)(res);                                             \
+      } while (0)
+    #undef  LSS_RETURN
+    #define LSS_RETURN(type, res) _LSS_RETURN(type, res, uintptr_t)
+
+    #undef  _LSS_BODY
+    #define _LSS_BODY(nr, type, name, cast, ...)                              \
+          long long __res;                                                    \
+          __asm__ __volatile__(LSS_BODY_ASM##nr LSS_ENTRYPOINT                \
+            : "=a" (__res)                                                    \
+            : "0" (__NR_##name) LSS_BODY_ARG##nr(__VA_ARGS__)                 \
+            : LSS_BODY_CLOBBER##nr "r11", "rcx", "memory");                   \
+          _LSS_RETURN(type, __res, cast)
     #undef  LSS_BODY
-    #define LSS_BODY(type,name, ...)                                          \
-          long __res;                                                         \
-          __asm__ __volatile__(LSS_ENTRYPOINT                                 \
-            : "=a" (__res) : "0" (__NR_##name),                               \
-            ##__VA_ARGS__ : "r11", "rcx", "memory");                          \
-          LSS_RETURN(type, __res)
+    #define LSS_BODY(nr, type, name, args...) \
+      _LSS_BODY(nr, type, name, uintptr_t, ## args)
+
+    #undef  LSS_BODY_ASM0
+    #undef  LSS_BODY_ASM1
+    #undef  LSS_BODY_ASM2
+    #undef  LSS_BODY_ASM3
+    #undef  LSS_BODY_ASM4
+    #undef  LSS_BODY_ASM5
+    #undef  LSS_BODY_ASM6
+    #define LSS_BODY_ASM0
+    #define LSS_BODY_ASM1 LSS_BODY_ASM0
+    #define LSS_BODY_ASM2 LSS_BODY_ASM1
+    #define LSS_BODY_ASM3 LSS_BODY_ASM2
+    #define LSS_BODY_ASM4 LSS_BODY_ASM3 "movq %5,%%r10;"
+    #define LSS_BODY_ASM5 LSS_BODY_ASM4 "movq %6,%%r8;"
+    #define LSS_BODY_ASM6 LSS_BODY_ASM5 "movq %7,%%r9;"
+
+    #undef  LSS_BODY_CLOBBER0
+    #undef  LSS_BODY_CLOBBER1
+    #undef  LSS_BODY_CLOBBER2
+    #undef  LSS_BODY_CLOBBER3
+    #undef  LSS_BODY_CLOBBER4
+    #undef  LSS_BODY_CLOBBER5
+    #undef  LSS_BODY_CLOBBER6
+    #define LSS_BODY_CLOBBER0
+    #define LSS_BODY_CLOBBER1 LSS_BODY_CLOBBER0
+    #define LSS_BODY_CLOBBER2 LSS_BODY_CLOBBER1
+    #define LSS_BODY_CLOBBER3 LSS_BODY_CLOBBER2
+    #define LSS_BODY_CLOBBER4 LSS_BODY_CLOBBER3 "r10",
+    #define LSS_BODY_CLOBBER5 LSS_BODY_CLOBBER4 "r8",
+    #define LSS_BODY_CLOBBER6 LSS_BODY_CLOBBER5 "r9",
+
+    #undef  LSS_BODY_ARG0
+    #undef  LSS_BODY_ARG1
+    #undef  LSS_BODY_ARG2
+    #undef  LSS_BODY_ARG3
+    #undef  LSS_BODY_ARG4
+    #undef  LSS_BODY_ARG5
+    #undef  LSS_BODY_ARG6
+    #define LSS_BODY_ARG0()
+    #define LSS_BODY_ARG1(arg1) \
+      LSS_BODY_ARG0(), "D" (arg1)
+    #define LSS_BODY_ARG2(arg1, arg2) \
+      LSS_BODY_ARG1(arg1), "S" (arg2)
+    #define LSS_BODY_ARG3(arg1, arg2, arg3) \
+      LSS_BODY_ARG2(arg1, arg2), "d" (arg3)
+    #define LSS_BODY_ARG4(arg1, arg2, arg3, arg4) \
+      LSS_BODY_ARG3(arg1, arg2, arg3), "r" (arg4)
+    #define LSS_BODY_ARG5(arg1, arg2, arg3, arg4, arg5) \
+      LSS_BODY_ARG4(arg1, arg2, arg3, arg4), "r" (arg5)
+    #define LSS_BODY_ARG6(arg1, arg2, arg3, arg4, arg5, arg6) \
+      LSS_BODY_ARG5(arg1, arg2, arg3, arg4, arg5), "r" (arg6)
+
     #undef _syscall0
     #define _syscall0(type,name)                                              \
       type LSS_NAME(name)(void) {                                             \
-        LSS_BODY(type, name);                                                 \
+        LSS_BODY(0, type, name);                                              \
       }
     #undef _syscall1
     #define _syscall1(type,name,type1,arg1)                                   \
       type LSS_NAME(name)(type1 arg1) {                                       \
-        LSS_BODY(type, name, "D" ((long)(arg1)));                             \
+        LSS_BODY(1, type, name, LSS_SYSCALL_ARG(arg1));                       \
       }
     #undef _syscall2
     #define _syscall2(type,name,type1,arg1,type2,arg2)                        \
       type LSS_NAME(name)(type1 arg1, type2 arg2) {                           \
-        LSS_BODY(type, name, "D" ((long)(arg1)), "S" ((long)(arg2)));         \
+        LSS_BODY(2, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2));\
       }
     #undef _syscall3
     #define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3)             \
       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3) {               \
-        LSS_BODY(type, name, "D" ((long)(arg1)), "S" ((long)(arg2)),          \
-                             "d" ((long)(arg3)));                             \
+        LSS_BODY(3, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2), \
+                                LSS_SYSCALL_ARG(arg3));                       \
       }
     #undef _syscall4
     #define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4)  \
       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4) {   \
-          long __res;                                                         \
-          __asm__ __volatile__("movq %5,%%r10;" LSS_ENTRYPOINT :              \
-            "=a" (__res) : "0" (__NR_##name),                                 \
-            "D" ((long)(arg1)), "S" ((long)(arg2)), "d" ((long)(arg3)),       \
-            "r" ((long)(arg4)) : "r10", "r11", "rcx", "memory");              \
-          LSS_RETURN(type, __res);                                            \
+        LSS_BODY(4, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2), \
+                                LSS_SYSCALL_ARG(arg3), LSS_SYSCALL_ARG(arg4));\
       }
     #undef _syscall5
     #define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
                       type5,arg5)                                             \
       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
                           type5 arg5) {                                       \
-          long __res;                                                         \
-          __asm__ __volatile__("movq %5,%%r10; movq %6,%%r8;" LSS_ENTRYPOINT :\
-            "=a" (__res) : "0" (__NR_##name),                                 \
-            "D" ((long)(arg1)), "S" ((long)(arg2)), "d" ((long)(arg3)),       \
-            "r" ((long)(arg4)), "r" ((long)(arg5)) :                          \
-            "r8", "r10", "r11", "rcx", "memory");                             \
-          LSS_RETURN(type, __res);                                            \
+        LSS_BODY(5, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2), \
+                                LSS_SYSCALL_ARG(arg3), LSS_SYSCALL_ARG(arg4), \
+                                LSS_SYSCALL_ARG(arg5));                       \
       }
     #undef _syscall6
     #define _syscall6(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,  \
                       type5,arg5,type6,arg6)                                  \
       type LSS_NAME(name)(type1 arg1, type2 arg2, type3 arg3, type4 arg4,     \
                           type5 arg5, type6 arg6) {                           \
-          long __res;                                                         \
-          __asm__ __volatile__("movq %5,%%r10; movq %6,%%r8; movq %7,%%r9;"   \
-                               LSS_ENTRYPOINT :                               \
-            "=a" (__res) : "0" (__NR_##name),                                 \
-            "D" ((long)(arg1)), "S" ((long)(arg2)), "d" ((long)(arg3)),       \
-            "r" ((long)(arg4)), "r" ((long)(arg5)), "r" ((long)(arg6)) :      \
-            "r8", "r9", "r10", "r11", "rcx", "memory");                       \
-          LSS_RETURN(type, __res);                                            \
+        LSS_BODY(6, type, name, LSS_SYSCALL_ARG(arg1), LSS_SYSCALL_ARG(arg2), \
+                                LSS_SYSCALL_ARG(arg3), LSS_SYSCALL_ARG(arg4), \
+                                LSS_SYSCALL_ARG(arg5), LSS_SYSCALL_ARG(arg6));\
       }
     LSS_INLINE int LSS_NAME(clone)(int (*fn)(void *), void *child_stack,
                                    int flags, void *arg, int *parent_tidptr,
                                    void *newtls, int *child_tidptr) {
-      long __res;
+      long long __res;
       {
         __asm__ __volatile__(/* if (fn == NULL)
                               *   return -EINVAL;
                               */
                              "testq  %4,%4\n"
                              "jz     1f\n"
 
                              /* if (child_stack == NULL)
                               *   return -EINVAL;
                               */
@@ skipping 42 matching lines @@
                               */
                              "movq   %%rax,%%rdi\n"
                              "movq   %3,%%rax\n"
                              LSS_ENTRYPOINT
 
                              /* Return to parent.
                               */
                            "1:\n"
                              : "=a" (__res)
                              : "0"(-EINVAL), "i"(__NR_clone), "i"(__NR_exit),
-                               "r"(fn), "S"(child_stack), "D"(flags), "r"(arg),
-                               "d"(parent_tidptr), "r"(newtls),
-                               "r"(child_tidptr)
+                               "r"(LSS_SYSCALL_ARG(fn)),
+                               "S"(LSS_SYSCALL_ARG(child_stack)),
+                               "D"(LSS_SYSCALL_ARG(flags)),
+                               "r"(LSS_SYSCALL_ARG(arg)),
+                               "d"(LSS_SYSCALL_ARG(parent_tidptr)),
+                               "r"(LSS_SYSCALL_ARG(newtls)),
+                               "r"(LSS_SYSCALL_ARG(child_tidptr))
                              : "rsp", "memory", "r8", "r10", "r11", "rcx");
       }
       LSS_RETURN(int, __res);
     }
     LSS_INLINE _syscall2(int, arch_prctl, int, c, void *, a)
-    LSS_INLINE _syscall4(int, fadvise64, int, fd, loff_t, offset, loff_t, len,
-                         int,  advice)
+
+    /* Need to make sure loff_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE int LSS_NAME(fadvise64)(int fd, loff_t offset, loff_t len,
+                                       int advice) {
+      LSS_BODY(4, int, fadvise64, LSS_SYSCALL_ARG(fd), (uint64_t)(offset),
+                                  (uint64_t)(len), LSS_SYSCALL_ARG(advice));
+    }
 
     LSS_INLINE void (*LSS_NAME(restore_rt)(void))(void) {
       /* On x86-64, the kernel does not know how to return from
        * a signal handler. Instead, it relies on user space to provide a
        * restorer function that calls the rt_sigreturn() system call.
        * Unfortunately, we cannot just reference the glibc version of this
        * function, as glibc goes out of its way to make it inaccessible.
        */
-      void (*res)(void);
+      long long res;
       __asm__ __volatile__("call   2f\n"
                          "0:.align 16\n"
                          "1:movq   %1,%%rax\n"
                            LSS_ENTRYPOINT
                          "2:popq   %0\n"
                            "addq   $(1b-0b),%0\n"
                            : "=a" (res)
                            : "i"  (__NR_rt_sigreturn));
-      return res;
+      return (void (*)())(uintptr_t)res;

[Mark Seaborn, 2013/04/02 15:47:17]

I noticed that this breaks the NaCl build, which uses stricter warnings
(-Wstrict-prototypes):

In file included from src/trusted/service_runtime/linux/nacl_bootstrap.c:33:
/mnt/data/b/build/slave/chromium-rel-linux-morenacl/build/src/third_party/lss/linux_syscall_support.h:
In function 'sys_restore_rt':
/mnt/data/b/build/slave/chromium-rel-linux-morenacl/build/src/third_party/lss/linux_syscall_support.h:2039:
error: function declaration isn't a prototype [-Wstrict-prototypes]

- from
http://build.chromium.org/p/chromium.fyi/builders/More%20NaCl%20Tests%20%28li...

So this should be "(void (*)(void))".

Can you do a follow-on change to fix, please?

     }
   #elif defined(__ARM_ARCH_3__)
     /* Most definitions of _syscallX() neglect to mark "memory" as being
      * clobbered. This causes problems with compilers, that do a better job
      * at optimizing across __asm__ calls.
      * So, we just have to redefine all of the _syscallX() macros.
      */
     #undef LSS_REG
     #define LSS_REG(r,a) register long __r##r __asm__("r"#r) = (long)a
     #undef  LSS_BODY
@@ skipping 685 matching lines @@
                        const char*const*,a,const char*const*, e)
   LSS_INLINE _syscall1(int,     _exit,           int,         e)
   LSS_INLINE _syscall1(int,     exit_group,      int,         e)
   LSS_INLINE _syscall3(int,     fcntl,           int,         f,
                        int,            c, long,   a)
   LSS_INLINE _syscall0(pid_t,   fork)
   LSS_INLINE _syscall2(int,     fstat,           int,         f,
                       struct kernel_stat*,   b)
   LSS_INLINE _syscall2(int,     fstatfs,         int,         f,
                       struct kernel_statfs*, b)
-  LSS_INLINE _syscall2(int, ftruncate,           int,         f,
-                       off_t,          l)
+  #if defined(__x86_64__)
+    /* Need to make sure off_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE int LSS_NAME(ftruncate)(int f, off_t l) {
+      LSS_BODY(2, int, ftruncate, LSS_SYSCALL_ARG(f), (uint64_t)(l));
+    }
+  #else
+    LSS_INLINE _syscall2(int, ftruncate,           int,         f,
+                         off_t,          l)
+  #endif
   LSS_INLINE _syscall4(int,     futex,           int*,        a,
                        int,            o, int,    v,
                       struct kernel_timespec*, t)
   LSS_INLINE _syscall3(int,     getdents,        int,         f,
                       struct kernel_dirent*, d, int,    c)
   LSS_INLINE _syscall3(int,     getdents64,      int,         f,
                       struct kernel_dirent64*, d, int,    c)
   LSS_INLINE _syscall0(gid_t,   getegid)
   LSS_INLINE _syscall0(uid_t,   geteuid)
   LSS_INLINE _syscall0(pid_t,   getpgrp)
@@ skipping 28 matching lines @@
   LSS_INLINE _syscall3(ssize_t, llistxattr,      const char *,p,
                        char *,   l,              size_t,      s)
   LSS_INLINE _syscall3(int,     ioctl,           int,         d,
                        int,     r,               void *,      a)
   LSS_INLINE _syscall2(int,     ioprio_get,      int,         which,
                        int,     who)
   LSS_INLINE _syscall3(int,     ioprio_set,      int,         which,
                        int,     who,             int,         ioprio)
   LSS_INLINE _syscall2(int,     kill,            pid_t,       p,
                        int,            s)
-  LSS_INLINE _syscall3(off_t,   lseek,           int,         f,
-                       off_t,          o, int,    w)
+  #if defined(__x86_64__)
+    /* Need to make sure off_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE off_t LSS_NAME(lseek)(int f, off_t o, int w) {
+      _LSS_BODY(3, off_t, lseek, off_t, LSS_SYSCALL_ARG(f), (uint64_t)(o),
+                                        LSS_SYSCALL_ARG(w));
+    }
+  #else
+    LSS_INLINE _syscall3(off_t,   lseek,           int,         f,
+                         off_t,          o, int,    w)
+  #endif
   LSS_INLINE _syscall2(int,     munmap,          void*,       s,
                        size_t,         l)
   LSS_INLINE _syscall6(long,    move_pages,      pid_t,       p,
                        unsigned long,  n, void **,g, int *,   d,
                        int *,          s, int,    f)
   LSS_INLINE _syscall3(int,     mprotect,        const void *,a,
                        size_t,         l,        int,         p)
   LSS_INLINE _syscall5(void*,   _mremap,         void*,       o,
                        size_t,         os,       size_t,      ns,
                        unsigned long,  f, void *, a)
@@ skipping 78 matching lines @@
                          int,                     f,
                          const struct kernel_sockaddr*, a, int, t)
     LSS_INLINE _syscall2(int, shutdown,           int,   s,
                          int,                     h)
     LSS_INLINE _syscall3(int, socket,             int,   d,
                          int,                     t, int,       p)
     LSS_INLINE _syscall4(int, socketpair,         int,   d,
                          int,                     t, int,       p, int*, s)
   #endif
   #if defined(__x86_64__)
-    LSS_INLINE _syscall4(int, fallocate, int, fd, int, mode,
-                         loff_t, offset, loff_t, len)
+    /* Need to make sure loff_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE int LSS_NAME(fallocate)(int f, int mode, loff_t offset,
+                                       loff_t len) {
+      LSS_BODY(4, int, fallocate, LSS_SYSCALL_ARG(f), LSS_SYSCALL_ARG(mode),
+                                  (uint64_t)(offset), (uint64_t)(len));
+    }
 
     LSS_INLINE int LSS_NAME(getresgid32)(gid_t *rgid,
                                          gid_t *egid,
                                          gid_t *sgid) {
       return LSS_NAME(getresgid)(rgid, egid, sgid);
     }
 
     LSS_INLINE int LSS_NAME(getresuid32)(uid_t *ruid,
                                          uid_t *euid,
                                          uid_t *suid) {
       return LSS_NAME(getresuid)(ruid, euid, suid);
     }
 
-    LSS_INLINE _syscall6(void*, mmap,              void*, s,
-                         size_t,                   l, int,               p,
-                         int,                      f, int,               d,
-                         __off64_t,                o)
+    /* Need to make sure __off64_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE void* LSS_NAME(mmap)(void *s, size_t l, int p, int f, int d,
+                                    __off64_t o) {
+      LSS_BODY(6, void*, mmap, LSS_SYSCALL_ARG(s), LSS_SYSCALL_ARG(l),
+                               LSS_SYSCALL_ARG(p), LSS_SYSCALL_ARG(f),
+                               LSS_SYSCALL_ARG(d), (uint64_t)(o));
+    }
 
     LSS_INLINE _syscall4(int, newfstatat,         int,   d,
                          const char *,            p,
                         struct kernel_stat*,       b, int, f)
 
     LSS_INLINE int LSS_NAME(setfsgid32)(gid_t gid) {
       return LSS_NAME(setfsgid)(gid);
     }
 
     LSS_INLINE int LSS_NAME(setfsuid32)(uid_t uid) {
@@ skipping 623 matching lines @@
             ? 8192 : limit.rlim_cur;
 #endif
       }
       case _SC_PAGESIZE:
         return __getpagesize();
       default:
         LSS_ERRNO = ENOSYS;
         return -1;
     }
   }
-  #if defined(__x86_64__) ||                                                  \
-     (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI64)
+  #if defined(__x86_64__)
+    /* Need to make sure loff_t isn't truncated to 32-bits under x32.  */
+    LSS_INLINE ssize_t LSS_NAME(pread64)(int f, void *b, size_t c, loff_t o) {
+      LSS_BODY(4, ssize_t, pread64, LSS_SYSCALL_ARG(f), LSS_SYSCALL_ARG(b),
+                                    LSS_SYSCALL_ARG(c), (uint64_t)(o));
+    }
+
+    LSS_INLINE ssize_t LSS_NAME(pwrite64)(int f, const void *b, size_t c,
+                                          loff_t o) {
+      LSS_BODY(4, ssize_t, pwrite64, LSS_SYSCALL_ARG(f), LSS_SYSCALL_ARG(b),
+                                     LSS_SYSCALL_ARG(c), (uint64_t)(o));
+    }
+
+    LSS_INLINE int LSS_NAME(readahead)(int f, loff_t o, unsigned c) {
+      LSS_BODY(3, int, readahead, LSS_SYSCALL_ARG(f), (uint64_t)(o),
+                                  LSS_SYSCALL_ARG(c));
+    }
+  #elif defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI64
     LSS_INLINE _syscall4(ssize_t, pread64,        int,         f,
                          void *,         b, size_t,   c,
                          loff_t,         o)
     LSS_INLINE _syscall4(ssize_t, pwrite64,       int,         f,
                          const void *,   b, size_t,   c,
                          loff_t,         o)
     LSS_INLINE _syscall3(int,     readahead,      int,         f,
                          loff_t,         o, unsigned, c)
   #else
     #define __NR__pread64   __NR_pread64
@@ skipping 56 matching lines @@
 # pragma pop_macro("fstat64")
 # pragma pop_macro("lstat64")
 #endif
 
 #if defined(__cplusplus) && !defined(SYS_CPLUSPLUS)
 }
 #endif
 
 #endif
 #endif