From: Borislav Petkov <bp@alien8.de>
To: ira.weiny@intel.com
Cc: Rik van Riel <riel@surriel.com>,
Dave Hansen <dave.hansen@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com
Subject: Re: [RFC PATCH 2/5] entry: Add calls for save/restore auxiliary pt_regs
Date: Tue, 9 Aug 2022 14:05:15 +0200 [thread overview]
Message-ID: <YvJNe2rzXfcogFFX@zn.tnic> (raw)
In-Reply-To: <20220805173009.3128098-3-ira.weiny@intel.com>
On Fri, Aug 05, 2022 at 10:30:06AM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> Some architectures have auxiliary pt_regs space available to store
> information on the stack during exceptions. This information is easier
> to obtain and store within C code rather than in arch specific assembly.
There are others?
Because I would've done this whole thing in arch/x86/ only...
> diff --git a/kernel/entry/common.c b/kernel/entry/common.c
> index 8c0f334c4b75..a70a0f314aee 100644
> --- a/kernel/entry/common.c
> +++ b/kernel/entry/common.c
> @@ -317,7 +317,7 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
>
> if (user_mode(regs)) {
> irqentry_enter_from_user_mode(regs);
> - return ret;
> + goto aux_save;
Why do you have to goto and do the instrumentation sandwitch around it
at the goto label?
Why not simply do
if (user_mode(regs)) {
irqentry_enter_from_user_mode(regs);
arch_save_aux_pt_regs(regs);
return ret;
and so on?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2022-08-09 12:05 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-05 17:30 [RFC PATCH 0/5] Print CPU at segfault time ira.weiny
2022-08-05 17:30 ` [RFC PATCH 1/5] entry: Pass pt_regs to irqentry_exit_cond_resched() ira.weiny
2022-08-05 18:33 ` Rik van Riel
2022-08-08 10:38 ` Borislav Petkov
2022-08-08 17:34 ` Ira Weiny
2022-08-08 17:38 ` Borislav Petkov
2022-08-08 17:43 ` Dave Hansen
2022-08-08 17:52 ` Borislav Petkov
2022-08-09 23:18 ` Thomas Gleixner
2022-08-10 7:25 ` Thomas Gleixner
2022-08-05 17:30 ` [RFC PATCH 2/5] entry: Add calls for save/restore auxiliary pt_regs ira.weiny
2022-08-05 18:34 ` Rik van Riel
2022-08-09 12:05 ` Borislav Petkov [this message]
2022-08-09 18:38 ` Ira Weiny
2022-08-09 18:49 ` Borislav Petkov
2022-08-09 21:14 ` Thomas Gleixner
2022-08-09 21:38 ` Borislav Petkov
2022-08-09 22:33 ` Ira Weiny
2022-08-09 21:49 ` Ira Weiny
2022-08-09 23:53 ` Thomas Gleixner
2022-08-05 17:30 ` [RFC PATCH 3/5] x86/entry: Add auxiliary pt_regs space ira.weiny
2022-08-05 18:45 ` Rik van Riel
2022-08-05 17:30 ` [RFC PATCH 4/5] x86,mm: print likely CPU at segfault time ira.weiny
2022-08-05 17:30 ` [RFC PATCH 5/5] x86/entry: Store CPU info on exception entry ira.weiny
2022-08-05 18:46 ` Rik van Riel
2022-08-05 18:47 ` Dave Hansen
2022-08-06 9:01 ` Ingo Molnar
2022-08-06 9:11 ` Borislav Petkov
2022-08-07 10:02 ` Ingo Molnar
2022-08-07 10:35 ` Borislav Petkov
2022-08-07 20:02 ` Ira Weiny
2022-08-08 11:03 ` Ingo Molnar
2022-08-08 12:01 ` Borislav Petkov
2022-08-09 20:06 ` Thomas Gleixner
2022-08-08 16:16 ` Dave Hansen
2022-08-08 17:24 ` Rik van Riel
2022-08-09 21:19 ` Andy Lutomirski
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