diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/i386/sysdep.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/i386/sysdep.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h index 99f9bf1edf..cb5767955c 100644 --- a/sysdeps/unix/sysv/linux/i386/sysdep.h +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h @@ -558,4 +558,24 @@ asm (".L__X'%ebx = 1\n\t" #endif /* __ASSEMBLER__ */ + +/* Pointer mangling support. */ +#if defined NOT_IN_libc && defined IS_IN_rtld +/* We cannot use the thread descriptor because in ld.so we use setjmp + earlier than the descriptor is initialized. Using a global variable + is too complicated here since we have no PC-relative addressing mode. */ +#else +# ifdef __ASSEMBLER__ +# define PTR_MANGLE(reg) xorl %gs:POINTER_GUARD, reg +# define PTR_DEMANGLE(reg) PTR_MANGLE (reg) +# else +# define PTR_MANGLE(var) asm ("xorl %%gs:%c2, %0" \ + : "=r" (var) \ + : "0" (var), \ + "i" (offsetof (tcbhead_t, \ + pointer_guard))) +# define PTR_DEMANGLE(var) PTR_MANGLE (var) +# endif +#endif + #endif /* linux/i386/sysdep.h */ |