On Sun, Apr 22, 2007 at 12:10:33AM +0200, Andi Kleen wrote: > > unwind code to even attempt to avoid the problem what should be done? > > How about: > > > > (1) Make it clear the Fault Injection with STACKTRACE on x86_64 is at > > best "Russian Roulette" -- maybe a !X86_64 in Kconfig.debug? > > > > (2) Introduce FRAME_POINTER support back into the x86_64 code. This is > > what Fault Injection really wants. > > > > (3) Keep the saved stack address entries array out of sight of the > > fallback save_stack_trace() code. Lockdep does this by storing it in > > static space but this requires locking which would be ugly for Fault > > Injection. Another option is to mask the saved addresses so they fail > > the __kernel_text_address() test but fail_stacktrace() uses the same > > mask to make it's comparisons. There's still the problem of avoiding > > kernel text addresses stored on the stack by other code (that is, other > > than the expected stack chain uses). > > Some hack in (3) would be probably best, otherwise (1). > At some point I hope we can get the dwarf2 unwinder back, then > the problem should be also solved. But then you would need to force > the dwarf2 unwinder with fault injection on, but that shouldn't > be a problem.
I'm goint to send the patch that disables stacktrace filter (CONFIG_FAULT_INJECTION_STACKTRACE_FILTER) on x86_64. But dwarf2 unwinder is still available on -mm. So I'll send -mm only patch that enables it at the same time. BTW, are there any pending issues in dwarf2 unwinder? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
