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![Vasily Gorbik](/assets/img/avatar_default.png)
vdso_fault used is_compat_task function (on s390 it tests "current" thread_info flags) to distinguish compat tasks and map 31-bit vdso pages. But "current" task might not correspond to mm context. When 31-bit compat inferior is executed under gdb, gdb does PTRACE_PEEKTEXT on vdso page, causing vdso_fault with "current" being 64-bit gdb process. So, 31-bit inferior ends up with 64-bit vdso mapped. To avoid this problem a new compat_mm flag has been introduced into mm context. This flag is used in vdso_fault and vdso_mremap instead of is_compat_task. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __MMU_H
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#define __MMU_H
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#include <linux/cpumask.h>
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#include <linux/errno.h>
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typedef struct {
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spinlock_t lock;
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cpumask_t cpu_attach_mask;
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atomic_t flush_count;
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unsigned int flush_mm;
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struct list_head pgtable_list;
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struct list_head gmap_list;
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unsigned long gmap_asce;
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unsigned long asce;
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unsigned long asce_limit;
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unsigned long vdso_base;
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/*
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* The following bitfields need a down_write on the mm
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* semaphore when they are written to. As they are only
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* written once, they can be read without a lock.
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*
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* The mmu context allocates 4K page tables.
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*/
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unsigned int alloc_pgste:1;
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/* The mmu context uses extended page tables. */
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unsigned int has_pgste:1;
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/* The mmu context uses storage keys. */
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unsigned int uses_skeys:1;
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/* The mmu context uses CMM. */
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unsigned int uses_cmm:1;
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/* The gmaps associated with this context are allowed to use huge pages. */
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unsigned int allow_gmap_hpage_1m:1;
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/* The mmu context is for compat task */
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unsigned int compat_mm:1;
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} mm_context_t;
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#define INIT_MM_CONTEXT(name) \
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.context.lock = __SPIN_LOCK_UNLOCKED(name.context.lock), \
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.context.pgtable_list = LIST_HEAD_INIT(name.context.pgtable_list), \
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.context.gmap_list = LIST_HEAD_INIT(name.context.gmap_list),
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static inline int tprot(unsigned long addr)
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{
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int rc = -EFAULT;
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asm volatile(
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" tprot 0(%1),0\n"
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"0: ipm %0\n"
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" srl %0,28\n"
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"1:\n"
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EX_TABLE(0b,1b)
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: "+d" (rc) : "a" (addr) : "cc");
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return rc;
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}
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#endif
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