linux-kernel - [tip:x86/asm] x86/traps: Enable all exception handler callbacks early

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Date:	Wed, 13 Apr 2016 04:44:31 -0700
From:	tip-bot for Andy Lutomirski <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	bp@...en8.de, mingo@...nel.org, luto@...nel.org,
	boris.ostrovsky@...cle.com, hpa@...or.com, kvm@...r.kernel.org,
	Xen-devel@...ts.xen.org, pbonzini@...hat.com, tglx@...utronix.de,
	peterz@...radead.org, linux-kernel@...r.kernel.org,
	arjan@...ux.intel.com, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org
Subject: [tip:x86/asm] x86/traps: Enable all exception handler callbacks
 early

Commit-ID:  ae7ef45e12354a1e2f6013b46df0c9f5bbb6ffbe
Gitweb:     http://git.kernel.org/tip/ae7ef45e12354a1e2f6013b46df0c9f5bbb6ffbe
Author:     Andy Lutomirski <luto@...nel.org>
AuthorDate: Sat, 2 Apr 2016 07:01:35 -0700
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 13 Apr 2016 11:37:45 +0200

x86/traps: Enable all exception handler callbacks early

Now that early_fixup_exception() has pt_regs, we can just call
fixup_exception() from it.  This will make fancy exception handlers
work early.

Tested-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Signed-off-by: Andy Lutomirski <luto@...nel.org>
Acked-by: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Arjan van de Ven <arjan@...ux.intel.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: KVM list <kvm@...r.kernel.org>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: xen-devel <Xen-devel@...ts.xen.org>
Link: http://lkml.kernel.org/r/20fc047d926150cb08cb9b9f2923519b07ec1a15.1459605520.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/mm/extable.c | 19 ++-----------------
 1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index da442f3..061a237 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -88,10 +88,6 @@ extern unsigned int early_recursion_flag;
 /* Restricted version used during very early boot */
 void __init early_fixup_exception(struct pt_regs *regs, int trapnr)
 {
-	const struct exception_table_entry *e;
-	unsigned long new_ip;
-	ex_handler_t handler;
-
 	/* Ignore early NMIs. */
 	if (trapnr == X86_TRAP_NMI)
 		return;
@@ -102,19 +98,8 @@ void __init early_fixup_exception(struct pt_regs *regs, int trapnr)
 	if (regs->cs != __KERNEL_CS)
 		goto fail;
 
-	e = search_exception_tables(regs->ip);
-	if (!e)
-		goto fail;
-
-	new_ip  = ex_fixup_addr(e);
-	handler = ex_fixup_handler(e);
-
-	/* special handling not supported during early boot */
-	if (handler != ex_handler_default)
-		goto fail;
-
-	regs->ip = new_ip;
-	return;
+	if (fixup_exception(regs, trapnr))
+		return;
 
 fail:
 	early_printk("PANIC: early exception 0x%02x IP %lx:%lx error %lx cr2 0x%lx\n",