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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/include/asm/thread_info.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/include/asm/thread_info.h')
-rw-r--r--arch/x86/include/asm/thread_info.h237
1 files changed, 237 insertions, 0 deletions
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
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+++ b/arch/x86/include/asm/thread_info.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+/* thread_info.h: low-level thread information
+ *
+ * Copyright (C) 2002 David Howells (dhowells@redhat.com)
+ * - 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.
+ */
+#ifdef CONFIG_X86_32
+# ifdef CONFIG_VM86
+# define TOP_OF_KERNEL_STACK_PADDING 16
+# else
+# define TOP_OF_KERNEL_STACK_PADDING 8
+# endif
+#else
+# define TOP_OF_KERNEL_STACK_PADDING 0
+#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 {
+ unsigned long flags; /* low level flags */
+ unsigned long syscall_work; /* SYSCALL_WORK_ flags */
+ u32 status; /* thread synchronous flags */
+#ifdef CONFIG_SMP
+ u32 cpu; /* current CPU */
+#endif
+};
+
+#define INIT_THREAD_INFO(tsk) \
+{ \
+ .flags = 0, \
+}
+
+#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 1 /* callback before returning to user */
+#define TIF_SIGPENDING 2 /* signal pending */
+#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
+#define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
+#define TIF_SSBD 5 /* Speculative store bypass disable */
+#define TIF_SPEC_IB 9 /* Indirect branch speculation mitigation */
+#define TIF_SPEC_L1D_FLUSH 10 /* Flush L1D on mm switches (processes) */
+#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
+#define TIF_UPROBE 12 /* breakpointed or singlestepping */
+#define TIF_PATCH_PENDING 13 /* pending live patching update */
+#define TIF_NEED_FPU_LOAD 14 /* load FPU on return to userspace */
+#define TIF_NOCPUID 15 /* CPUID is not accessible in userland */
+#define TIF_NOTSC 16 /* TSC is not accessible in userland */
+#define TIF_NOTIFY_SIGNAL 17 /* signal notifications exist */
+#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
+#define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */
+#define TIF_IO_BITMAP 22 /* uses I/O bitmap */
+#define TIF_SPEC_FORCE_UPDATE 23 /* Force speculation MSR update in context switch */
+#define TIF_FORCED_TF 24 /* true if TF in eflags artificially */
+#define TIF_BLOCKSTEP 25 /* set when we want DEBUGCTLMSR_BTF */
+#define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */
+#define TIF_ADDR32 29 /* 32-bit address space on 64 bits */
+
+#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
+#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
+#define _TIF_SSBD (1 << TIF_SSBD)
+#define _TIF_SPEC_IB (1 << TIF_SPEC_IB)
+#define _TIF_SPEC_L1D_FLUSH (1 << TIF_SPEC_L1D_FLUSH)
+#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
+#define _TIF_UPROBE (1 << TIF_UPROBE)
+#define _TIF_PATCH_PENDING (1 << TIF_PATCH_PENDING)
+#define _TIF_NEED_FPU_LOAD (1 << TIF_NEED_FPU_LOAD)
+#define _TIF_NOCPUID (1 << TIF_NOCPUID)
+#define _TIF_NOTSC (1 << TIF_NOTSC)
+#define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL)
+#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
+#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
+#define _TIF_SPEC_FORCE_UPDATE (1 << TIF_SPEC_FORCE_UPDATE)
+#define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
+#define _TIF_BLOCKSTEP (1 << TIF_BLOCKSTEP)
+#define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES)
+#define _TIF_ADDR32 (1 << TIF_ADDR32)
+
+/* flags to check in __switch_to() */
+#define _TIF_WORK_CTXSW_BASE \
+ (_TIF_NOCPUID | _TIF_NOTSC | _TIF_BLOCKSTEP | \
+ _TIF_SSBD | _TIF_SPEC_FORCE_UPDATE)
+
+/*
+ * Avoid calls to __switch_to_xtra() on UP as STIBP is not evaluated.
+ */
+#ifdef CONFIG_SMP
+# define _TIF_WORK_CTXSW (_TIF_WORK_CTXSW_BASE | _TIF_SPEC_IB)
+#else
+# define _TIF_WORK_CTXSW (_TIF_WORK_CTXSW_BASE)
+#endif
+
+#ifdef CONFIG_X86_IOPL_IOPERM
+# define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW| _TIF_USER_RETURN_NOTIFY | \
+ _TIF_IO_BITMAP)
+#else
+# define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW| _TIF_USER_RETURN_NOTIFY)
+#endif
+
+#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
+
+#define STACK_WARN (THREAD_SIZE/8)
+
+/*
+ * 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)
+ */
+static inline int arch_within_stack_frames(const void * const stack,
+ const void * const stackend,
+ const void *obj, unsigned long len)
+{
+#if defined(CONFIG_FRAME_POINTER)
+ const void *frame = NULL;
+ const void *oldframe;
+
+ oldframe = __builtin_frame_address(1);
+ if (oldframe)
+ frame = __builtin_frame_address(2);
+ /*
+ * low ----------------------------------------------> high
+ * [saved bp][saved ip][args][local vars][saved bp][saved ip]
+ * ^----------------^
+ * allow copies only within here
+ */
+ while (stack <= frame && frame < stackend) {
+ /*
+ * If obj + len extends past the last frame, this
+ * check won't pass and the next frame will be 0,
+ * causing us to bail out and correctly report
+ * the copy as invalid.
+ */
+ if (obj + len <= frame)
+ return obj >= oldframe + 2 * sizeof(void *) ?
+ GOOD_FRAME : BAD_STACK;
+ oldframe = frame;
+ frame = *(const void * const *)frame;
+ }
+ return BAD_STACK;
+#else
+ return NOT_STACK;
+#endif
+}
+
+#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 0x0002 /* 32bit syscall active (64BIT)*/
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_COMPAT
+#define TS_I386_REGS_POKED 0x0004 /* regs poked by 32-bit ptracer */
+
+#define arch_set_restart_data(restart) \
+ do { restart->arch_data = current_thread_info()->status; } while (0)
+
+#endif
+
+#ifdef CONFIG_X86_32
+#define in_ia32_syscall() true
+#else
+#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \
+ current_thread_info()->status & TS_COMPAT)
+#endif
+
+extern void arch_task_cache_init(void);
+extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
+extern void arch_release_task_struct(struct task_struct *tsk);
+extern void arch_setup_new_exec(void);
+#define arch_setup_new_exec arch_setup_new_exec
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_X86_THREAD_INFO_H */