u-boot/arch/powerpc/cpu/mpc86xx/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

115 lines
3.2 KiB
C

/*
* (C) Copyright 2000-2002
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* (C) Copyright 2002 (440 port)
* Scott McNutt, Artesyn Communication Producs, smcnutt@artsyncp.com
*
* (C) Copyright 2003 Motorola Inc. (MPC85xx port)
* Xianghua Xiao (X.Xiao@motorola.com)
*
* (C) Copyright 2004, 2007 Freescale Semiconductor. (MPC86xx Port)
* Jeff Brown
* Srikanth Srinivasan (srikanth.srinivasan@freescale.com)
*
* 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 <common.h>
#include <mpc86xx.h>
#include <command.h>
#include <asm/processor.h>
int interrupt_init_cpu(unsigned long *decrementer_count)
{
volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
volatile ccsr_pic_t *pic = &immr->im_pic;
pic->gcr = MPC86xx_PICGCR_RST;
while (pic->gcr & MPC86xx_PICGCR_RST)
;
pic->gcr = MPC86xx_PICGCR_MODE;
*decrementer_count = get_tbclk() / CONFIG_SYS_HZ;
debug("interrupt init: tbclk() = %d MHz, decrementer_count = %ld\n",
(get_tbclk() / 1000000),
*decrementer_count);
#ifdef CONFIG_INTERRUPTS
pic->iivpr1 = 0x810001; /* 50220 enable mcm interrupts */
debug("iivpr1@%x = %x\n", &pic->iivpr1, pic->iivpr1);
pic->iivpr2 = 0x810002; /* 50240 enable ddr interrupts */
debug("iivpr2@%x = %x\n", &pic->iivpr2, pic->iivpr2);
pic->iivpr3 = 0x810003; /* 50260 enable lbc interrupts */
debug("iivpr3@%x = %x\n", &pic->iivpr3, pic->iivpr3);
#if defined(CONFIG_PCI1) || defined(CONFIG_PCIE1)
pic->iivpr8 = 0x810008; /* enable pcie1 interrupts */
debug("iivpr8@%x = %x\n", &pic->iivpr8, pic->iivpr8);
#endif
#if defined(CONFIG_PCI2) || defined(CONFIG_PCIE2)
pic->iivpr9 = 0x810009; /* enable pcie2 interrupts */
debug("iivpr9@%x = %x\n", &pic->iivpr9, pic->iivpr9);
#endif
pic->ctpr = 0; /* 40080 clear current task priority register */
#endif
return 0;
}
/*
* timer_interrupt - gets called when the decrementer overflows,
* with interrupts disabled.
* Trivial implementation - no need to be really accurate.
*/
void timer_interrupt_cpu(struct pt_regs *regs)
{
/* nothing to do here */
}
/*
* Install and free a interrupt handler. Not implemented yet.
*/
void irq_install_handler(int vec, interrupt_handler_t *handler, void *arg)
{
}
void irq_free_handler(int vec)
{
}
/*
* irqinfo - print information about PCI devices,not implemented.
*/
int do_irqinfo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
return 0;
}
/*
* Handle external interrupts
*/
void external_interrupt(struct pt_regs *regs)
{
puts("external_interrupt (oops!)\n");
}