Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux

Pull arm updates from Russell King:
 "Updates for 7.3:

   - add module description for kprobes testing module

   - remove references to CONFIG_CPU_ARM92x_CPU_IDLE options

   - expand comment in ARM's __switch_to()

  Also a number of fixes that missed 7.2:

   - disable broken eBPF on RiscPC

   - more BKPT fixes (guys, it's a *very* bad idea when everyone uses
     the BKPT instruction for their own differing purposes)

   - another preempt-rt fix, this time for siglock / CPU timers

   - fix another path where we try to send signals to processes with
     interrupts disabled

   - acquire mmap write lock for show_pte() with user faults"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux:
  ARM: 9480/1: entry: expand comment in __switch_to
  ARM: 9478/1: Remove references to removed CONFIG_CPU_ARM92x_CPU_IDLE options
  ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faults
  ARM: 9484/1: enable interrupts when unhandled user faults are triggered
  ARM: 9483/1: select HAVE_POSIX_CPU_TIMERS_TASK_WORK
  ARM: 9481/2: breakpoint: CFI breakpoints only on demand
  ARM: 9477/1: Disable broken eBPF JIT on the Risc PC
  ARM: 9473/1: kprobes: test: add MODULE_DESCRIPTION

arch/arm/Kconfig

@@ -99,7 +99,7 @@ config ARM
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
 	select HAVE_ARM_SMCCC if CPU_V7
-	select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
+	select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32 && !CPU_32v3
 	select HAVE_CONTEXT_TRACKING_USER
 	select HAVE_C_RECORDMCOUNT
 	select HAVE_BUILDTIME_MCOUNT_SORT
@@ -134,6 +134,7 @@ config ARM
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
 	select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_RSEQ

arch/arm/kernel/entry-armv.S

@@ -557,9 +557,16 @@ ENTRY(__switch_to)
 	ldmia	r4, {r4 - sl, fp, ip, lr}	@ Load all regs saved previously
 #ifdef CONFIG_VMAP_STACK
 	@
-	@ Do a dummy read from the new stack while running from the old one so
-	@ that we can rely on do_translation_fault() to fix up any stale PMD
-	@ entries covering the vmalloc region.
+	@ For a non-lazy mm switch, check_vmalloc_seq() has ensured that
+	@ that the active mm's page tables have mappings for the prev
+	@ task's stack and the next task's stack.
+	@
+	@ For a lazy mm switch the active mm's page tables have mappings
+	@ for the prev task's stack but might not have mappings for the
+	@ new task's stack. Do a dummy read from the new stack while
+	@ running from the old stack so that we can rely on
+	@ do_translation_fault() to populate missing PMD entries covering the
+	@ new task's stack in the old task's page tables.
 	@
 	ldr	r2, [ip]
 #ifdef CONFIG_KASAN_VMALLOC

arch/arm/kernel/hw_breakpoint.c

@@ -929,10 +929,6 @@ static void hw_breakpoint_cfi_handler(struct pt_regs *regs)
 		break;
 	}
 }
-#else
-static void hw_breakpoint_cfi_handler(struct pt_regs *regs)
-{
-}
 #endif
 
 /*
@@ -964,9 +960,14 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr,
 	case ARM_ENTRY_SYNC_WATCHPOINT:
 		watchpoint_handler(addr, fsr, regs);
 		break;
+#ifdef CONFIG_CFI
 	case ARM_ENTRY_CFI_BREAKPOINT:
-		hw_breakpoint_cfi_handler(regs);
+		if (user_mode(regs))
+			ret = 1; /* Don't handle userspace BKPT */
+		else
+			hw_breakpoint_cfi_handler(regs);
 		break;
+#endif
 	default:
 		ret = 1; /* Unhandled fault. */
 	}

arch/arm/mm/fault.c

@@ -181,7 +181,11 @@ __do_user_fault(unsigned long addr, unsigned int fsr, unsigned int sig,
 		pr_err("8<--- cut here ---\n");
 		pr_err("%s: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n",
 		       tsk->comm, sig, addr, fsr);
-		show_pte(KERN_ERR, tsk->mm, addr);
+		if (likely(addr < TASK_SIZE)) {
+			mmap_write_lock(tsk->mm);
+			show_pte(KERN_ERR, tsk->mm, addr);
+			mmap_write_unlock(tsk->mm);
+		}
 		show_regs(regs);
 	}
 #endif
@@ -633,10 +637,21 @@ do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs))
 		return;
 
+	if (likely(user_mode(regs)))
+		local_irq_enable();
+
 	pr_alert("8<--- cut here ---\n");
 	pr_alert("Unhandled fault: %s (0x%03x) at 0x%08lx\n",
 		inf->name, fsr, addr);
-	show_pte(KERN_ALERT, current->mm, addr);
+	if (likely(user_mode(regs))) {
+		if (addr < TASK_SIZE) {
+			mmap_write_lock(current->mm);
+			show_pte(KERN_ALERT, current->mm, addr);
+			mmap_write_unlock(current->mm);
+		}
+	} else {
+		show_pte(KERN_ALERT, current->mm, addr);
+	}
 
 	arm_notify_die("", regs, inf->sig, inf->code, (void __user *)addr,
 		       fsr, 0);
@@ -663,6 +678,9 @@ do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
 	if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs))
 		return;
 
+	if (likely(user_mode(regs)))
+		local_irq_enable();
+
 	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/proc-arm920.S

@@ -8,8 +8,6 @@
  *
  * These are the low level assembler for performing cache and TLB
  * functions on the arm920.
- *
- *  CONFIG_CPU_ARM920_CPU_IDLE -> nohlt
  */
 #include <linux/linkage.h>
 #include <linux/init.h>

arch/arm/mm/proc-arm922.S

@@ -9,8 +9,6 @@
  *
  * These are the low level assembler for performing cache and TLB
  * functions on the arm922.
- *
- *  CONFIG_CPU_ARM922_CPU_IDLE -> nohlt
  */
 #include <linux/linkage.h>
 #include <linux/init.h>

arch/arm/mm/proc-arm925.S

@@ -15,8 +15,6 @@
  * These are the low level assembler for performing cache and TLB
  * functions on the arm925.
  *
- *  CONFIG_CPU_ARM925_CPU_IDLE -> nohlt
- *
  * Some additional notes based on deciphering the TI TRM on OMAP-5910:
  *
  * NOTE1: The TI925T Configuration Register bit "D-cache clean and flush

arch/arm/mm/proc-arm926.S

@@ -8,8 +8,6 @@
  *
  * These are the low level assembler for performing cache and TLB
  * functions on the arm926.
- *
- *  CONFIG_CPU_ARM926_CPU_IDLE -> nohlt
  */
 #include <linux/linkage.h>
 #include <linux/init.h>

arch/arm/probes/kprobes/test-core.c

@@ -1649,24 +1649,16 @@ static int __init run_all_tests(void)
 
 	return ret;
 }
-
+late_initcall(run_all_tests);
 
 /*
  * Module setup
  */
 
-#ifdef MODULE
-
 static void __exit kprobe_test_exit(void)
 {
 }
-
-module_init(run_all_tests)
 module_exit(kprobe_test_exit)
+
+MODULE_DESCRIPTION("Test code for ARM kprobes");
 MODULE_LICENSE("GPL");
-
-#else /* !MODULE */
-
-late_initcall(run_all_tests);
-
-#endif