linux-kernel - [PATCH 02 of 31] xen: fix UP setup of shared

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <8c4f7164541786e23ed8.1205797013@localhost>
Date:	Mon, 17 Mar 2008 16:36:53 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Stable Kernel <stable@...nel.org>,
	Xen-devel <xen-devel@...ts.xensource.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ian Campbell <ijc@...lion.org.uk>
Subject: [PATCH 02 of 31] xen: fix UP setup of shared_info

We need to set up the shared_info pointer once we've mapped the real
shared_info into its fixmap slot.  That needs to happen once the general
pagetable setup has been done.  Previously, the UP shared_info was set
up one in xen_start_kernel, but that was left pointing to the dummy
shared info.  Unfortunately there's no really good place to do a later
setup of the shared_info in UP, so just do it once the pagetable setup
has been done.

[ Stable: needed in 2.6.24.x ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com>
Cc: Stable Kernel <stable@...nel.org>
---
 arch/x86/xen/enlighten.c |   51 +++++++++++++++++++++++++---------------------
 1 file changed, 28 insertions(+), 23 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -104,6 +104,7 @@
 	int err;
 	struct vcpu_info *vcpup;
 
+	BUG_ON(HYPERVISOR_shared_info == &dummy_shared_info);
 	per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
 
 	if (!have_vcpu_info_placement)
@@ -806,6 +807,31 @@
 			  PFN_DOWN(__pa(xen_start_info->pt_base)));
 }
 
+static __init void setup_shared_info(void)
+{
+	if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+		unsigned long addr = fix_to_virt(FIX_PARAVIRT_BOOTMAP);
+
+		/*
+		 * Create a mapping for the shared info page.
+		 * Should be set_fixmap(), but shared_info is a machine
+		 * address with no corresponding pseudo-phys address.
+		 */
+		set_pte_mfn(addr,
+			    PFN_DOWN(xen_start_info->shared_info),
+			    PAGE_KERNEL);
+
+		HYPERVISOR_shared_info = (struct shared_info *)addr;
+	} else
+		HYPERVISOR_shared_info =
+			(struct shared_info *)__va(xen_start_info->shared_info);
+
+#ifndef CONFIG_SMP
+	/* In UP this is as good a place as any to set up shared info */
+	xen_setup_vcpu_info_placement();
+#endif
+}
+
 static __init void xen_pagetable_setup_done(pgd_t *base)
 {
 	/* This will work as long as patching hasn't happened yet
@@ -816,22 +842,7 @@
 	pv_mmu_ops.release_pd = xen_release_pt;
 	pv_mmu_ops.set_pte = xen_set_pte;
 
-	if (!xen_feature(XENFEAT_auto_translated_physmap)) {
-		/*
-		 * Create a mapping for the shared info page.
-		 * Should be set_fixmap(), but shared_info is a machine
-		 * address with no corresponding pseudo-phys address.
-		 */
-		set_pte_mfn(fix_to_virt(FIX_PARAVIRT_BOOTMAP),
-			    PFN_DOWN(xen_start_info->shared_info),
-			    PAGE_KERNEL);
-
-		HYPERVISOR_shared_info =
-			(struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
-
-	} else
-		HYPERVISOR_shared_info =
-			(struct shared_info *)__va(xen_start_info->shared_info);
+	setup_shared_info();
 
 	/* Actually pin the pagetable down, but we can't set PG_pinned
 	   yet because the page structures don't exist yet. */
@@ -1182,15 +1193,9 @@
 	x86_write_percpu(xen_cr3, __pa(pgd));
 	x86_write_percpu(xen_current_cr3, __pa(pgd));
 
-#ifdef CONFIG_SMP
 	/* Don't do the full vcpu_info placement stuff until we have a
-	   possible map. */
+	   possible map and a non-dummy shared_info. */
 	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
-#else
-	/* May as well do it now, since there's no good time to call
-	   it later on UP. */
-	xen_setup_vcpu_info_placement();
-#endif
 
 	pv_info.kernel_rpl = 1;
 	if (xen_feature(XENFEAT_supervisor_mode_kernel))


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/