Re: [PATCH x86/mm 08/11] x86 ia32 ptrace getreg/putreg merge

Christoph Hellwig
2007-11-29T17:37:50Z

On Thu, Nov 29, 2007 at 04:00:31AM -0800, Roland McGrath wrote:
> +#define R32(l,q) \
> + case offsetof(struct user32, regs.l): \
> + regs->q = value; break
> +
> +#define SEG32(rs) \
> + case offsetof(struct user32, regs.rs): \
> + return set_segment_reg(child, \
> + offsetof(struct user_regs_struct, rs), \
> + value); \
> + break

The code would be a lot more readable if you just opencoded this in the
caller instead of these obsfucated macros.

> +
> +static int putreg32(struct task_struct *child, unsigned regno, u32 value)
> +{
> + struct pt_regs *regs = task_pt_regs(child);
> +
> + switch (regno) {
> +
> + SEG32(cs);
> + SEG32(ds);
> + SEG32(es);
> + SEG32(fs);
> + SEG32(gs);
> + SEG32(ss);
> +
> + R32(ebx, bx);
> + R32(ecx, cx);
> + R32(edx, dx);
> + R32(edi, di);
> + R32(esi, si);
> + R32(ebp, bp);
> + R32(eax, ax);
> + R32(orig_eax, orig_ax);
> + R32(eip, ip);
> + R32(esp, sp);
> +
> + case offsetof(struct user32, regs.eflags):
> + return set_flags(child, value);
> +
> + case offsetof(struct user32, u_debugreg[0]) ...
> + offsetof(struct user32, u_debugreg[7]):
> + regno -= offsetof(struct user32, u_debugreg[0]);
> + return ptrace_set_debugreg(child, regno / 4, value);
> +
> + default:
> + if (regno > sizeof(struct user32) || (regno & 3))
> + return -EIO;
> +
> + /*
> + * Other dummy fields in the virtual user structure
> + * are ignored
> + */
> + break;
> + }
> + return 0;
> +}
> +
> +#undef R32
> +#undef SEG32
> +
> +#define R32(l,q) \
> + case offsetof(struct user32, regs.l): \
> + *val = regs->q; break
> +
> +#define SEG32(rs) \
> + case offsetof(struct user32, regs.rs): \
> + *val = get_segment_reg(child, \
> + offsetof(struct user_regs_struct, rs)); \
> + break
> +
> +static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
> +{
> + struct pt_regs *regs = task_pt_regs(child);
> +
> + switch (regno) {
> +
> + SEG32(ds);
> + SEG32(es);
> + SEG32(fs);
> + SEG32(gs);
> +
> + R32(cs, cs);
> + R32(ss, ss);
> + R32(ebx, bx);
> + R32(ecx, cx);
> + R32(edx, dx);
> + R32(edi, di);
> + R32(esi, si);
> + R32(ebp, bp);
> + R32(eax, ax);
> + R32(orig_eax, orig_ax);
> + R32(eip, ip);
> + R32(esp, sp);
> +
> + case offsetof(struct user32, regs.eflags):
> + *val = get_flags(child);
> + break;
> +
> + case offsetof(struct user32, u_debugreg[0]) ...
> + offsetof(struct user32, u_debugreg[7]):
> + regno -= offsetof(struct user32, u_debugreg[0]);
> + *val = ptrace_get_debugreg(child, regno / 4);
> + break;
> +
> + default:
> + if (regno > sizeof(struct user32) || (regno & 3))
> + return -EIO;
> +
> + /*
> + * Other dummy fields in the virtual user structure
> + * are ignored
> + */
> + *val = 0;
> + break;
> + }
> + return 0;
> +}
> +
> +#undef R32
> +#undef SEG32
> +
> +#endif /* CONFIG_IA32_EMULATION */
> +
> #ifdef CONFIG_X86_32
>
> void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
> -
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