mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-23 16:39:53 +07:00
c98f5827f8
Pull x86 fixes from Ingo Molnar: "Two fixes and a cleanup-fix, to the syscall entry code and to ptrace" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/syscalls/64: Add compat_sys_keyctl for 32-bit userspace x86/ptrace: Stop setting TS_COMPAT in ptrace code x86/vdso: Error out if the vDSO isn't a valid DSO
255 lines
8.2 KiB
C
255 lines
8.2 KiB
C
/* thread_info.h: low-level thread information
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*
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* Copyright (C) 2002 David Howells (dhowells@redhat.com)
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* - Incorporating suggestions made by Linus Torvalds and Dave Miller
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*/
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#ifndef _ASM_X86_THREAD_INFO_H
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#define _ASM_X86_THREAD_INFO_H
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#include <linux/compiler.h>
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#include <asm/page.h>
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#include <asm/percpu.h>
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#include <asm/types.h>
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/*
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* TOP_OF_KERNEL_STACK_PADDING is a number of unused bytes that we
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* reserve at the top of the kernel stack. We do it because of a nasty
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* 32-bit corner case. On x86_32, the hardware stack frame is
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* variable-length. Except for vm86 mode, struct pt_regs assumes a
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* maximum-length frame. If we enter from CPL 0, the top 8 bytes of
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* pt_regs don't actually exist. Ordinarily this doesn't matter, but it
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* does in at least one case:
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*
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* If we take an NMI early enough in SYSENTER, then we can end up with
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* pt_regs that extends above sp0. On the way out, in the espfix code,
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* we can read the saved SS value, but that value will be above sp0.
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* Without this offset, that can result in a page fault. (We are
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* careful that, in this case, the value we read doesn't matter.)
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*
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* In vm86 mode, the hardware frame is much longer still, so add 16
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* bytes to make room for the real-mode segments.
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*
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* x86_64 has a fixed-length stack frame.
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*/
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#ifdef CONFIG_X86_32
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# ifdef CONFIG_VM86
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# define TOP_OF_KERNEL_STACK_PADDING 16
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# else
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# define TOP_OF_KERNEL_STACK_PADDING 8
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# endif
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#else
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# define TOP_OF_KERNEL_STACK_PADDING 0
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#endif
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/*
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* low level task data that entry.S needs immediate access to
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* - this struct should fit entirely inside of one cache line
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* - this struct shares the supervisor stack pages
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*/
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#ifndef __ASSEMBLY__
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struct task_struct;
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#include <asm/cpufeature.h>
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#include <linux/atomic.h>
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struct thread_info {
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struct task_struct *task; /* main task structure */
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__u32 flags; /* low level flags */
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__u32 status; /* thread synchronous flags */
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__u32 cpu; /* current CPU */
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};
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.flags = 0, \
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.cpu = 0, \
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}
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#define init_thread_info (init_thread_union.thread_info)
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#define init_stack (init_thread_union.stack)
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#else /* !__ASSEMBLY__ */
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#include <asm/asm-offsets.h>
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#endif
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/*
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* thread information flags
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* - these are process state flags that various assembly files
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* may need to access
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* - pending work-to-be-done flags are in LSW
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* - other flags in MSW
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* Warning: layout of LSW is hardcoded in entry.S
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*/
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#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
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#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
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#define TIF_SIGPENDING 2 /* signal pending */
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#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
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#define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
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#define TIF_SYSCALL_EMU 6 /* syscall emulation active */
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#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
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#define TIF_SECCOMP 8 /* secure computing */
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#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
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#define TIF_UPROBE 12 /* breakpointed or singlestepping */
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#define TIF_NOTSC 16 /* TSC is not accessible in userland */
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#define TIF_IA32 17 /* IA32 compatibility process */
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#define TIF_FORK 18 /* ret_from_fork */
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#define TIF_NOHZ 19 /* in adaptive nohz mode */
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#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
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#define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */
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#define TIF_IO_BITMAP 22 /* uses I/O bitmap */
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#define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
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#define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */
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#define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
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#define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */
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#define TIF_ADDR32 29 /* 32-bit address space on 64 bits */
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#define TIF_X32 30 /* 32-bit native x86-64 binary */
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#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
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#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
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#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
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#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
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#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
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#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
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#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
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#define _TIF_SECCOMP (1 << TIF_SECCOMP)
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#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
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#define _TIF_UPROBE (1 << TIF_UPROBE)
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#define _TIF_NOTSC (1 << TIF_NOTSC)
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#define _TIF_IA32 (1 << TIF_IA32)
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#define _TIF_FORK (1 << TIF_FORK)
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#define _TIF_NOHZ (1 << TIF_NOHZ)
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#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
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#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
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#define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
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#define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
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#define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
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#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
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#define _TIF_ADDR32 (1 << TIF_ADDR32)
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#define _TIF_X32 (1 << TIF_X32)
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/*
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* work to do in syscall_trace_enter(). Also includes TIF_NOHZ for
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* enter_from_user_mode()
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*/
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#define _TIF_WORK_SYSCALL_ENTRY \
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(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
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_TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
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_TIF_NOHZ)
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/* work to do on any return to user space */
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#define _TIF_ALLWORK_MASK \
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((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT | \
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_TIF_NOHZ)
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/* flags to check in __switch_to() */
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#define _TIF_WORK_CTXSW \
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(_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
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#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
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#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
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#define STACK_WARN (THREAD_SIZE/8)
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/*
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* macros/functions for gaining access to the thread information structure
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*
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* preempt_count needs to be 1 initially, until the scheduler is functional.
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*/
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#ifndef __ASSEMBLY__
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static inline struct thread_info *current_thread_info(void)
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{
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return (struct thread_info *)(current_top_of_stack() - THREAD_SIZE);
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}
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static inline unsigned long current_stack_pointer(void)
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{
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unsigned long sp;
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#ifdef CONFIG_X86_64
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asm("mov %%rsp,%0" : "=g" (sp));
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#else
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asm("mov %%esp,%0" : "=g" (sp));
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#endif
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return sp;
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}
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#else /* !__ASSEMBLY__ */
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#ifdef CONFIG_X86_64
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# define cpu_current_top_of_stack (cpu_tss + TSS_sp0)
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#endif
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/*
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* ASM operand which evaluates to a 'thread_info' address of
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* the current task, if it is known that "reg" is exactly "off"
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* bytes below the top of the stack currently.
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*
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* ( The kernel stack's size is known at build time, it is usually
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* 2 or 4 pages, and the bottom of the kernel stack contains
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* the thread_info structure. So to access the thread_info very
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* quickly from assembly code we can calculate down from the
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* top of the kernel stack to the bottom, using constant,
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* build-time calculations only. )
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*
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* For example, to fetch the current thread_info->flags value into %eax
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* on x86-64 defconfig kernels, in syscall entry code where RSP is
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* currently at exactly SIZEOF_PTREGS bytes away from the top of the
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* stack:
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*
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* mov ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS), %eax
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*
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* will translate to:
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*
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* 8b 84 24 b8 c0 ff ff mov -0x3f48(%rsp), %eax
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*
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* which is below the current RSP by almost 16K.
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*/
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#define ASM_THREAD_INFO(field, reg, off) ((field)+(off)-THREAD_SIZE)(reg)
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#endif
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/*
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* Thread-synchronous status.
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*
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* This is different from the flags in that nobody else
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* ever touches our thread-synchronous status, so we don't
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* have to worry about atomic accesses.
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*/
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#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
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#ifdef CONFIG_COMPAT
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#define TS_I386_REGS_POKED 0x0004 /* regs poked by 32-bit ptracer */
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#endif
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#ifndef __ASSEMBLY__
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static inline bool in_ia32_syscall(void)
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{
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#ifdef CONFIG_X86_32
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return true;
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#endif
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#ifdef CONFIG_IA32_EMULATION
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if (current_thread_info()->status & TS_COMPAT)
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return true;
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#endif
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return false;
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}
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/*
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* Force syscall return via IRET by making it look as if there was
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* some work pending. IRET is our most capable (but slowest) syscall
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* return path, which is able to restore modified SS, CS and certain
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* EFLAGS values that other (fast) syscall return instructions
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* are not able to restore properly.
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*/
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#define force_iret() set_thread_flag(TIF_NOTIFY_RESUME)
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extern void arch_task_cache_init(void);
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extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
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extern void arch_release_task_struct(struct task_struct *tsk);
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_X86_THREAD_INFO_H */
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