Russell King wrote:
Plainly, %ebx changed across the call to serial_in() at c01c0f7b.
First thing to notice is this violates the C code - "up" can not
change.
Now let's look at serial_in:
c01bfa70: 55 push %ebp
c01bfa71: 89 e5 mov %esp,%ebp
c01bfa73: 53 push %ebx
...
c01bfab7: 5b pop %ebx
c01bfab8: 5d pop %ebp
c01bfab9: c3 ret
This code tells the CPU to preserves %ebx and %ebp. But we know %ebx
_wasn't_ preserved. Ergo, your CPU is plainly not doing what the code
told it to do.
... assuming nothing else clobbered the stack slot (which would be a
compiler error, or a wild pointer.)
Got a disassembly of the whole function?
-hpa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
