#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/stringify.h>
+#include <linux/security.h>
+#include <linux/vs_memory.h>
#include <asm/proto.h>
#include <asm/tlbflush.h>
#include <asm/ia32_unistd.h>
-/* 32bit VDSOs mapped into user space. */
-asm(".section \".init.data\",\"aw\"\n"
- "syscall32_syscall:\n"
- ".incbin \"arch/x86_64/ia32/vsyscall-syscall.so\"\n"
- "syscall32_syscall_end:\n"
- "syscall32_sysenter:\n"
- ".incbin \"arch/x86_64/ia32/vsyscall-sysenter.so\"\n"
- "syscall32_sysenter_end:\n"
- ".previous");
-
+#ifdef USE_INT80
+extern unsigned char syscall32_int80[], syscall32_int80_end[];
+#endif
extern unsigned char syscall32_syscall[], syscall32_syscall_end[];
extern unsigned char syscall32_sysenter[], syscall32_sysenter_end[];
extern int sysctl_vsyscall32;
char *syscall32_page;
+#ifndef USE_INT80
static int use_sysenter = -1;
+#endif
-/*
- * Map the 32bit vsyscall page on demand.
- *
- * RED-PEN: This knows too much about high level VM.
- *
- * Alternative would be to generate a vma with appropriate backing options
- * and let it be handled by generic VM.
- */
-int __map_syscall32(struct mm_struct *mm, unsigned long address)
-{
- pgd_t *pgd;
- pud_t *pud;
- pte_t *pte;
- pmd_t *pmd;
- int err = -ENOMEM;
-
- spin_lock(&mm->page_table_lock);
- pgd = pgd_offset(mm, address);
- pud = pud_alloc(mm, pgd, address);
- if (pud) {
- pmd = pmd_alloc(mm, pud, address);
- if (pmd && (pte = pte_alloc_map(mm, pmd, address)) != NULL) {
- if (pte_none(*pte)) {
- set_pte(pte,
- mk_pte(virt_to_page(syscall32_page),
- PAGE_KERNEL_VSYSCALL32));
- }
- /* Flush only the local CPU. Other CPUs taking a fault
- will just end up here again
- This probably not needed and just paranoia. */
- __flush_tlb_one(address);
- err = 0;
- }
+static struct page *
+syscall32_nopage(struct vm_area_struct *vma, unsigned long adr, int *type)
+{
+ struct page *p = virt_to_page(adr - vma->vm_start + syscall32_page);
+ get_page(p);
+ return p;
+}
+
+/* Prevent VMA merging */
+static void syscall32_vma_close(struct vm_area_struct *vma)
+{
+}
+
+static struct vm_operations_struct syscall32_vm_ops = {
+ .close = syscall32_vma_close,
+ .nopage = syscall32_nopage,
+};
+
+struct linux_binprm;
+
+/* Setup a VMA at program startup for the vsyscall page */
+int syscall32_setup_pages(struct linux_binprm *bprm, int exstack,
+ unsigned long start_code,
+ unsigned long interp_map_address)
+{
+ int npages = (VSYSCALL32_END - VSYSCALL32_BASE) >> PAGE_SHIFT;
+ struct vm_area_struct *vma;
+ struct mm_struct *mm = current->mm;
+ int ret;
+
+ vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+ if (!vma)
+ return -ENOMEM;
+
+ memset(vma, 0, sizeof(struct vm_area_struct));
+ /* Could randomize here */
+ vma->vm_start = VSYSCALL32_BASE;
+ vma->vm_end = VSYSCALL32_END;
+ /* MAYWRITE to allow gdb to COW and set breakpoints */
+ vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE;
+ /*
+ * Make sure the vDSO gets into every core dump.
+ * Dumping its contents makes post-mortem fully interpretable later
+ * without matching up the same kernel and hardware config to see
+ * what PC values meant.
+ */
+ vma->vm_flags |= VM_ALWAYSDUMP;
+ vma->vm_flags |= mm->def_flags;
+ vma->vm_page_prot = protection_map[vma->vm_flags & 7];
+ vma->vm_ops = &syscall32_vm_ops;
+ vma->vm_mm = mm;
+
+ down_write(&mm->mmap_sem);
+ if ((ret = insert_vm_struct(mm, vma))) {
+ up_write(&mm->mmap_sem);
+ kmem_cache_free(vm_area_cachep, vma);
+ return ret;
}
- spin_unlock(&mm->page_table_lock);
- return err;
+ vx_vmpages_add(mm, npages);
+ up_write(&mm->mmap_sem);
+ return 0;
}
-int map_syscall32(struct mm_struct *mm, unsigned long address)
+const char *arch_vma_name(struct vm_area_struct *vma)
{
- int err;
- down_read(&mm->mmap_sem);
- err = __map_syscall32(mm, address);
- up_read(&mm->mmap_sem);
- return err;
+ if (vma->vm_start == VSYSCALL32_BASE &&
+ vma->vm_mm && vma->vm_mm->task_size == IA32_PAGE_OFFSET)
+ return "[vdso]";
+ return NULL;
}
static int __init init_syscall32(void)
syscall32_page = (void *)get_zeroed_page(GFP_KERNEL);
if (!syscall32_page)
panic("Cannot allocate syscall32 page");
- SetPageReserved(virt_to_page(syscall32_page));
+
+#ifdef USE_INT80
+ /*
+ * At this point we use int 0x80.
+ */
+ memcpy(syscall32_page, syscall32_int80,
+ syscall32_int80_end - syscall32_int80);
+#else
if (use_sysenter > 0) {
memcpy(syscall32_page, syscall32_sysenter,
syscall32_sysenter_end - syscall32_sysenter);
memcpy(syscall32_page, syscall32_syscall,
syscall32_syscall_end - syscall32_syscall);
}
+#endif
return 0;
}
-
-__initcall(init_syscall32);
+
+/*
+ * This must be done early in case we have an initrd containing 32-bit
+ * binaries (e.g., hotplug). This could be pushed upstream to arch/x86_64.
+ */
+core_initcall(init_syscall32);
/* May not be __init: called during resume */
void syscall32_cpu_init(void)
{
+#ifndef USE_INT80
if (use_sysenter < 0)
use_sysenter = (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL);
checking_wrmsrl(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
wrmsrl(MSR_CSTAR, ia32_cstar_target);
+#endif
}
git://git.onelab.eu / linux-2.6.git / blobdiff