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linux/include/asm-s390/mmu_context.h

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Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* include/asm-s390/mmu_context.h
*
* S390 version
*
* Derived from "include/asm-i386/mmu_context.h"
*/
#ifndef __S390_MMU_CONTEXT_H
#define __S390_MMU_CONTEXT_H
[S390] noexec protection This provides a noexec protection on s390 hardware. Our hardware does not have any bits left in the pte for a hw noexec bit, so this is a different approach using shadow page tables and a special addressing mode that allows separate address spaces for code and data. As a special feature of our "secondary-space" addressing mode, separate page tables can be specified for the translation of data addresses (storage operands) and instruction addresses. The shadow page table is used for the instruction addresses and the standard page table for the data addresses. The shadow page table is linked to the standard page table by a pointer in page->lru.next of the struct page corresponding to the page that contains the standard page table (since page->private is not really private with the pte_lock and the page table pages are not in the LRU list). Depending on the software bits of a pte, it is either inserted into both page tables or just into the standard (data) page table. Pages of a vma that does not have the VM_EXEC bit set get mapped only in the data address space. Any try to execute code on such a page will cause a page translation exception. The standard reaction to this is a SIGSEGV with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the kernel to the signal stack frame. Unfortunately, the signal return mechanism cannot be modified to use an SA_RESTORER because the exception unwinding code depends on the system call opcode stored behind the signal stack frame. This feature requires that user space is executed in secondary-space mode and the kernel in home-space mode, which means that the addressing modes need to be switched and that the noexec protection only works for user space. After switching the addressing modes, we cannot use the mvcp/mvcs instructions anymore to copy between kernel and user space. A new mvcos instruction has been added to the z9 EC/BC hardware which allows to copy between arbitrary address spaces, but on older hardware the page tables need to be walked manually. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-05 20:18:17 +00:00
#include <asm/pgalloc.h>
[PATCH] x86: PARAVIRT: add hooks to intercept mm creation and destruction Add hooks to allow a paravirt implementation to track the lifetime of an mm. Paravirtualization requires three hooks, but only two are needed in common code. They are: arch_dup_mmap, which is called when a new mmap is created at fork arch_exit_mmap, which is called when the last process reference to an mm is dropped, which typically happens on exit and exec. The third hook is activate_mm, which is called from the arch-specific activate_mm() macro/function, and so doesn't need stub versions for other architectures. It's called when an mm is first used. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: linux-arch@vger.kernel.org Cc: James Bottomley <James.Bottomley@SteelEye.com> Acked-by: Ingo Molnar <mingo@elte.hu>
2007-05-02 17:27:14 +00:00
#include <asm-generic/mm_hooks.h>
[S390] Fix tlb flushing with idte. The clear-by-asce operation of the idte instruction gets an asce (address-space-control-element) as argument to specify which TLBs need to get flushed. The current code passes a plain pointer to the start of the pgd without the additional bits which would make the pointer an asce. The current machines don't mind the difference but a future model might want to use the designation type control bits in the asce as a filter for the TLBs to flush. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26 13:10:58 +00:00
static inline int init_new_context(struct task_struct *tsk,
struct mm_struct *mm)
{
mm->context = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
#ifdef CONFIG_64BIT
mm->context |= _ASCE_TYPE_REGION3;
#endif
return 0;
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#define destroy_context(mm) do { } while (0)
[S390] noexec protection This provides a noexec protection on s390 hardware. Our hardware does not have any bits left in the pte for a hw noexec bit, so this is a different approach using shadow page tables and a special addressing mode that allows separate address spaces for code and data. As a special feature of our "secondary-space" addressing mode, separate page tables can be specified for the translation of data addresses (storage operands) and instruction addresses. The shadow page table is used for the instruction addresses and the standard page table for the data addresses. The shadow page table is linked to the standard page table by a pointer in page->lru.next of the struct page corresponding to the page that contains the standard page table (since page->private is not really private with the pte_lock and the page table pages are not in the LRU list). Depending on the software bits of a pte, it is either inserted into both page tables or just into the standard (data) page table. Pages of a vma that does not have the VM_EXEC bit set get mapped only in the data address space. Any try to execute code on such a page will cause a page translation exception. The standard reaction to this is a SIGSEGV with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the kernel to the signal stack frame. Unfortunately, the signal return mechanism cannot be modified to use an SA_RESTORER because the exception unwinding code depends on the system call opcode stored behind the signal stack frame. This feature requires that user space is executed in secondary-space mode and the kernel in home-space mode, which means that the addressing modes need to be switched and that the noexec protection only works for user space. After switching the addressing modes, we cannot use the mvcp/mvcs instructions anymore to copy between kernel and user space. A new mvcos instruction has been added to the z9 EC/BC hardware which allows to copy between arbitrary address spaces, but on older hardware the page tables need to be walked manually. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-05 20:18:17 +00:00
#ifndef __s390x__
#define LCTL_OPCODE "lctl"
#else
#define LCTL_OPCODE "lctlg"
#endif
[S390] Cleanup page table definitions. - De-confuse the defines for the address-space-control-elements and the segment/region table entries. - Create out of line functions for page table allocation / freeing. - Simplify get_shadow_xxx functions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22 10:52:47 +00:00
static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[S390] Fix tlb flushing with idte. The clear-by-asce operation of the idte instruction gets an asce (address-space-control-element) as argument to specify which TLBs need to get flushed. The current code passes a plain pointer to the start of the pgd without the additional bits which would make the pointer an asce. The current machines don't mind the difference but a future model might want to use the designation type control bits in the asce as a filter for the TLBs to flush. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26 13:10:58 +00:00
S390_lowcore.user_asce = mm->context | __pa(mm->pgd);
[S390] Cleanup page table definitions. - De-confuse the defines for the address-space-control-elements and the segment/region table entries. - Create out of line functions for page table allocation / freeing. - Simplify get_shadow_xxx functions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22 10:52:47 +00:00
if (switch_amode) {
/* Load primary space page table origin. */
[S390] Fix tlb flushing with idte. The clear-by-asce operation of the idte instruction gets an asce (address-space-control-element) as argument to specify which TLBs need to get flushed. The current code passes a plain pointer to the start of the pgd without the additional bits which would make the pointer an asce. The current machines don't mind the difference but a future model might want to use the designation type control bits in the asce as a filter for the TLBs to flush. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26 13:10:58 +00:00
pgd_t *shadow_pgd = get_shadow_table(mm->pgd) ? : mm->pgd;
S390_lowcore.user_exec_asce = mm->context | __pa(shadow_pgd);
[S390] Cleanup page table definitions. - De-confuse the defines for the address-space-control-elements and the segment/region table entries. - Create out of line functions for page table allocation / freeing. - Simplify get_shadow_xxx functions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22 10:52:47 +00:00
asm volatile(LCTL_OPCODE" 1,1,%0\n"
: : "m" (S390_lowcore.user_exec_asce) );
} else
/* Load home space page table origin. */
asm volatile(LCTL_OPCODE" 13,13,%0"
: : "m" (S390_lowcore.user_asce) );
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
[S390] noexec protection This provides a noexec protection on s390 hardware. Our hardware does not have any bits left in the pte for a hw noexec bit, so this is a different approach using shadow page tables and a special addressing mode that allows separate address spaces for code and data. As a special feature of our "secondary-space" addressing mode, separate page tables can be specified for the translation of data addresses (storage operands) and instruction addresses. The shadow page table is used for the instruction addresses and the standard page table for the data addresses. The shadow page table is linked to the standard page table by a pointer in page->lru.next of the struct page corresponding to the page that contains the standard page table (since page->private is not really private with the pte_lock and the page table pages are not in the LRU list). Depending on the software bits of a pte, it is either inserted into both page tables or just into the standard (data) page table. Pages of a vma that does not have the VM_EXEC bit set get mapped only in the data address space. Any try to execute code on such a page will cause a page translation exception. The standard reaction to this is a SIGSEGV with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the kernel to the signal stack frame. Unfortunately, the signal return mechanism cannot be modified to use an SA_RESTORER because the exception unwinding code depends on the system call opcode stored behind the signal stack frame. This feature requires that user space is executed in secondary-space mode and the kernel in home-space mode, which means that the addressing modes need to be switched and that the noexec protection only works for user space. After switching the addressing modes, we cannot use the mvcp/mvcs instructions anymore to copy between kernel and user space. A new mvcos instruction has been added to the z9 EC/BC hardware which allows to copy between arbitrary address spaces, but on older hardware the page tables need to be walked manually. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-05 20:18:17 +00:00
struct task_struct *tsk)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
{
[S390] Cleanup page table definitions. - De-confuse the defines for the address-space-control-elements and the segment/region table entries. - Create out of line functions for page table allocation / freeing. - Simplify get_shadow_xxx functions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22 10:52:47 +00:00
if (unlikely(prev == next))
return;
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
cpu_set(smp_processor_id(), next->cpu_vm_mask);
[S390] Cleanup page table definitions. - De-confuse the defines for the address-space-control-elements and the segment/region table entries. - Create out of line functions for page table allocation / freeing. - Simplify get_shadow_xxx functions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22 10:52:47 +00:00
update_mm(next, tsk);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
}
[S390] Cleanup page table definitions. - De-confuse the defines for the address-space-control-elements and the segment/region table entries. - Create out of line functions for page table allocation / freeing. - Simplify get_shadow_xxx functions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22 10:52:47 +00:00
#define enter_lazy_tlb(mm,tsk) do { } while (0)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#define deactivate_mm(tsk,mm) do { } while (0)
[PATCH] s390: "extern inline" -> "static inline" "extern inline" -> "static inline" Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 05:34:42 +00:00
static inline void activate_mm(struct mm_struct *prev,
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
struct mm_struct *next)
{
switch_mm(prev, next, current);
set_fs(current->thread.mm_segment);
}
[S390] noexec protection This provides a noexec protection on s390 hardware. Our hardware does not have any bits left in the pte for a hw noexec bit, so this is a different approach using shadow page tables and a special addressing mode that allows separate address spaces for code and data. As a special feature of our "secondary-space" addressing mode, separate page tables can be specified for the translation of data addresses (storage operands) and instruction addresses. The shadow page table is used for the instruction addresses and the standard page table for the data addresses. The shadow page table is linked to the standard page table by a pointer in page->lru.next of the struct page corresponding to the page that contains the standard page table (since page->private is not really private with the pte_lock and the page table pages are not in the LRU list). Depending on the software bits of a pte, it is either inserted into both page tables or just into the standard (data) page table. Pages of a vma that does not have the VM_EXEC bit set get mapped only in the data address space. Any try to execute code on such a page will cause a page translation exception. The standard reaction to this is a SIGSEGV with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the kernel to the signal stack frame. Unfortunately, the signal return mechanism cannot be modified to use an SA_RESTORER because the exception unwinding code depends on the system call opcode stored behind the signal stack frame. This feature requires that user space is executed in secondary-space mode and the kernel in home-space mode, which means that the addressing modes need to be switched and that the noexec protection only works for user space. After switching the addressing modes, we cannot use the mvcp/mvcs instructions anymore to copy between kernel and user space. A new mvcos instruction has been added to the z9 EC/BC hardware which allows to copy between arbitrary address spaces, but on older hardware the page tables need to be walked manually. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-05 20:18:17 +00:00
#endif /* __S390_MMU_CONTEXT_H */
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