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sh: Fix exception_handling_table alignment.

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With the recent change ripping out interrupt_table, explicit
padding of the table was missing, causing bad things to happen
when manually inserting handlers in to the table. This problem
particularly showed up in relation to do_fpu_state_restore()
which was inserted quite deeply in to the table and ended up
scribbling over a slab object.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Paul Mundt 2006-10-19 16:20:25 +09:00
parent 082c44d20e
commit 1f666587db
4 changed files with 44 additions and 24 deletions
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9
arch/sh/kernel/cpu/sh3/ex.S
View File

@ -4,7 +4,7 @@
* The SH-3 exception vector table.
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
* Copyright (C) 2003 Paul Mundt
* Copyright (C) 2003 - 2006 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
@ -49,3 +49,10 @@ ENTRY(nmi_slot)
#endif
ENTRY(user_break_point_trap)
.long break_point_trap /* 1E0 */
/*
* Pad the remainder of the table out, exceptions residing in far
* away offsets can be manually inserted in to their appropriate
* location via set_exception_table_{evt,vec}().
*/
.balign 4096,0,4096

9
arch/sh/kernel/cpu/sh4/ex.S
View File

@ -4,7 +4,7 @@
* The SH-4 exception vector table.
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
* Copyright (C) 2003 Paul Mundt
* Copyright (C) 2003 - 2006 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
@ -53,3 +53,10 @@ ENTRY(nmi_slot)
#endif
ENTRY(user_break_point_trap)
.long break_point_trap /* 1E0 */
/*
* Pad the remainder of the table out, exceptions residing in far
* away offsets can be manually inserted in to their appropriate
* location via set_exception_table_{evt,vec}().
*/
.balign 4096,0,4096

43
arch/sh/kernel/traps.c
View File

@ -11,27 +11,15 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include <asm/processor.h>
#include <asm/sections.h>
#ifdef CONFIG_SH_KGDB
#include <asm/kgdb.h>
@ -581,7 +569,10 @@ int is_dsp_inst(struct pt_regs *regs)
#define is_dsp_inst(regs) (0)
#endif /* CONFIG_SH_DSP */
extern int do_fpu_inst(unsigned short, struct pt_regs*);
/* arch/sh/kernel/cpu/sh4/fpu.c */
extern int do_fpu_inst(unsigned short, struct pt_regs *);
extern asmlinkage void do_fpu_state_restore(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7, struct pt_regs regs);
asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
@ -740,14 +731,20 @@ void __init per_cpu_trap_init(void)
: "memory");
}
void __init trap_init(void)
void *set_exception_table_vec(unsigned int vec, void *handler)
{
extern void *exception_handling_table[];
void *old_handler;
old_handler = exception_handling_table[vec];
exception_handling_table[vec] = handler;
return old_handler;
}
exception_handling_table[TRAP_RESERVED_INST]
= (void *)do_reserved_inst;
exception_handling_table[TRAP_ILLEGAL_SLOT_INST]
= (void *)do_illegal_slot_inst;
void __init trap_init(void)
{
set_exception_table_vec(TRAP_RESERVED_INST, do_reserved_inst);
set_exception_table_vec(TRAP_ILLEGAL_SLOT_INST, do_illegal_slot_inst);
#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \
defined(CONFIG_SH_FPU_EMU)
@ -756,9 +753,11 @@ void __init trap_init(void)
* reserved. They'll be handled in the math-emu case, or faulted on
* otherwise.
*/
/* entry 64 corresponds to EXPEVT=0x800 */
exception_handling_table[64] = (void *)do_reserved_inst;
exception_handling_table[65] = (void *)do_illegal_slot_inst;
set_exception_table_evt(0x800, do_reserved_inst);
set_exception_table_evt(0x820, do_illegal_slot_inst);
#elif defined(CONFIG_SH_FPU)
set_exception_table_evt(0x800, do_fpu_state_restore);
set_exception_table_evt(0x820, do_fpu_state_restore);
#endif
/* Setup VBR for boot cpu */

7
include/asm-sh/system.h
View File

@ -353,6 +353,13 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
(unsigned long)_n_, sizeof(*(ptr))); \
})
extern void *set_exception_table_vec(unsigned int vec, void *handler);
static inline void *set_exception_table_evt(unsigned int evt, void *handler)
{
return set_exception_table_vec(evt >> 5, handler);
}
/* XXX
* disable hlt during certain critical i/o operations
*/