Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 111 insertions, 0 deletions

diff --git a/arch/x86_64/ia32/syscall32.c b/arch/x86_64/ia32/syscall32.c
new file mode 100644
index 00000000000..399ff498509
--- /dev/null
+++ b/arch/x86_64/ia32/syscall32.c
@@ -0,0 +1,111 @@
+/* Copyright 2002,2003 Andi Kleen, SuSE Labs */
+
+/* vsyscall handling for 32bit processes. Map a stub page into it 
+   on demand because 32bit cannot reach the kernel's fixmaps */
+
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/init.h>
+#include <linux/stringify.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");
+
+extern unsigned char syscall32_syscall[], syscall32_syscall_end[];
+extern unsigned char syscall32_sysenter[], syscall32_sysenter_end[];
+extern int sysctl_vsyscall32;
+
+char *syscall32_page; 
+static int use_sysenter = -1;
+
+/*
+ * 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;
+		}
+	}
+	spin_unlock(&mm->page_table_lock);
+	return err;
+}
+
+int map_syscall32(struct mm_struct *mm, unsigned long address)
+{
+	int err;
+	down_read(&mm->mmap_sem);
+	err = __map_syscall32(mm, address);
+	up_read(&mm->mmap_sem);
+	return err;
+}
+
+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));
+ 	if (use_sysenter > 0) {
+ 		memcpy(syscall32_page, syscall32_sysenter,
+ 		       syscall32_sysenter_end - syscall32_sysenter);
+ 	} else {
+  		memcpy(syscall32_page, syscall32_syscall,
+  		       syscall32_syscall_end - syscall32_syscall);
+  	}	
+	return 0;
+} 
+	
+__initcall(init_syscall32); 
+
+/* May not be __init: called during resume */
+void syscall32_cpu_init(void)
+{
+	if (use_sysenter < 0)
+ 		use_sysenter = (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL);
+
+	/* Load these always in case some future AMD CPU supports
+	   SYSENTER from compat mode too. */
+	checking_wrmsrl(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
+	checking_wrmsrl(MSR_IA32_SYSENTER_ESP, 0ULL);
+	checking_wrmsrl(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
+
+	wrmsrl(MSR_CSTAR, ia32_cstar_target);
+}