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Avoid the use of a `switch(){}' statement before _rtld_init() is called. 

`switch()' code may be translated using a jump table approach which causes
it to reference the equivalent of a global variable, something that must
be avoided before _rtld_init() has run.
This commit is contained in:
pk 2001-02-03 13:25:00 +00:00
parent b26a441f6a
commit 38fd9b8f99
1 changed files with 30 additions and 11 deletions
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41
libexec/ld.elf_so/rtld.c
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@ -1,4 +1,4 @@
/* $NetBSD: rtld.c,v 1.43 2000/11/10 23:53:04 mycroft Exp $ */
/* $NetBSD: rtld.c,v 1.44 2001/02/03 13:25:00 pk Exp $ */
/*
* Copyright 1996 John D. Polstra.
@ -334,12 +334,40 @@ _rtld(sp)
}
aux = (const AuxInfo *) sp;
/* Digest the auxiliary vector. */
pAUX_base = pAUX_entry = pAUX_execfd = NULL;
pAUX_phdr = pAUX_phent = pAUX_phnum = NULL;
#ifdef VARPSZ
pAUX_pagesz = NULL;
#endif
/*
* First pass through the the auxiliary vector, avoiding the use
* of a `switch() {}' statement at this stage. A `switch()' may
* be translated into code utilizing a jump table approach which
* references the equivalent of a global variable. This must be
* avoided until _rtld_init() has done its job.
*
* _rtld_init() only needs `pAUX_base' and possibly `pAUX_pagesz',
* so we look for just those in this pass.
*/
for (auxp = aux; auxp->a_type != AT_NULL; ++auxp) {
if (auxp->a_type == AT_BASE)
pAUX_base = auxp;
#ifdef VARPSZ
if (auxp->a_type == AT_PAGESZ)
pAUX_pagesz = auxp;
#endif
}
/* Initialize and relocate ourselves. */
assert(pAUX_base != NULL);
#ifdef VARPSZ
assert(pAUX_pagesz != NULL);
_rtld_init((caddr_t) pAUX_base->a_v, (int)pAUX_pagesz->a_v);
#else
_rtld_init((caddr_t) pAUX_base->a_v, 0);
#endif
/* Digest the auxiliary vector (full pass now that we can afford it). */
for (auxp = aux; auxp->a_type != AT_NULL; ++auxp) {
switch (auxp->a_type) {
case AT_BASE:
@ -368,15 +396,6 @@ _rtld(sp)
}
}
/* Initialize and relocate ourselves. */
assert(pAUX_base != NULL);
#ifdef VARPSZ
assert(pAUX_pagesz != NULL);
_rtld_init((caddr_t) pAUX_base->a_v, (int)pAUX_pagesz->a_v);
#else
_rtld_init((caddr_t) pAUX_base->a_v, 0);
#endif
#ifdef VARPSZ
_rtld_pagesz = (int)pAUX_pagesz->a_v;
#endif