Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 279 insertions, 0 deletions

diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
new file mode 100644
index 000000000..b5e4c3575
--- /dev/null
+++ b/arch/x86/include/asm/thread_info.h
@@ -0,0 +1,279 @@
+/* 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 */
+	u32			status;		/* thread synchronous flags */
+};
+
+#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_SYSCALL_TRACE	0	/* syscall trace active */
+#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_SYSCALL_EMU		6	/* syscall emulation active */
+#define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
+#define TIF_SECCOMP		8	/* secure computing */
+#define TIF_SPEC_IB		9	/* Indirect branch speculation mitigation */
+#define TIF_SPEC_FORCE_UPDATE	10	/* Force speculation MSR update in context switch */
+#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_NOCPUID		15	/* CPUID is not accessible in userland */
+#define TIF_NOTSC		16	/* TSC is not accessible in userland */
+#define TIF_IA32		17	/* IA32 compatibility process */
+#define TIF_NOHZ		19	/* in adaptive nohz mode */
+#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_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_SYSCALL_TRACEPOINT	28	/* syscall tracepoint instrumentation */
+#define TIF_ADDR32		29	/* 32-bit address space on 64 bits */
+#define TIF_X32			30	/* 32-bit native x86-64 binary */
+#define TIF_FSCHECK		31	/* Check FS is USER_DS on return */
+
+#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
+#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_SYSCALL_EMU	(1 << TIF_SYSCALL_EMU)
+#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
+#define _TIF_SECCOMP		(1 << TIF_SECCOMP)
+#define _TIF_SPEC_IB		(1 << TIF_SPEC_IB)
+#define _TIF_SPEC_FORCE_UPDATE	(1 << TIF_SPEC_FORCE_UPDATE)
+#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_NOCPUID		(1 << TIF_NOCPUID)
+#define _TIF_NOTSC		(1 << TIF_NOTSC)
+#define _TIF_IA32		(1 << TIF_IA32)
+#define _TIF_NOHZ		(1 << TIF_NOHZ)
+#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
+#define _TIF_IO_BITMAP		(1 << TIF_IO_BITMAP)
+#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_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
+#define _TIF_ADDR32		(1 << TIF_ADDR32)
+#define _TIF_X32		(1 << TIF_X32)
+#define _TIF_FSCHECK		(1 << TIF_FSCHECK)
+
+/*
+ * work to do in syscall_trace_enter().  Also includes TIF_NOHZ for
+ * enter_from_user_mode()
+ */
+#define _TIF_WORK_SYSCALL_ENTRY	\
+	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT |	\
+	 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT |	\
+	 _TIF_NOHZ)
+
+/* work to do on any return to user space */
+#define _TIF_ALLWORK_MASK						\
+	(_TIF_SYSCALL_TRACE | _TIF_NOTIFY_RESUME | _TIF_SIGPENDING |	\
+	 _TIF_NEED_RESCHED | _TIF_SINGLESTEP | _TIF_SYSCALL_EMU |	\
+	 _TIF_SYSCALL_AUDIT | _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE |	\
+	 _TIF_PATCH_PENDING | _TIF_NOHZ | _TIF_SYSCALL_TRACEPOINT |	\
+	 _TIF_FSCHECK)
+
+/* flags to check in __switch_to() */
+#define _TIF_WORK_CTXSW_BASE						\
+	(_TIF_IO_BITMAP|_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
+
+#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
+#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
+}
+
+#else /* !__ASSEMBLY__ */
+
+#ifdef CONFIG_X86_64
+# define cpu_current_top_of_stack (cpu_tss_rw + TSS_sp1)
+#endif
+
+#endif
+
+/*
+ * 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 TS_COMPAT_RESTART	0x0008
+
+#define arch_set_restart_data	arch_set_restart_data
+
+static inline void arch_set_restart_data(struct restart_block *restart)
+{
+	struct thread_info *ti = current_thread_info();
+	if (ti->status & TS_COMPAT)
+		ti->status |= TS_COMPAT_RESTART;
+	else
+		ti->status &= ~TS_COMPAT_RESTART;
+}
+#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
+
+/*
+ * Force syscall return via IRET by making it look as if there was
+ * some work pending. IRET is our most capable (but slowest) syscall
+ * return path, which is able to restore modified SS, CS and certain
+ * EFLAGS values that other (fast) syscall return instructions
+ * are not able to restore properly.
+ */
+#define force_iret() set_thread_flag(TIF_NOTIFY_RESUME)
+
+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 */