Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1230578

[PATCH 3.19.y-ckt 002/102] x86/ldt: Make modify_ldt synchronous

From Kamal Mostafa <kamal@canonical.com>
Newsgroups linux.kernel
Subject [PATCH 3.19.y-ckt 002/102] x86/ldt: Make modify_ldt synchronous
Date 2015-09-22 20:00 +0200
Message-ID <qbA1d-46k-49@gated-at.bofh.it> (permalink)
References <qbA1c-46k-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


3.19.8-ckt7 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Lutomirski <luto@kernel.org>

commit 37868fe113ff2ba814b3b4eb12df214df555f8dc upstream.

modify_ldt() has questionable locking and does not synchronize
threads.  Improve it: redesign the locking and synchronize all
threads' LDTs using an IPI on all modifications.

This will dramatically slow down modify_ldt in multithreaded
programs, but there shouldn't be any multithreaded programs that
care about modify_ldt's performance in the first place.

This fixes some fallout from the CVE-2015-5157 fixes.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/4c6978476782160600471bd865b318db34c7b628.1438291540.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[ kamal: backport to 3.13-stable: dropped comment changes in switch_mm();
  included asm/mmu_context.h in perf_event.c; context ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 arch/x86/include/asm/desc.h        |  15 ---
 arch/x86/include/asm/mmu.h         |   3 +-
 arch/x86/include/asm/mmu_context.h |  48 ++++++-
 arch/x86/kernel/cpu/common.c       |   4 +-
 arch/x86/kernel/cpu/perf_event.c   |  13 +-
 arch/x86/kernel/ldt.c              | 262 ++++++++++++++++++++-----------------
 arch/x86/kernel/process_64.c       |   4 +-
 arch/x86/kernel/step.c             |   6 +-
 arch/x86/power/cpu.c               |   3 +-
 9 files changed, 208 insertions(+), 150 deletions(-)

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index a94b82e..6912618 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -280,21 +280,6 @@ static inline void clear_LDT(void)
 	set_ldt(NULL, 0);
 }
 
-/*
- * load one particular LDT into the current CPU
- */
-static inline void load_LDT_nolock(mm_context_t *pc)
-{
-	set_ldt(pc->ldt, pc->size);
-}
-
-static inline void load_LDT(mm_context_t *pc)
-{
-	preempt_disable();
-	load_LDT_nolock(pc);
-	preempt_enable();
-}
-
 static inline unsigned long get_desc_base(const struct desc_struct *desc)
 {
 	return (unsigned)(desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24));
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h
index 876e74e..b6b7bc3 100644
--- a/arch/x86/include/asm/mmu.h
+++ b/arch/x86/include/asm/mmu.h
@@ -9,8 +9,7 @@
  * we put the segment information here.
  */
 typedef struct {
-	void *ldt;
-	int size;
+	struct ldt_struct *ldt;
 
 #ifdef CONFIG_X86_64
 	/* True if mm supports a task running in 32 bit compatibility mode. */
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 4b75d59..1ab38a4 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -19,6 +19,50 @@ static inline void paravirt_activate_mm(struct mm_struct *prev,
 #endif	/* !CONFIG_PARAVIRT */
 
 /*
+ * ldt_structs can be allocated, used, and freed, but they are never
+ * modified while live.
+ */
+struct ldt_struct {
+	/*
+	 * Xen requires page-aligned LDTs with special permissions.  This is
+	 * needed to prevent us from installing evil descriptors such as
+	 * call gates.  On native, we could merge the ldt_struct and LDT
+	 * allocations, but it's not worth trying to optimize.
+	 */
+	struct desc_struct *entries;
+	int size;
+};
+
+static inline void load_mm_ldt(struct mm_struct *mm)
+{
+	struct ldt_struct *ldt;
+
+	/* lockless_dereference synchronizes with smp_store_release */
+	ldt = lockless_dereference(mm->context.ldt);
+
+	/*
+	 * Any change to mm->context.ldt is followed by an IPI to all
+	 * CPUs with the mm active.  The LDT will not be freed until
+	 * after the IPI is handled by all such CPUs.  This means that,
+	 * if the ldt_struct changes before we return, the values we see
+	 * will be safe, and the new values will be loaded before we run
+	 * any user code.
+	 *
+	 * NB: don't try to convert this to use RCU without extreme care.
+	 * We would still need IRQs off, because we don't want to change
+	 * the local LDT after an IPI loaded a newer value than the one
+	 * that we can see.
+	 */
+
+	if (unlikely(ldt))
+		set_ldt(ldt->entries, ldt->size);
+	else
+		clear_LDT();
+
+	DEBUG_LOCKS_WARN_ON(preemptible());
+}
+
+/*
  * Used for LDT copy/destruction.
  */
 int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
@@ -63,7 +107,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 		 * prev->context.ldt won't be equal to next->context.ldt.
 		 */
 		if (unlikely(prev->context.ldt != next->context.ldt))
-			load_LDT_nolock(&next->context);
+			load_mm_ldt(next);
 	}
 #ifdef CONFIG_SMP
 	  else {
@@ -85,7 +129,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 			 */
 			load_cr3(next->pgd);
 			trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
-			load_LDT_nolock(&next->context);
+			load_mm_ldt(next);
 		}
 	}
 #endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index c604965..382a097 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1366,7 +1366,7 @@ void cpu_init(void)
 	load_sp0(t, &current->thread);
 	set_tss_desc(cpu, t);
 	load_TR_desc();
-	load_LDT(&init_mm.context);
+	load_mm_ldt(&init_mm);
 
 	clear_all_debug_regs();
 	dbg_restore_debug_regs();
@@ -1409,7 +1409,7 @@ void cpu_init(void)
 	load_sp0(t, thread);
 	set_tss_desc(cpu, t);
 	load_TR_desc();
-	load_LDT(&init_mm.context);
+	load_mm_ldt(&init_mm);
 
 	t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
 
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 143e5f5..82adb1a 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -31,6 +31,7 @@
 #include <asm/nmi.h>
 #include <asm/smp.h>
 #include <asm/alternative.h>
+#include <asm/mmu_context.h>
 #include <asm/timer.h>
 #include <asm/desc.h>
 #include <asm/ldt.h>
@@ -1986,21 +1987,25 @@ static unsigned long get_segment_base(unsigned int segment)
 	int idx = segment >> 3;
 
 	if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) {
+		struct ldt_struct *ldt;
+
 		if (idx > LDT_ENTRIES)
 			return 0;
 
-		if (idx > current->active_mm->context.size)
+		/* IRQs are off, so this synchronizes with smp_store_release */
+		ldt = lockless_dereference(current->active_mm->context.ldt);
+		if (!ldt || idx > ldt->size)
 			return 0;
 
-		desc = current->active_mm->context.ldt;
+		desc = &ldt->entries[idx];
 	} else {
 		if (idx > GDT_ENTRIES)
 			return 0;
 
-		desc = raw_cpu_ptr(gdt_page.gdt);
+		desc = raw_cpu_ptr(gdt_page.gdt) + idx;
 	}
 
-	return get_desc_base(desc + idx);
+	return get_desc_base(desc);
 }
 
 #ifdef CONFIG_COMPAT
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index c37886d..2bcc052 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -12,6 +12,7 @@
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
+#include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/uaccess.h>
 
@@ -20,82 +21,82 @@
 #include <asm/mmu_context.h>
 #include <asm/syscalls.h>
 
-#ifdef CONFIG_SMP
+/* context.lock is held for us, so we don't need any locking. */
 static void flush_ldt(void *current_mm)
 {
-	if (current->active_mm == current_mm)
-		load_LDT(&current->active_mm->context);
+	mm_context_t *pc;
+
+	if (current->active_mm != current_mm)
+		return;
+
+	pc = &current->active_mm->context;
+	set_ldt(pc->ldt->entries, pc->ldt->size);
 }
-#endif
 
-static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
+/* The caller must call finalize_ldt_struct on the result. LDT starts zeroed. */
+static struct ldt_struct *alloc_ldt_struct(int size)
 {
-	void *oldldt, *newldt;
-	int oldsize;
-
-	if (mincount <= pc->size)
-		return 0;
-	oldsize = pc->size;
-	mincount = (mincount + (PAGE_SIZE / LDT_ENTRY_SIZE - 1)) &
-			(~(PAGE_SIZE / LDT_ENTRY_SIZE - 1));
-	if (mincount * LDT_ENTRY_SIZE > PAGE_SIZE)
-		newldt = vmalloc(mincount * LDT_ENTRY_SIZE);
+	struct ldt_struct *new_ldt;
+	int alloc_size;
+
+	if (size > LDT_ENTRIES)
+		return NULL;
+
+	new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL);
+	if (!new_ldt)
+		return NULL;
+
+	BUILD_BUG_ON(LDT_ENTRY_SIZE != sizeof(struct desc_struct));
+	alloc_size = size * LDT_ENTRY_SIZE;
+
+	/*
+	 * Xen is very picky: it requires a page-aligned LDT that has no
+	 * trailing nonzero bytes in any page that contains LDT descriptors.
+	 * Keep it simple: zero the whole allocation and never allocate less
+	 * than PAGE_SIZE.
+	 */
+	if (alloc_size > PAGE_SIZE)
+		new_ldt->entries = vzalloc(alloc_size);
 	else
-		newldt = (void *)__get_free_page(GFP_KERNEL);
-
-	if (!newldt)
-		return -ENOMEM;
+		new_ldt->entries = kzalloc(PAGE_SIZE, GFP_KERNEL);
 
-	if (oldsize)
-		memcpy(newldt, pc->ldt, oldsize * LDT_ENTRY_SIZE);
-	oldldt = pc->ldt;
-	memset(newldt + oldsize * LDT_ENTRY_SIZE, 0,
-	       (mincount - oldsize) * LDT_ENTRY_SIZE);
+	if (!new_ldt->entries) {
+		kfree(new_ldt);
+		return NULL;
+	}
 
-	paravirt_alloc_ldt(newldt, mincount);
+	new_ldt->size = size;
+	return new_ldt;
+}
 
-#ifdef CONFIG_X86_64
-	/* CHECKME: Do we really need this ? */
-	wmb();
-#endif
-	pc->ldt = newldt;
-	wmb();
-	pc->size = mincount;
-	wmb();
-
-	if (reload) {
-#ifdef CONFIG_SMP
-		preempt_disable();
-		load_LDT(pc);
-		if (!cpumask_equal(mm_cpumask(current->mm),
-				   cpumask_of(smp_processor_id())))
-			smp_call_function(flush_ldt, current->mm, 1);
-		preempt_enable();
-#else
-		load_LDT(pc);
-#endif
-	}
-	if (oldsize) {
-		paravirt_free_ldt(oldldt, oldsize);
-		if (oldsize * LDT_ENTRY_SIZE > PAGE_SIZE)
-			vfree(oldldt);
-		else
-			put_page(virt_to_page(oldldt));
-	}
-	return 0;
+/* After calling this, the LDT is immutable. */
+static void finalize_ldt_struct(struct ldt_struct *ldt)
+{
+	paravirt_alloc_ldt(ldt->entries, ldt->size);
 }
 
-static inline int copy_ldt(mm_context_t *new, mm_context_t *old)
+/* context.lock is held */
+static void install_ldt(struct mm_struct *current_mm,
+			struct ldt_struct *ldt)
 {
-	int err = alloc_ldt(new, old->size, 0);
-	int i;
+	/* Synchronizes with lockless_dereference in load_mm_ldt. */
+	smp_store_release(&current_mm->context.ldt, ldt);
+
+	/* Activate the LDT for all CPUs using current_mm. */
+	on_each_cpu_mask(mm_cpumask(current_mm), flush_ldt, current_mm, true);
+}
 
-	if (err < 0)
-		return err;
+static void free_ldt_struct(struct ldt_struct *ldt)
+{
+	if (likely(!ldt))
+		return;
 
-	for (i = 0; i < old->size; i++)
-		write_ldt_entry(new->ldt, i, old->ldt + i * LDT_ENTRY_SIZE);
-	return 0;
+	paravirt_free_ldt(ldt->entries, ldt->size);
+	if (ldt->size * LDT_ENTRY_SIZE > PAGE_SIZE)
+		vfree(ldt->entries);
+	else
+		kfree(ldt->entries);
+	kfree(ldt);
 }
 
 /*
@@ -104,17 +105,37 @@ static inline int copy_ldt(mm_context_t *new, mm_context_t *old)
  */
 int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 {
+	struct ldt_struct *new_ldt;
 	struct mm_struct *old_mm;
 	int retval = 0;
 
 	mutex_init(&mm->context.lock);
-	mm->context.size = 0;
 	old_mm = current->mm;
-	if (old_mm && old_mm->context.size > 0) {
-		mutex_lock(&old_mm->context.lock);
-		retval = copy_ldt(&mm->context, &old_mm->context);
-		mutex_unlock(&old_mm->context.lock);
+	if (!old_mm) {
+		mm->context.ldt = NULL;
+		return 0;
 	}
+
+	mutex_lock(&old_mm->context.lock);
+	if (!old_mm->context.ldt) {
+		mm->context.ldt = NULL;
+		goto out_unlock;
+	}
+
+	new_ldt = alloc_ldt_struct(old_mm->context.ldt->size);
+	if (!new_ldt) {
+		retval = -ENOMEM;
+		goto out_unlock;
+	}
+
+	memcpy(new_ldt->entries, old_mm->context.ldt->entries,
+	       new_ldt->size * LDT_ENTRY_SIZE);
+	finalize_ldt_struct(new_ldt);
+
+	mm->context.ldt = new_ldt;
+
+out_unlock:
+	mutex_unlock(&old_mm->context.lock);
 	return retval;
 }
 
@@ -125,53 +146,47 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
  */
 void destroy_context(struct mm_struct *mm)
 {
-	if (mm->context.size) {
-#ifdef CONFIG_X86_32
-		/* CHECKME: Can this ever happen ? */
-		if (mm == current->active_mm)
-			clear_LDT();
-#endif
-		paravirt_free_ldt(mm->context.ldt, mm->context.size);
-		if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
-			vfree(mm->context.ldt);
-		else
-			put_page(virt_to_page(mm->context.ldt));
-		mm->context.size = 0;
-	}
+	free_ldt_struct(mm->context.ldt);
+	mm->context.ldt = NULL;
 }
 
 static int read_ldt(void __user *ptr, unsigned long bytecount)
 {
-	int err;
+	int retval;
 	unsigned long size;
 	struct mm_struct *mm = current->mm;
 
-	if (!mm->context.size)
-		return 0;
+	mutex_lock(&mm->context.lock);
+
+	if (!mm->context.ldt) {
+		retval = 0;
+		goto out_unlock;
+	}
+
 	if (bytecount > LDT_ENTRY_SIZE * LDT_ENTRIES)
 		bytecount = LDT_ENTRY_SIZE * LDT_ENTRIES;
 
-	mutex_lock(&mm->context.lock);
-	size = mm->context.size * LDT_ENTRY_SIZE;
+	size = mm->context.ldt->size * LDT_ENTRY_SIZE;
 	if (size > bytecount)
 		size = bytecount;
 
-	err = 0;
-	if (copy_to_user(ptr, mm->context.ldt, size))
-		err = -EFAULT;
-	mutex_unlock(&mm->context.lock);
-	if (err < 0)
-		goto error_return;
+	if (copy_to_user(ptr, mm->context.ldt->entries, size)) {
+		retval = -EFAULT;
+		goto out_unlock;
+	}
+
 	if (size != bytecount) {
-		/* zero-fill the rest */
-		if (clear_user(ptr + size, bytecount - size) != 0) {
-			err = -EFAULT;
-			goto error_return;
+		/* Zero-fill the rest and pretend we read bytecount bytes. */
+		if (clear_user(ptr + size, bytecount - size)) {
+			retval = -EFAULT;
+			goto out_unlock;
 		}
 	}
-	return bytecount;
-error_return:
-	return err;
+	retval = bytecount;
+
+out_unlock:
+	mutex_unlock(&mm->context.lock);
+	return retval;
 }
 
 static int read_default_ldt(void __user *ptr, unsigned long bytecount)
@@ -195,6 +210,8 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
 	struct desc_struct ldt;
 	int error;
 	struct user_desc ldt_info;
+	int oldsize, newsize;
+	struct ldt_struct *new_ldt, *old_ldt;
 
 	error = -EINVAL;
 	if (bytecount != sizeof(ldt_info))
@@ -213,34 +230,39 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
 			goto out;
 	}
 
-	mutex_lock(&mm->context.lock);
-	if (ldt_info.entry_number >= mm->context.size) {
-		error = alloc_ldt(&current->mm->context,
-				  ldt_info.entry_number + 1, 1);
-		if (error < 0)
-			goto out_unlock;
-	}
-
-	/* Allow LDTs to be cleared by the user. */
-	if (ldt_info.base_addr == 0 && ldt_info.limit == 0) {
-		if (oldmode || LDT_empty(&ldt_info)) {
-			memset(&ldt, 0, sizeof(ldt));
-			goto install;
+	if ((oldmode && !ldt_info.base_addr && !ldt_info.limit) ||
+	    LDT_empty(&ldt_info)) {
+		/* The user wants to clear the entry. */
+		memset(&ldt, 0, sizeof(ldt));
+	} else {
+		if (!IS_ENABLED(CONFIG_X86_16BIT) && !ldt_info.seg_32bit) {
+			error = -EINVAL;
+			goto out;
 		}
+
+		fill_ldt(&ldt, &ldt_info);
+		if (oldmode)
+			ldt.avl = 0;
 	}
 
-	if (!IS_ENABLED(CONFIG_X86_16BIT) && !ldt_info.seg_32bit) {
-		error = -EINVAL;
+	mutex_lock(&mm->context.lock);
+
+	old_ldt = mm->context.ldt;
+	oldsize = old_ldt ? old_ldt->size : 0;
+	newsize = max((int)(ldt_info.entry_number + 1), oldsize);
+
+	error = -ENOMEM;
+	new_ldt = alloc_ldt_struct(newsize);
+	if (!new_ldt)
 		goto out_unlock;
-	}
 
-	fill_ldt(&ldt, &ldt_info);
-	if (oldmode)
-		ldt.avl = 0;
+	if (old_ldt)
+		memcpy(new_ldt->entries, old_ldt->entries, oldsize * LDT_ENTRY_SIZE);
+	new_ldt->entries[ldt_info.entry_number] = ldt;
+	finalize_ldt_struct(new_ldt);
 
-	/* Install the new entry ...  */
-install:
-	write_ldt_entry(mm->context.ldt, ldt_info.entry_number, &ldt);
+	install_ldt(mm, new_ldt);
+	free_ldt_struct(old_ldt);
 	error = 0;
 
 out_unlock:
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 5a2c029..ec03938 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -122,11 +122,11 @@ void __show_regs(struct pt_regs *regs, int all)
 void release_thread(struct task_struct *dead_task)
 {
 	if (dead_task->mm) {
-		if (dead_task->mm->context.size) {
+		if (dead_task->mm->context.ldt) {
 			pr_warn("WARNING: dead process %s still has LDT? <%p/%d>\n",
 				dead_task->comm,
 				dead_task->mm->context.ldt,
-				dead_task->mm->context.size);
+				dead_task->mm->context.ldt->size);
 			BUG();
 		}
 	}
diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c
index 9b4d51d..6273324 100644
--- a/arch/x86/kernel/step.c
+++ b/arch/x86/kernel/step.c
@@ -5,6 +5,7 @@
 #include <linux/mm.h>
 #include <linux/ptrace.h>
 #include <asm/desc.h>
+#include <asm/mmu_context.h>
 
 unsigned long convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs)
 {
@@ -30,10 +31,11 @@ unsigned long convert_ip_to_linear(struct task_struct *child, struct pt_regs *re
 		seg &= ~7UL;
 
 		mutex_lock(&child->mm->context.lock);
-		if (unlikely((seg >> 3) >= child->mm->context.size))
+		if (unlikely(!child->mm->context.ldt ||
+			     (seg >> 3) >= child->mm->context.ldt->size))
 			addr = -1L; /* bogus selector, access would fault */
 		else {
-			desc = child->mm->context.ldt + seg;
+			desc = &child->mm->context.ldt->entries[seg];
 			base = get_desc_base(desc);
 
 			/* 16-bit code segment? */
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 6ec7910..f846180 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -23,6 +23,7 @@
 #include <asm/debugreg.h>
 #include <asm/fpu-internal.h> /* pcntxt_mask */
 #include <asm/cpu.h>
+#include <asm/mmu_context.h>
 
 #ifdef CONFIG_X86_32
 __visible unsigned long saved_context_ebx;
@@ -157,7 +158,7 @@ static void fix_processor_context(void)
 	syscall_init();				/* This sets MSR_*STAR and related */
 #endif
 	load_TR_desc();				/* This does ltr */
-	load_LDT(&current->active_mm->context);	/* This does lldt */
+	load_mm_ldt(current->active_mm);	/* This does lldt */
 }
 
 /**
-- 
1.9.1

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

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[3.19.y-ckt stable] Linux 3.19.8-ckt7 stable review Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 049/102] fsnotify: fix oops in fsnotify_clear_marks_by_group_flags() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 102/102] netlink: don't hold mutex in rcu callback when releasing mmapd ring Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 018/102] crypto: ixp4xx - Remove bogus BUG_ON on scattered dst buffer Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 093/102] net: phy: add locking to phy_read_mmd_indirect()/phy_write_mmd_indirect() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 092/102] udp: fix dst races with multicast early demux Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 072/102] SCSI: Fix NULL pointer dereference in runtime PM Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 100/102] Revert "sit: Add gro callbacks to sit_offload" Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 002/102] x86/ldt: Make modify_ldt synchronous Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 097/102] net: pktgen: fix race between pktgen_thread_worker() and kthread_stop() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 098/102] net: Fix skb csum races when peeking Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 082/102] perf: Fix PERF_EVENT_IOC_PERIOD migration race Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 099/102] ipv6: lock socket in ip6_datagram_connect() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 006/102] ipmi/powernv: Fix minor locking bug Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 096/102] net/tipc: initialize security state for new connection socket Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 001/102] [3.19-stable only] Revert "dmaengine: pl330: Fix overflow when reporting residue in memcpy" Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 094/102] sparc64: Fix userspace FPU register corruptions. Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:00 +0200
  [PATCH 3.19.y-ckt 088/102] bridge: netlink: account for the IFLA_BRPORT_PROXYARP attribute size and policy Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 083/102] net: Fix RCU splat in af_key Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 066/102] ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 087/102] fq_codel: explicitly reset flows in ->reset() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 047/102] ipc: modify message queue accounting to not take kernel data structures into account Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 078/102] Add factory recertified Crucial M500s to blacklist Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 086/102] rds: fix an integer overflow test in rds_info_getsockopt() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 070/102] drm/i915: Flag the execlists context object as dirty after every use Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 085/102] net: Fix skb_set_peeked use-after-free bug Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 077/102] ALSA: usb: Add native DSD support for Gustard DAC-X20U Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 091/102] rocker: free netdevice during netdevice removal Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 084/102] bna: fix interrupts storm caused by erroneous packets Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 080/102] batman-adv: protect tt_local_entry from concurrent delete events Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 089/102] batman-adv: fix kernel crash due to missing NULL checks Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 069/102] x86/ldt: Further fix FPU emulation Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 090/102] fbdev: select versatile helpers for the integrator Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 073/102] ALSA: usb-audio: Fix runtime PM unbalance Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 081/102] ip6_gre: release cached dst on tunnel removal Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 075/102] Input: gpio_keys_polled - request GPIO pin as input. Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 076/102] PCI: Don't use 64-bit bus addresses on PA-RISC Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 071/102] fnic: Use the local variable instead of I/O flag to acquire io_req_lock in fnic_queuecommand() to avoid deadloack Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 067/102] ipc/sem.c: update/correct memory barriers Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 079/102] arm64: KVM: Fix host crash when injecting a fault into a 32bit guest Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:10 +0200
  [PATCH 3.19.y-ckt 042/102] perf: Fix fasync handling on inherited events Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 003/102] x86/ldt: Correct LDT access in single stepping logic Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 057/102] drm/radeon: add new OLAND pci id Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 061/102] sd: Fix maximum I/O size for BLOCK_PC requests Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 044/102] ALSA: fireworks/firewire-lib: add support for recent firmware quirk Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 048/102] ocfs2: fix BUG in ocfs2_downconvert_thread_do_work() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 064/102] drm/vmwgfx: Fix execbuf locking issues Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 068/102] MIPS: Fix seccomp syscall argument for MIPS64 Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 046/102] MIPS: Make set_pte() SMP safe. Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 058/102] libiscsi: Fix host busy blocking during connection teardown Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 051/102] x86/xen: build "Xen PV" APIC driver for domU as well Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 004/102] x86/ldt: Correct FPU emulation access to LDT Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 056/102] dm btree: add ref counting ops for the leaves of top level btrees Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 054/102] localmodconfig: Use Kbuild files too Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 065/102] mm/hwpoison: fix page refcount of unknown non LRU page Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 050/102] KVM: x86: Use adjustment in guest cycles when handling MSR_IA32_TSC_ADJUST Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 055/102] dm thin metadata: delete btrees when releasing metadata snapshot Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 052/102] cpuset: use trialcs->mems_allowed as a temp variable Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 053/102] drm/dp/mst: Remove port after removing connector. Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 063/102] crypto: caam - fix memory corruption in ahash_final_ctx Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 060/102] libfc: Fix fc_fcp_cleanup_each_cmd() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 059/102] libfc: Fix fc_exch_recv_req() error path Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:20 +0200
  [PATCH 3.19.y-ckt 041/102] dm: fix dm_merge_bvec regression on 32 bit systems Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 027/102] rbd: fix copyup completion race Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 040/102] staging: vt6655: vnt_bss_info_changed check conf->beacon_rate is not NULL Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 037/102] usb: udc: core: add device_del() call to error pathway Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 033/102] MIPS: show_stack: Fix stack trace with EVA Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 016/102] usb: chipidea: ehci_init_driver is intended to call one time Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 045/102] mm, vmscan: Do not wait for page writeback for GFP_NOFS allocations Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 030/102] MIPS: Fix sched_getaffinity with MT FPAFF enabled Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 032/102] MIPS: do_mcheck: Fix kernel code dump with EVA Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 036/102] MIPS: Flush RPS on kernel entry with EVA Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 026/102] target/iscsi: Fix double free of a TUR followed by a solicited NOPOUT Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 022/102] usb: gadget: f_uac2: fix calculation of uac2->p_interval Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 024/102] USB: sierra: add 1199:68AB device ID Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 029/102] target: REPORT LUNS should return LUN 0 even for dynamic ACLs Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 017/102] crypto: qat - Fix invalid synchronization between register/unregister sym algs Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 031/102] MIPS: Malta: Don't reinitialise RTC Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 043/102] drm/dp-mst: Remove debug WARN_ON Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 035/102] rtlwifi: rtl8723be: Add module parameter for MSI interrupts Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 039/102] drivers/usb: Delete XHCI command timer if necessary Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 038/102] xhci: fix off by one error in TRB DMA address boundary check Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 034/102] MIPS: Export get_c0_perfcount_int() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 023/102] hwrng: core - correct error check of kthread_run call Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:30 +0200
  [PATCH 3.19.y-ckt 013/102] USB: qcserial/option: make AT URCs work for Sierra Wireless MC7305/MC7355 Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 019/102] mfd: arizona: Fix initialisation of the PM runtime Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 008/102] virtio-net: drop NETIF_F_FRAGLIST Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 014/102] USB: qcserial: Add support for Dell Wireless 5809e 4G Modem Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 015/102] nfsd: Drop BUG_ON and ignore SECLABEL on absent filesystem Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 007/102] ipv6: addrconf: validate new MTU before applying it Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 021/102] xen-blkback: replace work_pending with work_busy in purge_persistent_gnt() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 009/102] RDS: verify the underlying transport exists before creating a connection Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 005/102] md: flush ->event_work before stopping array. Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 012/102] PCI: Restore PCI_MSIX_FLAGS_BIRMASK definition Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 011/102] xen/gntdevt: Fix race condition in gntdev_release() Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 010/102] xen/gntdev: convert priv->lock to a mutex Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200
  [PATCH 3.19.y-ckt 020/102] xen-blkfront: don't add indirect pages to list when !feature_persistent Kamal Mostafa <kamal@canonical.com> - 2015-09-22 20:40 +0200

csiph-web