[PATCH 16/19] modify get_desc_base

Glauber de Oliveira Costa
2007-12-13T16:45:30Z

This patch makes get_desc_base() receive a struct desc_struct,
and then uses its internal fields to compute the base address.
This is done at both i386 and x86_64, and then it is moved
to common header

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
---
arch/x86/kernel/tls.c | 2 +-
arch/x86/mm/fault_32.c | 2 +-
include/asm-x86/desc.h | 8 ++------
3 files changed, 4 insertions(+), 8 deletions(-)

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
@@ -112,7 +112,7 @@ int do_get_thread_area(struct task_struc

memset(&info, 0, sizeof(struct user_desc));
info.entry_number = idx;
- info.base_addr = get_desc_base((void *)desc);
+ info.base_addr = get_desc_base((struct desc_struct *)desc);
info.limit = GET_LIMIT(desc);
info.seg_32bit = GET_32BIT(desc);
info.contents = GET_CONTENTS(desc);
Index: linux-2.6-x86/arch/x86/mm/fault_32.c
===================================================================
--- linux-2.6-x86.orig/arch/x86/mm/fault_32.c
+++ linux-2.6-x86/arch/x86/mm/fault_32.c
@@ -115,7 +115,7 @@ static inline unsigned long get_segment_
}

/* Decode the code segment base from the descriptor */
- base = get_desc_base((unsigned long *)desc);
+ base = get_desc_base((struct desc_struct *)desc);

if (seg & (1<<2)) {
mutex_unlock(&current->mm->context.lock);
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
@@ -69,6 +69,11 @@ static inline void load_LDT(mm_context_t
preempt_enable();
}

+static inline unsigned long get_desc_base(struct desc_struct *desc)
+{
+ return desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24);
+}
+
#else
/*
* GET_DESC_BASE reads the descriptor base of the specified segment.
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
@@ -168,14 +168,6 @@ static inline void __set_tss_desc(unsign

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

-static inline unsigned long get_desc_base(unsigned long *desc)
-{
- unsigned long base;
- base = ((desc[0] >> 16) & 0x0000ffff) |
- ((desc[1] << 16) & 0x00ff0000) |
- (desc[1] & 0xff000000);
- return base;
-}
#endif /* !__ASSEMBLY__ */

#endif
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
@@ -156,15 +156,6 @@ static inline void load_TLS(struct threa
gdt[i] = t->tls_array[i];
}

-static inline unsigned long get_desc_base(const void *ptr)
-{
- const u32 *desc = ptr;
- unsigned long base;
- base = ((desc[0] >> 16) & 0x0000ffff) |
- ((desc[1] << 16) & 0x00ff0000) |
- (desc[1] & 0xff000000);
- return base;
-}
#endif /* !__ASSEMBLY__ */

#endif