On Tue, Dec 3, 2013 at 7:08 PM, Will Deacon will.deacon@arm.com wrote:
On Tue, Dec 03, 2013 at 11:21:39AM +0000, Will Deacon wrote:
On Tue, Dec 03, 2013 at 10:16:37AM +0000, Mark Rutland wrote:
I think that there's a slight problem with this on BE systems.
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On Sat, Nov 30, 2013 at 06:32:26AM +0000, vijay.kilari@gmail.com wrote:
{ "pstate", 4, offsetof(struct pt_regs, pstate)},As pt_regs::pstate is a u64, we're only describing half of the field here (to match GDB's expectations). While we happen to get the half we're interested in on an LE system, on a BE system this will point at the zeroed half.
Yup, I think you're right. It's almost as if this hasn't been tested on a BE system.
Given that a large proportion of this CC list *do* actually care about BE, I'd like to see a tested-by from one of them before this gets merged. I'm pretty sure GDB has a testsuite which might be of some use.
Having said that, our ptrace interface (built around regsets) treats pstate as 64-bit, so we should do the same thing for kgdb and let GDB work out which bits it's interested in.
So: make pstate 8 bytes and test/fix GDB to deal with that (like it should do for userspace already).
I have tested with BE & LE. it works fine except displaying 'pstate' contents in BE is wrong
If I change pstate offset as below, it works
#ifdef __AARCH64EB__ { "pstate", 4, offsetof(struct pt_regs, pstate) + 4}, #else { "pstate", 4, offsetof(struct pt_regs, pstate)}, #endif
I am checking with tool chain guy to patch GDB to make pstate as 8 bytes. After that, I will re-send the patch series
Will