Attachment 298994 Details for Bug 434759 – xen execshield: Add xen-specific load_user_cs_desc()

[patch] xen execshield: Add xen-specific load_user_cs_desc()

0001-xen-execshield-Add-xen-specific-load_user_cs_desc.patch (text/plain), 4.28 KB, created by Mark McLoughlin on 2008-03-25 10:54:42 UTC

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Creator: Mark McLoughlin

Created: 2008-03-25 10:54:42 UTC

Size: 4.28 KB

patch

obsolete

>From aae8f8b516f4cdfdab403165ae0cc47acbd75ea1 Mon Sep 17 00:00:00 2001
>From: Stephen Tweedie <sct@redhat.com>
>Date: Tue, 11 Mar 2008 18:05:30 +0000
>Subject: [PATCH] xen execshield: Add xen-specific load_user_cs_desc()
>
>x86 32-bit execshield uses load_user_cs_desc() to setup the user CS
>descriptor, but the Xen version needs to do this via a hypercall.
>
>Add this via a new pv_cpu_ops->load_user_cs_desc pv_ops indirection
>so that it can be selected appropriately at run-time.
>
>Signed-off-by: Stephen Tweedie <sct@redhat.com>
>---
> arch/x86/kernel/paravirt.c |    1 +
> arch/x86/xen/enlighten.c   |   17 +++++++++++++++++
> include/asm-x86/desc.h     |    8 ++++++--
> include/asm-x86/paravirt.h |    6 ++++++
> 4 files changed, 30 insertions(+), 2 deletions(-)
>
>diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
>index 075962c..d59db07 100644
>--- a/arch/x86/kernel/paravirt.c
>+++ b/arch/x86/kernel/paravirt.c
>@@ -331,6 +331,7 @@ struct pv_cpu_ops pv_cpu_ops = {
> 	.read_tscp = native_read_tscp,
> 	.load_tr_desc = native_load_tr_desc,
> 	.set_ldt = native_set_ldt,
>+	.load_user_cs_desc = native_load_user_cs_desc,
> 	.load_gdt = native_load_gdt,
> 	.load_idt = native_load_idt,
> 	.store_gdt = native_store_gdt,
>diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
>index 8b9ee27..e9a84f6 100644
>--- a/arch/x86/xen/enlighten.c
>+++ b/arch/x86/xen/enlighten.c
>@@ -289,6 +289,22 @@ static void xen_set_ldt(const void *addr, unsigned entries)
> 	xen_mc_issue(PARAVIRT_LAZY_CPU);
> }
> 
>+static inline void xen_load_user_cs_desc(int cpu, struct mm_struct *mm)
>+{
>+	void *gdt;
>+	xmaddr_t mgdt;
>+	u64 descriptor;
>+	struct desc_struct user_cs;
>+	
>+	gdt = &get_cpu_gdt_table(cpu)[GDT_ENTRY_DEFAULT_USER_CS];
>+	mgdt = virt_to_machine(gdt);
>+
>+	user_cs = mm->context.user_cs;
>+	descriptor = (u64) user_cs.a | ((u64) user_cs.b) << 32;
>+
>+	HYPERVISOR_update_descriptor(mgdt.maddr, descriptor);
>+}
>+
> static void xen_load_gdt(const struct desc_ptr *dtr)
> {
> 	unsigned long *frames;
>@@ -974,6 +990,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = {
> 
> 	.load_tr_desc = paravirt_nop,
> 	.set_ldt = xen_set_ldt,
>+	.load_user_cs_desc = xen_load_user_cs_desc,
> 	.load_gdt = xen_load_gdt,
> 	.load_idt = xen_load_idt,
> 	.load_tls = xen_load_tls,
>diff --git a/include/asm-x86/desc.h b/include/asm-x86/desc.h
>index 7ad80b9..ec3a84a 100644
>--- a/include/asm-x86/desc.h
>+++ b/include/asm-x86/desc.h
>@@ -6,6 +6,7 @@
> #include <asm/ldt.h>
> #include <asm/mmu.h>
> #include <linux/smp.h>
>+#include <linux/mm_types.h>
> 
> static inline void fill_ldt(struct desc_struct *desc,
> 			    const struct user_desc *info)
>@@ -94,6 +95,7 @@ static inline int desc_empty(const void *ptr)
> 
> #define load_TLS(t, cpu) native_load_tls(t, cpu)
> #define set_ldt native_set_ldt
>+#define load_user_cs_desc native_load_user_cs_desc
> 
> #define write_ldt_entry(dt, entry, desc) \
> 				native_write_ldt_entry(dt, entry, desc)
>@@ -360,8 +362,10 @@ static inline void set_user_cs(struct desc_struct *desc, unsigned long limit)
> 	desc->b = (limit & 0xf0000) | 0x00c0fb00;
> }
> 
>-#define load_user_cs_desc(cpu, mm) \
>-	get_cpu_gdt_table(cpu)[GDT_ENTRY_DEFAULT_USER_CS] = (mm)->context.user_cs
>+static inline void native_load_user_cs_desc(int cpu, struct mm_struct *mm)
>+{
>+	get_cpu_gdt_table(cpu)[GDT_ENTRY_DEFAULT_USER_CS] = mm->context.user_cs;
>+}
> 
> #ifdef CONFIG_X86_32
> extern void arch_add_exec_range(struct mm_struct *mm, unsigned long limit);
>diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h
>index d6236eb..ff8d218 100644
>--- a/include/asm-x86/paravirt.h
>+++ b/include/asm-x86/paravirt.h
>@@ -113,6 +113,7 @@ struct pv_cpu_ops {
> 	void (*store_gdt)(struct desc_ptr *);
> 	void (*store_idt)(struct desc_ptr *);
> 	void (*set_ldt)(const void *desc, unsigned entries);
>+	void (*load_user_cs_desc)(int cpu, struct mm_struct *mm);
> 	unsigned long (*store_tr)(void);
> 	void (*load_tls)(struct thread_struct *t, unsigned int cpu);
> 	void (*write_ldt_entry)(struct desc_struct *ldt, int entrynum,
>@@ -754,6 +755,11 @@ static inline void set_ldt(const void *addr, unsigned entries)
> {
> 	PVOP_VCALL2(pv_cpu_ops.set_ldt, addr, entries);
> }
>+static inline void load_user_cs_desc(unsigned int cpu, 
>+				     struct mm_struct *mm)
>+{
>+	PVOP_VCALL2(pv_cpu_ops.load_user_cs_desc, cpu, mm);
>+}
> static inline void store_gdt(struct desc_ptr *dtr)
> {
> 	PVOP_VCALL1(pv_cpu_ops.store_gdt, dtr);
>-- 
>1.5.4.1
>

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Attachments on bug 434759: 298994 | 298996 | 299014