On Monday 13 July 2009, liqin.chen@xxxxxxxxxxxxx wrote:
>
> unsigned long pad0[6];
>
> was place at the start of pt_regs use
> to hold the arguments from userland.
> caller(exception handler) not need to
> change stack pointer.
>
> unsigned long orig_r4;
> unsigned long orig_r7;
> move to end of the pt_regs haven't
> problem.
Ok, I see.
Maybe to get a nicer layout, you can define separate
structures then:
struct user_regs_struct {
unsigned long regs[32];
unsigned long cel;
unsigned long ceh;
unsigned long sr0; /* cnt */
unsigned long sr1; /* lcr */
unsigned long sr2; /* scr */
unsigned long cp0_epc;
unsigned long cp0_ema;
unsigned long cp0_psr;
unsigned long cp0_ecr;
unsigned long cp0_condition;
unsigned long reserved[6]; /* future extensions */
};
#ifdef __KERNEL__
struct pt_regs {
/* stack arguments */
unsigned long pad0[6];
/* internal use */
unsigned long orig_r4;
unsigned long orig_r7;
long is_syscall;
/* saved registers */
struct user_regs_struct uregs;
};
#endif
That would keep the user struct relatively clean.
Arnd <><
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