/* SPDX-License-Identifier: GPL-2.0 */ /* thread_info.h: low-level thread information * * Copyright (C) 2002 David Howells ([email protected]) * - Incorporating suggestions made by Linus Torvalds and Dave Miller */ #ifndef _ASM_X86_THREAD_INFO_H #define _ASM_X86_THREAD_INFO_H #include <linux/compiler.h> #include <asm/page.h> #include <asm/percpu.h> #include <asm/types.h> /* * TOP_OF_KERNEL_STACK_PADDING is a number of unused bytes that we * reserve at the top of the kernel stack. We do it because of a nasty * 32-bit corner case. On x86_32, the hardware stack frame is * variable-length. Except for vm86 mode, struct pt_regs assumes a * maximum-length frame. If we enter from CPL 0, the top 8 bytes of * pt_regs don't actually exist. Ordinarily this doesn't matter, but it * does in at least one case: * * If we take an NMI early enough in SYSENTER, then we can end up with * pt_regs that extends above sp0. On the way out, in the espfix code, * we can read the saved SS value, but that value will be above sp0. * Without this offset, that can result in a page fault. (We are * careful that, in this case, the value we read doesn't matter.) * * In vm86 mode, the hardware frame is much longer still, so add 16 * bytes to make room for the real-mode segments. * * x86-64 has a fixed-length stack frame, but it depends on whether * or not FRED is enabled. Future versions of FRED might make this * dynamic, but for now it is always 2 words longer. */ #ifdef CONFIG_X86_32 # ifdef CONFIG_VM86 #define TOP_OF_KERNEL_STACK_PADDING … # else #define TOP_OF_KERNEL_STACK_PADDING … # endif #else /* x86-64 */ # ifdef CONFIG_X86_FRED #define TOP_OF_KERNEL_STACK_PADDING … # else #define TOP_OF_KERNEL_STACK_PADDING … # endif #endif /* * low level task data that entry.S needs immediate access to * - this struct should fit entirely inside of one cache line * - this struct shares the supervisor stack pages */ #ifndef __ASSEMBLY__ struct task_struct; #include <asm/cpufeature.h> #include <linux/atomic.h> struct thread_info { … }; #define INIT_THREAD_INFO(tsk) … #else /* !__ASSEMBLY__ */ #include <asm/asm-offsets.h> #endif /* * thread information flags * - these are process state flags that various assembly files * may need to access */ #define TIF_NOTIFY_RESUME … #define TIF_SIGPENDING … #define TIF_NEED_RESCHED … #define TIF_SINGLESTEP … #define TIF_SSBD … #define TIF_SPEC_IB … #define TIF_SPEC_L1D_FLUSH … #define TIF_USER_RETURN_NOTIFY … #define TIF_UPROBE … #define TIF_PATCH_PENDING … #define TIF_NEED_FPU_LOAD … #define TIF_NOCPUID … #define TIF_NOTSC … #define TIF_NOTIFY_SIGNAL … #define TIF_MEMDIE … #define TIF_POLLING_NRFLAG … #define TIF_IO_BITMAP … #define TIF_SPEC_FORCE_UPDATE … #define TIF_FORCED_TF … #define TIF_BLOCKSTEP … #define TIF_LAZY_MMU_UPDATES … #define TIF_ADDR32 … #define _TIF_NOTIFY_RESUME … #define _TIF_SIGPENDING … #define _TIF_NEED_RESCHED … #define _TIF_SINGLESTEP … #define _TIF_SSBD … #define _TIF_SPEC_IB … #define _TIF_SPEC_L1D_FLUSH … #define _TIF_USER_RETURN_NOTIFY … #define _TIF_UPROBE … #define _TIF_PATCH_PENDING … #define _TIF_NEED_FPU_LOAD … #define _TIF_NOCPUID … #define _TIF_NOTSC … #define _TIF_NOTIFY_SIGNAL … #define _TIF_POLLING_NRFLAG … #define _TIF_IO_BITMAP … #define _TIF_SPEC_FORCE_UPDATE … #define _TIF_FORCED_TF … #define _TIF_BLOCKSTEP … #define _TIF_LAZY_MMU_UPDATES … #define _TIF_ADDR32 … /* flags to check in __switch_to() */ #define _TIF_WORK_CTXSW_BASE … /* * Avoid calls to __switch_to_xtra() on UP as STIBP is not evaluated. */ #ifdef CONFIG_SMP #define _TIF_WORK_CTXSW … #else #define _TIF_WORK_CTXSW … #endif #ifdef CONFIG_X86_IOPL_IOPERM #define _TIF_WORK_CTXSW_PREV … #else #define _TIF_WORK_CTXSW_PREV … #endif #define _TIF_WORK_CTXSW_NEXT … #define STACK_WARN … /* * macros/functions for gaining access to the thread information structure * * preempt_count needs to be 1 initially, until the scheduler is functional. */ #ifndef __ASSEMBLY__ /* * Walks up the stack frames to make sure that the specified object is * entirely contained by a single stack frame. * * Returns: * GOOD_FRAME if within a frame * BAD_STACK if placed across a frame boundary (or outside stack) * NOT_STACK unable to determine (no frame pointers, etc) * * This function reads pointers from the stack and dereferences them. The * pointers may not have their KMSAN shadow set up properly, which may result * in false positive reports. Disable instrumentation to avoid those. */ __no_kmsan_checks static inline int arch_within_stack_frames(const void * const stack, const void * const stackend, const void *obj, unsigned long len) { … } #endif /* !__ASSEMBLY__ */ /* * Thread-synchronous status. * * This is different from the flags in that nobody else * ever touches our thread-synchronous status, so we don't * have to worry about atomic accesses. */ #define TS_COMPAT … #ifndef __ASSEMBLY__ #ifdef CONFIG_COMPAT #define TS_I386_REGS_POKED … #define arch_set_restart_data(restart) … #endif #ifdef CONFIG_X86_32 #define in_ia32_syscall … #else #define in_ia32_syscall() … #endif extern void arch_setup_new_exec(void); #define arch_setup_new_exec … #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_THREAD_INFO_H */
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