Messages in this thread | | | Date | Wed, 7 May 2014 09:40:30 +0200 | Subject | Re: [PATCH 3/3] perf tools: Add libdw DWARF post unwind support for ARM64 | From | Jean Pihet <> |
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Hi Will,
On Tue, May 6, 2014 at 7:52 PM, Will Deacon <will.deacon@arm.com> wrote: > On Tue, May 06, 2014 at 06:41:55PM +0100, Jean Pihet wrote: >> Hi Will, >> >> On 6 May 2014 19:00, Will Deacon <will.deacon@arm.com> wrote: >> > Hi Jean, >> > >> > On Tue, May 06, 2014 at 04:55:33PM +0100, Jean Pihet wrote: >> >> Adding libdw DWARF post unwind support, which is part >> >> of elfutils-devel/libdw-dev package from version 0.158. >> >> >> >> Note: the libdw code needs some support for dwarf unwinding >> >> on ARM64, this code is submitted seperately on the elfutils >> >> ML. >> >> >> >> The new code is contained in unwin-libdw.c object, and >> >> implements unwind__get_entries unwind interface function. >> > >> > Are you planning to implement support for 32-bit ARM too? If so, we'll need >> > compat handling here again (your favourite!). >> Yes! Another patch set (sent just before this one) targets ARM. There >> is a nice ToDo in the cover letter: handle compat mode correctly. In >> fact I sent a patch to libdw, so it supports it already but is >> somewhat broken for compat mode. This is on my prefered ToDo list ;-) >> >> > >> >> +bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) >> >> +{ >> >> + struct unwind_info *ui = arg; >> >> + struct regs_dump *user_regs = &ui->sample->user_regs; >> >> + Dwarf_Word dwarf_regs[PERF_REG_ARM64_MAX]; >> > >> > Shouldn't this be PERF_REG_ARM64_MAX - 1? >> Ah, well spotted! I will change although it shouldn't harm, right? > > Actually, looking again, I think I'm wrong and your code was right first > time! It looks like dwfl_thread_state_registers takes the limit too, so I > don't think you need to change anything (except for adding compat support). > > Sorry about that, My bad, I haven't checked carefully enough before replying.
Thx! Jean > > Will > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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