parisc: Move thread_info into task struct

This implements the CONFIG_THREAD_INFO_IN_TASK option.

With this change:
- before thread_info was part of the stack and located at the beginning of the stack
- now the thread_info struct is moved and located inside the task_struct structure
- the stack is allocated and handled like the major other platforms
- drop the cpu field of thread_info and use instead the one in task_struct
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sven Schnelle <svens@stackframe.org>

Documentation/features/core/thread-info-in-task/arch-support.txt

@@ -20,7 +20,7 @@
     |       nds32: |  ok  |
     |       nios2: | TODO |
     |    openrisc: | TODO |
-    |      parisc: | TODO |
+    |      parisc: |  ok  |
     |     powerpc: |  ok  |
     |       riscv: |  ok  |
     |        s390: |  ok  |

arch/parisc/Kconfig

@@ -56,6 +56,7 @@ config PARISC
 	select HAVE_UNSTABLE_SCHED_CLOCK if SMP
 	select LEGACY_TIMER_TICK
 	select CPU_NO_EFFICIENT_FFS
+	select THREAD_INFO_IN_TASK
 	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 	select HAVE_ARCH_KGDB

arch/parisc/include/asm/current.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_PARISC_CURRENT_H
+#define _ASM_PARISC_CURRENT_H
+
+#include <asm/special_insns.h>
+
+#ifndef __ASSEMBLY__
+struct task_struct;
+
+static __always_inline struct task_struct *get_current(void)
+{
+	return (struct task_struct *) mfctl(30);
+}
+
+#define current get_current()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_PARISC_CURRENT_H */

arch/parisc/include/asm/processor.h

@@ -102,8 +102,6 @@ DECLARE_PER_CPU(struct cpuinfo_parisc, cpu_data);
 
 #define CPU_HVERSION ((boot_cpu_data.hversion >> 4) & 0x0FFF)
 
-#define ARCH_MIN_TASKALIGN	FRAME_ALIGN
-
 struct thread_struct {
 	struct pt_regs regs;
 	unsigned long  task_size;

arch/parisc/include/asm/smp.h

@@ -34,8 +34,23 @@ extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
 
 #endif /* !ASSEMBLY */
 
-#define raw_smp_processor_id()	(current_thread_info()->cpu)
-
+/*
+ * This is particularly ugly: it appears we can't actually get the definition
+ * of task_struct here, but we need access to the CPU this task is running on.
+ * Instead of using task_struct we're using TASK_CPU which is extracted from
+ * asm-offsets.h by kbuild to get the current processor ID.
+ *
+ * This also needs to be safeguarded when building asm-offsets.s because at
+ * that time TASK_CPU is not defined yet. It could have been guarded by
+ * TASK_CPU itself, but we want the build to fail if TASK_CPU is missing
+ * when building something else than asm-offsets.s
+ */
+#ifdef GENERATING_ASM_OFFSETS
+#define raw_smp_processor_id()		(0)
+#else
+#include <asm/asm-offsets.h>
+#define raw_smp_processor_id()		(*(unsigned int *)((void *)current + TASK_CPU))
+#endif
 #else /* CONFIG_SMP */
 
 static inline void smp_send_all_nop(void) { return; }

arch/parisc/include/asm/thread_info.h

@@ -9,23 +9,16 @@
 #include <asm/special_insns.h>
 
 struct thread_info {
-	struct task_struct *task;	/* main task structure */
 	unsigned long flags;		/* thread_info flags (see TIF_*) */
-	__u32 cpu;			/* current CPU */
 	int preempt_count;		/* 0=premptable, <0=BUG; will also serve as bh-counter */
 };
 
 #define INIT_THREAD_INFO(tsk)			\
 {						\
-	.task		= &tsk,			\
 	.flags		= 0,			\
-	.cpu		= 0,			\
 	.preempt_count	= INIT_PREEMPT_COUNT,	\
 }
 
-/* how to get the thread information struct from C */
-#define current_thread_info()	((struct thread_info *)mfctl(30))
-
 #endif /* !__ASSEMBLY */
 
 /* thread information allocation */

arch/parisc/kernel/asm-offsets.c

@@ -14,6 +14,8 @@
  *    Copyright (C) 2003 James Bottomley <jejb at parisc-linux.org>
  */
 
+#define GENERATING_ASM_OFFSETS /* asm/smp.h */
+
 #include <linux/types.h>
 #include <linux/sched.h>
 #include <linux/thread_info.h>
@@ -35,13 +37,16 @@
 
 int main(void)
 {
-	DEFINE(TASK_THREAD_INFO, offsetof(struct task_struct, stack));
-	DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags));
+	DEFINE(TASK_TI_FLAGS, offsetof(struct task_struct, thread_info.flags));
 	DEFINE(TASK_SIGPENDING, offsetof(struct task_struct, pending));
 	DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace));
 	DEFINE(TASK_MM, offsetof(struct task_struct, mm));
 	DEFINE(TASK_PERSONALITY, offsetof(struct task_struct, personality));
 	DEFINE(TASK_PID, offsetof(struct task_struct, pid));
+	DEFINE(TASK_STACK, offsetof(struct task_struct, stack));
+#ifdef CONFIG_SMP
+	DEFINE(TASK_CPU, offsetof(struct task_struct, cpu));
+#endif
 	BLANK();
 	DEFINE(TASK_REGS, offsetof(struct task_struct, thread.regs));
 	DEFINE(TASK_PT_PSW, offsetof(struct task_struct, thread.regs.gr[ 0]));
@@ -129,10 +134,6 @@ int main(void)
 	DEFINE(TASK_PT_ISR, offsetof(struct task_struct, thread.regs.isr));
 	DEFINE(TASK_PT_IOR, offsetof(struct task_struct, thread.regs.ior));
 	BLANK();
-	DEFINE(TASK_SZ, sizeof(struct task_struct));
-	/* TASK_SZ_ALGN includes space for a stack frame. */
-	DEFINE(TASK_SZ_ALGN, align_frame(sizeof(struct task_struct), FRAME_ALIGN));
-	BLANK();
 	DEFINE(PT_PSW, offsetof(struct pt_regs, gr[ 0]));
 	DEFINE(PT_GR1, offsetof(struct pt_regs, gr[ 1]));
 	DEFINE(PT_GR2, offsetof(struct pt_regs, gr[ 2]));
@@ -217,17 +218,11 @@ int main(void)
 	DEFINE(PT_IIR, offsetof(struct pt_regs, iir));
 	DEFINE(PT_ISR, offsetof(struct pt_regs, isr));
 	DEFINE(PT_IOR, offsetof(struct pt_regs, ior));
-	DEFINE(PT_SIZE, sizeof(struct pt_regs));
 	/* PT_SZ_ALGN includes space for a stack frame. */
 	DEFINE(PT_SZ_ALGN, align_frame(sizeof(struct pt_regs), FRAME_ALIGN));
 	BLANK();
-	DEFINE(TI_TASK, offsetof(struct thread_info, task));
 	DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
-	DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
-	DEFINE(TI_PRE_COUNT, offsetof(struct thread_info, preempt_count));
-	DEFINE(THREAD_SZ, sizeof(struct thread_info));
-	/* THREAD_SZ_ALGN includes space for a stack frame. */
-	DEFINE(THREAD_SZ_ALGN, align_frame(sizeof(struct thread_info), FRAME_ALIGN));
+	DEFINE(TI_PRE_COUNT, offsetof(struct task_struct, thread_info.preempt_count));
 	BLANK();
 	DEFINE(ICACHE_BASE, offsetof(struct pdc_cache_info, ic_base));
 	DEFINE(ICACHE_STRIDE, offsetof(struct pdc_cache_info, ic_stride));

arch/parisc/kernel/entry.S

@@ -63,8 +63,8 @@
 	 *          Need to set up a kernel stack, so call the
 	 *          get_stack_use_cr30 macro to set up a pointer
 	 *          to the pt_regs structure contained within the
-	 *          task pointer pointed to by cr30. Set the stack
-	 *          pointer to point to the end of the task structure.
+	 *          task pointer pointed to by cr30. Load the stack
+	 *          pointer from the task structure.
 	 *
 	 * Note that we use shadowed registers for temps until
 	 * we can save %r26 and %r29. %r26 is used to preserve
@@ -76,8 +76,6 @@
 	 * or handle_interruption. %r29 is used to hold a pointer
 	 * the register save area, and once again, it needs to
 	 * be a non-shadowed register so that it survives the rfir.
-	 *
-	 * N.B. TASK_SZ_ALGN and PT_SZ_ALGN include space for a stack frame.
 	 */
 
 	.macro  get_stack_use_cr30
@@ -86,12 +84,11 @@
 
 	copy	%r30, %r17
 	mfctl   %cr30, %r1
-	ldo	THREAD_SZ_ALGN(%r1), %r30
-	mtsp	%r0,%sr7
+	tophys  %r1,%r9		/* task_struct */
+	LDREG	TASK_STACK(%r9),%r30
+	ldo	PT_SZ_ALGN(%r30),%r30
+	mtsp	%r0,%sr7	/* clear sr7 after kernel stack was set! */
 	mtsp	%r16,%sr3
-	tophys  %r1,%r9
-	LDREG	TI_TASK(%r9), %r1	/* thread_info -> task_struct */
-	tophys  %r1,%r9
 	ldo     TASK_REGS(%r9),%r9
 	STREG   %r17,PT_GR30(%r9)
 	STREG   %r29,PT_GR29(%r9)
@@ -733,7 +730,7 @@ ENTRY(ret_from_kernel_thread)
 	BL	schedule_tail, %r2
 	nop
 
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
+	mfctl	%cr30,%r1	/* task_struct */
 	LDREG	TASK_PT_GR25(%r1), %r26
 #ifdef CONFIG_64BIT
 	LDREG	TASK_PT_GR27(%r1), %r27
@@ -764,7 +761,6 @@ ENTRY_CFI(_switch_to)
 
 	STREG	%r30, TASK_PT_KSP(%r26)
 	LDREG	TASK_PT_KSP(%r25), %r30
-	LDREG	TASK_THREAD_INFO(%r25), %r25
 	bv	%r0(%r2)
 	mtctl   %r25,%cr30
 
@@ -795,8 +791,7 @@ ENDPROC_CFI(_switch_to)
 	.align	PAGE_SIZE
 
 ENTRY_CFI(syscall_exit_rfi)
-	mfctl   %cr30,%r16
-	LDREG	TI_TASK(%r16), %r16	/* thread_info -> task_struct */
+	mfctl	%cr30,%r16		/* task_struct */
 	ldo	TASK_REGS(%r16),%r16
 	/* Force iaoq to userspace, as the user has had access to our current
 	 * context via sigcontext. Also Filter the PSW for the same reason.
@@ -841,14 +836,14 @@ ENTRY_CFI(syscall_exit_rfi)
 ENTRY(intr_return)
 	/* check for reschedule */
 	mfctl   %cr30,%r1
-	LDREG   TI_FLAGS(%r1),%r19	/* sched.h: TIF_NEED_RESCHED */
+	LDREG   TASK_TI_FLAGS(%r1),%r19	/* sched.h: TIF_NEED_RESCHED */
 	bb,<,n	%r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */
 
 	.import do_notify_resume,code
 intr_check_sig:
 	/* As above */
 	mfctl   %cr30,%r1
-	LDREG	TI_FLAGS(%r1),%r19
+	LDREG	TASK_TI_FLAGS(%r1),%r19
 	ldi	(_TIF_USER_WORK_MASK & ~_TIF_NEED_RESCHED), %r20
 	and,COND(<>)	%r19, %r20, %r0
 	b,n	intr_restore	/* skip past if we've nothing to do */
@@ -1692,7 +1687,7 @@ dtlb_fault:
 
 	.macro	fork_like name
 ENTRY_CFI(sys_\name\()_wrapper)
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
+	mfctl	%cr30,%r1
 	ldo	TASK_REGS(%r1),%r1
 	reg_save %r1
 	mfctl	%cr27, %r28
@@ -1712,7 +1707,7 @@ ENTRY(child_return)
 	BL	schedule_tail, %r2
 	nop
 finish_child_return:
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
+	mfctl	%cr30,%r1
 	ldo	TASK_REGS(%r1),%r1	 /* get pt regs */
 
 	LDREG	PT_CR27(%r1), %r3
@@ -1723,7 +1718,7 @@ finish_child_return:
 END(child_return)
 
 ENTRY_CFI(sys_rt_sigreturn_wrapper)
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26
+	mfctl	%cr30,%r26
 	ldo	TASK_REGS(%r26),%r26	/* get pt regs */
 	/* Don't save regs, we are going to restore them from sigcontext. */
 	STREG	%r2, -RP_OFFSET(%r30)
@@ -1740,7 +1735,7 @@ ENTRY_CFI(sys_rt_sigreturn_wrapper)
 	LDREG	-RP_OFFSET(%r30), %r2
 
 	/* FIXME: I think we need to restore a few more things here. */
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
+	mfctl	%cr30,%r1
 	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
 	reg_restore %r1
 
@@ -1759,9 +1754,7 @@ ENTRY(syscall_exit)
 	 */
 
 	/* save return value now */
-
 	mfctl     %cr30, %r1
-	LDREG     TI_TASK(%r1),%r1
 	STREG     %r28,TASK_PT_GR28(%r1)
 
 	/* Seems to me that dp could be wrong here, if the syscall involved
@@ -1772,13 +1765,14 @@ ENTRY(syscall_exit)
 syscall_check_resched:
 
 	/* check for reschedule */
-
-	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19	/* long */
+	mfctl	%cr30,%r19
+	LDREG	TASK_TI_FLAGS(%r19),%r19	/* long */
 	bb,<,n	%r19, 31-TIF_NEED_RESCHED, syscall_do_resched /* forward */
 
 	.import do_signal,code
 syscall_check_sig:
-	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
+	mfctl	%cr30,%r19
+	LDREG	TASK_TI_FLAGS(%r19),%r19
 	ldi	(_TIF_USER_WORK_MASK & ~_TIF_NEED_RESCHED), %r26
 	and,COND(<>)	%r19, %r26, %r0
 	b,n	syscall_restore	/* skip past if we've nothing to do */
@@ -1789,7 +1783,7 @@ syscall_do_signal:
 	 * consistent with all the relevant state of the process
 	 * before the syscall.  We need to verify this.
 	 */
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
+	mfctl	%cr30,%r1
 	ldo	TASK_REGS(%r1), %r26		/* struct pt_regs *regs */
 	reg_save %r26
 
@@ -1800,17 +1794,17 @@ syscall_do_signal:
 	BL	do_notify_resume,%r2
 	ldi	1, %r25				/* long in_syscall = 1 */
 
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
+	mfctl	%cr30,%r1
 	ldo	TASK_REGS(%r1), %r20		/* reload pt_regs */
 	reg_restore %r20
 
 	b,n     syscall_check_sig
 
 syscall_restore:
-	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
+	mfctl	%cr30,%r1
 
 	/* Are we being ptraced? */
-	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
+	LDREG	TASK_TI_FLAGS(%r1),%r19
 	ldi	_TIF_SYSCALL_TRACE_MASK,%r2
 	and,COND(=)	%r19,%r2,%r0
 	b,n	syscall_restore_rfi

arch/parisc/kernel/head.S

@@ -35,7 +35,8 @@ END(boot_args)
 	__HEAD
 
 	.align	4
-	.import init_thread_union,data
+	.import init_task,data
+	.import init_stack,data
 	.import fault_vector_20,code    /* IVA parisc 2.0 32 bit */
 #ifndef CONFIG_64BIT
         .import fault_vector_11,code    /* IVA parisc 1.1 32 bit */
@@ -123,12 +124,12 @@ $pgt_fill_loop:
 	load32		start_parisc,%r11
 
 	/* And the initial task pointer */
-	load32		init_thread_union,%r6
+	load32		init_task,%r6
 	mtctl           %r6,%cr30
 
 	/* And the stack pointer too */
-	ldo             THREAD_SZ_ALGN(%r6),%sp
-
+	load32		init_stack,%sp
+	tophys_r1	%sp
 #if defined(CONFIG_64BIT) && defined(CONFIG_FUNCTION_TRACER)
 	.import _mcount,data
 	/* initialize mcount FPTR */
@@ -186,12 +187,11 @@ common_stext:
 #endif /*CONFIG_SMP*/
 
 #ifdef CONFIG_64BIT
-	tophys_r1	%sp
+	mfctl		%cr30,%r6		/* PCX-W2 firmware bug */
+	tophys_r1	%r6
 
 	/* Save the rfi target address */
-	ldd             TI_TASK-THREAD_SZ_ALGN(%sp), %r10
-	tophys_r1       %r10
-	std             %r11,  TASK_PT_GR11(%r10)
+	STREG		%r11,  TASK_PT_GR11(%r6)
 	/* Switch to wide mode Superdome doesn't support narrow PDC
 	** calls.
 	*/
@@ -206,7 +206,6 @@ common_stext:
         ** Someday, palo might not do this for the Monarch either.
         */
 2:
-	mfctl		%cr30,%r6		/* PCX-W2 firmware bug */
 
 	ldo             PDC_PSW(%r0),%arg0              /* 21 */
 	ldo             PDC_PSW_SET_DEFAULTS(%r0),%arg1 /* 2 */
@@ -216,13 +215,9 @@ common_stext:
 	copy            %r0,%arg3
 
 stext_pdc_ret:
+	LDREG		TASK_PT_GR11(%r6), %r11
+	tovirt_r1	%r6
 	mtctl		%r6,%cr30		/* restore task thread info */
-
-	/* restore rfi target address*/
-	ldd             TI_TASK-THREAD_SZ_ALGN(%sp), %r10
-	tophys_r1       %r10
-	ldd             TASK_PT_GR11(%r10), %r11
-	tovirt_r1       %sp
 #endif
 	
 	/* PARANOID: clear user scratch/user space SR's */
@@ -287,7 +282,9 @@ aligned_rfi:
 
 	load32		KERNEL_PSW,%r10
 	mtctl		%r10,%ipsw
-	
+
+	tovirt_r1	%sp
+
 	/* Jump through hyperspace to Virt Mode */
 	rfi
 	nop
@@ -343,12 +340,13 @@ smp_slave_stext:
 #endif
 
 	/*  Initialize the SP - monarch sets up smp_init_current_idle_task */
-	load32		PA(smp_init_current_idle_task),%sp
-	LDREG		0(%sp),%sp	/* load task address */
+	load32		PA(smp_init_current_idle_task),%r6
+	LDREG		0(%r6),%r6
+	mtctl		%r6,%cr30
+	tophys_r1	%r6
+	LDREG           TASK_STACK(%r6),%sp
 	tophys_r1	%sp
-	LDREG		TASK_THREAD_INFO(%sp),%sp
-	mtctl           %sp,%cr30       /* store in cr30 */
-	ldo             THREAD_SZ_ALGN(%sp),%sp
+	ldo		FRAME_SIZE(%sp),%sp
 
 	/* point CPU to kernel page tables */
 	load32		PA(swapper_pg_dir),%r4

arch/parisc/kernel/irq.c

@@ -15,6 +15,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/seq_file.h>
 #include <linux/types.h>
+#include <linux/sched/task_stack.h>
 #include <asm/io.h>
 
 #include <asm/softirq_stack.h>
@@ -399,8 +400,7 @@ static inline void stack_overflow_check(struct pt_regs *regs)
 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 	#define STACK_MARGIN	(256*6)
 
-	/* Our stack starts directly behind the thread_info struct. */
-	unsigned long stack_start = (unsigned long) current_thread_info();
+	unsigned long stack_start = (unsigned long) task_stack_page(current);
 	unsigned long sp = regs->gr[30];
 	unsigned long stack_usage;
 	unsigned int *last_usage;
@@ -476,7 +476,7 @@ static void execute_on_irq_stack(void *func, unsigned long param1)
 	union_ptr = &per_cpu(irq_stack_union, smp_processor_id());
 	irq_stack = (unsigned long) &union_ptr->stack;
 	irq_stack = ALIGN(irq_stack + sizeof(irq_stack_union.slock),
-			 64); /* align for stack frame usage */
+			FRAME_ALIGN); /* align for stack frame usage */
 
 	/* We may be called recursive. If we are already using the irq stack,
 	 * just continue to use it. Use spinlocks to serialize

arch/parisc/kernel/process.c

@@ -205,7 +205,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 		/* Must exit via ret_from_kernel_thread in order
 		 * to call schedule_tail()
 		 */
-		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
+		cregs->ksp = (unsigned long) stack + FRAME_SIZE + PT_SZ_ALGN;
 		cregs->kpc = (unsigned long) &ret_from_kernel_thread;
 		/*
 		 * Copy function and argument to be called from
@@ -228,7 +228,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 			if (likely(usp))
 				cregs->gr[30] = usp;
 		}
-		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE;
+		cregs->ksp = (unsigned long) stack + FRAME_SIZE;
 		cregs->kpc = (unsigned long) &child_return;
 
 		/* Setup thread TLS area */

arch/parisc/kernel/smp.c

@@ -324,7 +324,7 @@ int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 	const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
 	long timeout;
 
-	task_thread_info(idle)->cpu = cpuid;
+	idle->cpu = cpuid;
 
 	/* Let _start know what logical CPU we're booting
 	** (offset into init_tasks[],cpu_data[])

arch/parisc/kernel/syscall.S

@@ -139,9 +139,9 @@ linux_gateway_entry:
 	xor     %r1,%r30,%r30                   /* ye olde xor trick */
 	xor     %r1,%r30,%r1
 	xor     %r1,%r30,%r30
-	
-	ldo     THREAD_SZ_ALGN+FRAME_SIZE(%r30),%r30  /* set up kernel stack */
 
+	LDREG	TASK_STACK(%r30),%r30		/* set up kernel stack */
+	ldo	FRAME_SIZE(%r30),%r30
 	/* N.B.: It is critical that we don't set sr7 to 0 until r30
 	 *       contains a valid kernel stack pointer. It is also
 	 *       critical that we don't start using the kernel stack
@@ -152,7 +152,6 @@ linux_gateway_entry:
 	ssm	PSW_SM_I, %r0			/* enable interrupts */
 	STREGM	%r1,FRAME_SIZE(%r30)		/* save r1 (usp) here for now */
 	mfctl	%cr30,%r1			/* get task ptr in %r1 */
-	LDREG	TI_TASK(%r1),%r1
 
 	/* Save some registers for sigcontext and potential task
 	   switch (see entry.S for the details of which ones are
@@ -207,7 +206,7 @@ linux_gateway_entry:
 
 	/* Are we being ptraced? */
 	mfctl	%cr30, %r1
-	LDREG	TI_FLAGS(%r1),%r1
+	LDREG	TASK_TI_FLAGS(%r1),%r1
 	ldi	_TIF_SYSCALL_TRACE_MASK, %r19
 	and,COND(=) %r1, %r19, %r0
 	b,n	.Ltracesys
@@ -272,8 +271,7 @@ tracesys:
 	 * C bit set, a non-straced syscall entry results in C and D clear
 	 * in the saved PSW.
 	 */
-	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
-	LDREG	TI_TASK(%r1), %r1
+	mfctl	%cr30,%r1			/* get task ptr */
 	ssm	0,%r2
 	STREG	%r2,TASK_PT_PSW(%r1)		/* Lower 8 bits only!! */
 	mfsp	%sr0,%r2
@@ -327,8 +325,7 @@ tracesys_next:
 	 */
 	copy	%ret0,%r20
 
-	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
-	LDREG	TI_TASK(%r1), %r1
+	mfctl	%cr30,%r1			/* get task ptr */
 	LDREG   TASK_PT_GR28(%r1), %r28		/* Restore return value */
 	LDREG   TASK_PT_GR26(%r1), %r26		/* Restore the users args */
 	LDREG   TASK_PT_GR25(%r1), %r25
@@ -385,16 +382,14 @@ tracesys_next:
 	makes a direct call to syscall_trace. */
 	
 tracesys_exit:
-	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
-	LDREG	TI_TASK(%r1), %r1
+	mfctl	%cr30,%r1			/* get task ptr */
 #ifdef CONFIG_64BIT
 	ldo	-16(%r30),%r29			/* Reference param save area */
 #endif
 	ldo	TASK_REGS(%r1),%r26
 	BL	do_syscall_trace_exit,%r2
 	STREG   %r28,TASK_PT_GR28(%r1)          /* save return value now */
-	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
-	LDREG	TI_TASK(%r1), %r1
+	mfctl	%cr30,%r1			/* get task ptr */
 	LDREG   TASK_PT_GR28(%r1), %r28		/* Restore return val. */
 
 	ldil	L%syscall_exit,%r1
@@ -407,8 +402,7 @@ tracesys_exit:
 	ldo	R%tracesys_sigexit(%r2),%r2
 
 tracesys_sigexit:
-	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
-	LDREG	TI_TASK(%r1), %r1
+	mfctl	%cr30,%r1			/* get task ptr */
 #ifdef CONFIG_64BIT
 	ldo	-16(%r30),%r29			/* Reference param save area */
 #endif

arch/parisc/kernel/traps.c

@@ -144,7 +144,7 @@ void show_regs(struct pt_regs *regs)
 	printk("%s IIR: %08lx    ISR: " RFMT "  IOR: " RFMT "\n",
 	       level, regs->iir, regs->isr, regs->ior);
 	printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
-	       level, current_thread_info()->cpu, cr30, cr31);
+	       level, task_cpu(current), cr30, cr31);
 	printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
 
 	if (user) {

arch/parisc/kernel/unwind.c

@@ -14,6 +14,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/sort.h>
+#include <linux/sched/task_stack.h>
 
 #include <linux/uaccess.h>
 #include <asm/assembly.h>
@@ -299,12 +300,9 @@ static void unwind_frame_regs(struct unwind_frame_info *info)
 			info->prev_sp = sp - 64;
 			info->prev_ip = 0;
 
-			/* The stack is at the end inside the thread_union
-			 * struct. If we reach data, we have reached the
-			 * beginning of the stack and should stop unwinding. */
-			if (info->prev_sp >= (unsigned long) task_thread_info(info->t) &&
-			    info->prev_sp < ((unsigned long) task_thread_info(info->t)
-						+ THREAD_SZ_ALGN)) {
+			/* Check if stack is inside kernel stack area */
+			if ((info->prev_sp - (unsigned long) task_stack_page(info->t))
+					>= THREAD_SIZE) {
 				info->prev_sp = 0;
 				break;
 			}