aa770aa790
This is fixes a problem where we could jump to the wrong address. By doing a "p0 = reti; jump (p0)". If a different, higher level interrupt came in, just before, rather than returning to the calling function, we would return to a random place in the kernel. This very elegant fix from Bernd grabs the return location off the stack, and places it into P0, so when we do a return, it goes to the correct place. Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Bryan Wu <bryan.wu@analog.com>
101 lines
2.1 KiB
ArmAsm
101 lines
2.1 KiB
ArmAsm
/*
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* File: arch/blackfin/kernel/entry.S
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* Based on:
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* Author:
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*
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* Created:
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* Description:
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*
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* Modified:
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* Copyright 2004-2006 Analog Devices Inc.
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*
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* Bugs: Enter bugs at http://blackfin.uclinux.org/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see the file COPYING, or write
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* to the Free Software Foundation, Inc.,
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/linkage.h>
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#include <asm/thread_info.h>
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#include <asm/errno.h>
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#include <asm/asm-offsets.h>
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#include <asm/mach-common/context.S>
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#ifdef CONFIG_EXCPT_IRQ_SYSC_L1
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.section .l1.text
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#else
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.text
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#endif
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ENTRY(_ret_from_fork)
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SP += -12;
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call _schedule_tail;
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SP += 12;
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r0 = [sp + PT_IPEND];
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cc = bittst(r0,1);
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if cc jump .Lin_kernel;
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RESTORE_CONTEXT
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rti;
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.Lin_kernel:
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bitclr(r0,1);
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[sp + PT_IPEND] = r0;
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/* do a 'fake' RTI by jumping to [RETI]
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* to avoid clearing supervisor mode in child
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*/
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r0 = [sp + PT_PC];
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[sp + PT_P0] = r0;
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RESTORE_ALL_SYS
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jump (p0);
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ENDPROC(_ret_from_fork)
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ENTRY(_sys_fork)
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r0 = -EINVAL;
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rts;
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ENDPROC(_sys_fork)
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ENTRY(_sys_vfork)
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r0 = sp;
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r0 += 24;
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[--sp] = rets;
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SP += -12;
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call _bfin_vfork;
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SP += 12;
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rets = [sp++];
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rts;
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ENDPROC(_sys_vfork)
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ENTRY(_sys_clone)
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r0 = sp;
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r0 += 24;
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[--sp] = rets;
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SP += -12;
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call _bfin_clone;
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SP += 12;
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rets = [sp++];
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rts;
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ENDPROC(_sys_clone)
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ENTRY(_sys_rt_sigreturn)
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r0 = sp;
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r0 += 24;
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[--sp] = rets;
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SP += -12;
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call _do_rt_sigreturn;
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SP += 12;
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rets = [sp++];
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rts;
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ENDPROC(_sys_rt_sigreturn)
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