[patch V2 27/44] x86/ldttss: Cleanup 32bit descriptors

Thomas Gleixner
2017-08-25T22:04:51Z

[-- Attachment #1: x86-ldttss--Cleanup-32bit-descriptors.patch --]
[-- Type: text/plain, Size: 2660 bytes --]

Like the IDT descriptors the LDT/TSS descriptors are pointlessly different
on 32 and 64 bit.

Unify them and get rid of the duplicated code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/desc.h | 26 +++-----------------------
arch/x86/include/asm/desc_defs.h | 27 ++++++++++++---------------
2 files changed, 15 insertions(+), 38 deletions(-)

--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -166,42 +166,22 @@ native_write_gdt_entry(struct desc_struc
memcpy(&gdt[entry], desc, size);
}

-static inline void pack_descriptor(struct desc_struct *desc, unsigned long base,
- unsigned long limit, unsigned char type,
- unsigned char flags)
-{
- desc->limit0 = (u16) limit;
- desc->base0 = (u16) base;
- desc->base1 = (base >> 16) & 0xFF;
- desc->type = type & 0x0F;
- desc->s = 0;
- desc->dpl = 0;
- desc->p = 1;
- desc->limit1 = (limit >> 16) & 0xF;
- desc->avl = (flags >> 0) & 0x01;
- desc->l = (flags >> 1) & 0x01;
- desc->d = (flags >> 2) & 0x01;
- desc->g = (flags >> 3) & 0x01;
-}
-
static inline void set_tssldt_descriptor(void *d, unsigned long addr,
unsigned type, unsigned size)
{
-#ifdef CONFIG_X86_64
- struct ldttss_desc64 *desc = d;
+ struct ldttss_desc *desc = d;

memset(desc, 0, sizeof(*desc));

- desc->limit0 = size & 0xFFFF;
+ desc->limit0 = (u16) size;
desc->base0 = (u16) addr;
desc->base1 = (addr >> 16) & 0xFF;
desc->type = type;
desc->p = 1;
desc->limit1 = (size >> 16) & 0xF;
desc->base2 = (addr >> 24) & 0xFF;
+#ifdef CONFIG_X86_64
desc->base3 = (u32) (addr >> 32);
-#else
- pack_descriptor((struct desc_struct *)d, addr, size, type, 0);
#endif
}

--- a/arch/x86/include/asm/desc_defs.h
+++ b/arch/x86/include/asm/desc_defs.h
@@ -49,24 +49,21 @@ enum {
DESCTYPE_S = 0x10, /* !system */
};

-/* LDT or TSS descriptor in the GDT. 16 bytes. */
-struct ldttss_desc64 {
- u16 limit0;
- u16 base0;
- unsigned base1 : 8, type : 5, dpl : 2, p : 1;
- unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
- u32 base3;
- u32 zero1;
-} __attribute__((packed));
-
+/* LDT or TSS descriptor in the GDT. */
+struct ldttss_desc {
+ u16 limit0;
+ u16 base0;

+ u16 base1 : 8, type : 5, dpl : 2, p : 1;
+ u16 limit1 : 4, zero0 : 3, g : 1, base2 : 8;
#ifdef CONFIG_X86_64
-typedef struct ldttss_desc64 ldt_desc;
-typedef struct ldttss_desc64 tss_desc;
-#else
-typedef struct desc_struct ldt_desc;
-typedef struct desc_struct tss_desc;
+ u32 base3;
+ u32 zero1;
#endif
+} __attribute__((packed));
+
+typedef struct ldttss_desc ldt_desc;
+typedef struct ldttss_desc tss_desc;

struct idt_bits {
u16 ist : 3,