]> nv-tegra.nvidia Code Review - linux-2.6.git/commitdiff
Merge branch 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
authorLinus Torvalds <torvalds@linux-foundation.org>
Mon, 14 Sep 2009 17:23:49 +0000 (10:23 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 14 Sep 2009 17:23:49 +0000 (10:23 -0700)
* 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: split __phys_addr out into separate file
  xen: use stronger barrier after unlocking lock
  xen: only enable interrupts while actually blocking for spinlock
  xen: make -fstack-protector work under Xen

arch/x86/mm/Makefile
arch/x86/mm/ioremap.c
arch/x86/mm/physaddr.c [new file with mode: 0644]
arch/x86/mm/physaddr.h [new file with mode: 0644]
arch/x86/xen/Makefile
arch/x86/xen/enlighten.c
arch/x86/xen/smp.c
arch/x86/xen/spinlock.c
drivers/xen/Makefile

index eefdeee8a871175d49a8a7f10bdebd37ed90265c..9b5a9f59a478781bd32025a938826e9c239e0d17 100644 (file)
@@ -1,5 +1,9 @@
 obj-y  :=  init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
-           pat.o pgtable.o gup.o
+           pat.o pgtable.o physaddr.o gup.o
+
+# Make sure __phys_addr has no stackprotector
+nostackp := $(call cc-option, -fno-stack-protector)
+CFLAGS_physaddr.o              := $(nostackp)
 
 obj-$(CONFIG_SMP)              += tlb.o
 
index 8a450930834fab4d6e2692e9b5ecadb6ed40861a..04e1ad60c63a23a3527960a01cf6e2cff091d959 100644 (file)
 #include <asm/pgalloc.h>
 #include <asm/pat.h>
 
-static inline int phys_addr_valid(resource_size_t addr)
-{
-#ifdef CONFIG_PHYS_ADDR_T_64BIT
-       return !(addr >> boot_cpu_data.x86_phys_bits);
-#else
-       return 1;
-#endif
-}
-
-#ifdef CONFIG_X86_64
-
-unsigned long __phys_addr(unsigned long x)
-{
-       if (x >= __START_KERNEL_map) {
-               x -= __START_KERNEL_map;
-               VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE);
-               x += phys_base;
-       } else {
-               VIRTUAL_BUG_ON(x < PAGE_OFFSET);
-               x -= PAGE_OFFSET;
-               VIRTUAL_BUG_ON(!phys_addr_valid(x));
-       }
-       return x;
-}
-EXPORT_SYMBOL(__phys_addr);
-
-bool __virt_addr_valid(unsigned long x)
-{
-       if (x >= __START_KERNEL_map) {
-               x -= __START_KERNEL_map;
-               if (x >= KERNEL_IMAGE_SIZE)
-                       return false;
-               x += phys_base;
-       } else {
-               if (x < PAGE_OFFSET)
-                       return false;
-               x -= PAGE_OFFSET;
-               if (!phys_addr_valid(x))
-                       return false;
-       }
-
-       return pfn_valid(x >> PAGE_SHIFT);
-}
-EXPORT_SYMBOL(__virt_addr_valid);
-
-#else
-
-#ifdef CONFIG_DEBUG_VIRTUAL
-unsigned long __phys_addr(unsigned long x)
-{
-       /* VMALLOC_* aren't constants  */
-       VIRTUAL_BUG_ON(x < PAGE_OFFSET);
-       VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
-       return x - PAGE_OFFSET;
-}
-EXPORT_SYMBOL(__phys_addr);
-#endif
-
-bool __virt_addr_valid(unsigned long x)
-{
-       if (x < PAGE_OFFSET)
-               return false;
-       if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
-               return false;
-       if (x >= FIXADDR_START)
-               return false;
-       return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
-}
-EXPORT_SYMBOL(__virt_addr_valid);
-
-#endif
+#include "physaddr.h"
 
 int page_is_ram(unsigned long pagenr)
 {
diff --git a/arch/x86/mm/physaddr.c b/arch/x86/mm/physaddr.c
new file mode 100644 (file)
index 0000000..d2e2735
--- /dev/null
@@ -0,0 +1,70 @@
+#include <linux/mmdebug.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+
+#include <asm/page.h>
+
+#include "physaddr.h"
+
+#ifdef CONFIG_X86_64
+
+unsigned long __phys_addr(unsigned long x)
+{
+       if (x >= __START_KERNEL_map) {
+               x -= __START_KERNEL_map;
+               VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE);
+               x += phys_base;
+       } else {
+               VIRTUAL_BUG_ON(x < PAGE_OFFSET);
+               x -= PAGE_OFFSET;
+               VIRTUAL_BUG_ON(!phys_addr_valid(x));
+       }
+       return x;
+}
+EXPORT_SYMBOL(__phys_addr);
+
+bool __virt_addr_valid(unsigned long x)
+{
+       if (x >= __START_KERNEL_map) {
+               x -= __START_KERNEL_map;
+               if (x >= KERNEL_IMAGE_SIZE)
+                       return false;
+               x += phys_base;
+       } else {
+               if (x < PAGE_OFFSET)
+                       return false;
+               x -= PAGE_OFFSET;
+               if (!phys_addr_valid(x))
+                       return false;
+       }
+
+       return pfn_valid(x >> PAGE_SHIFT);
+}
+EXPORT_SYMBOL(__virt_addr_valid);
+
+#else
+
+#ifdef CONFIG_DEBUG_VIRTUAL
+unsigned long __phys_addr(unsigned long x)
+{
+       /* VMALLOC_* aren't constants  */
+       VIRTUAL_BUG_ON(x < PAGE_OFFSET);
+       VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
+       return x - PAGE_OFFSET;
+}
+EXPORT_SYMBOL(__phys_addr);
+#endif
+
+bool __virt_addr_valid(unsigned long x)
+{
+       if (x < PAGE_OFFSET)
+               return false;
+       if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
+               return false;
+       if (x >= FIXADDR_START)
+               return false;
+       return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
+}
+EXPORT_SYMBOL(__virt_addr_valid);
+
+#endif /* CONFIG_X86_64 */
diff --git a/arch/x86/mm/physaddr.h b/arch/x86/mm/physaddr.h
new file mode 100644 (file)
index 0000000..a3cd5a0
--- /dev/null
@@ -0,0 +1,10 @@
+#include <asm/processor.h>
+
+static inline int phys_addr_valid(resource_size_t addr)
+{
+#ifdef CONFIG_PHYS_ADDR_T_64BIT
+       return !(addr >> boot_cpu_data.x86_phys_bits);
+#else
+       return 1;
+#endif
+}
index 7410640db173b842db79b835dbdc2206e01c0c2a..3bb4fc21f4f28b79eff0fb6f8b0ae50b112842ef 100644 (file)
@@ -8,6 +8,7 @@ endif
 # Make sure early boot has no stackprotector
 nostackp := $(call cc-option, -fno-stack-protector)
 CFLAGS_enlighten.o             := $(nostackp)
+CFLAGS_mmu.o                   := $(nostackp)
 
 obj-y          := enlighten.o setup.o multicalls.o mmu.o irq.o \
                        time.o xen-asm.o xen-asm_$(BITS).o \
@@ -16,3 +17,4 @@ obj-y         := enlighten.o setup.o multicalls.o mmu.o irq.o \
 obj-$(CONFIG_SMP)              += smp.o
 obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o
 obj-$(CONFIG_XEN_DEBUG_FS)     += debugfs.o
+
index b62ccb840cfb1a6a3a64735781249f2ef412d179..0dd0c2c6cae0ff1fb8aa1ce563636e7ad38ad880 100644 (file)
@@ -51,6 +51,7 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 #include <asm/reboot.h>
+#include <asm/stackprotector.h>
 
 #include "xen-ops.h"
 #include "mmu.h"
@@ -330,18 +331,28 @@ static void xen_load_gdt(const struct desc_ptr *dtr)
        unsigned long frames[pages];
        int f;
 
-       /* A GDT can be up to 64k in size, which corresponds to 8192
-          8-byte entries, or 16 4k pages.. */
+       /*
+        * A GDT can be up to 64k in size, which corresponds to 8192
+        * 8-byte entries, or 16 4k pages..
+        */
 
        BUG_ON(size > 65536);
        BUG_ON(va & ~PAGE_MASK);
 
        for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
                int level;
-               pte_t *ptep = lookup_address(va, &level);
+               pte_t *ptep;
                unsigned long pfn, mfn;
                void *virt;
 
+               /*
+                * The GDT is per-cpu and is in the percpu data area.
+                * That can be virtually mapped, so we need to do a
+                * page-walk to get the underlying MFN for the
+                * hypercall.  The page can also be in the kernel's
+                * linear range, so we need to RO that mapping too.
+                */
+               ptep = lookup_address(va, &level);
                BUG_ON(ptep == NULL);
 
                pfn = pte_pfn(*ptep);
@@ -358,6 +369,44 @@ static void xen_load_gdt(const struct desc_ptr *dtr)
                BUG();
 }
 
+/*
+ * load_gdt for early boot, when the gdt is only mapped once
+ */
+static __init void xen_load_gdt_boot(const struct desc_ptr *dtr)
+{
+       unsigned long va = dtr->address;
+       unsigned int size = dtr->size + 1;
+       unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
+       unsigned long frames[pages];
+       int f;
+
+       /*
+        * A GDT can be up to 64k in size, which corresponds to 8192
+        * 8-byte entries, or 16 4k pages..
+        */
+
+       BUG_ON(size > 65536);
+       BUG_ON(va & ~PAGE_MASK);
+
+       for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
+               pte_t pte;
+               unsigned long pfn, mfn;
+
+               pfn = virt_to_pfn(va);
+               mfn = pfn_to_mfn(pfn);
+
+               pte = pfn_pte(pfn, PAGE_KERNEL_RO);
+
+               if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
+                       BUG();
+
+               frames[f] = mfn;
+       }
+
+       if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
+               BUG();
+}
+
 static void load_TLS_descriptor(struct thread_struct *t,
                                unsigned int cpu, unsigned int i)
 {
@@ -581,6 +630,29 @@ static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
        preempt_enable();
 }
 
+/*
+ * Version of write_gdt_entry for use at early boot-time needed to
+ * update an entry as simply as possible.
+ */
+static __init void xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
+                                           const void *desc, int type)
+{
+       switch (type) {
+       case DESC_LDT:
+       case DESC_TSS:
+               /* ignore */
+               break;
+
+       default: {
+               xmaddr_t maddr = virt_to_machine(&dt[entry]);
+
+               if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
+                       dt[entry] = *(struct desc_struct *)desc;
+       }
+
+       }
+}
+
 static void xen_load_sp0(struct tss_struct *tss,
                         struct thread_struct *thread)
 {
@@ -965,6 +1037,23 @@ static const struct machine_ops __initdata xen_machine_ops = {
        .emergency_restart = xen_emergency_restart,
 };
 
+/*
+ * Set up the GDT and segment registers for -fstack-protector.  Until
+ * we do this, we have to be careful not to call any stack-protected
+ * function, which is most of the kernel.
+ */
+static void __init xen_setup_stackprotector(void)
+{
+       pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
+       pv_cpu_ops.load_gdt = xen_load_gdt_boot;
+
+       setup_stack_canary_segment(0);
+       switch_to_new_gdt(0);
+
+       pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
+       pv_cpu_ops.load_gdt = xen_load_gdt;
+}
+
 /* First C function to be called on Xen boot */
 asmlinkage void __init xen_start_kernel(void)
 {
@@ -983,13 +1072,28 @@ asmlinkage void __init xen_start_kernel(void)
        pv_apic_ops = xen_apic_ops;
        pv_mmu_ops = xen_mmu_ops;
 
-#ifdef CONFIG_X86_64
        /*
-        * Setup percpu state.  We only need to do this for 64-bit
-        * because 32-bit already has %fs set properly.
+        * Set up some pagetable state before starting to set any ptes.
         */
-       load_percpu_segment(0);
-#endif
+
+       /* Prevent unwanted bits from being set in PTEs. */
+       __supported_pte_mask &= ~_PAGE_GLOBAL;
+       if (!xen_initial_domain())
+               __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
+
+       __supported_pte_mask |= _PAGE_IOMAP;
+
+       xen_setup_features();
+
+       /* Get mfn list */
+       if (!xen_feature(XENFEAT_auto_translated_physmap))
+               xen_build_dynamic_phys_to_machine();
+
+       /*
+        * Set up kernel GDT and segment registers, mainly so that
+        * -fstack-protector code can be executed.
+        */
+       xen_setup_stackprotector();
 
        xen_init_irq_ops();
        xen_init_cpuid_mask();
@@ -1001,8 +1105,6 @@ asmlinkage void __init xen_start_kernel(void)
        set_xen_basic_apic_ops();
 #endif
 
-       xen_setup_features();
-
        if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
                pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
                pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
@@ -1019,17 +1121,8 @@ asmlinkage void __init xen_start_kernel(void)
 
        xen_smp_init();
 
-       /* Get mfn list */
-       if (!xen_feature(XENFEAT_auto_translated_physmap))
-               xen_build_dynamic_phys_to_machine();
-
        pgd = (pgd_t *)xen_start_info->pt_base;
 
-       /* Prevent unwanted bits from being set in PTEs. */
-       __supported_pte_mask &= ~_PAGE_GLOBAL;
-       if (!xen_initial_domain())
-               __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
-
 #ifdef CONFIG_X86_64
        /* Work out if we support NX */
        check_efer();
index 429834ec1687d9b7de965027f3f8d1c862ea88cd..fe03eeed7b48d383ec76d04bb9d0d92e6b53a7ff 100644 (file)
@@ -236,6 +236,7 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
        ctxt->user_regs.ss = __KERNEL_DS;
 #ifdef CONFIG_X86_32
        ctxt->user_regs.fs = __KERNEL_PERCPU;
+       ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
 #else
        ctxt->gs_base_kernel = per_cpu_offset(cpu);
 #endif
index 5601506f2dd96d49031873216d7e8aa12c689a91..36a5141108dfac6f6ad72a0591d40cded14d23a4 100644 (file)
@@ -187,7 +187,6 @@ static noinline int xen_spin_lock_slow(struct raw_spinlock *lock, bool irq_enabl
        struct xen_spinlock *prev;
        int irq = __get_cpu_var(lock_kicker_irq);
        int ret;
-       unsigned long flags;
        u64 start;
 
        /* If kicker interrupts not initialized yet, just spin */
@@ -199,16 +198,12 @@ static noinline int xen_spin_lock_slow(struct raw_spinlock *lock, bool irq_enabl
        /* announce we're spinning */
        prev = spinning_lock(xl);
 
-       flags = __raw_local_save_flags();
-       if (irq_enable) {
-               ADD_STATS(taken_slow_irqenable, 1);
-               raw_local_irq_enable();
-       }
-
        ADD_STATS(taken_slow, 1);
        ADD_STATS(taken_slow_nested, prev != NULL);
 
        do {
+               unsigned long flags;
+
                /* clear pending */
                xen_clear_irq_pending(irq);
 
@@ -228,6 +223,12 @@ static noinline int xen_spin_lock_slow(struct raw_spinlock *lock, bool irq_enabl
                        goto out;
                }
 
+               flags = __raw_local_save_flags();
+               if (irq_enable) {
+                       ADD_STATS(taken_slow_irqenable, 1);
+                       raw_local_irq_enable();
+               }
+
                /*
                 * Block until irq becomes pending.  If we're
                 * interrupted at this point (after the trylock but
@@ -238,13 +239,15 @@ static noinline int xen_spin_lock_slow(struct raw_spinlock *lock, bool irq_enabl
                 * pending.
                 */
                xen_poll_irq(irq);
+
+               raw_local_irq_restore(flags);
+
                ADD_STATS(taken_slow_spurious, !xen_test_irq_pending(irq));
        } while (!xen_test_irq_pending(irq)); /* check for spurious wakeups */
 
        kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
 
 out:
-       raw_local_irq_restore(flags);
        unspinning_lock(xl, prev);
        spin_time_accum_blocked(start);
 
@@ -323,8 +326,13 @@ static void xen_spin_unlock(struct raw_spinlock *lock)
        smp_wmb();              /* make sure no writes get moved after unlock */
        xl->lock = 0;           /* release lock */
 
-       /* make sure unlock happens before kick */
-       barrier();
+       /*
+        * Make sure unlock happens before checking for waiting
+        * spinners.  We need a strong barrier to enforce the
+        * write-read ordering to different memory locations, as the
+        * CPU makes no implied guarantees about their ordering.
+        */
+       mb();
 
        if (unlikely(xl->spinners))
                xen_spin_unlock_slow(xl);
index ec2a39b1e26f0438f6a2266cd77ff6173fd7bbc7..7c284342f30fef956900f93e3386179152873bd0 100644 (file)
@@ -1,6 +1,9 @@
 obj-y  += grant-table.o features.o events.o manage.o
 obj-y  += xenbus/
 
+nostackp := $(call cc-option, -fno-stack-protector)
+CFLAGS_features.o                      := $(nostackp)
+
 obj-$(CONFIG_HOTPLUG_CPU)      += cpu_hotplug.o
 obj-$(CONFIG_XEN_XENCOMM)      += xencomm.o
 obj-$(CONFIG_XEN_BALLOON)      += balloon.o