From 858259cf7d1c443c836a2022b78cb281f0a9b95e Mon Sep 17 00:00:00 2001 From: Bodo Stroesser Date: Mon, 7 Nov 2005 00:58:55 -0800 Subject: [PATCH] uml: maintain own LDT entries Patch imlements full LDT handling in SKAS: * UML holds it's own LDT table, used to deliver data on modify_ldt(READ) * UML disables the default_ldt, inherited from the host (SKAS3) or resets LDT entries, set by host's clib and inherited in SKAS0 * A new global variable skas_needs_stub is inserted, that can be used to decide, whether stub-pages must be supported or not. * Uses the syscall-stub to replace missing PTRACE_LDT (therefore, write_ldt_entry needs to be modified) Signed-off-by: Bodo Stroesser Signed-off-by: Jeff Dike Cc: Paolo Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-um/ldt-i386.h | 69 +++++++++++++++++++++++++++++++++++++++++++++++ include/asm-um/ldt.h | 69 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 138 insertions(+) create mode 100644 include/asm-um/ldt-i386.h (limited to 'include') diff --git a/include/asm-um/ldt-i386.h b/include/asm-um/ldt-i386.h new file mode 100644 index 00000000000..b42662929b6 --- /dev/null +++ b/include/asm-um/ldt-i386.h @@ -0,0 +1,69 @@ +/* + * Copyright (C) 2004 Fujitsu Siemens Computers GmbH + * Licensed under the GPL + * + * Author: Bodo Stroesser + */ + +#ifndef __ASM_LDT_I386_H +#define __ASM_LDT_I386_H + +#include "asm/semaphore.h" +#include "asm/arch/ldt.h" + +struct mmu_context_skas; +extern void ldt_host_info(void); +extern long init_new_ldt(struct mmu_context_skas * to_mm, + struct mmu_context_skas * from_mm); +extern void free_ldt(struct mmu_context_skas * mm); + +#define LDT_PAGES_MAX \ + ((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE) +#define LDT_ENTRIES_PER_PAGE \ + (PAGE_SIZE/LDT_ENTRY_SIZE) +#define LDT_DIRECT_ENTRIES \ + ((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE) + +struct ldt_entry { + __u32 a; + __u32 b; +}; + +typedef struct uml_ldt { + int entry_count; + struct semaphore semaphore; + union { + struct ldt_entry * pages[LDT_PAGES_MAX]; + struct ldt_entry entries[LDT_DIRECT_ENTRIES]; + }; +} uml_ldt_t; + +/* + * macros stolen from include/asm-i386/desc.h + */ +#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 && \ + (info)->contents == 0 && \ + (info)->read_exec_only == 1 && \ + (info)->seg_32bit == 0 && \ + (info)->limit_in_pages == 0 && \ + (info)->seg_not_present == 1 && \ + (info)->useable == 0 ) + +#endif diff --git a/include/asm-um/ldt.h b/include/asm-um/ldt.h index e908439d338..4466ff6de0f 100644 --- a/include/asm-um/ldt.h +++ b/include/asm-um/ldt.h @@ -1,3 +1,72 @@ +/* + * Copyright (C) 2004 Fujitsu Siemens Computers GmbH + * Licensed under the GPL + * + * Author: Bodo Stroesser + */ + +#ifndef __ASM_LDT_I386_H +#define __ASM_LDT_I386_H + +#include "asm/semaphore.h" +#include "asm/arch/ldt.h" + +struct mmu_context_skas; +extern void ldt_host_info(void); +extern long init_new_ldt(struct mmu_context_skas * to_mm, + struct mmu_context_skas * from_mm); +extern void free_ldt(struct mmu_context_skas * mm); + +#define LDT_PAGES_MAX \ + ((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE) +#define LDT_ENTRIES_PER_PAGE \ + (PAGE_SIZE/LDT_ENTRY_SIZE) +#define LDT_DIRECT_ENTRIES \ + ((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE) + +struct ldt_entry { + __u32 a; + __u32 b; +}; + +typedef struct uml_ldt { + int entry_count; + struct semaphore semaphore; + union { + struct ldt_entry * pages[LDT_PAGES_MAX]; + struct ldt_entry entries[LDT_DIRECT_ENTRIES]; + }; +} uml_ldt_t; + +/* + * macros stolen from include/asm-i386/desc.h + */ +#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 && \ + (info)->contents == 0 && \ + (info)->read_exec_only == 1 && \ + (info)->seg_32bit == 0 && \ + (info)->limit_in_pages == 0 && \ + (info)->seg_not_present == 1 && \ + (info)->useable == 0 ) + +#endif #ifndef __UM_LDT_H #define __UM_LDT_H -- cgit v1.2.3