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/* Stack executability handling for GNU dynamic linker. OpenSolaris version.
Copyright (C) 2003, 2004, 2008 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <ldsodefs.h>
#include <errno.h>
#include <sys/ucontext.h>
#include <sys/syscall.h>
/* There is no portable way to know the bounds of the initial thread's stack
so as to mprotect it. */
int
internal_function
_dl_make_stack_executable (void **stack_endp)
{
/* We can get the stack base and size from getcontext. */
sysret_t ret;
ucontext_t ctx;
int errval = __systemcall (&ret, SYS_context, GETCONTEXT, &ctx);
if (errval != 0)
return errval;
/* The given stack pointer better be in range. */
if (*stack_endp < ctx.uc_stack.ss_sp ||
*stack_endp > (ctx.uc_stack.ss_sp + ctx.uc_stack.ss_size))
return ENOTSUP;
errval = __systemcall (&ret, SYS_mprotect, ctx.uc_stack.ss_sp,
ctx.uc_stack.ss_size, PROT_READ | PROT_WRITE | PROT_EXEC);
if (errval != 0)
return errval;
*stack_endp = NULL;
return 0;
}
rtld_hidden_def (_dl_make_stack_executable)
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