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,
Will