Hi Christoph,
Thank you for review.
Christoph Hellwig wrote:
> You might want to run this past linux-arch to make sure this is suitable
> for other architectures.
Frankly, I'm not sure about linux-arch, could you explain it?
Anyway, I'm interested in that idea.
>> --- a/arch/x86/include/asm/ptrace.h
>> +++ b/arch/x86/include/asm/ptrace.h
>> @@ -7,6 +7,7 @@
>>
>> #ifdef __KERNEL__
>> #include <asm/segment.h>
>> +#include <asm/page_types.h>
>> #endif
>
> I really wonder if we should split asm/ptrace.h into one file
> just defining pt_regs both for userspace and the kernel, and one with
> all kinds of register access helpers and maybe another one for the
> ptrace architecture interface.
Agreed, pt_regs is used more broadly than ptrace itself in kernel.
> Unforuntately we would have to keep the ptrace.h name for the one
> carrying pt_regs as it's exposed to userland.
Perhaps, we should split pt_regs from ptrace.h, like as ptrace-regs.h.
>> +static inline unsigned long get_register(struct pt_regs *regs, unsigned offset)
>> +{
>
> I woner if all these names aren't a bit generic. Shoud we maybe add a
> regs_ prefix to make it clear it operates on a pt_regs register set?
Indeed.
> Also some kerneldoc documentation for all these helpers would be nice.
Sure.
>> +/* Get Nth argument at function call */
>> +static inline unsigned long get_argument_nth(struct pt_regs *regs, unsigned n)
>> +{
>> +#ifdef CONFIG_X86_32
>> +#define NR_REGPARMS 3
>
> I think completely separate version for 32 vs 64 bit for this one would
> be cleaner.
Agreed,
>
>> + if (n < NR_REGPARMS) {
>> + switch (n) {
>> + case 0: return regs->ax;
>> + case 1: return regs->dx;
>> + case 2: return regs->cx;
>> + }
>
> Normal kernel style would be
>
> switch (n) {
> case 0:
> return regs->ax;
> case 1:
> return regs->dx;
> case 2:
> return regs->cx;
> }
Oops, thanks,
>
>> +#define REG_OFFSET(r) offsetof(struct pt_regs, r)
>> +#define REG_OFFSET_NAME(r) {.name = #r, .offset = REG_OFFSET(r)}
>> +#define REG_OFFSET_END {.name = NULL, .offset = 0}
>
> At least the REG_OFFSET macro seems superflous to me.
>
Exactly.
Thank you again!
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division
e-mail: mhiramat@xxxxxxxxxx
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