[PATCH 09/19] introduce fill_ldt

Glauber de Oliveira Costa
2007-12-13T04:51:39Z

This patch introduces fill_ldt(), which populates a ldt descriptor
from a user_desc in once, instead of relying in the LDT_entry_a and
LDT_entry_b macros

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
---
arch/x86/kernel/ldt.c | 3 +--
arch/x86/kernel/process_64.c | 3 +--
arch/x86/kernel/tls.c | 7 +++----
include/asm-x86/desc_32.h | 15 ---------------
include/asm-x86/desc_64.h | 17 -----------------
include/asm-x86/ldt.h | 19 +++++++++++++++++++
6 files changed, 24 insertions(+), 40 deletions(-)

Index: linux-2.6-x86/arch/x86/kernel/ldt.c
===================================================================
--- linux-2.6-x86.orig/arch/x86/kernel/ldt.c
+++ linux-2.6-x86/arch/x86/kernel/ldt.c
@@ -223,8 +223,7 @@ static int write_ldt(void __user *ptr, u
}
}

- ldt.a = LDT_entry_a(&ldt_info);
- ldt.b = LDT_entry_b(&ldt_info);
+ fill_ldt(&ldt, &ldt_info);
if (oldmode)
ldt.avl = 0;

Index: linux-2.6-x86/arch/x86/kernel/process_64.c
===================================================================
--- linux-2.6-x86.orig/arch/x86/kernel/process_64.c
+++ linux-2.6-x86/arch/x86/kernel/process_64.c
@@ -446,8 +446,7 @@ static inline void set_32bit_tls(struct
};
struct desc_struct *desc = (void *)t->thread.tls_array;
desc += tls;
- desc->a = LDT_entry_a(&ud);
- desc->b = LDT_entry_b(&ud);
+ fill_ldt(desc, &ud);
}

static inline u32 read_32bit_tls(struct task_struct *t, int tls)
Index: linux-2.6-x86/arch/x86/kernel/tls.c
===================================================================
--- linux-2.6-x86.orig/arch/x86/kernel/tls.c
+++ linux-2.6-x86/arch/x86/kernel/tls.c
@@ -67,10 +67,9 @@ int do_set_thread_area(struct task_struc
if (LDT_empty(&info)) {
desc[0] = 0;
desc[1] = 0;
- } else {
- desc[0] = LDT_entry_a(&info);
- desc[1] = LDT_entry_b(&info);
- }
+ } else
+ fill_ldt((struct desc_struct *)desc, &info);
+
if (t == &current->thread)
load_TLS(t, cpu);

Index: linux-2.6-x86/include/asm-x86/desc_32.h
===================================================================
--- linux-2.6-x86.orig/include/asm-x86/desc_32.h
+++ linux-2.6-x86/include/asm-x86/desc_32.h
@@ -163,21 +163,6 @@ static inline void __set_tss_desc(unsign

#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)

-#define LDT_entry_a(info) \
- ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
-
-#define LDT_entry_b(info) \
- (((info)->base_addr & 0xff000000) | \
- (((info)->base_addr & 0x00ff0000) >> 16) | \
- ((info)->limit & 0xf0000) | \
- (((info)->read_exec_only ^ 1) << 9) | \
- ((info)->contents << 10) | \
- (((info)->seg_not_present ^ 1) << 15) | \
- ((info)->seg_32bit << 22) | \
- ((info)->limit_in_pages << 23) | \
- ((info)->useable << 20) | \
- 0x7000)
-
#define LDT_empty(info) (\
(info)->base_addr == 0 && \
(info)->limit == 0 && \
Index: linux-2.6-x86/include/asm-x86/desc_64.h
===================================================================
--- linux-2.6-x86.orig/include/asm-x86/desc_64.h
+++ linux-2.6-x86/include/asm-x86/desc_64.h
@@ -147,23 +147,6 @@ static inline void set_ldt_desc(unsigned
(unsigned long)addr, DESC_LDT, size * 8 - 1);
}

-#define LDT_entry_a(info) \
- ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
-/* Don't allow setting of the lm bit. It is useless anyways because
- 64bit system calls require __USER_CS. */
-#define LDT_entry_b(info) \
- (((info)->base_addr & 0xff000000) | \
- (((info)->base_addr & 0x00ff0000) >> 16) | \
- ((info)->limit & 0xf0000) | \
- (((info)->read_exec_only ^ 1) << 9) | \
- ((info)->contents << 10) | \
- (((info)->seg_not_present ^ 1) << 15) | \
- ((info)->seg_32bit << 22) | \
- ((info)->limit_in_pages << 23) | \
- ((info)->useable << 20) | \
- /* ((info)->lm << 21) | */ \
- 0x7000)
-
#define LDT_empty(info) (\
(info)->base_addr == 0 && \
(info)->limit == 0 && \
Index: linux-2.6-x86/include/asm-x86/desc.h
===================================================================
--- linux-2.6-x86.orig/include/asm-x86/desc.h
+++ linux-2.6-x86/include/asm-x86/desc.h
@@ -1,5 +1,34 @@
+#ifndef _ASM_DESC_H_
+#define _ASM_DESC_H_
+
+#ifndef __ASSEMBLY__
+#include <asm/desc_defs.h>
+#include <asm/ldt.h>
+
+static inline void fill_ldt(struct desc_struct *desc, struct user_desc *info)
+{
+ desc->limit0 = info->limit & 0x0ffff;
+ desc->base0 = info->base_addr & 0x0000ffff;
+
+ desc->base1 = (info->base_addr & 0x00ff0000) >> 16;
+ desc->type = (info->read_exec_only ^ 1) << 1;
+ desc->type |= info->contents << 2;
+ desc->s = 1;
+ desc->dpl = 0x3;
+ desc->p = info->seg_not_present ^ 1;
+ desc->limit = (info->limit & 0xf0000) >> 16;
+ desc->avl = info->useable;
+ desc->d = info->seg_32bit;
+ desc->g = info->limit_in_pages;
+ desc->base2 = (info->base_addr & 0xff000000) >> 24;
+}
+
+#endif
+
#ifdef CONFIG_X86_32
# include "desc_32.h"
#else
# include "desc_64.h"
#endif
+
+#endif