* [GIT PULL] x86/vdso tree changes for v3.19
@ 2014-12-09 14:21 Ingo Molnar
0 siblings, 0 replies; only message in thread
From: Ingo Molnar @ 2014-12-09 14:21 UTC (permalink / raw)
To: Linus Torvalds
Cc: linux-kernel, Thomas Gleixner, H. Peter Anvin, Andrew Morton
Linus,
Please pull the latest x86-vdso-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-vdso-for-linus
# HEAD: 26893107aa717cd11010f0c278d02535defa1ac9 x86_64/vsyscall: Restore orig_ax after vsyscall seccomp
Various vDSO updates from Andy Lutomirski, mostly cleanups and
reorganization to improve maintainability, but also some
micro-optimizations and robustization changes.
Thanks,
Ingo
------------------>
Andrew Morton (1):
x86: vdso: Fix build with older gcc
Andy Lutomirski (13):
x86_64/vsyscall: Move all of the gate_area code to vsyscall_64.c
x86_64/vdso: Move getcpu code from vsyscall_64.c to vdso/vma.c
x86/vdso: Change the PER_CPU segment to use struct desc_struct
x86/vdso: Make the PER_CPU segment start out accessed
x86/vdso: Make the PER_CPU segment 32 bits
x86_64/vdso: Remove jiffies from the vvar page
x86_64/vdso: Clean up vgetcpu init and merge the vdso initcalls
x86,vdso: Use LSL unconditionally for vgetcpu
x86_64, vsyscall: Turn vsyscalls all the way off when vsyscall==none
x86_64, vsyscall: Rewrite comment and clean up headers in vsyscall code
x86_64,vsyscall: Make vsyscall emulation configurable
x86_64: Add a comment explaining the TASK_SIZE_MAX guard page
x86_64/vsyscall: Restore orig_ax after vsyscall seccomp
arch/x86/Kconfig | 18 +++++
arch/x86/include/asm/fixmap.h | 2 +
arch/x86/include/asm/page_64.h | 4 +-
arch/x86/include/asm/processor.h | 8 ++-
arch/x86/include/asm/vgtod.h | 19 +++++
arch/x86/include/asm/vsyscall.h | 33 ++-------
arch/x86/include/asm/vvar.h | 2 -
arch/x86/kernel/Makefile | 3 +-
arch/x86/kernel/cpu/common.c | 10 ---
arch/x86/kernel/setup.c | 2 -
arch/x86/kernel/time.c | 2 +-
arch/x86/kernel/vsyscall_64.c | 147 +++++++++++++++++----------------------
arch/x86/mm/init_64.c | 49 -------------
arch/x86/vdso/vgetcpu.c | 2 -
arch/x86/vdso/vma.c | 83 +++++++++++++++++-----
arch/x86/xen/mmu.c | 6 +-
16 files changed, 190 insertions(+), 200 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f2327e88e07c..cd10436d7d1c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -984,6 +984,24 @@ config X86_ESPFIX64
def_bool y
depends on X86_16BIT && X86_64
+config X86_VSYSCALL_EMULATION
+ bool "Enable vsyscall emulation" if EXPERT
+ default y
+ depends on X86_64
+ ---help---
+ This enables emulation of the legacy vsyscall page. Disabling
+ it is roughly equivalent to booting with vsyscall=none, except
+ that it will also disable the helpful warning if a program
+ tries to use a vsyscall. With this option set to N, offending
+ programs will just segfault, citing addresses of the form
+ 0xffffffffff600?00.
+
+ This option is required by many programs built before 2013, and
+ care should be used even with newer programs if set to N.
+
+ Disabling this option saves about 7K of kernel size and
+ possibly 4K of additional runtime pagetable memory.
+
config TOSHIBA
tristate "Toshiba Laptop support"
depends on X86_32
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h
index ffb1733ac91f..d8d5bcb2a0b5 100644
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -69,7 +69,9 @@ enum fixed_addresses {
#ifdef CONFIG_X86_32
FIX_HOLE,
#else
+#ifdef CONFIG_X86_VSYSCALL_EMULATION
VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
+#endif
#ifdef CONFIG_PARAVIRT_CLOCK
PVCLOCK_FIXMAP_BEGIN,
PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index f408caf73430..b3bebf9e5746 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -39,6 +39,8 @@ void copy_page(void *to, void *from);
#endif /* !__ASSEMBLY__ */
-#define __HAVE_ARCH_GATE_AREA 1
+#ifdef CONFIG_X86_VSYSCALL_EMULATION
+# define __HAVE_ARCH_GATE_AREA 1
+#endif
#endif /* _ASM_X86_PAGE_64_H */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index eb71ec794732..82d93ea13c0c 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -893,7 +893,13 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk);
#else
/*
- * User space process size. 47bits minus one guard page.
+ * User space process size. 47bits minus one guard page. The guard
+ * page is necessary on Intel CPUs: if a SYSCALL instruction is at
+ * the highest possible canonical userspace address, then that
+ * syscall will enter the kernel with a non-canonical return
+ * address, and SYSRET will explode dangerously. We avoid this
+ * particular problem by preventing anything from being mapped
+ * at the maximum canonical address.
*/
#define TASK_SIZE_MAX ((1UL << 47) - PAGE_SIZE)
diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h
index 3c3366c2e37f..e7e9682a33e9 100644
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -70,4 +70,23 @@ static inline void gtod_write_end(struct vsyscall_gtod_data *s)
++s->seq;
}
+#ifdef CONFIG_X86_64
+
+#define VGETCPU_CPU_MASK 0xfff
+
+static inline unsigned int __getcpu(void)
+{
+ unsigned int p;
+
+ /*
+ * Load per CPU data from GDT. LSL is faster than RDTSCP and
+ * works on all CPUs.
+ */
+ asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG));
+
+ return p;
+}
+
+#endif /* CONFIG_X86_64 */
+
#endif /* _ASM_X86_VGTOD_H */
diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h
index 2a46ca720afc..6ba66ee79710 100644
--- a/arch/x86/include/asm/vsyscall.h
+++ b/arch/x86/include/asm/vsyscall.h
@@ -4,15 +4,7 @@
#include <linux/seqlock.h>
#include <uapi/asm/vsyscall.h>
-#define VGETCPU_RDTSCP 1
-#define VGETCPU_LSL 2
-
-/* kernel space (writeable) */
-extern int vgetcpu_mode;
-extern struct timezone sys_tz;
-
-#include <asm/vvar.h>
-
+#ifdef CONFIG_X86_VSYSCALL_EMULATION
extern void map_vsyscall(void);
/*
@@ -20,25 +12,12 @@ extern void map_vsyscall(void);
* Returns true if handled.
*/
extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address);
-
-#ifdef CONFIG_X86_64
-
-#define VGETCPU_CPU_MASK 0xfff
-
-static inline unsigned int __getcpu(void)
+#else
+static inline void map_vsyscall(void) {}
+static inline bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
{
- unsigned int p;
-
- if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) {
- /* Load per CPU data from RDTSCP */
- native_read_tscp(&p);
- } else {
- /* Load per CPU data from GDT */
- asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG));
- }
-
- return p;
+ return false;
}
-#endif /* CONFIG_X86_64 */
+#endif
#endif /* _ASM_X86_VSYSCALL_H */
diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index 5d2b9ad2c6d2..3f32dfc2ab73 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -44,8 +44,6 @@ extern char __vvar_page;
/* DECLARE_VVAR(offset, type, name) */
-DECLARE_VVAR(0, volatile unsigned long, jiffies)
-DECLARE_VVAR(16, int, vgetcpu_mode)
DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data)
#undef DECLARE_VVAR
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 8f1e77440b2b..5d4502c8b983 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -28,8 +28,7 @@ obj-$(CONFIG_X86_32) += i386_ksyms_32.o
obj-$(CONFIG_X86_64) += sys_x86_64.o x8664_ksyms_64.o
obj-$(CONFIG_X86_64) += mcount_64.o
obj-y += syscall_$(BITS).o vsyscall_gtod.o
-obj-$(CONFIG_X86_64) += vsyscall_64.o
-obj-$(CONFIG_X86_64) += vsyscall_emu_64.o
+obj-$(CONFIG_X86_VSYSCALL_EMULATION) += vsyscall_64.o vsyscall_emu_64.o
obj-$(CONFIG_X86_ESPFIX64) += espfix_64.o
obj-$(CONFIG_SYSFS) += ksysfs.o
obj-y += bootflag.o e820.o
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4b4f78c9ba19..175372b854be 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -956,14 +956,6 @@ static void identify_cpu(struct cpuinfo_x86 *c)
}
#ifdef CONFIG_X86_64
-static void vgetcpu_set_mode(void)
-{
- if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
- vgetcpu_mode = VGETCPU_RDTSCP;
- else
- vgetcpu_mode = VGETCPU_LSL;
-}
-
#ifdef CONFIG_IA32_EMULATION
/* May not be __init: called during resume */
static void syscall32_cpu_init(void)
@@ -1006,8 +998,6 @@ void __init identify_boot_cpu(void)
#ifdef CONFIG_X86_32
sysenter_setup();
enable_sep_cpu();
-#else
- vgetcpu_set_mode();
#endif
cpu_detect_tlb(&boot_cpu_data);
}
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 235cfd39e0d7..59a6f884fdad 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1190,9 +1190,7 @@ void __init setup_arch(char **cmdline_p)
tboot_probe();
-#ifdef CONFIG_X86_64
map_vsyscall();
-#endif
generic_apic_probe();
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
index 0fa29609b2c4..25adc0e16eaa 100644
--- a/arch/x86/kernel/time.c
+++ b/arch/x86/kernel/time.c
@@ -23,7 +23,7 @@
#include <asm/time.h>
#ifdef CONFIG_X86_64
-__visible DEFINE_VVAR(volatile unsigned long, jiffies) = INITIAL_JIFFIES;
+__visible volatile unsigned long jiffies __cacheline_aligned = INITIAL_JIFFIES;
#endif
unsigned long profile_pc(struct pt_regs *regs)
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 957779f4eb40..2dcc6ff6fdcc 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -1,59 +1,43 @@
/*
+ * Copyright (c) 2012-2014 Andy Lutomirski <luto@amacapital.net>
+ *
+ * Based on the original implementation which is:
* Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
* Copyright 2003 Andi Kleen, SuSE Labs.
*
- * [ NOTE: this mechanism is now deprecated in favor of the vDSO. ]
+ * Parts of the original code have been moved to arch/x86/vdso/vma.c
+ *
+ * This file implements vsyscall emulation. vsyscalls are a legacy ABI:
+ * Userspace can request certain kernel services by calling fixed
+ * addresses. This concept is problematic:
*
- * Thanks to hpa@transmeta.com for some useful hint.
- * Special thanks to Ingo Molnar for his early experience with
- * a different vsyscall implementation for Linux/IA32 and for the name.
+ * - It interferes with ASLR.
+ * - It's awkward to write code that lives in kernel addresses but is
+ * callable by userspace at fixed addresses.
+ * - The whole concept is impossible for 32-bit compat userspace.
+ * - UML cannot easily virtualize a vsyscall.
*
- * vsyscall 1 is located at -10Mbyte, vsyscall 2 is located
- * at virtual address -10Mbyte+1024bytes etc... There are at max 4
- * vsyscalls. One vsyscall can reserve more than 1 slot to avoid
- * jumping out of line if necessary. We cannot add more with this
- * mechanism because older kernels won't return -ENOSYS.
+ * As of mid-2014, I believe that there is no new userspace code that
+ * will use a vsyscall if the vDSO is present. I hope that there will
+ * soon be no new userspace code that will ever use a vsyscall.
*
- * Note: the concept clashes with user mode linux. UML users should
- * use the vDSO.
+ * The code in this file emulates vsyscalls when notified of a page
+ * fault to a vsyscall address.
*/
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/time.h>
-#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/timer.h>
-#include <linux/seqlock.h>
-#include <linux/jiffies.h>
-#include <linux/sysctl.h>
-#include <linux/topology.h>
-#include <linux/timekeeper_internal.h>
-#include <linux/getcpu.h>
-#include <linux/cpu.h>
-#include <linux/smp.h>
-#include <linux/notifier.h>
#include <linux/syscalls.h>
#include <linux/ratelimit.h>
#include <asm/vsyscall.h>
-#include <asm/pgtable.h>
-#include <asm/compat.h>
-#include <asm/page.h>
#include <asm/unistd.h>
#include <asm/fixmap.h>
-#include <asm/errno.h>
-#include <asm/io.h>
-#include <asm/segment.h>
-#include <asm/desc.h>
-#include <asm/topology.h>
#include <asm/traps.h>
#define CREATE_TRACE_POINTS
#include "vsyscall_trace.h"
-DEFINE_VVAR(int, vgetcpu_mode);
-
static enum { EMULATE, NATIVE, NONE } vsyscall_mode = EMULATE;
static int __init vsyscall_setup(char *str)
@@ -222,6 +206,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
"seccomp tried to change syscall nr or ip");
do_exit(SIGSYS);
}
+ regs->orig_ax = -1;
if (tmp)
goto do_ret; /* skip requested */
@@ -284,46 +269,54 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
}
/*
- * Assume __initcall executes before all user space. Hopefully kmod
- * doesn't violate that. We'll find out if it does.
+ * A pseudo VMA to allow ptrace access for the vsyscall page. This only
+ * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
+ * not need special handling anymore:
*/
-static void vsyscall_set_cpu(int cpu)
+static const char *gate_vma_name(struct vm_area_struct *vma)
{
- unsigned long d;
- unsigned long node = 0;
-#ifdef CONFIG_NUMA
- node = cpu_to_node(cpu);
-#endif
- if (cpu_has(&cpu_data(cpu), X86_FEATURE_RDTSCP))
- write_rdtscp_aux((node << 12) | cpu);
-
- /*
- * Store cpu number in limit so that it can be loaded quickly
- * in user space in vgetcpu. (12 bits for the CPU and 8 bits for the node)
- */
- d = 0x0f40000000000ULL;
- d |= cpu;
- d |= (node & 0xf) << 12;
- d |= (node >> 4) << 48;
-
- write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);
+ return "[vsyscall]";
}
-
-static void cpu_vsyscall_init(void *arg)
+static struct vm_operations_struct gate_vma_ops = {
+ .name = gate_vma_name,
+};
+static struct vm_area_struct gate_vma = {
+ .vm_start = VSYSCALL_ADDR,
+ .vm_end = VSYSCALL_ADDR + PAGE_SIZE,
+ .vm_page_prot = PAGE_READONLY_EXEC,
+ .vm_flags = VM_READ | VM_EXEC,
+ .vm_ops = &gate_vma_ops,
+};
+
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
- /* preemption should be already off */
- vsyscall_set_cpu(raw_smp_processor_id());
+#ifdef CONFIG_IA32_EMULATION
+ if (!mm || mm->context.ia32_compat)
+ return NULL;
+#endif
+ if (vsyscall_mode == NONE)
+ return NULL;
+ return &gate_vma;
}
-static int
-cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg)
+int in_gate_area(struct mm_struct *mm, unsigned long addr)
{
- long cpu = (long)arg;
+ struct vm_area_struct *vma = get_gate_vma(mm);
+
+ if (!vma)
+ return 0;
- if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
- smp_call_function_single(cpu, cpu_vsyscall_init, NULL, 1);
+ return (addr >= vma->vm_start) && (addr < vma->vm_end);
+}
- return NOTIFY_DONE;
+/*
+ * Use this when you have no reliable mm, typically from interrupt
+ * context. It is less reliable than using a task's mm and may give
+ * false positives.
+ */
+int in_gate_area_no_mm(unsigned long addr)
+{
+ return vsyscall_mode != NONE && (addr & PAGE_MASK) == VSYSCALL_ADDR;
}
void __init map_vsyscall(void)
@@ -331,24 +324,12 @@ void __init map_vsyscall(void)
extern char __vsyscall_page;
unsigned long physaddr_vsyscall = __pa_symbol(&__vsyscall_page);
- __set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,
- vsyscall_mode == NATIVE
- ? PAGE_KERNEL_VSYSCALL
- : PAGE_KERNEL_VVAR);
+ if (vsyscall_mode != NONE)
+ __set_fixmap(VSYSCALL_PAGE, physaddr_vsyscall,
+ vsyscall_mode == NATIVE
+ ? PAGE_KERNEL_VSYSCALL
+ : PAGE_KERNEL_VVAR);
+
BUILD_BUG_ON((unsigned long)__fix_to_virt(VSYSCALL_PAGE) !=
(unsigned long)VSYSCALL_ADDR);
}
-
-static int __init vsyscall_init(void)
-{
- cpu_notifier_register_begin();
-
- on_each_cpu(cpu_vsyscall_init, NULL, 1);
- /* notifier priority > KVM */
- __hotcpu_notifier(cpu_vsyscall_notifier, 30);
-
- cpu_notifier_register_done();
-
- return 0;
-}
-__initcall(vsyscall_init);
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 4cb8763868fc..dd9ca9becc0f 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1193,55 +1193,6 @@ int kern_addr_valid(unsigned long addr)
return pfn_valid(pte_pfn(*pte));
}
-/*
- * A pseudo VMA to allow ptrace access for the vsyscall page. This only
- * covers the 64bit vsyscall page now. 32bit has a real VMA now and does
- * not need special handling anymore:
- */
-static const char *gate_vma_name(struct vm_area_struct *vma)
-{
- return "[vsyscall]";
-}
-static struct vm_operations_struct gate_vma_ops = {
- .name = gate_vma_name,
-};
-static struct vm_area_struct gate_vma = {
- .vm_start = VSYSCALL_ADDR,
- .vm_end = VSYSCALL_ADDR + PAGE_SIZE,
- .vm_page_prot = PAGE_READONLY_EXEC,
- .vm_flags = VM_READ | VM_EXEC,
- .vm_ops = &gate_vma_ops,
-};
-
-struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
-{
-#ifdef CONFIG_IA32_EMULATION
- if (!mm || mm->context.ia32_compat)
- return NULL;
-#endif
- return &gate_vma;
-}
-
-int in_gate_area(struct mm_struct *mm, unsigned long addr)
-{
- struct vm_area_struct *vma = get_gate_vma(mm);
-
- if (!vma)
- return 0;
-
- return (addr >= vma->vm_start) && (addr < vma->vm_end);
-}
-
-/*
- * Use this when you have no reliable mm, typically from interrupt
- * context. It is less reliable than using a task's mm and may give
- * false positives.
- */
-int in_gate_area_no_mm(unsigned long addr)
-{
- return (addr & PAGE_MASK) == VSYSCALL_ADDR;
-}
-
static unsigned long probe_memory_block_size(void)
{
/* start from 2g */
diff --git a/arch/x86/vdso/vgetcpu.c b/arch/x86/vdso/vgetcpu.c
index 2f94b039e55b..8ec3d1f4ce9a 100644
--- a/arch/x86/vdso/vgetcpu.c
+++ b/arch/x86/vdso/vgetcpu.c
@@ -7,9 +7,7 @@
#include <linux/kernel.h>
#include <linux/getcpu.h>
-#include <linux/jiffies.h>
#include <linux/time.h>
-#include <asm/vsyscall.h>
#include <asm/vgtod.h>
notrace long
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 970463b566cf..009495b9ab4b 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -1,7 +1,8 @@
/*
- * Set up the VMAs to tell the VM about the vDSO.
* Copyright 2007 Andi Kleen, SUSE Labs.
* Subject to the GPL, v.2
+ *
+ * This contains most of the x86 vDSO kernel-side code.
*/
#include <linux/mm.h>
#include <linux/err.h>
@@ -10,17 +11,17 @@
#include <linux/init.h>
#include <linux/random.h>
#include <linux/elf.h>
-#include <asm/vsyscall.h>
+#include <linux/cpu.h>
#include <asm/vgtod.h>
#include <asm/proto.h>
#include <asm/vdso.h>
+#include <asm/vvar.h>
#include <asm/page.h>
#include <asm/hpet.h>
+#include <asm/desc.h>
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
-
-extern unsigned short vdso_sync_cpuid;
#endif
void __init init_vdso_image(const struct vdso_image *image)
@@ -38,20 +39,6 @@ void __init init_vdso_image(const struct vdso_image *image)
image->alt_len));
}
-#if defined(CONFIG_X86_64)
-static int __init init_vdso(void)
-{
- init_vdso_image(&vdso_image_64);
-
-#ifdef CONFIG_X86_X32_ABI
- init_vdso_image(&vdso_image_x32);
-#endif
-
- return 0;
-}
-subsys_initcall(init_vdso);
-#endif
-
struct linux_binprm;
/* Put the vdso above the (randomized) stack with another randomized offset.
@@ -238,3 +225,63 @@ static __init int vdso_setup(char *s)
}
__setup("vdso=", vdso_setup);
#endif
+
+#ifdef CONFIG_X86_64
+static void vgetcpu_cpu_init(void *arg)
+{
+ int cpu = smp_processor_id();
+ struct desc_struct d = { };
+ unsigned long node = 0;
+#ifdef CONFIG_NUMA
+ node = cpu_to_node(cpu);
+#endif
+ if (cpu_has(&cpu_data(cpu), X86_FEATURE_RDTSCP))
+ write_rdtscp_aux((node << 12) | cpu);
+
+ /*
+ * Store cpu number in limit so that it can be loaded
+ * quickly in user space in vgetcpu. (12 bits for the CPU
+ * and 8 bits for the node)
+ */
+ d.limit0 = cpu | ((node & 0xf) << 12);
+ d.limit = node >> 4;
+ d.type = 5; /* RO data, expand down, accessed */
+ d.dpl = 3; /* Visible to user code */
+ d.s = 1; /* Not a system segment */
+ d.p = 1; /* Present */
+ d.d = 1; /* 32-bit */
+
+ write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);
+}
+
+static int
+vgetcpu_cpu_notifier(struct notifier_block *n, unsigned long action, void *arg)
+{
+ long cpu = (long)arg;
+
+ if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
+ smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1);
+
+ return NOTIFY_DONE;
+}
+
+static int __init init_vdso(void)
+{
+ init_vdso_image(&vdso_image_64);
+
+#ifdef CONFIG_X86_X32_ABI
+ init_vdso_image(&vdso_image_x32);
+#endif
+
+ cpu_notifier_register_begin();
+
+ on_each_cpu(vgetcpu_cpu_init, NULL, 1);
+ /* notifier priority > KVM */
+ __hotcpu_notifier(vgetcpu_cpu_notifier, 30);
+
+ cpu_notifier_register_done();
+
+ return 0;
+}
+subsys_initcall(init_vdso);
+#endif /* CONFIG_X86_64 */
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index a8a1a3d08d4d..8906cf0e536f 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1457,8 +1457,10 @@ static int xen_pgd_alloc(struct mm_struct *mm)
page->private = (unsigned long)user_pgd;
if (user_pgd != NULL) {
+#ifdef CONFIG_X86_VSYSCALL_EMULATION
user_pgd[pgd_index(VSYSCALL_ADDR)] =
__pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
+#endif
ret = 0;
}
@@ -2021,7 +2023,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
# ifdef CONFIG_HIGHMEM
case FIX_KMAP_BEGIN ... FIX_KMAP_END:
# endif
-#else
+#elif defined(CONFIG_X86_VSYSCALL_EMULATION)
case VSYSCALL_PAGE:
#endif
case FIX_TEXT_POKE0:
@@ -2060,7 +2062,7 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t phys, pgprot_t prot)
__native_set_fixmap(idx, pte);
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_VSYSCALL_EMULATION
/* Replicate changes to map the vsyscall page into the user
pagetable vsyscall mapping. */
if (idx == VSYSCALL_PAGE) {
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2014-12-09 14:21 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-12-09 14:21 [GIT PULL] x86/vdso tree changes for v3.19 Ingo Molnar
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.