sparc32: get rid of odd callers of copy_regset_to_user()

the life is much simpler if copy_regset_to_user() (and ->get())
gets called only with pos == 0; sparc32 PTRACE_GETREGS and
PTRACE_GETFPREGS are among the few things that use it to fetch
pieces of regset _not_ starting at the beginning.  It's actually
easier to define a separate regset that would provide what
we need, rather than trying to cobble that from the one
PTRACE_GETREGSET uses.

Extra ->get() instances do not amount to much code and once
we get the conversion of ->get() to new API (dependent upon the
lack of weird callers of ->get()) they'll shrink a lot, along
with the rest of ->get() instances...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-05-22 13:19:47 -04:00
parent 030754c995
commit 87d805331a

View File

@ -99,15 +99,13 @@ static int genregs32_get(struct task_struct *target,
if (ret || !count)
return ret;
if (pos < 32 * sizeof(u32)) {
if (regwindow32_get(target, regs, uregs))
return -EFAULT;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
uregs,
16 * sizeof(u32), 32 * sizeof(u32));
if (ret || !count)
return ret;
}
if (regwindow32_get(target, regs, uregs))
return -EFAULT;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
uregs,
16 * sizeof(u32), 32 * sizeof(u32));
if (ret)
return ret;
uregs[0] = regs->psr;
uregs[1] = regs->pc;
@ -288,6 +286,73 @@ static const struct user_regset sparc32_regsets[] = {
},
};
static int getregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
const struct pt_regs *regs = target->thread.kregs;
u32 v[4];
int ret;
if (target == current)
flush_user_windows();
v[0] = regs->psr;
v[1] = regs->pc;
v[2] = regs->npc;
v[3] = regs->y;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
v,
0 * sizeof(u32), 4 * sizeof(u32));
if (ret)
return ret;
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
regs->u_regs + 1,
4 * sizeof(u32), 19 * sizeof(u32));
}
static int getfpregs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
const unsigned long *fpregs = target->thread.float_regs;
int ret = 0;
#if 0
if (target == current)
save_and_clear_fpu();
#endif
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
fpregs,
0, 32 * sizeof(u32));
if (ret)
return ret;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.fsr,
32 * sizeof(u32), 33 * sizeof(u32));
if (ret)
return ret;
return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
33 * sizeof(u32), 68 * sizeof(u32));
}
static const struct user_regset ptrace32_regsets[] = {
[REGSET_GENERAL] = {
.n = 19, .size = sizeof(u32), .get = getregs_get,
},
[REGSET_FP] = {
.n = 68, .size = sizeof(u32), .get = getfpregs_get,
},
};
static const struct user_regset_view ptrace32_view = {
.regsets = ptrace32_regsets, .n = ARRAY_SIZE(ptrace32_regsets)
};
static const struct user_regset_view user_sparc32_view = {
.name = "sparc", .e_machine = EM_SPARC,
.regsets = sparc32_regsets, .n = ARRAY_SIZE(sparc32_regsets)
@ -327,15 +392,10 @@ long arch_ptrace(struct task_struct *child, long request,
switch(request) {
case PTRACE_GETREGS: {
ret = copy_regset_to_user(child, view, REGSET_GENERAL,
32 * sizeof(u32),
4 * sizeof(u32),
&pregs->psr);
if (!ret)
copy_regset_to_user(child, view, REGSET_GENERAL,
1 * sizeof(u32),
15 * sizeof(u32),
&pregs->u_regs[0]);
ret = copy_regset_to_user(child, &ptrace32_view,
REGSET_GENERAL, 0,
19 * sizeof(u32),
pregs);
break;
}
@ -353,23 +413,10 @@ long arch_ptrace(struct task_struct *child, long request,
}
case PTRACE_GETFPREGS: {
ret = copy_regset_to_user(child, view, REGSET_FP,
0 * sizeof(u32),
32 * sizeof(u32),
&fps->regs[0]);
if (!ret)
ret = copy_regset_to_user(child, view, REGSET_FP,
33 * sizeof(u32),
1 * sizeof(u32),
&fps->fsr);
if (!ret) {
if (__put_user(0, &fps->fpqd) ||
__put_user(0, &fps->flags) ||
__put_user(0, &fps->extra) ||
clear_user(fps->fpq, sizeof(fps->fpq)))
ret = -EFAULT;
}
ret = copy_regset_to_user(child, &ptrace32_view,
REGSET_FP, 0,
68 * sizeof(u32),
fps);
break;
}