mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-30 22:08:52 +09:00
![Wolfgang Denk](/assets/img/avatar_default.png)
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>
105 lines
2.8 KiB
C
105 lines
2.8 KiB
C
/*
|
|
* (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
|
|
*/
|
|
|
|
/*
|
|
* interrupts.c - just enough support for the decrementer/timer
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <mpc8xx.h>
|
|
#include <mpc8xx_irq.h>
|
|
#include <asm/processor.h>
|
|
#include <commproc.h>
|
|
#include <command.h>
|
|
|
|
int interrupt_init_cpu (unsigned *decrementer_count)
|
|
{
|
|
debug("interrupt_init: GT main cause reg: %08x:%08x\n",
|
|
GTREGREAD(LOW_INTERRUPT_CAUSE_REGISTER),
|
|
GTREGREAD(HIGH_INTERRUPT_CAUSE_REGISTER));
|
|
debug("interrupt_init: ethernet cause regs: %08x %08x %08x\n",
|
|
GTREGREAD(ETHERNET0_INTERRUPT_CAUSE_REGISTER),
|
|
GTREGREAD(ETHERNET1_INTERRUPT_CAUSE_REGISTER),
|
|
GTREGREAD(ETHERNET2_INTERRUPT_CAUSE_REGISTER));
|
|
debug("interrupt_init: ethernet mask regs: %08x %08x %08x\n",
|
|
GTREGREAD(ETHERNET0_INTERRUPT_MASK_REGISTER),
|
|
GTREGREAD(ETHERNET1_INTERRUPT_MASK_REGISTER),
|
|
GTREGREAD(ETHERNET2_INTERRUPT_MASK_REGISTER));
|
|
debug("interrupt_init: setting decrementer_count\n");
|
|
|
|
*decrementer_count = get_tbclk() / CONFIG_SYS_HZ;
|
|
|
|
return (0);
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
/*
|
|
* Handle external interrupts
|
|
*/
|
|
void
|
|
external_interrupt(struct pt_regs *regs)
|
|
{
|
|
puts("external_interrupt (oops!)\n");
|
|
}
|
|
|
|
volatile ulong timestamp = 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 */
|
|
return;
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
/*
|
|
* Install and free a interrupt handler.
|
|
*/
|
|
|
|
void
|
|
irq_install_handler(int vec, interrupt_handler_t *handler, void *arg)
|
|
{
|
|
|
|
}
|
|
|
|
void
|
|
irq_free_handler(int vec)
|
|
{
|
|
|
|
}
|
|
|
|
/****************************************************************************/
|
|
|
|
void
|
|
do_irqinfo(cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char * const argv[])
|
|
{
|
|
puts("IRQ related functions are unimplemented currently.\n");
|
|
}
|