From: Ingo Molnar <mingo@kernel.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: X86 ML <x86@kernel.org>, Borislav Petkov <bpetkov@suse.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Brian Gerst <brgerst@gmail.com>,
Dave Hansen <dave.hansen@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH v2 13/20] x86/asm/64: Pass sp0 directly to load_sp0()
Date: Thu, 2 Nov 2017 10:48:13 +0100 [thread overview]
Message-ID: <20171102094813.idw77gu2rarcu4zq@gmail.com> (raw)
In-Reply-To: <2655d8b42ed940aa384fe18ee1129bbbcf730a08.1509609304.git.luto@kernel.org>
* Andy Lutomirski <luto@kernel.org> wrote:
> load_sp0() had an odd signature:
>
> void load_sp0(struct tss_struct *tss, struct thread_struct *thread);
>
> Simplify it to:
>
> void load_sp0(unsigned long sp0);
I also added this to the changelog:
> Also simplify a few get_cpu()/put_cpu() sequences to
> preempt_disable()/preempt_enable().
Plus:
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -1572,7 +1572,7 @@ void cpu_init(void)
> initialize_tlbstate_and_flush();
> enter_lazy_tlb(&init_mm, me);
>
> - load_sp0(t, ¤t->thread);
> + load_sp0(current->thread.sp0);
> set_tss_desc(cpu, t);
> load_TR_desc();
> load_mm_ldt(&init_mm);
> @@ -1627,7 +1627,7 @@ void cpu_init(void)
> initialize_tlbstate_and_flush();
> enter_lazy_tlb(&init_mm, curr);
>
> - load_sp0(t, thread);
> + load_sp0(thread->sp0);
> set_tss_desc(cpu, t);
> load_TR_desc();
> load_mm_ldt(&init_mm);
In the 32-bit path this was the last use of 'thread', making the local variable
unused - I removed it.
Just curious: did you build/boot-test 32-bit kernels, or should we consider it
mostly untested?
Thanks,
Ingo
next prev parent reply other threads:[~2017-11-02 9:48 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-02 7:58 [PATCH v2 00/20] Pile o' entry/exit/sp0 changes Andy Lutomirski
2017-11-02 7:58 ` [PATCH v2 01/20] x86/asm/64: Remove the restore_c_regs_and_iret label Andy Lutomirski
2017-11-02 10:49 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:58 ` [PATCH v2 02/20] x86/asm/64: Split the iret-to-user and iret-to-kernel paths Andy Lutomirski
2017-11-02 10:49 ` [tip:x86/asm] x86/entry/64: Split the IRET-to-user and IRET-to-kernel paths tip-bot for Andy Lutomirski
2017-11-02 10:50 ` [PATCH v2 02/20] x86/asm/64: Split the iret-to-user and iret-to-kernel paths Borislav Petkov
2017-11-02 12:09 ` [PATCH] x86/entry/64: Shorten TEST instructions Borislav Petkov
2017-11-02 12:48 ` [tip:x86/asm] " tip-bot for Borislav Petkov
2017-11-02 7:59 ` [PATCH v2 03/20] x86/asm/64: Move SWAPGS into the common iret-to-usermode path Andy Lutomirski
2017-11-02 10:49 ` [tip:x86/asm] x86/entry/64: Move SWAPGS into the common IRET-to-usermode path tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 04/20] x86/asm/64: Simplify reg restore code in the standard IRET paths Andy Lutomirski
2017-11-02 10:50 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 05/20] x86/asm/64: Shrink paranoid_exit_restore and make labels local Andy Lutomirski
2017-11-02 10:50 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 06/20] x86/asm/64: Use pop instead of movq in syscall_return_via_sysret Andy Lutomirski
2017-11-02 10:51 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 07/20] x86/asm/64: Merge the fast and slow SYSRET paths Andy Lutomirski
2017-11-02 10:51 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 08/20] x86/entry/64: Use POP instead of MOV to restore regs on NMI return Andy Lutomirski
2017-11-02 10:51 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 09/20] x86/entry/64: Remove the RESTORE_..._REGS infrastructure Andy Lutomirski
2017-11-02 10:52 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 10/20] xen: add xen nmi trap entry Andy Lutomirski
2017-11-02 10:52 ` [tip:x86/asm] xen, x86/entry/64: Add xen NMI " tip-bot for Juergen Gross
2017-11-02 7:59 ` [PATCH v2 11/20] x86/asm/64: De-Xen-ify our NMI code Andy Lutomirski
2017-11-02 10:53 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 12/20] x86/asm/32: Pull MSR_IA32_SYSENTER_CS update code out of native_load_sp0() Andy Lutomirski
2017-11-02 10:53 ` [tip:x86/asm] x86/entry/32: Pull the " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 13/20] x86/asm/64: Pass sp0 directly to load_sp0() Andy Lutomirski
2017-11-02 9:48 ` Ingo Molnar [this message]
2017-11-02 9:53 ` Ingo Molnar
2017-11-02 10:32 ` Andy Lutomirski
2017-11-02 10:53 ` [tip:x86/asm] x86/entry/64: Pass SP0 " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 14/20] x86/asm: Add task_top_of_stack() to find the top of a task's stack Andy Lutomirski
2017-11-02 10:54 ` [tip:x86/asm] x86/entry: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 15/20] x86/xen/64: Clean up SP code in cpu_initialize_context() Andy Lutomirski
2017-11-02 9:56 ` Juergen Gross
2017-11-02 10:54 ` [tip:x86/asm] x86/xen/64, x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 16/20] x86/boot/64: Stop initializing TSS.sp0 at boot Andy Lutomirski
2017-11-02 10:55 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 17/20] x86/asm/64: Remove all remaining direct thread_struct::sp0 reads Andy Lutomirski
2017-11-02 10:55 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 18/20] x86/boot/32: Fix cpu_current_top_of_stack initialization at boot Andy Lutomirski
2017-11-02 10:56 ` [tip:x86/asm] x86/entry/32: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 19/20] x86/asm/64: Remove thread_struct::sp0 Andy Lutomirski
2017-11-02 10:56 ` [tip:x86/asm] x86/entry/64: " tip-bot for Andy Lutomirski
2017-11-02 7:59 ` [PATCH v2 20/20] x86/traps: Use a new on_thread_stack() helper to clean up an assertion Andy Lutomirski
2017-11-02 10:56 ` [tip:x86/asm] " tip-bot for Andy Lutomirski
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