Re: [patch 00/11] Hardware Breakpoint interfaces

Alan Stern
2009-03-10T14:24:37Z

On Tue, 10 Mar 2009, Ingo Molnar wrote:

>
> There's also a few checkpatch warnings that need to be
> addressed:
>
> ERROR: do not use assignment in if condition
> #1084: FILE: arch/x86/kernel/ptrace.c:581:
> + else if ((thbi = alloc_thread_hw_breakpoint(tsk)) ==
> NULL)

Changing this to remove the assignment from within the "if" condition
would make the code less readable, not more. It's part of a long
series of tests; in schematic form:

if (n == 4 || n == 5)
...
else if (n == 6) {
...
}
else if (!tsk->thread.hw_breakpoint_info && val == 0)
...
else if ((thbi = alloc_thread_hw_breakpoint(tsk)) == NULL)
...
else if (n < HB_NUM) {
...
}
else
...

If you can suggest a way to change the code without making it worse,
I'm sure Prasad will be happy to adopt it.

Alan Stern