yes, I mean crash command line is lacking support of some advanced
arithmetic, like this pd command, it doesn't have to send it to gdb;
BTW, these days I am looking for an advanced scripting in crash,
does crash provide some builtin script language ?
Or have you looked this pykdump project, to embed a python interpreter
sounds like a good idea, since gdb has support python scripting as well,
Thanks,
On Wednesday, May 20, 2015 11:17 AM, Dave Anderson <anderson@xxxxxxxxxx> wrote:
----- Original Message -----
>
> Hi Dave,
> Does this sound like a bug, it need right shift of the subtraction result,
> crash-git> pd (678324157984276 >> 32)
> $10 = 157934
> crash-git> pd ((681670518181331-678324157984276) >> 32)
> p: gdb request failed: p ((681670518181331-678324157984276)
> crash-git>
>
> It might be lacking support of some advanced arithmetic, so what is a proper
> wayto do some arithmetic like this?
No, it is a crash bug. If you turn on the console mode, you can see the string
that is passed on to gdb. Simple example:
crash> !tty
/dev/pts/8
crash> set console /dev/pts/8
debug console [2850]: /dev/pts/8
console: /dev/pts/8
crash> set debug 1
debug: 1
crash>
The simple shift case works, and you can see the string that gets passed
to gdb on the 2nd line of output, in the bracket after gdb_pass_through:
crash> pd (15 >> 1)
error() trace: 467e99 => 51c147 => 518ca6 => 46eaff
gdb_pass_through: [p (15 >> 1)]
p: per_cpu_symbol_search((15 >> 1)): NULL
$9 = 7
crash>
But by adding the internal set of parentheses, the string gets
clipped, and just "p ((15+1)" gets passed to gdb:
crash> pd ((15+1) >> 1)
error() trace: 467e99 => 51c147 => 518ca6 => 46eaff
p: per_cpu_symbol_search(((15+1)): NULL
gdb_pass_through: [p ((15+1)]
error() trace: 467e99 => 51c1e7 => 51a7d5 => 46eaff
p: gdb request failed: p ((15+1)
crash>
So it's either related to the crash command line redirection code,
or in the process_gdb_output() function. (Feel free to debug it
if you have the time...)
Thanks,
Dave
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