u-boot/arch/sparc/cpu/leon2/interrupts.c
Wolfgang Denk 54841ab50c Make sure that argv[] argument pointers are not modified.
The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands.  Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".

This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:

int main (int argc, char **argv)
{
	while (--argc > 0 && **++argv == '-') {
/* ====> */	while (*++*argv) {
			switch (**argv) {
			case 'd':
				debug++;
				break;
			...
			default:
				usage ();
			}
		}
	}
	...
}

The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell.  With the modification, the compiler will prevent this with
an
	error: increment of read-only location '*argv'

N.B.: The code above can be trivially rewritten like this:

	while (--argc > 0 && **++argv == '-') {
		char *arg = *argv;
		while (*++arg) {
			switch (*arg) {
			...

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2010-07-04 23:55:42 +02:00

217 lines
5.3 KiB
C

/*
* (C) Copyright 2007
* Daniel Hellstrom, Gaisler Research, daniel@gaisler.com
*
* (C) Copyright 2006
* Detlev Zundel, DENX Software Engineering, dzu@denx.de
*
* (C) Copyright -2003
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* (C) Copyright 2001
* Josh Huber <huber@mclx.com>, Mission Critical Linux, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <asm/stack.h>
#include <common.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <command.h>
#include <asm/irq.h>
#include <asm/leon.h>
/* 15 normal irqs and a non maskable interrupt */
#define NR_IRQS 15
struct irq_action {
interrupt_handler_t *handler;
void *arg;
unsigned int count;
};
static struct irq_action irq_handlers[NR_IRQS] = { {0}, };
static int spurious_irq_cnt = 0;
static int spurious_irq = 0;
static inline unsigned int leon2_get_irqmask(unsigned int irq)
{
if ((irq < 0) || (irq >= NR_IRQS)) {
return 0;
} else {
return (1 << irq);
}
}
static void leon2_ic_disable(unsigned int irq)
{
unsigned int mask, pil;
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
pil = intLock();
/* get mask of interrupt */
mask = leon2_get_irqmask(irq);
/* set int level */
leon2->Interrupt_Mask =
SPARC_NOCACHE_READ(&leon2->Interrupt_Mask) & (~mask);
intUnlock(pil);
}
static void leon2_ic_enable(unsigned int irq)
{
unsigned int mask, pil;
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
pil = intLock();
/* get mask of interrupt */
mask = leon2_get_irqmask(irq);
/* set int level */
leon2->Interrupt_Mask =
SPARC_NOCACHE_READ(&leon2->Interrupt_Mask) | mask;
intUnlock(pil);
}
void handler_irq(int irq, struct pt_regs *regs)
{
if (irq_handlers[irq].handler) {
if (((unsigned int)irq_handlers[irq].handler > CONFIG_SYS_RAM_END) ||
((unsigned int)irq_handlers[irq].handler < CONFIG_SYS_RAM_BASE)
) {
printf("handler_irq: bad handler: %x, irq number %d\n",
(unsigned int)irq_handlers[irq].handler, irq);
return;
}
irq_handlers[irq].handler(irq_handlers[irq].arg);
irq_handlers[irq].count++;
} else {
spurious_irq_cnt++;
spurious_irq = irq;
}
}
void leon2_force_int(int irq)
{
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
if ((irq >= NR_IRQS) || (irq < 0))
return;
printf("Forcing interrupt %d\n", irq);
leon2->Interrupt_Force =
SPARC_NOCACHE_READ(&leon2->Interrupt_Force) | (1 << irq);
}
/****************************************************************************/
int interrupt_init_cpu(void)
{
return (0);
}
/****************************************************************************/
/* Handle Timer 0 IRQ */
void timer_interrupt_cpu(void *arg)
{
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
leon2->Timer_Control_1 =
(LEON2_TIMER_CTRL_EN | LEON2_TIMER_CTRL_RS | LEON2_TIMER_CTRL_LD);
/* nothing to do here */
return;
}
/****************************************************************************/
/*
* Install and free a interrupt handler.
*/
void irq_install_handler(int irq, interrupt_handler_t * handler, void *arg)
{
if (irq < 0 || irq >= NR_IRQS) {
printf("irq_install_handler: bad irq number %d\n", irq);
return;
}
if (irq_handlers[irq].handler != NULL)
printf("irq_install_handler: 0x%08lx replacing 0x%08lx\n",
(ulong) handler, (ulong) irq_handlers[irq].handler);
if (((unsigned int)handler > CONFIG_SYS_RAM_END) ||
((unsigned int)handler < CONFIG_SYS_RAM_BASE)
) {
printf("irq_install_handler: bad handler: %x, irq number %d\n",
(unsigned int)handler, irq);
return;
}
irq_handlers[irq].handler = handler;
irq_handlers[irq].arg = arg;
/* enable irq on LEON2 hardware */
leon2_ic_enable(irq);
}
void irq_free_handler(int irq)
{
if (irq < 0 || irq >= NR_IRQS) {
printf("irq_free_handler: bad irq number %d\n", irq);
return;
}
/* disable irq on LEON2 hardware */
leon2_ic_disable(irq);
irq_handlers[irq].handler = NULL;
irq_handlers[irq].arg = NULL;
}
/****************************************************************************/
#if defined(CONFIG_CMD_IRQ)
void do_irqinfo(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
{
int irq;
unsigned int pil = get_pil();
printf("PIL level: %u\n\r", pil);
printf("Spurious IRQ: %u, last unknown IRQ: %d\n",
spurious_irq_cnt, spurious_irq);
puts("\nInterrupt-Information:\n" "Nr Routine Arg Count\n");
for (irq = 0; irq < NR_IRQS; irq++) {
if (irq_handlers[irq].handler != NULL) {
printf("%02d %08lx %08lx %ld\n", irq,
(unsigned int)irq_handlers[irq].handler,
(unsigned int)irq_handlers[irq].arg,
irq_handlers[irq].count);
}
}
}
#endif