[Toybox] default SIGPIPE handler that calls _exit(0)?

[enh]

On Sat, May 2, 2015 at 1:32 PM, Rich Felker <dalias at libc.org> wrote:
> On Sat, May 02, 2015 at 12:04:31PM -0700, enh wrote:
>> On Wed, Apr 29, 2015 at 12:24 PM, Rob Landley <rob at landley.net> wrote:
>> > On 04/27/2015 11:26 AM, enh wrote:
>> >>>> it would also result in things like top(1) not exiting.
>> >>>
>> >>> If top is using stdio, it's easy to add a single ferror(stdout) check
>> >>> to the main loop. If it's using write(), it _must_ be checking for
>> >>> errors anyway since write can always return with a short/partial
>> >>> write. But top is unlikely to be hooked up to a pipe or socket anyway;
>> >>> it normally needs a terminal.
>> >>
>> >> the point is that then people need to think. if that were a plausible
>> >> solution, this thread wouldn't exist. the advantage of the signal
>> >> handler is that humans can keep on being humans.
>> >
>> > I _so_ should have called this project Dorodango. (See
>> > http://www.dorodango.com.)
>> >
>> > The point of this project is to do things right. I want to _fix_
>> > everything I can. My insane cleanup review passes involve trying to find
>> > all this stuff and make sure we get it right.
>> >
>> > Sure, outside toybox yay sigpipe. But inside, the question is what the
>> > correct behavior should be.
>> >
>> > It sounds like android wants _exit(0)
>>
>> no, not particularly. we're arguing internally about whether SIGPIPE
>> is a crash or not. i think even undoing the dynamic linker's
>> installation of a crash reporter by setting it back to SIG_DFL would
>> be fine for toybox --- the real problem is that the dynamic linker
>> doesn't know whether it's dealing with an Android app (where you
>> probably do want the crash reporting) or a command-line tool (where
>> you probably don't), let alone corner cases like a command-line tool
>> that's implemented in Java.
>
> In that case the crash-reporting signal handler setup should be in the
> Android app init code, not the dynamic linker, no?

there are a large number of native-only daemons running on the average
Android device, most of which we only see as binary blobs.

-- 
Elliott Hughes - http://who/enh - http://jessies.org/~enh/
Android native code/tools questions? Mail me/drop by/add me as a reviewer.

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