[PATCH 8/8] x86_64,vdso: Clean up vgetcpu init and merge the vdso initcalls

From: Andy Lutomirski
Date: Mon Jun 16 2014 - 22:24:56 EST


Now vdso/vma.c has a single initcall and no references to
"vsyscall".

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
---
arch/x86/vdso/vma.c | 61 +++++++++++++++++++----------------------------------
1 file changed, 22 insertions(+), 39 deletions(-)

diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 8973b4e..84df79b 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>
@@ -11,7 +12,6 @@
#include <linux/random.h>
#include <linux/elf.h>
#include <linux/cpu.h>
-#include <asm/vsyscall.h>
#include <asm/vgtod.h>
#include <asm/proto.h>
#include <asm/vdso.h>
@@ -22,8 +22,6 @@

#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)
@@ -41,20 +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.
@@ -237,12 +221,9 @@ __setup("vdso=", vdso_setup);
#endif

#ifdef CONFIG_X86_64
-/*
- * Assume __initcall executes before all user space. Hopefully kmod
- * doesn't violate that. We'll find out if it does.
- */
-static void vsyscall_set_cpu(int cpu)
+static void vgetcpu_cpu_init(void *arg)
{
+ int cpu = smp_processor_id();
unsigned long d;
unsigned long node = 0;
#ifdef CONFIG_NUMA
@@ -252,45 +233,47 @@ static void vsyscall_set_cpu(int cpu)
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)
+ * 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);
-}
-
-static void cpu_vsyscall_init(void *arg)
-{
- /* preemption should be already off */
- vsyscall_set_cpu(raw_smp_processor_id());
+ write_gdt_entry(get_cpu_gdt_table(cpu),
+ GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);
}

static int
-cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg)
+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, cpu_vsyscall_init, NULL, 1);
+ smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1);

return NOTIFY_DONE;
}

-static int __init vsyscall_init(void)
+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(cpu_vsyscall_init, NULL, 1);
+ on_each_cpu(vgetcpu_cpu_init, NULL, 1);
/* notifier priority > KVM */
- __hotcpu_notifier(cpu_vsyscall_notifier, 30);
+ __hotcpu_notifier(vgetcpu_cpu_notifier, 30);

cpu_notifier_register_done();

return 0;
}
-__initcall(vsyscall_init);
-#endif
+subsys_initcall(init_vdso);
+#endif /* CONFIG_X86_64 */
--
1.9.3

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