From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@ozlabs.org
Cc: npiggin@gmail.com
Subject: Re: [1/3] powerpc: Split user/kernel definitions of struct pt_regs
Date: Mon, 15 Oct 2018 15:01:13 +1100 (AEDT) [thread overview]
Message-ID: <42YPrB1H6nz9sj2@ozlabs.org> (raw)
In-Reply-To: <20181013105646.5147-1-mpe@ellerman.id.au>
On Sat, 2018-10-13 at 10:56:44 UTC, Michael Ellerman wrote:
> We use a shared definition for struct pt_regs in uapi/asm/ptrace.h.
> That means the layout of the structure is ABI, ie. we can't change it.
>
> That would be fine if it was only used to describe the user-visible
> register state of a process, but it's also the struct we use in the
> kernel to describe the registers saved in an interrupt frame.
>
> We'd like more flexibility in the content (and possibly layout) of the
> kernel version of the struct, but currently that's not possible.
>
> So split the definition into a user-visible definition which remains
> unchanged, and a kernel internal one.
>
> At the moment they're still identical, and we check that at build
> time. That's because we have code (in ptrace etc.) that assumes that
> they are the same. We will fix that code in future patches, and then
> we can break the strict symmetry between the two structs.
>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Series applied to powerpc next.
https://git.kernel.org/powerpc/c/002af9391bfbe84f8e491bb10bd9c6
cheers
prev parent reply other threads:[~2018-10-15 4:46 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-13 10:56 [PATCH 1/3] powerpc: Split user/kernel definitions of struct pt_regs Michael Ellerman
2018-10-13 10:56 ` [PATCH 2/3] powerpc/ptrace: Don't use sizeof(struct pt_regs) in ptrace code Michael Ellerman
2018-10-13 10:56 ` [PATCH 3/3] powerpc/64: Interrupts save PPR on stack rather than thread_struct Michael Ellerman
2018-10-13 12:27 ` [PATCH 1/3] powerpc: Split user/kernel definitions of struct pt_regs Nicholas Piggin
2018-10-15 12:02 ` Michael Ellerman
2018-10-14 6:36 ` Madhavan Srinivasan
2018-10-15 11:08 ` Michael Ellerman
2018-10-15 12:39 ` Madhavan Srinivasan
2018-10-16 10:50 ` Michael Ellerman
2018-10-15 4:01 ` Michael Ellerman [this message]
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