From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch <linux-arch@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
David Miller <davem@davemloft.net>,
Tony Luck <tony.luck@intel.com>, Will Deacon <will@kernel.org>
Subject: Re: [PATCH 18/41] regset: new method and helpers for it
Date: Tue, 30 Jun 2020 20:40:12 +0100 [thread overview]
Message-ID: <20200630194012.GH2786714@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAHk-=whAuAEXw1s2jF01nmT7iPWEeRv+ggKgCJ1U96-6KGgCmg@mail.gmail.com>
On Tue, Jun 30, 2020 at 09:53:12AM -0700, Linus Torvalds wrote:
> On Tue, Jun 30, 2020 at 6:25 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > How about ->regset_get()?
>
> Sounds good to me. And if you ever do something similar for 'set', you
> have a natural name to pick.
Umm... Something similar for 'set' would, AFAICS, work reasonably well
with the following primitives.
membuf_read(&from, data, size) -- copy min(size, amount left)
membuf_fetch(&from, data) -- copy min(sizeof(data), amount left) into data
(obviously a macro)
membuf_skip(&from, size) -- obvious
membuf_pick(&from, size), along the lines of
if (unlikely(size > p->left)
return ERR_PTR(-EINVAL);
res = p->p;
p->p += size;
p->left -= size;
return res;
So it would be something like
int regset_tls_set(struct task_struct *target, const struct user_regset *regset,
struct membuf from)
{
const struct user_desc *info;
int n = from.left / sizeof(*info);
int i;
info = membuf_pick(&from, n * sizeof(*info)); // can't fail here
for (i = 0; i < n; i++)
if (!tls_desc_okay(info + i))
return -EINVAL;
set_tls_desc(target, GDT_ENTRY_TLS_MIN, info, n);
return 0;
}
and
static int genregs32_set(struct task_struct *target,
const struct user_regset *regset,
struct membuf from)
{
int err;
unsigned pos, v;
for (pos = 0; from.left; pos += sizeof(u32)) {
membuf_fetch(&from, v);
err = putreg32(target, pos, v);
if (err)
return err;
}
return 0;
}
or
/*
* Copy the supplied 64-bit NT_MIPS_DSP buffer to the DSP context.
*/
static int dsp64_set(struct task_struct *target,
const struct user_regset *regset,
struct membuf from)
{
if (!cpu_has_dsp)
return -EIO;
membuf_read(&from, target->thread.dsp.dspr, NUM_DSP_REGS * sizeof(u64));
return membuf_read(&from, target->thread.dsp.dspcontrol, sizeof(u64));
}
etc.
next prev parent reply other threads:[~2020-06-30 19:40 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-29 18:23 [RFC][PATCHSET] regset ->get() rework Al Viro
2020-06-29 18:25 ` [PATCH 01/41] introduction of regset ->get() wrappers, switching ELF coredumps to those Al Viro
2020-06-29 18:25 ` [PATCH 02/41] x86: copy_fpstate_to_sigframe(): have fpregs_soft_get() use kernel buffer Al Viro
2020-06-29 18:25 ` [PATCH 03/41] x86: kill dump_fpu() Al Viro
2020-06-29 18:25 ` [PATCH 04/41] [ia64] sanitize elf_access_gpreg() Al Viro
2020-06-29 18:25 ` [PATCH 05/41] [ia64] teach elf_access_reg() to handle the missing range (r16..r31) Al Viro
2020-06-29 18:25 ` [PATCH 06/41] [ia64] regularize do_gpregs_[gs]et() Al Viro
2020-06-29 18:25 ` [PATCH 07/41] [ia64] access_uarea(): stop bothering with gpregs_[gs]et() Al Viro
2020-06-29 18:25 ` [PATCH 08/41] [ia64] access_uarea(): don't bother with fpregs_[gs]et() Al Viro
2020-06-29 18:25 ` [PATCH 09/41] sparc64: switch genregs32_get() to use of get_from_target() Al Viro
2020-06-29 18:25 ` [PATCH 10/41] sparc32: get rid of odd callers of copy_regset_to_user() Al Viro
2020-06-29 18:25 ` [PATCH 11/41] sparc64: " Al Viro
2020-06-29 18:25 ` [PATCH 12/41] sparc32: get rid of odd callers of copy_regset_from_user() Al Viro
2020-06-29 18:26 ` [PATCH 13/41] sparc64: " Al Viro
2020-06-29 18:26 ` [PATCH 14/41] arm64: take fetching compat reg out of pt_regs into a new helper Al Viro
2020-06-29 18:26 ` [PATCH 15/41] arm64: get rid of copy_regset_to_user() in compat_ptrace_read_user() Al Viro
2020-06-29 18:26 ` [PATCH 16/41] arm64: sanitize compat_ptrace_write_user() Al Viro
2020-06-29 18:26 ` [PATCH 17/41] copy_regset_to_user(): do all copyout at once Al Viro
2020-06-29 18:26 ` [PATCH 18/41] regset: new method and helpers for it Al Viro
2020-06-29 19:23 ` Linus Torvalds
2020-06-29 20:30 ` Al Viro
2020-06-30 13:25 ` Al Viro
2020-06-30 16:53 ` Linus Torvalds
2020-06-30 19:40 ` Al Viro [this message]
2020-06-29 18:26 ` [PATCH 19/41] x86: switch to ->get2() Al Viro
2020-06-29 18:26 ` [PATCH 20/41] powerpc: " Al Viro
2020-06-29 18:26 ` [PATCH 21/41] s390: " Al Viro
2020-06-29 18:26 ` [PATCH 22/41] sparc: " Al Viro
2020-06-30 13:16 ` Al Viro
2020-06-29 18:26 ` [PATCH 23/41] mips: " Al Viro
2020-06-29 18:26 ` [PATCH 24/41] arm64: " Al Viro
2020-06-29 18:26 ` [PATCH 25/41] sh: convert " Al Viro
2020-06-29 18:26 ` [PATCH 26/41] arm: switch " Al Viro
2020-06-29 18:26 ` [PATCH 27/41] arc: " Al Viro
2020-06-29 18:26 ` [PATCH 28/41] ia64: " Al Viro
2020-06-29 18:26 ` [PATCH 29/41] c6x: " Al Viro
2020-06-29 18:26 ` [PATCH 30/41] riscv: " Al Viro
2020-06-29 18:26 ` [PATCH 31/41] openrisc: " Al Viro
2020-06-29 18:26 ` [PATCH 32/41] h8300: " Al Viro
2020-06-29 18:26 ` [PATCH 33/41] hexagon: " Al Viro
2020-08-11 18:35 ` Brian Cain
2020-06-29 18:26 ` [PATCH 34/41] nios2: " Al Viro
2020-06-29 18:26 ` [PATCH 35/41] nds32: " Al Viro
2020-06-29 18:26 ` [PATCH 36/41] parisc: " Al Viro
2020-06-29 18:26 ` [PATCH 37/41] xtensa: " Al Viro
2020-06-29 18:26 ` [PATCH 38/41] csky: " Al Viro
2020-06-29 18:26 ` [PATCH 39/41] regset: kill ->get() Al Viro
2020-06-29 18:26 ` [PATCH 40/41] regset(): kill ->get_size() Al Viro
2020-06-29 18:26 ` [PATCH 41/41] regset: kill user_regset_copyout{,_zero}() Al Viro
2020-07-23 8:00 ` [RFC][PATCHSET] regset ->get() rework Christoph Hellwig
2020-07-23 17:27 ` Al Viro
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