Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:

 - remove a misuse of kernel-doc comment

 - use "Call trace:" for backtraces like other architectures

 - implement copy_from_kernel_nofault_allowed() to fix a LKDTM test

 - add a "cut here" line for prefetch aborts

 - remove unnecessary Kconfing entry for FRAME_POINTER

 - remove iwmmxy support for PJ4/PJ4B cores

 - use bitfield helpers in ptrace to improve readabililty

 - check if folio is reserved before flushing

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 9359/1: flush: check if the folio is reserved for no-mapping addresses
  ARM: 9354/1: ptrace: Use bitfield helpers
  ARM: 9352/1: iwmmxt: Remove support for PJ4/PJ4B cores
  ARM: 9353/1: remove unneeded entry for CONFIG_FRAME_POINTER
  ARM: 9351/1: fault: Add "cut here" line for prefetch aborts
  ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed()
  ARM: 9349/1: unwind: Add missing "Call trace:" line
  ARM: 9334/1: mm: init: remove misuse of kernel-doc comment

arch/arm/Kconfig

@@ -505,8 +505,8 @@ source "arch/arm/mm/Kconfig"
 
 config IWMMXT
 	bool "Enable iWMMXt support"
-	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
-	default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
+	depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
+	default y if PXA27x || PXA3xx || ARCH_MMP
 	help
 	  Enable support for iWMMXt context switching at run time if
 	  running on a CPU that supports it.

arch/arm/Kconfig.debug

@@ -90,9 +90,6 @@ config BACKTRACE_VERBOSE
 	  In most cases, say N here, unless you are intending to debug the
 	  kernel and have access to the kernel binary image.
 
-config FRAME_POINTER
-	bool
-
 config DEBUG_USER
 	bool "Verbose user fault messages"
 	help

arch/arm/include/asm/ptrace.h

@@ -10,6 +10,7 @@
 #include <uapi/asm/ptrace.h>
 
 #ifndef __ASSEMBLY__
+#include <linux/bitfield.h>
 #include <linux/types.h>
 
 struct pt_regs {
@@ -35,8 +36,8 @@ struct svc_pt_regs {
 
 #ifndef CONFIG_CPU_V7M
 #define isa_mode(regs) \
-	((((regs)->ARM_cpsr & PSR_J_BIT) >> (__ffs(PSR_J_BIT) - 1)) | \
-	 (((regs)->ARM_cpsr & PSR_T_BIT) >> (__ffs(PSR_T_BIT))))
+	(FIELD_GET(PSR_J_BIT, (regs)->ARM_cpsr) << 1 | \
+	 FIELD_GET(PSR_T_BIT, (regs)->ARM_cpsr))
 #else
 #define isa_mode(regs) 1 /* Thumb */
 #endif

arch/arm/kernel/Makefile

@@ -76,8 +76,6 @@ obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
 obj-$(CONFIG_CPU_XSCALE)	+= xscale-cp0.o
 obj-$(CONFIG_CPU_XSC3)		+= xscale-cp0.o
 obj-$(CONFIG_CPU_MOHAWK)	+= xscale-cp0.o
-obj-$(CONFIG_CPU_PJ4)		+= pj4-cp0.o
-obj-$(CONFIG_CPU_PJ4B)		+= pj4-cp0.o
 obj-$(CONFIG_IWMMXT)		+= iwmmxt.o
 obj-$(CONFIG_PERF_EVENTS)	+= perf_regs.o perf_callchain.o
 obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event_xscale.o perf_event_v6.o \

arch/arm/kernel/iwmmxt.S

@@ -18,18 +18,6 @@
 #include <asm/assembler.h>
 #include "iwmmxt.h"
 
-#if defined(CONFIG_CPU_PJ4) || defined(CONFIG_CPU_PJ4B)
-#define PJ4(code...)		code
-#define XSC(code...)
-#elif defined(CONFIG_CPU_MOHAWK) || \
-	defined(CONFIG_CPU_XSC3) || \
-	defined(CONFIG_CPU_XSCALE)
-#define PJ4(code...)
-#define XSC(code...)		code
-#else
-#error "Unsupported iWMMXt architecture"
-#endif
-
 #define MMX_WR0		 	(0x00)
 #define MMX_WR1		 	(0x08)
 #define MMX_WR2		 	(0x10)
@@ -81,17 +69,13 @@ ENDPROC(iwmmxt_undef_handler)
 ENTRY(iwmmxt_task_enable)
 	inc_preempt_count r10, r3
 
-	XSC(mrc	p15, 0, r2, c15, c1, 0)
-	PJ4(mrc p15, 0, r2, c1, c0, 2)
+	mrc	p15, 0, r2, c15, c1, 0
 	@ CP0 and CP1 accessible?
-	XSC(tst	r2, #0x3)
-	PJ4(tst	r2, #0xf)
+	tst	r2, #0x3
 	bne	4f				@ if so no business here
 	@ enable access to CP0 and CP1
-	XSC(orr	r2, r2, #0x3)
-	XSC(mcr	p15, 0, r2, c15, c1, 0)
-	PJ4(orr	r2, r2, #0xf)
-	PJ4(mcr	p15, 0, r2, c1, c0, 2)
+	orr	r2, r2, #0x3
+	mcr	p15, 0, r2, c15, c1, 0
 
 	ldr	r3, =concan_owner
 	ldr	r2, [r0, #S_PC]			@ current task pc value
@@ -218,12 +202,9 @@ ENTRY(iwmmxt_task_disable)
 	bne	1f				@ no: quit
 
 	@ enable access to CP0 and CP1
-	XSC(mrc	p15, 0, r4, c15, c1, 0)
-	XSC(orr	r4, r4, #0x3)
-	XSC(mcr	p15, 0, r4, c15, c1, 0)
-	PJ4(mrc p15, 0, r4, c1, c0, 2)
-	PJ4(orr	r4, r4, #0xf)
-	PJ4(mcr	p15, 0, r4, c1, c0, 2)
+	mrc	p15, 0, r4, c15, c1, 0
+	orr	r4, r4, #0x3
+	mcr	p15, 0, r4, c15, c1, 0
 
 	mov	r0, #0				@ nothing to load
 	str	r0, [r3]			@ no more current owner
@@ -232,10 +213,8 @@ ENTRY(iwmmxt_task_disable)
 	bl	concan_save
 
 	@ disable access to CP0 and CP1
-	XSC(bic	r4, r4, #0x3)
-	XSC(mcr	p15, 0, r4, c15, c1, 0)
-	PJ4(bic	r4, r4, #0xf)
-	PJ4(mcr	p15, 0, r4, c1, c0, 2)
+	bic	r4, r4, #0x3
+	mcr	p15, 0, r4, c15, c1, 0
 
 	mrc	p15, 0, r2, c2, c0, 0
 	mov	r2, r2				@ cpwait
@@ -330,11 +309,9 @@ ENDPROC(iwmmxt_task_restore)
  */
 ENTRY(iwmmxt_task_switch)
 
-	XSC(mrc	p15, 0, r1, c15, c1, 0)
-	PJ4(mrc	p15, 0, r1, c1, c0, 2)
+	mrc	p15, 0, r1, c15, c1, 0
 	@ CP0 and CP1 accessible?
-	XSC(tst	r1, #0x3)
-	PJ4(tst	r1, #0xf)
+	tst	r1, #0x3
 	bne	1f				@ yes: block them for next task
 
 	ldr	r2, =concan_owner
@@ -344,10 +321,8 @@ ENTRY(iwmmxt_task_switch)
 	retne	lr				@ no: leave Concan disabled
 
 1:	@ flip Concan access
-	XSC(eor	r1, r1, #0x3)
-	XSC(mcr	p15, 0, r1, c15, c1, 0)
-	PJ4(eor r1, r1, #0xf)
-	PJ4(mcr	p15, 0, r1, c1, c0, 2)
+	eor	r1, r1, #0x3
+	mcr	p15, 0, r1, c15, c1, 0
 
 	mrc	p15, 0, r1, c2, c0, 0
 	sub	pc, lr, r1, lsr #32		@ cpwait and return

arch/arm/kernel/pj4-cp0.c

-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * linux/arch/arm/kernel/pj4-cp0.c
- *
- * PJ4 iWMMXt coprocessor context switching and handling
- *
- * Copyright (c) 2010 Marvell International Inc.
- */
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/signal.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/io.h>
-#include <asm/thread_notify.h>
-#include <asm/cputype.h>
-
-static int iwmmxt_do(struct notifier_block *self, unsigned long cmd, void *t)
-{
-	struct thread_info *thread = t;
-
-	switch (cmd) {
-	case THREAD_NOTIFY_FLUSH:
-		/*
-		 * flush_thread() zeroes thread->fpstate, so no need
-		 * to do anything here.
-		 *
-		 * FALLTHROUGH: Ensure we don't try to overwrite our newly
-		 * initialised state information on the first fault.
-		 */
-
-	case THREAD_NOTIFY_EXIT:
-		iwmmxt_task_release(thread);
-		break;
-
-	case THREAD_NOTIFY_SWITCH:
-		iwmmxt_task_switch(thread);
-		break;
-	}
-
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block __maybe_unused iwmmxt_notifier_block = {
-	.notifier_call	= iwmmxt_do,
-};
-
-
-static u32 __init pj4_cp_access_read(void)
-{
-	u32 value;
-
-	__asm__ __volatile__ (
-		"mrc	p15, 0, %0, c1, c0, 2\n\t"
-		: "=r" (value));
-	return value;
-}
-
-static void __init pj4_cp_access_write(u32 value)
-{
-	u32 temp;
-
-	__asm__ __volatile__ (
-		"mcr	p15, 0, %1, c1, c0, 2\n\t"
-#ifdef CONFIG_THUMB2_KERNEL
-		"isb\n\t"
-#else
-		"mrc	p15, 0, %0, c1, c0, 2\n\t"
-		"mov	%0, %0\n\t"
-		"sub	pc, pc, #4\n\t"
-#endif
-		: "=r" (temp) : "r" (value));
-}
-
-static int __init pj4_get_iwmmxt_version(void)
-{
-	u32 cp_access, wcid;
-
-	cp_access = pj4_cp_access_read();
-	pj4_cp_access_write(cp_access | 0xf);
-
-	/* check if coprocessor 0 and 1 are available */
-	if ((pj4_cp_access_read() & 0xf) != 0xf) {
-		pj4_cp_access_write(cp_access);
-		return -ENODEV;
-	}
-
-	/* read iWMMXt coprocessor id register p1, c0 */
-	__asm__ __volatile__ ("mrc    p1, 0, %0, c0, c0, 0\n" : "=r" (wcid));
-
-	pj4_cp_access_write(cp_access);
-
-	/* iWMMXt v1 */
-	if ((wcid & 0xffffff00) == 0x56051000)
-		return 1;
-	/* iWMMXt v2 */
-	if ((wcid & 0xffffff00) == 0x56052000)
-		return 2;
-
-	return -EINVAL;
-}
-
-/*
- * Disable CP0/CP1 on boot, and let call_fpe() and the iWMMXt lazy
- * switch code handle iWMMXt context switching.
- */
-static int __init pj4_cp0_init(void)
-{
-	u32 __maybe_unused cp_access;
-	int vers;
-
-	if (!cpu_is_pj4())
-		return 0;
-
-	vers = pj4_get_iwmmxt_version();
-	if (vers < 0)
-		return 0;
-
-#ifndef CONFIG_IWMMXT
-	pr_info("PJ4 iWMMXt coprocessor detected, but kernel support is missing.\n");
-#else
-	cp_access = pj4_cp_access_read() & ~0xf;
-	pj4_cp_access_write(cp_access);
-
-	pr_info("PJ4 iWMMXt v%d coprocessor enabled.\n", vers);
-	elf_hwcap |= HWCAP_IWMMXT;
-	thread_register_notifier(&iwmmxt_notifier_block);
-	register_iwmmxt_undef_handler();
-#endif
-
-	return 0;
-}
-
-late_initcall(pj4_cp0_init);

arch/arm/kernel/traps.c

@@ -220,7 +220,7 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
 	unsigned int fp, mode;
 	int ok = 1;
 
-	printk("%sBacktrace: ", loglvl);
+	printk("%sCall trace: ", loglvl);
 
 	if (!tsk)
 		tsk = current;

arch/arm/kernel/unwind.c

@@ -524,6 +524,8 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk,
 {
 	struct stackframe frame;
 
+	printk("%sCall trace: ", loglvl);
+
 	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
 
 	if (!tsk)

arch/arm/mm/fault.c

@@ -25,6 +25,13 @@
 
 #include "fault.h"
 
+bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+{
+	unsigned long addr = (unsigned long)unsafe_src;
+
+	return addr >= TASK_SIZE && ULONG_MAX - addr >= size;
+}
+
 #ifdef CONFIG_MMU
 
 /*
@@ -588,6 +595,7 @@ do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
 	if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs))
 		return;
 
+	pr_alert("8<--- cut here ---\n");
 	pr_alert("Unhandled prefetch abort: %s (0x%03x) at 0x%08lx\n",
 		inf->name, ifsr, addr);
 

arch/arm/mm/flush.c

@@ -296,6 +296,9 @@ void __sync_icache_dcache(pte_t pteval)
 		return;
 
 	folio = page_folio(pfn_to_page(pfn));
+	if (folio_test_reserved(folio))
+		return;
+
 	if (cache_is_vipt_aliasing())
 		mapping = folio_flush_mapping(folio);
 	else

arch/arm/mm/init.c

@@ -418,7 +418,7 @@ static void set_section_perms(struct section_perm *perms, int n, bool set,
 
 }
 
-/**
+/*
  * update_sections_early intended to be called only through stop_machine
  * framework and executed by only one CPU while all other CPUs will spin and
  * wait, so no locking is required in this function.