From: Simon Marchi <simark@simark.ca>
To: John Baldwin <jhb@FreeBSD.org>, gdb-patches@sourceware.org
Cc: Aleksandar Paunovic <aleksandar.paunovic@intel.com>
Subject: Re: [PATCH v4 01/13] x86: Add an x86_xsave_layout structure to handle variable XSAVE layouts.
Date: Mon, 10 Apr 2023 21:19:25 -0400 [thread overview]
Message-ID: <d1c76d6c-eefd-17bc-8162-73baf62af8fb@simark.ca> (raw)
In-Reply-To: <113146d6-48af-f0a3-0e87-4495a4529ca0@FreeBSD.org>
>>> +i386_fetch_xsave_layout ()
>>> +{
>>> + struct x86_xsave_layout layout;
>>> + LONGEST len = target_read (current_inferior ()->top_target (),
>>> + TARGET_OBJECT_X86_XSAVE_LAYOUT, nullptr,
>>> + (gdb_byte *) &layout, 0, sizeof (layout));
>>> + if (len != sizeof (layout))
>>> + return {};
>>
>> Do you have an idea of which conditions can make it so `len != sizeof
>> (layout)`? If I understand correctly, the contract for
>> TARGET_OBJECT_X86_XSAVE_LAYOUT is that the caller passes a pointer to an
>> x86_xsave_layout object and the callee fills it. This is all internal
>> to GDB. I don't imagine how a target could return something else than
>> ;`sizeof (layout)` (indicating success) or TARGET_XFER_E_IO (indicating
>> failure), other than being buggy.
>>
>> All of this to say, should it be an assert?
>
> Hmm, in the case of TARGET_XFER_E_IO this function needs to return an
> empty object (e.g. for native targets that don't support XSAVE at all).
>
> I should perhaps make it check for an error explicitly and then assert
> that otherwise they are equal?
That sounds good. My thinking is that if a target mistakenly returns a
wrong length, I think we want to know about it, and not silently presume
the target doesn't support the xsave layout query.
Simon
next prev parent reply other threads:[~2023-04-11 1:19 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-18 1:08 [PATCH v4 00/13] Handle " John Baldwin
2023-03-18 1:08 ` [PATCH v4 01/13] x86: Add an x86_xsave_layout structure to handle " John Baldwin
2023-03-28 11:35 ` George, Jini Susan
2023-04-10 19:28 ` John Baldwin
2023-04-06 19:09 ` Simon Marchi
2023-04-10 20:03 ` John Baldwin
2023-04-11 1:19 ` Simon Marchi [this message]
2023-04-11 14:23 ` Pedro Alves
2023-04-11 16:02 ` John Baldwin
2023-03-18 1:08 ` [PATCH v4 02/13] core: Support fetching TARGET_OBJECT_X86_XSAVE_LAYOUT from architectures John Baldwin
2023-04-06 19:28 ` Simon Marchi
2023-04-10 20:42 ` John Baldwin
2023-04-11 1:49 ` Simon Marchi
2023-04-11 16:06 ` John Baldwin
2023-04-11 16:21 ` Simon Marchi
2023-04-11 23:59 ` John Baldwin
2023-03-18 1:08 ` [PATCH v4 03/13] nat/x86-cpuid.h: Add x86_cpuid_count wrapper around __get_cpuid_count John Baldwin
2023-04-06 19:33 ` Simon Marchi
2023-04-10 20:49 ` John Baldwin
2023-04-11 1:49 ` Simon Marchi
2023-03-18 1:08 ` [PATCH v4 04/13] x86 nat: Add helper functions to save the XSAVE layout for the host John Baldwin
2023-04-06 19:40 ` Simon Marchi
2023-04-10 21:00 ` John Baldwin
2023-04-11 1:51 ` Simon Marchi
2023-03-18 1:08 ` [PATCH v4 05/13] gdb: Update x86 FreeBSD architectures to support XSAVE layouts John Baldwin
2023-04-06 19:54 ` Simon Marchi
2023-04-10 21:02 ` John Baldwin
2023-04-11 1:55 ` Simon Marchi
2023-03-18 1:08 ` [PATCH v4 06/13] gdb: Support XSAVE layouts for the current host in the FreeBSD x86 targets John Baldwin
2023-04-06 20:18 ` Simon Marchi
2023-04-10 21:27 ` John Baldwin
2023-04-11 2:23 ` Simon Marchi
2023-04-11 16:19 ` John Baldwin
2023-04-11 16:46 ` Simon Marchi
2023-04-11 21:37 ` John Baldwin
2023-04-11 22:35 ` John Baldwin
2023-04-12 14:35 ` Simon Marchi
2023-03-18 1:08 ` [PATCH v4 07/13] gdb: Update x86 Linux architectures to support XSAVE layouts John Baldwin
2023-04-07 1:43 ` Simon Marchi
2023-04-10 21:29 ` John Baldwin
2023-03-18 1:09 ` [PATCH v4 08/13] gdb: Support XSAVE layouts for the current host in the Linux x86 targets John Baldwin
2023-04-07 1:54 ` Simon Marchi
2023-03-18 1:09 ` [PATCH v4 09/13] gdb: Use x86_xstate_layout to parse the XSAVE extended state area John Baldwin
2023-04-07 2:13 ` Simon Marchi
2023-04-10 21:40 ` John Baldwin
2023-03-18 1:09 ` [PATCH v4 10/13] gdbserver: Add a function to set the XSAVE mask and size John Baldwin
2023-04-12 15:08 ` Simon Marchi
2023-04-27 17:24 ` John Baldwin
2023-03-18 1:09 ` [PATCH v4 11/13] gdbserver: Refactor the legacy region within the xsave struct John Baldwin
2023-04-12 18:34 ` Simon Marchi
2023-04-27 19:51 ` John Baldwin
2023-03-18 1:09 ` [PATCH v4 12/13] gdbserver: Read offsets of the XSAVE extended region via CPUID John Baldwin
2023-04-11 14:46 ` Pedro Alves
2023-04-11 16:25 ` John Baldwin
2023-04-12 19:11 ` Simon Marchi
2023-04-12 21:07 ` John Baldwin
2023-04-13 15:07 ` Simon Marchi
2023-03-18 1:09 ` [PATCH v4 13/13] x86: Remove X86_XSTATE_SIZE and related constants John Baldwin
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