On Fri, Apr 13, 2018 at 12:53:49PM -0700, Linus Torvalds wrote: > On Fri, Apr 13, 2018 at 11:45 AM, Dave Martin <dave.mar...@arm.com> wrote: > > > > Most uses I've seen do nothing more than use the FPE_xyz value to > > format diagnostic messages while dying. I struggled to find code that > > made a meaningful functional decision based on the value, though that's > > not proof... > > Yeah. I've seen code that cares about SIGFPE deeply, but it's almost > invariably about some emulated environment (eg Java VM, or CPU > emulation). > > And the siginfo data is basically never good enough for those > environments anyway on its own, so they will go and look at the actual > instruction that caused the fault and the register state instead, > because they need *all* the information. > > The cases that use si_code are the ones that just trapped signals in > order to give a more helpful abort message. > > So I could certainly imagine that si_code is actually used by somebody > who then decides to actuall act differently on it, but aside from > perhaps printing out a different message, it sounds far-fetched.
Okay, in that case let's just use FPE_FLTINV. That makes the patch easily back-portable for stable kernels. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up
