There is no wonky.
Field pc in blackfin struct pt_regs is the same as reti register.
gdb_regs[BFIN_RETI] = regs->pc;
Field BFIN_PC in array gdb_regs contains the address which gdb thinks the
kernel should resume from. And field retx is the resume address on current
kernel stack.
regs->retx = gdb_regs[BFIN_PC];
Jason's patch is fine to me.
Sonic
-----Original Message-----
From: Mike Frysinger [mailto:vapier.adi@xxxxxxxxx]
Sent: Sunday, December 27, 2009 5:12 AM
To: Jason Wessel
Cc: linux-kernel@xxxxxxxxxxxxxxx; kgdb-bugreport@xxxxxxxxxxxxxxxxxxxxx;
kdb@xxxxxxxxxxx; mingo@xxxxxxx; 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 <vapier@xxxxxxxxxx>
> Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
> ---
> arch/blackfin/kernel/kgdb.c | 5 +++++
> 1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/arch/blackfin/kernel/kgdb.c b/arch/blackfin/kernel/kgdb.c
> 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)
> return bfin_probe_kernel_write((char *)addr, bundle,
> BREAK_INSTR_SIZE);
> }
>
> +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) {
> + regs->retx = ip;
> +}
> +
> int kgdb_arch_init(void)
> {
> kgdb_single_step = 0;
Sonic should be able to check this. our 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 *regs) { ...
gdb_regs[BFIN_RETI] = regs->pc;
gdb_regs[BFIN_RETX] = regs->retx;
gdb_regs[BFIN_PC] = regs->pc;
...
}
...
void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) { ...
regs->pc = gdb_regs[BFIN_PC];
regs->retx = gdb_regs[BFIN_PC];
/* nothing for BFIN_RETI */
...
}
-mike
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