eae493d8a8
* spu/sbrk.c: Use the current stack pointer value rather than the
maximum available memory to determine the amount of heap space
left. Without this change calling sbrk() can allocate space that
is currently in use on the stack.
85 lines
2.7 KiB
C
85 lines
2.7 KiB
C
/*
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(C) Copyright IBM Corp. 2005, 2006
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of IBM nor the names of its contributors may be
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used to endorse or promote products derived from this software without
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specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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Author: Andreas Neukoetter (ti95neuk@de.ibm.com)
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*/
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#include <sys/types.h>
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#include <errno.h>
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#include <spu_intrinsics.h>
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extern int errno;
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extern caddr_t _end;
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#define STACKSIZE 4096
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void *
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sbrk (ptrdiff_t increment)
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{
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static caddr_t heap_ptr = NULL;
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caddr_t base;
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vector unsigned int sp_reg, sp_delta;
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vector unsigned int *sp_ptr;
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caddr_t sps;
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/* The stack pointer register. */
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volatile register vector unsigned int sp_r1 __asm__("1");
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if (heap_ptr == NULL)
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heap_ptr = (caddr_t) & _end;
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sps = (caddr_t) spu_extract (sp_r1, 0);
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if (((int) sps - STACKSIZE - (int) heap_ptr) >= increment)
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{
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base = heap_ptr;
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heap_ptr += increment;
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sp_delta = (vector unsigned int) spu_insert (increment, spu_splats (0), 1);
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/* Subtract sp_delta from the SP limit (word 1). */
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sp_r1 = spu_sub (sp_r1, sp_delta);
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/* Fix-up backchain. */
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sp_ptr = (vector unsigned int *) spu_extract (sp_r1, 0);
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do
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{
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sp_reg = *sp_ptr;
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*sp_ptr = (vector unsigned int) spu_sub (sp_reg, sp_delta);
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}
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while ((sp_ptr = (vector unsigned int *) spu_extract (sp_reg, 0)));
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return (base);
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}
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else
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{
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errno = ENOMEM;
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return ((void *) -1);
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}
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}
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