[PATCH 05/19] introduce gate_desc type.

Glauber de Oliveira Costa
2007-12-13T16:59:34Z

To account for the differences in gate descriptor in i386 and x86_64
a gate_desc type is introduced.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
---
arch/x86/kernel/traps_32.c | 3 ++-
include/asm-x86/desc_32.h | 15 ++++++++-------
include/asm-x86/desc_64.h | 4 ++--
include/asm-x86/desc_defs.h | 8 +++++++-
4 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 94c5aea..6b03d88 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -76,8 +76,8 @@ char ignore_fpu_irq = 0;
* F0 0F bug workaround.. We have a special link segment
* for this.
*/
-struct desc_struct idt_table[256]
- __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
+gate_desc idt_table[256]
+ __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };

asmlinkage void divide_error(void);
asmlinkage void debug(void);
diff --git a/include/asm-x86/desc_32.h b/include/asm-x86/desc_32.h
index bc5ca34..77f1e5a 100644
--- a/include/asm-x86/desc_32.h
+++ b/include/asm-x86/desc_32.h
@@ -3,6 +3,7 @@

#include <asm/ldt.h>
#include <asm/segment.h>
+#include <asm/desc_defs.h>

#ifndef __ASSEMBLY__

@@ -24,7 +25,7 @@ static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
}

extern struct desc_ptr idt_descr;
-extern struct desc_struct idt_table[];
+extern gate_desc idt_table[];
extern void set_intr_gate(unsigned int irq, void * addr);

static inline void pack_descriptor(__u32 *a, __u32 *b,
@@ -35,11 +36,11 @@ static inline void pack_descriptor(__u32 *a, __u32 *b,
(limit & 0x000f0000) | ((type & 0xff) << 8) | ((flags & 0xf) << 20);
}

-static inline void pack_gate(__u32 *a, __u32 *b,
+static inline void pack_gate(gate_desc *gate,
unsigned long base, unsigned short seg, unsigned char type, unsigned char flags)
{
- *a = (seg << 16) | (base & 0xffff);
- *b = (base & 0xffff0000) | ((type & 0xff) << 8) | (flags & 0xff);
+ gate->a = (seg << 16) | (base & 0xffff);
+ gate->b = (base & 0xffff0000) | ((type & 0xff) << 8) | (flags & 0xff);
}

#define DESCTYPE_LDT 0x82 /* present, system, DPL-0, LDT */
@@ -139,9 +140,9 @@ static inline void native_load_tls(struct thread_struct *t, unsigned int cpu)

static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg)
{
- __u32 a, b;
- pack_gate(&a, &b, (unsigned long)addr, seg, type, 0);
- write_idt_entry(idt_table, gate, a, b);
+ gate_desc g;
+ pack_gate(&g, (unsigned long)addr, seg, type, 0);
+ write_idt_entry(idt_table, gate, g.a, g.b);
}

static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const void *addr)
diff --git a/include/asm-x86/desc_64.h b/include/asm-x86/desc_64.h
index 660cc84..ffc6c06 100644
--- a/include/asm-x86/desc_64.h
+++ b/include/asm-x86/desc_64.h
@@ -30,7 +30,7 @@ static inline unsigned long __store_tr(void)

#define store_tr(tr) (tr) = __store_tr()

-extern struct gate_struct idt_table[];
+extern gate_desc idt_table[];
extern struct desc_ptr cpu_gdt_descr[];

static inline void write_ldt_entry(struct desc_struct *ldt,
@@ -58,7 +58,7 @@ static inline void store_gdt(struct desc_ptr *ptr)
static inline void _set_gate(void *adr, unsigned type, unsigned long func,
unsigned dpl, unsigned ist)
{
- struct gate_struct s;
+ gate_desc s;

s.offset_low = PTR_LOW(func);
s.segment = __KERNEL_CS;
diff --git a/include/asm-x86/desc_defs.h b/include/asm-x86/desc_defs.h
index f37b44c..05eff93 100644
--- a/include/asm-x86/desc_defs.h
+++ b/include/asm-x86/desc_defs.h
@@ -39,7 +39,7 @@ enum {
};

// 16byte gate
-struct gate_struct {
+struct gate_struct64 {
u16 offset_low;
u16 segment;
unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
@@ -67,6 +67,12 @@ struct ldttss_desc {
u32 zero1;
} __attribute__((packed));

+#ifdef CONFIG_X86_64
+typedef struct gate_struct64 gate_desc;
+#else
+typedef struct desc_struct gate_desc;
+#endif
+
struct desc_ptr {
unsigned short size;
unsigned long address;
--
1.5.0.6