Re: [PATCH 09/37] kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin

I have to recall my last wrong patch.

In blackfin, kgdb is running in delayed exception IRQ5 other than in
exception IRQ3 directly.  Register reti other than retx in pt_regs is
the kgdb return address. So, don't put PC in gdb_regs into retx.

Sonic Zhang

Index: arch/blackfin/kernel/kgdb.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D
--- arch/blackfin/kernel/kgdb.c	(revision 8105)
+++ arch/blackfin/kernel/kgdb.c	(revision 8106)
@@ -147,7 +147,7 @@
 	regs->lb1 =3D gdb_regs[BFIN_LB1];
 	regs->usp =3D gdb_regs[BFIN_USP];
 	regs->syscfg =3D gdb_regs[BFIN_SYSCFG];
-	regs->retx =3D gdb_regs[BFIN_PC];
+	regs->retx =3D gdb_regs[BFIN_RETX];
 	regs->retn =3D gdb_regs[BFIN_RETN];
 	regs->rete =3D gdb_regs[BFIN_RETE];
 	regs->pc =3D gdb_regs[BFIN_PC];



On Mon, Dec 28, 2009 at 6:17 PM, Zhang, Sonic <[email protected]> =
wrote:
> A little update.
>
> GDB uses field BFIN_PC as the resume address from debugging mode. But=
, field pc in struct pt_regs is where kernel resumes from an interrupt.=
 So, BFIN_PC is actually retx when do kernel debugging.
>
>
> Sonic
>
>
> --- trunk/arch/blackfin/kernel/kgdb.c =A0 2009-12-28 09:27:27 UTC (re=
v 8085)
> +++ trunk/arch/blackfin/kernel/kgdb.c =A0 2009-12-28 10:08:30 UTC (re=
v 8086)
> @@ -79,7 +79,7 @@
> =A0 =A0 =A0 =A0gdb_regs[BFIN_RETX] =3D regs->retx;
> =A0 =A0 =A0 =A0gdb_regs[BFIN_RETN] =3D regs->retn;
> =A0 =A0 =A0 =A0gdb_regs[BFIN_RETE] =3D regs->rete;
> - =A0 =A0 =A0 gdb_regs[BFIN_PC] =3D regs->pc;
> + =A0 =A0 =A0 gdb_regs[BFIN_PC] =3D regs->retx;
> =A0 =A0 =A0 =A0gdb_regs[BFIN_CC] =3D 0;
> =A0 =A0 =A0 =A0gdb_regs[BFIN_EXTRA1] =3D 0;
> =A0 =A0 =A0 =A0gdb_regs[BFIN_EXTRA2] =3D 0;
> @@ -150,7 +150,7 @@
> =A0 =A0 =A0 =A0regs->retx =3D gdb_regs[BFIN_PC];
> =A0 =A0 =A0 =A0regs->retn =3D gdb_regs[BFIN_RETN];
> =A0 =A0 =A0 =A0regs->rete =3D gdb_regs[BFIN_RETE];
> - =A0 =A0 =A0 regs->pc =3D gdb_regs[BFIN_PC];
> + =A0 =A0 =A0 regs->pc =3D gdb_regs[BFIN_RETI];
>
> =A0#if 0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0/* can't =
change these */
> =A0 =A0 =A0 =A0regs->astat =3D gdb_regs[BFIN_ASTAT];
>
>
>
>
> -----Original Message-----
> From: Mike Frysinger [mailto:[email protected]]
> Sent: Sunday, December 27, 2009 5:12 AM
> To: Jason Wessel
> Cc: [email protected]; [email protected]=
t; [email protected]; [email protected]; Zhang, Sonic
> Subject: Re: [PATCH 09/37] kgdb,blackfin: Add in kgdb_arch_set_pc for=
 blackfin
>
> On Wed, Dec 23, 2009 at 16:19, Jason Wessel wrote:
>> The new debug core api requires all architectures that use to debug
>> core to implement a function to set the program counter.
>>
>> CC: Mike Frysinger <[email protected]>
>> Signed-off-by: Jason Wessel <[email protected]>
>> ---
>> =A0arch/blackfin/kernel/kgdb.c | =A0 =A05 +++++
>> =A01 files changed, 5 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/blackfin/kernel/kgdb.c b/arch/blackfin/kernel/kgdb=
=2Ec
>> index f1036b6..5965188 100644
>> --- a/arch/blackfin/kernel/kgdb.c
>> +++ b/arch/blackfin/kernel/kgdb.c
>> @@ -644,6 +644,11 @@ int kgdb_arch_remove_breakpoint(unsigned long
>> addr, char *bundle)
>> =A0 =A0 =A0 =A0return bfin_probe_kernel_write((char *)addr, bundle,
>> BREAK_INSTR_SIZE);
>> =A0}
>>
>> +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) {
>> + =A0 =A0 =A0 regs->retx =3D ip;
>> +}
>> +
>> =A0int kgdb_arch_init(void)
>> =A0{
>> =A0 =A0 =A0 =A0kgdb_single_step =3D 0;
>
> Sonic should be able to check this. =A0our pc handling seems a little=
 wonky atm:
>
> arch/blackfin/kernel/kgdb.c:
> void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *reg=
s) { ...
> =A0 =A0gdb_regs[BFIN_RETI] =3D regs->pc;
> =A0 =A0gdb_regs[BFIN_RETX] =3D regs->retx;
> =A0 =A0gdb_regs[BFIN_PC] =3D regs->pc;
> ...
> }
> ...
> void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *reg=
s) { ...
> =A0 =A0regs->pc =3D gdb_regs[BFIN_PC];
> =A0 =A0regs->retx =3D gdb_regs[BFIN_PC];
> =A0 =A0/* nothing for BFIN_RETI */
> ...
> }
> -mike
> --
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