Merge git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86

* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
  x86: fix deadlock, make pgd_lock irq-safe
  virtio: fix trivial build bug
  x86: fix mttr trimming
  x86: delay CPA self-test and repeat it
  x86: fix 64-bit sections
  generic: add __FINITDATA
  x86: remove suprious ifdefs from pageattr.c
  x86: mark the .rodata section also NX
  x86: fix iret exception recovery on 64-bit
  cpuidle: dubious one-bit signed bitfield in cpuidle.h
  x86: fix sparse warnings in powernow-k8.c
  x86: fix sparse error in traps_32.c
  x86: trivial sparse/checkpatch in quirks.c
  x86 ptrace: disallow null cs/ss
  MAINTAINERS: RDC R-321x SoC maintainer
  brk randomization: introduce CONFIG_COMPAT_BRK
  brk: check the lower bound properly
  x86: remove X2 workaround
  x86: make spurious fault handler aware of large mappings
  x86: make traps on entry code be debuggable in user space, 64-bit

21 files changed, 193 insertions, 102 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index c5325d2..0885aa2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3224,6 +3224,12 @@ M:	mporter@kernel.crashing.org
 L:	linux-kernel@vger.kernel.org
 S:	Maintained
 
+RDC R-321X SoC
+P:	Florian Fainelli
+M:	florian.fainelli@telecomint.eu
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+
 RDC R6040 FAST ETHERNET DRIVER
 P:	Florian Fainelli
 M:	florian.fainelli@telecomint.eu
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 2e1e3af..fa55514 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -220,9 +220,9 @@ config DEBUG_BOOT_PARAMS
 	  This option will cause struct boot_params to be exported via debugfs.
 
 config CPA_DEBUG
-	bool "CPA self test code"
+	bool "CPA self-test code"
 	depends on DEBUG_KERNEL
 	help
-	  Do change_page_attr self tests at boot.
+	  Do change_page_attr() self-tests every 30 seconds.
 
 endmenu
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index a052273..5affe91 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -827,7 +827,6 @@ static int fill_powernow_table_pstate(struct powernow_k8_data *data, struct cpuf
 
 	for (i = 0; i < data->acpi_data.state_count; i++) {
 		u32 index;
-		u32 hi = 0, lo = 0;
 
 		index = data->acpi_data.states[i].control & HW_PSTATE_MASK;
 		if (index > data->max_hw_pstate) {
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 1e27b69..b6e136f 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -659,7 +659,7 @@ static __init int amd_special_default_mtrr(void)
  */
 int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
 {
-	unsigned long i, base, size, highest_addr = 0, def, dummy;
+	unsigned long i, base, size, highest_pfn = 0, def, dummy;
 	mtrr_type type;
 	u64 trim_start, trim_size;
 
@@ -682,28 +682,27 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
 		mtrr_if->get(i, &base, &size, &type);
 		if (type != MTRR_TYPE_WRBACK)
 			continue;
-		base <<= PAGE_SHIFT;
-		size <<= PAGE_SHIFT;
-		if (highest_addr < base + size)
-			highest_addr = base + size;
+		if (highest_pfn < base + size)
+			highest_pfn = base + size;
 	}
 
 	/* kvm/qemu doesn't have mtrr set right, don't trim them all */
-	if (!highest_addr) {
+	if (!highest_pfn) {
 		printk(KERN_WARNING "WARNING: strange, CPU MTRRs all blank?\n");
 		WARN_ON(1);
 		return 0;
 	}
 
-	if ((highest_addr >> PAGE_SHIFT) < end_pfn) {
+	if (highest_pfn < end_pfn) {
 		printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
-			" all of memory, losing %LdMB of RAM.\n",
-			(((u64)end_pfn << PAGE_SHIFT) - highest_addr) >> 20);
+			" all of memory, losing %luMB of RAM.\n",
+			(end_pfn - highest_pfn) >> (20 - PAGE_SHIFT));
 
 		WARN_ON(1);
 
 		printk(KERN_INFO "update e820 for mtrr\n");
-		trim_start = highest_addr;
+		trim_start = highest_pfn;
+		trim_start <<= PAGE_SHIFT;
 		trim_size = end_pfn;
 		trim_size <<= PAGE_SHIFT;
 		trim_size -= trim_start;
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index bea8474..c7341e8 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -582,7 +582,6 @@ retint_restore_args:	/* return to kernel space */
 	TRACE_IRQS_IRETQ
 restore_args:
 	RESTORE_ARGS 0,8,0						
-iret_label:	
 #ifdef CONFIG_PARAVIRT
 	INTERRUPT_RETURN
 #endif
@@ -593,13 +592,22 @@ ENTRY(native_iret)
 	.quad native_iret, bad_iret
 	.previous
 	.section .fixup,"ax"
-	/* force a signal here? this matches i386 behaviour */
-	/* running with kernel gs */
 bad_iret:
-	movq $11,%rdi	/* SIGSEGV */
-	TRACE_IRQS_ON
-	ENABLE_INTERRUPTS(CLBR_ANY | ~(CLBR_RDI))
-	jmp do_exit
+	/*
+	 * The iret traps when the %cs or %ss being restored is bogus.
+	 * We've lost the original trap vector and error code.
+	 * #GPF is the most likely one to get for an invalid selector.
+	 * So pretend we completed the iret and took the #GPF in user mode.
+	 *
+	 * We are now running with the kernel GS after exception recovery.
+	 * But error_entry expects us to have user GS to match the user %cs,
+	 * so swap back.
+	 */
+	pushq $0
+
+	SWAPGS
+	jmp general_protection
+
 	.previous
 
 	/* edi: workmask, edx: work */
@@ -911,7 +919,7 @@ error_kernelspace:
 	   iret run with kernel gs again, so don't set the user space flag.
 	   B stepping K8s sometimes report an truncated RIP for IRET 
 	   exceptions returning to compat mode. Check for these here too. */
-	leaq iret_label(%rip),%rbp
+	leaq native_iret(%rip),%rbp
 	cmpq %rbp,RIP(%rsp) 
 	je   error_swapgs
 	movl %ebp,%ebp	/* zero extend */
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 4f283ad..09b38d5 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -250,18 +250,13 @@ ENTRY(secondary_startup_64)
 	lretq
 
 	/* SMP bootup changes these two */
-#ifndef CONFIG_HOTPLUG_CPU
-	.pushsection .init.data
-#endif
+	__CPUINITDATA
 	.align	8
-	.globl	initial_code
-initial_code:
+	ENTRY(initial_code)
 	.quad	x86_64_start_kernel
-#ifndef CONFIG_HOTPLUG_CPU
-	.popsection
-#endif
-	.globl init_rsp
-init_rsp:
+	__FINITDATA
+
+	ENTRY(init_rsp)
 	.quad  init_thread_union+THREAD_SIZE-8
 
 bad_address:
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 96286df..702c33ef 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -103,9 +103,26 @@ static int set_segment_reg(struct task_struct *task,
 	if (invalid_selector(value))
 		return -EIO;
 
-	if (offset != offsetof(struct user_regs_struct, gs))
+	/*
+	 * For %cs and %ss we cannot permit a null selector.
+	 * We can permit a bogus selector as long as it has USER_RPL.
+	 * Null selectors are fine for other segment registers, but
+	 * we will never get back to user mode with invalid %cs or %ss
+	 * and will take the trap in iret instead.  Much code relies
+	 * on user_mode() to distinguish a user trap frame (which can
+	 * safely use invalid selectors) from a kernel trap frame.
+	 */
+	switch (offset) {
+	case offsetof(struct user_regs_struct, cs):
+	case offsetof(struct user_regs_struct, ss):
+		if (unlikely(value == 0))
+			return -EIO;
+
+	default:
 		*pt_regs_access(task_pt_regs(task), offset) = value;
-	else {
+		break;
+
+	case offsetof(struct user_regs_struct, gs):
 		task->thread.gs = value;
 		if (task == current)
 			/*
@@ -227,12 +244,16 @@ static int set_segment_reg(struct task_struct *task,
 		 * Can't actually change these in 64-bit mode.
 		 */
 	case offsetof(struct user_regs_struct,cs):
+		if (unlikely(value == 0))
+			return -EIO;
 #ifdef CONFIG_IA32_EMULATION
 		if (test_tsk_thread_flag(task, TIF_IA32))
 			task_pt_regs(task)->cs = value;
 #endif
 		break;
 	case offsetof(struct user_regs_struct,ss):
+		if (unlikely(value == 0))
+			return -EIO;
 #ifdef CONFIG_IA32_EMULATION
 		if (test_tsk_thread_flag(task, TIF_IA32))
 			task_pt_regs(task)->ss = value;
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 3cd7a2d..6ba33ca 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -380,19 +380,19 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NVIDIA, 0x0367,
 void force_hpet_resume(void)
 {
 	switch (force_hpet_resume_type) {
-	    case ICH_FORCE_HPET_RESUME:
-		return ich_force_hpet_resume();
-
-	    case OLD_ICH_FORCE_HPET_RESUME:
-		return old_ich_force_hpet_resume();
-
-	    case VT8237_FORCE_HPET_RESUME:
-		return vt8237_force_hpet_resume();
-
-	    case NVIDIA_FORCE_HPET_RESUME:
-		return nvidia_force_hpet_resume();
-
-	    default:
+	case ICH_FORCE_HPET_RESUME:
+		ich_force_hpet_resume();
+		return;
+	case OLD_ICH_FORCE_HPET_RESUME:
+		old_ich_force_hpet_resume();
+		return;
+	case VT8237_FORCE_HPET_RESUME:
+		vt8237_force_hpet_resume();
+		return;
+	case NVIDIA_FORCE_HPET_RESUME:
+		nvidia_force_hpet_resume();
+		return;
+	default:
 		break;
 	}
 }
diff --git a/arch/x86/kernel/test_nx.c b/arch/x86/kernel/test_nx.c
index 36c100c..10b8a6f 100644
--- a/arch/x86/kernel/test_nx.c
+++ b/arch/x86/kernel/test_nx.c
@@ -139,7 +139,6 @@ static int test_NX(void)
 	 * Until then, don't run them to avoid too many people getting scared
 	 * by the error message
 	 */
-#if 0
 
 #ifdef CONFIG_DEBUG_RODATA
 	/* Test 3: Check if the .rodata section is executable */
@@ -152,6 +151,7 @@ static int test_NX(void)
 	}
 #endif
 
+#if 0
 	/* Test 4: Check if the .data section of a module is executable */
 	if (test_address(&test_data)) {
 		printk(KERN_ERR "test_nx: .data section is executable\n");
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 3cf72977..b22c01e 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -1176,17 +1176,12 @@ void __init trap_init(void)
 #endif
 	set_trap_gate(19,&simd_coprocessor_error);
 
+	/*
+	 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
+	 * Generate a build-time error if the alignment is wrong.
+	 */
+	BUILD_BUG_ON(offsetof(struct task_struct, thread.i387.fxsave) & 15);
 	if (cpu_has_fxsr) {
-		/*
-		 * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
-		 * Generates a compile-time "error: zero width for bit-field" if
-		 * the alignment is wrong.
-		 */
-		struct fxsrAlignAssert {
-			int _:!(offsetof(struct task_struct,
-					thread.i387.fxsave) & 15);
-		};
-
 		printk(KERN_INFO "Enabling fast FPU save and restore... ");
 		set_in_cr4(X86_CR4_OSFXSR);
 		printk("done.\n");
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index ad8b973..621afb6 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -428,6 +428,16 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
 }
 #endif
 
+static int spurious_fault_check(unsigned long error_code, pte_t *pte)
+{
+	if ((error_code & PF_WRITE) && !pte_write(*pte))
+		return 0;
+	if ((error_code & PF_INSTR) && !pte_exec(*pte))
+		return 0;
+
+	return 1;
+}
+
 /*
  * Handle a spurious fault caused by a stale TLB entry.  This allows
  * us to lazily refresh the TLB when increasing the permissions of a
@@ -457,20 +467,21 @@ static int spurious_fault(unsigned long address,
 	if (!pud_present(*pud))
 		return 0;
 
+	if (pud_large(*pud))
+		return spurious_fault_check(error_code, (pte_t *) pud);
+
 	pmd = pmd_offset(pud, address);
 	if (!pmd_present(*pmd))
 		return 0;
 
+	if (pmd_large(*pmd))
+		return spurious_fault_check(error_code, (pte_t *) pmd);
+
 	pte = pte_offset_kernel(pmd, address);
 	if (!pte_present(*pte))
 		return 0;
 
-	if ((error_code & PF_WRITE) && !pte_write(*pte))
-		return 0;
-	if ((error_code & PF_INSTR) && !pte_exec(*pte))
-		return 0;
-
-	return 1;
+	return spurious_fault_check(error_code, pte);
 }
 
 /*
@@ -947,11 +958,12 @@ void vmalloc_sync_all(void)
 	for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) {
 		if (!test_bit(pgd_index(address), insync)) {
 			const pgd_t *pgd_ref = pgd_offset_k(address);
+			unsigned long flags;
 			struct page *page;
 
 			if (pgd_none(*pgd_ref))
 				continue;
-			spin_lock(&pgd_lock);
+			spin_lock_irqsave(&pgd_lock, flags);
 			list_for_each_entry(page, &pgd_list, lru) {
 				pgd_t *pgd;
 				pgd = (pgd_t *)page_address(page) + pgd_index(address);
@@ -960,7 +972,7 @@ void vmalloc_sync_all(void)
 				else
 					BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
 			}
-			spin_unlock(&pgd_lock);
+			spin_unlock_irqrestore(&pgd_lock, flags);
 			set_bit(pgd_index(address), insync);
 		}
 		if (address == start)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 3a98d6f..9b61c75 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -591,10 +591,17 @@ void mark_rodata_ro(void)
 	if (end <= start)
 		return;
 
-	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
 
 	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
 	       (end - start) >> 10);
+	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
+
+	/*
+	 * The rodata section (but not the kernel text!) should also be
+	 * not-executable.
+	 */
+	start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
+	set_memory_nx(start, (end - start) >> PAGE_SHIFT);
 
 	rodata_test();
 
diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c
index 398f3a5..ed82016 100644
--- a/arch/x86/mm/pageattr-test.c
+++ b/arch/x86/mm/pageattr-test.c
@@ -5,6 +5,7 @@
  * and compares page tables forwards and afterwards.
  */
 #include <linux/bootmem.h>
+#include <linux/kthread.h>
 #include <linux/random.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -14,8 +15,13 @@
 #include <asm/pgtable.h>
 #include <asm/kdebug.h>
 
+/*
+ * Only print the results of the first pass:
+ */
+static __read_mostly int print = 1;
+
 enum {
-	NTEST			= 4000,
+	NTEST			= 400,
 #ifdef CONFIG_X86_64
 	LPS			= (1 << PMD_SHIFT),
 #elif defined(CONFIG_X86_PAE)
@@ -31,7 +37,7 @@ struct split_state {
 	long min_exec, max_exec;
 };
 
-static __init int print_split(struct split_state *s)
+static int print_split(struct split_state *s)
 {
 	long i, expected, missed = 0;
 	int printed = 0;
@@ -82,10 +88,13 @@ static __init int print_split(struct split_state *s)
 				s->max_exec = addr;
 		}
 	}
-	printk(KERN_INFO
-		"CPA mapping 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
-		s->spg, s->lpg, s->gpg, s->exec,
-		s->min_exec != ~0UL ? s->min_exec : 0, s->max_exec, missed);
+	if (print) {
+		printk(KERN_INFO
+			" 4k %lu large %lu gb %lu x %lu[%lx-%lx] miss %lu\n",
+			s->spg, s->lpg, s->gpg, s->exec,
+			s->min_exec != ~0UL ? s->min_exec : 0,
+			s->max_exec, missed);
+	}
 
 	expected = (s->gpg*GPS + s->lpg*LPS)/PAGE_SIZE + s->spg + missed;
 	if (expected != i) {
@@ -96,11 +105,11 @@ static __init int print_split(struct split_state *s)
 	return err;
 }
 
-static unsigned long __initdata addr[NTEST];
-static unsigned int __initdata len[NTEST];
+static unsigned long addr[NTEST];
+static unsigned int len[NTEST];
 
 /* Change the global bit on random pages in the direct mapping */
-static __init int exercise_pageattr(void)
+static int pageattr_test(void)
 {
 	struct split_state sa, sb, sc;
 	unsigned long *bm;
@@ -110,7 +119,8 @@ static __init int exercise_pageattr(void)
 	int i, k;
 	int err;
 
-	printk(KERN_INFO "CPA exercising pageattr\n");
+	if (print)
+		printk(KERN_INFO "CPA self-test:\n");
 
 	bm = vmalloc((max_pfn_mapped + 7) / 8);
 	if (!bm) {
@@ -186,7 +196,6 @@ static __init int exercise_pageattr(void)
 
 	failed += print_split(&sb);
 
-	printk(KERN_INFO "CPA reverting everything\n");
 	for (i = 0; i < NTEST; i++) {
 		if (!addr[i])
 			continue;
@@ -214,12 +223,40 @@ static __init int exercise_pageattr(void)
 	failed += print_split(&sc);
 
 	if (failed) {
-		printk(KERN_ERR "CPA selftests NOT PASSED. Please report.\n");
+		printk(KERN_ERR "NOT PASSED. Please report.\n");
 		WARN_ON(1);
+		return -EINVAL;
 	} else {
-		printk(KERN_INFO "CPA selftests PASSED\n");
+		if (print)
+			printk(KERN_INFO "ok.\n");
 	}
 
 	return 0;
 }
-module_init(exercise_pageattr);
+
+static int do_pageattr_test(void *__unused)
+{
+	while (!kthread_should_stop()) {
+		schedule_timeout_interruptible(HZ*30);
+		if (pageattr_test() < 0)
+			break;
+		if (print)
+			print--;
+	}
+	return 0;
+}
+
+static int start_pageattr_test(void)
+{
+	struct task_struct *p;
+
+	p = kthread_create(do_pageattr_test, NULL, "pageattr-test");
+	if (!IS_ERR(p))
+		wake_up_process(p);
+	else
+		WARN_ON(1);
+
+	return 0;
+}
+
+module_init(start_pageattr_test);
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 16ce841..8493c85 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -167,8 +167,6 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address)
 	if (within(address, virt_to_highmap(_text), virt_to_highmap(_etext)))
 		pgprot_val(forbidden) |= _PAGE_NX;
 
-
-#ifdef CONFIG_DEBUG_RODATA
 	/* The .rodata section needs to be read-only */
 	if (within(address, (unsigned long)__start_rodata,
 				(unsigned long)__end_rodata))
@@ -179,7 +177,6 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address)
 	if (within(address, virt_to_highmap(__start_rodata),
 				virt_to_highmap(__end_rodata)))
 		pgprot_val(forbidden) |= _PAGE_RW;
-#endif
 
 	prot = __pgprot(pgprot_val(prot) & ~pgprot_val(forbidden));
 
@@ -260,17 +257,6 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
 	pgprot_t old_prot, new_prot;
 	int level, do_split = 1;
 
-	/*
-	 * An Athlon 64 X2 showed hard hangs if we tried to preserve
-	 * largepages and changed the PSE entry from RW to RO.
-	 *
-	 * As AMD CPUs have a long series of erratas in this area,
-	 * (and none of the known ones seem to explain this hang),
-	 * disable this code until the hang can be debugged:
-	 */
-	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
-		return 1;
-
 	spin_lock_irqsave(&pgd_lock, flags);
 	/*
 	 * Check for races, another CPU might have split this page
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 4628c42..111771d 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1077,7 +1077,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 	current->mm->start_stack = bprm->p;
 
 #ifdef arch_randomize_brk
-	if (current->flags & PF_RANDOMIZE)
+	if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
 		current->mm->brk = current->mm->start_brk =
 			arch_randomize_brk(current->mm);
 #endif
diff --git a/include/asm-x86/pgalloc_64.h b/include/asm-x86/pgalloc_64.h
index 315314c..4f6220d 100644
--- a/include/asm-x86/pgalloc_64.h
+++ b/include/asm-x86/pgalloc_64.h
@@ -42,19 +42,21 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
 static inline void pgd_list_add(pgd_t *pgd)
 {
 	struct page *page = virt_to_page(pgd);
+	unsigned long flags;
 
-	spin_lock(&pgd_lock);
+	spin_lock_irqsave(&pgd_lock, flags);
 	list_add(&page->lru, &pgd_list);
-	spin_unlock(&pgd_lock);
+	spin_unlock_irqrestore(&pgd_lock, flags);
 }
 
 static inline void pgd_list_del(pgd_t *pgd)
 {
 	struct page *page = virt_to_page(pgd);
+	unsigned long flags;
 
-	spin_lock(&pgd_lock);
+	spin_lock_irqsave(&pgd_lock, flags);
 	list_del(&page->lru);
-	spin_unlock(&pgd_lock);
+	spin_unlock_irqrestore(&pgd_lock, flags);
 }
 
 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index c4e0016..b0fd85a 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -79,7 +79,7 @@ struct cpuidle_state_kobj {
 };
 
 struct cpuidle_device {
-	int			enabled:1;
+	unsigned int		enabled:1;
 	unsigned int		cpu;
 
 	int			last_residency;
diff --git a/include/linux/init.h b/include/linux/init.h
index 90cdbbb..a404a00 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -110,6 +110,7 @@
 #define __FINIT		.previous
 
 #define __INITDATA	.section	".init.data","aw"
+#define __FINITDATA	.previous
 
 #define __DEVINIT        .section	".devinit.text", "ax"
 #define __DEVINITDATA    .section	".devinit.data", "aw"
diff --git a/init/Kconfig b/init/Kconfig
index 87f50df..92b23e2 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -541,6 +541,18 @@ config ELF_CORE
 	help
 	  Enable support for generating core dumps. Disabling saves about 4k.
 
+config COMPAT_BRK
+	bool "Disable heap randomization"
+	default y
+	help
+	  Randomizing heap placement makes heap exploits harder, but it
+	  also breaks ancient binaries (including anything libc5 based).
+	  This option changes the bootup default to heap randomization
+	  disabled, and can be overriden runtime by setting
+	  /proc/sys/kernel/randomize_va_space to 2.
+
+	  On non-ancient distros (post-2000 ones) Y is usually a safe choice.
+
 config BASE_FULL
 	default y
 	bool "Enable full-sized data structures for core" if EMBEDDED
diff --git a/mm/memory.c b/mm/memory.c
index 7bb7072..9d073fa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -82,7 +82,18 @@ void * high_memory;
 EXPORT_SYMBOL(num_physpages);
 EXPORT_SYMBOL(high_memory);
 
-int randomize_va_space __read_mostly = 1;
+/*
+ * Randomize the address space (stacks, mmaps, brk, etc.).
+ *
+ * ( When CONFIG_COMPAT_BRK=y we exclude brk from randomization,
+ *   as ancient (libc5 based) binaries can segfault. )
+ */
+int randomize_va_space __read_mostly =
+#ifdef CONFIG_COMPAT_BRK
+					1;
+#else
+					2;
+#endif
 
 static int __init disable_randmaps(char *s)
 {
diff --git a/mm/mmap.c b/mm/mmap.c
index bb4c963..ad6e4ea 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -245,7 +245,7 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
 
 	down_write(&mm->mmap_sem);
 
-	if (brk < mm->end_code)
+	if (brk < mm->start_brk)
 		goto out;
 
 	/*