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	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>
		
	
		
			
				
	
	
		
			27 lines
		
	
	
		
			587 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			27 lines
		
	
	
		
			587 B
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _TYPE_BEDBUG_H
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| #define _TYPE_BEDBUG_H
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| 
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| /* Supporting routines */
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| int bedbug_puts (const char *);
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| void bedbug_init (void);
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| void bedbug860_init (void);
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| void do_bedbug_breakpoint (struct pt_regs *);
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| void bedbug_main_loop (unsigned long, struct pt_regs *);
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| 
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| 
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| typedef struct {
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| 	int hw_debug_enabled;
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| 	int stopped;
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| 	int current_bp;
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| 	struct pt_regs *regs;
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| 
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| 	void (*do_break) (cmd_tbl_t *, int, int, char * const []);
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| 	void (*break_isr) (struct pt_regs *);
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| 	int (*find_empty) (void);
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| 	int (*set) (int, unsigned long);
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| 	int (*clear) (int);
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| } CPU_DEBUG_CTX;
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| 
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| 
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| #endif /* _TYPE_BEDBUG_H  */
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