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ff170cd059
The ia32_compat attribute is a weird thing. It mirrors TIF_IA32 and TIF_X32 and is used only in two very unrelated places: (1) to decide if the vsyscall page is accessible (2) for uprobes to find whether the patched instruction is 32 or 64 bit. In preparation to remove the TIF flags, a new mechanism is required for ia32_compat, but given its odd semantics, adding a real flags field which configures these specific behaviours is the best option. So, set_personality_x64() can ask for the vsyscall page, which is not available in x32/ia32 and set_personality_ia32() can configure the uprobe code as needed. uprobe cannot rely on other methods like user_64bit_mode() to decide how to patch, so it needs some specific flag like this. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski<luto@kernel.org> Link: https://lore.kernel.org/r/20201004032536.1229030-10-krisman@collabora.com
69 lines
1.7 KiB
C
69 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_MMU_H
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#define _ASM_X86_MMU_H
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#include <linux/spinlock.h>
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#include <linux/rwsem.h>
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#include <linux/mutex.h>
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#include <linux/atomic.h>
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#include <linux/bits.h>
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/* Uprobes on this MM assume 32-bit code */
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#define MM_CONTEXT_UPROBE_IA32 BIT(0)
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/* vsyscall page is accessible on this MM */
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#define MM_CONTEXT_HAS_VSYSCALL BIT(1)
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/*
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* x86 has arch-specific MMU state beyond what lives in mm_struct.
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*/
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typedef struct {
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/*
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* ctx_id uniquely identifies this mm_struct. A ctx_id will never
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* be reused, and zero is not a valid ctx_id.
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*/
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u64 ctx_id;
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/*
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* Any code that needs to do any sort of TLB flushing for this
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* mm will first make its changes to the page tables, then
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* increment tlb_gen, then flush. This lets the low-level
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* flushing code keep track of what needs flushing.
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*
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* This is not used on Xen PV.
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*/
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atomic64_t tlb_gen;
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#ifdef CONFIG_MODIFY_LDT_SYSCALL
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struct rw_semaphore ldt_usr_sem;
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struct ldt_struct *ldt;
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#endif
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#ifdef CONFIG_X86_64
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unsigned short flags;
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#endif
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struct mutex lock;
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void __user *vdso; /* vdso base address */
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const struct vdso_image *vdso_image; /* vdso image in use */
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atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */
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#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
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/*
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* One bit per protection key says whether userspace can
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* use it or not. protected by mmap_lock.
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*/
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u16 pkey_allocation_map;
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s16 execute_only_pkey;
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#endif
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} mm_context_t;
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#define INIT_MM_CONTEXT(mm) \
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.context = { \
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.ctx_id = 1, \
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.lock = __MUTEX_INITIALIZER(mm.context.lock), \
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}
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void leave_mm(int cpu);
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#define leave_mm leave_mm
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#endif /* _ASM_X86_MMU_H */
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