Messages in this thread | | | Date | Tue, 3 Apr 2012 09:31:45 +0200 | From | Ingo Molnar <> | Subject | Re: [RFC PATCH -tip 00/16] in-kernel x86 disassember |
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* H. Peter Anvin <hpa@zytor.com> wrote:
> On 04/01/2012 09:02 AM, Masami Hiramatsu wrote: > > Hi, > > > > Here is a series of patches of the in-kernel x86 disassembler > > for the latest tip tree. > > This will show you a pretty disassembled code instead of > > just a digital code sequence when you gets a kernel panic etc. > > (I know, we also have script/decodecode for the panic use) > > > > This feature is not for users, but mainly for kernel developers > > who can understand disassembly code of x86 ;). This is just like > > a joke feature in kernel. (yeah, I spend my spare time for this. > > It's my fun :)) > > > > This is cool, but I have one major reservation about it: it > will make kernel panics take a lot more screen real estate > without containing more information, and we already have > problems with things scrolling off way too easily.
Yes, I'm not sure we want to do it by default.
> For that reason I would like to request that this *only* > enabled by an explicit command-line option or similar > (disasm_oops, maybe?), so that the user has to opt-in.
The existing oops setup knob is an early_param() in kernel/panic.c, "oops=".
I'd suggesting extending that in an obvious way. Currently the only option that exists is "oops=panic", so a comma delimited list of attributes would be the natural extension, allowing:
oops=panic oops=panic,disasm oops=disasm
Detail: it should do a strncmp(5, str, "disas"), so that every usual variant works: oops=disasm, oops=disassemble, etc.
> [...] In other words, if *you* are debugging your own kernel, > and don't expect to ship oopses off to someone else.
Probably a DEBUG .config option as well, so that distros can enable it. OTOH, CONFIG_CMDLINE allows the setting of such parameters as well.
Thanks,
Ingo
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