On Fri, 12 Jan 2007, Michael Schmitz wrote:
Does anyone know why the PT_* definitions in include/asm-m68k/ptrace.h:
| #define PT_D1 0
| #define PT_D2 1
| #define PT_D3 2
| #define PT_D4 3
| #define PT_D5 4
| #define PT_D6 5
| #define PT_D7 6
| #define PT_A0 7
| #define PT_A1 8
| #define PT_A2 9
| #define PT_A3 10
| #define PT_A4 11
| #define PT_A5 12
| #define PT_A6 13
| #define PT_D0 14
| #define PT_USP 15
| #define PT_ORIG_D0 16
| #define PT_SR 17
| #define PT_PC 18
don't match with the PT_* definitions in include/asm-m68k/asm-offsets.h:
| #define PT_D0 32 /* offsetof(struct pt_regs, d0) */
| #define PT_ORIG_D0 36 /* offsetof(struct pt_regs, orig_d0) */
| #define PT_D1 0 /* offsetof(struct pt_regs, d1) */
| #define PT_D2 4 /* offsetof(struct pt_regs, d2) */
| #define PT_D3 8 /* offsetof(struct pt_regs, d3) */
| #define PT_D4 12 /* offsetof(struct pt_regs, d4) */
| #define PT_D5 16 /* offsetof(struct pt_regs, d5) */
| #define PT_A0 20 /* offsetof(struct pt_regs, a0) */
| #define PT_A1 24 /* offsetof(struct pt_regs, a1) */
| #define PT_A2 28 /* offsetof(struct pt_regs, a2) */
| #define PT_PC 46 /* offsetof(struct pt_regs, pc) */
| #define PT_SR 44 /* offsetof(struct pt_regs, sr) */
| #define PT_VECTOR 50 /* offsetof(struct pt_regs, pc) + 4 */
as generated from struct pt_regs in include/asm-m68k/ptrace.h:
| struct pt_regs {
| long d1;
| long d2;
| long d3;
| long d4;
| long d5;
| long a0;
| long a1;
| long a2;
| long d0;
| long orig_d0;
| long stkadj;
| unsigned short sr;
| unsigned long pc;
| unsigned format : 4; /* frame format specifier */
| unsigned vector : 12; /* vector offset */
| };
Looks like the PT_* offsets are in units of long, but otherwise correct?
Nope, we have PT_D7, but no pt_regs.d7.
I was trying to define task_thread_info() using TASK_INFO instead of using
struct task_struct directly (cfr. ia64), but these conflicts seem to prevent me
from doing this.
At some time in the past (2.6.13??) I had tried to do something similar
while debugging the Atari interrupt problems (the asm interrupt entries
used wrong offsets to tweak preempt_count() at that time). I gave up in
the end... If I understand Linus' suggestion right, he says we should take
the task struct from the stack instead of going over current (which we
keep in a2, and prefer to use for that reason)?
Yep, that's what he suggests. But we do it differently for `a good reason'.
Unfortunately I don't remember what good reason it was. Yesterday evening I
searched my lkml archives of 2005 and 2006, but apart from Roman and Al
agreeing we have `a good reason', I couldn't find it.
Roman, can you please refresh my (aging) brain?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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