From: Borislav Petkov <bp@alien8.de>
To: Juergen Gross <jgross@suse.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>,
linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
x86@kernel.org, Lai Jiangshan <jiangshan.ljs@antgroup.com>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>
Subject: Re: [PATCH V6 6/8] x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS
Date: Mon, 2 May 2022 19:56:16 +0200 [thread overview]
Message-ID: <YnAbQK9kLdCxxGSf@zn.tnic> (raw)
In-Reply-To: <3db51f9f-317a-352a-4214-0f159b6cd34c@suse.com>
On Mon, May 02, 2022 at 02:18:35PM +0200, Juergen Gross wrote:
> The syscall will land in the hypervisor, which then will activate
> the related registered callback (xen_sysenter_target).
Aha, that would do a bit of a fixup and then go to the common label
entry_SYSENTER_compat_after_hwframe.
We probably should document this so that it is clear what uses those...
---
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 9da5eef9affe..93065c4914ad 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -103,6 +103,11 @@ SYM_INNER_LABEL(entry_SYSCALL_64_safe_stack, SYM_L_GLOBAL)
pushq %r11 /* pt_regs->flags */
pushq $__USER_CS /* pt_regs->cs */
pushq %rcx /* pt_regs->ip */
+
+ /*
+ * XENPV jumps here after frame fixup in the respective entry points in
+ * ...xen-asm.S.
+ */
SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL)
pushq %rax /* pt_regs->orig_ax */
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index c5aeb0819707..b473f8e17afc 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -71,6 +71,11 @@ SYM_CODE_START(entry_SYSENTER_compat)
pushfq /* pt_regs->flags (except IF = 0) */
pushq $__USER32_CS /* pt_regs->cs */
pushq $0 /* pt_regs->ip = 0 (placeholder) */
+
+ /*
+ * XENPV jumps here after frame fixup in the respective entry points in
+ * ...xen-asm.S.
+ */
SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL)
/*
> I wouldn't insist on the CONFIG_DEBUG_ENTRY chunk.
Ok, simpler asm, cool, let's do it then.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2022-05-02 17:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-21 14:10 [PATCH V6 0/8] x86/entry: Clean up entry code Lai Jiangshan
2022-04-21 14:10 ` [PATCH V6 1/8] x86/traps: Move pt_regs only in fixup_bad_iret() Lai Jiangshan
2022-04-21 14:10 ` [PATCH V6 2/8] x86/entry: Switch the stack after error_entry() returns Lai Jiangshan
2022-04-21 14:10 ` [PATCH V6 3/8] x86/entry: Move PUSH_AND_CLEAR_REGS out of error_entry() Lai Jiangshan
2022-04-27 17:45 ` Borislav Petkov
2022-04-28 0:33 ` Lai Jiangshan
2022-04-28 10:26 ` Borislav Petkov
2022-05-02 12:42 ` Juergen Gross
2022-05-02 18:09 ` Borislav Petkov
2022-04-21 14:10 ` [PATCH V6 4/8] x86/entry: Move cld to the start of idtentry macro Lai Jiangshan
2022-04-21 14:10 ` [PATCH V6 5/8] x86/entry: Don't call error_entry() for XENPV Lai Jiangshan
2022-04-21 14:10 ` [PATCH V6 6/8] x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS Lai Jiangshan
2022-04-29 9:56 ` Borislav Petkov
2022-04-29 11:45 ` Lai Jiangshan
2022-04-29 12:22 ` Borislav Petkov
2022-05-02 12:18 ` Juergen Gross
2022-05-02 17:56 ` Borislav Petkov [this message]
2022-05-03 10:43 ` Borislav Petkov
2022-04-21 14:10 ` [PATCH V6 7/8] x86/entry: Remove the branch in sync_regs() Lai Jiangshan
2022-04-21 14:10 ` [PATCH V6 8/8] x86/entry: Use idtentry macro for entry_INT80_compat() Lai Jiangshan
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