u-boot-brain/include/kgdb.h
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

71 lines
1.8 KiB
C

#ifndef __KGDB_H__
#define __KGDB_H__
#include <asm/ptrace.h>
#define KGDBERR_BADPARAMS 1
#define KGDBERR_NOTHEXDIG 2
#define KGDBERR_MEMFAULT 3
#define KGDBERR_NOSPACE 4
#define KGDBERR_ALIGNFAULT 5
#define KGDBDATA_MAXREGS 8
#define KGDBDATA_MAXPRIV 8
#define KGDBEXIT_TYPEMASK 0xff
#define KGDBEXIT_KILL 0
#define KGDBEXIT_CONTINUE 1
#define KGDBEXIT_SINGLE 2
#define KGDBEXIT_WITHADDR 0x100
typedef
struct {
int num;
unsigned long val;
}
kgdb_reg;
typedef
struct {
int sigval;
int extype;
unsigned long exaddr;
int nregs;
kgdb_reg regs[KGDBDATA_MAXREGS];
unsigned long private[KGDBDATA_MAXPRIV];
}
kgdb_data;
/* these functions are provided by the generic kgdb support */
extern void kgdb_init(void);
extern void kgdb_error(int);
extern int kgdb_output_string(const char *, unsigned int);
extern void breakpoint(void);
/* these functions are provided by the platform specific kgdb support */
extern void kgdb_flush_cache_range(void *, void *);
extern void kgdb_flush_cache_all(void);
extern int kgdb_setjmp(long *);
extern void kgdb_longjmp(long *, int);
extern void kgdb_enter(struct pt_regs *, kgdb_data *);
extern void kgdb_exit(struct pt_regs *, kgdb_data *);
extern int kgdb_getregs(struct pt_regs *, char *, int);
extern void kgdb_putreg(struct pt_regs *, int, char *, int);
extern void kgdb_putregs(struct pt_regs *, char *, int);
extern int kgdb_trap(struct pt_regs *);
extern void kgdb_breakpoint(int argc, char * const argv[]);
/* these functions are provided by the platform serial driver */
extern void kgdb_serial_init(void);
extern int getDebugChar(void);
extern void putDebugChar(int);
extern void putDebugStr(const char *);
extern void kgdb_interruptible(int);
/* this is referenced in the trap handler for the platform */
extern int (*debugger_exception_handler)(struct pt_regs *);
#endif /* __KGDB_H__ */