7 files changed, 55 insertions, 7 deletions

diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c
index ab80e5c6f651..6d471c00c71a 100644
--- a/arch/parisc/kernel/firmware.c
+++ b/arch/parisc/kernel/firmware.c
@@ -233,6 +233,26 @@ int pdc_add_valid(unsigned long address)
 EXPORT_SYMBOL(pdc_add_valid);
 
 /**
+ * pdc_instr - Get instruction that invokes PDCE_CHECK in HPMC handler.
+ * @instr: Pointer to variable which will get instruction opcode.
+ *
+ * The return value is PDC_OK (0) in case call succeeded.
+ */
+int __init pdc_instr(unsigned int *instr)
+{
+	int retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdc_lock, flags);
+	retval = mem_pdc_call(PDC_INSTR, 0UL, __pa(pdc_result));
+	convert_to_wide(pdc_result);
+	*instr = pdc_result[0];
+	spin_unlock_irqrestore(&pdc_lock, flags);
+
+	return retval;
+}
+
+/**
  * pdc_chassis_info - Return chassis information.
  * @result: The return buffer.
  * @chassis_info: The memory buffer address.
diff --git a/arch/parisc/kernel/pdt.c b/arch/parisc/kernel/pdt.c
index 05730a83895c..00aed082969b 100644
--- a/arch/parisc/kernel/pdt.c
+++ b/arch/parisc/kernel/pdt.c
@@ -15,6 +15,7 @@
 #include <linux/memblock.h>
 #include <linux/seq_file.h>
 #include <linux/kthread.h>
+#include <linux/initrd.h>
 
 #include <asm/pdc.h>
 #include <asm/pdcpat.h>
@@ -216,8 +217,16 @@ void __init pdc_pdt_init(void)
 	}
 
 	for (i = 0; i < pdt_status.pdt_entries; i++) {
+		unsigned long addr;
+
 		report_mem_err(pdt_entry[i]);
 
+		addr = pdt_entry[i] & PDT_ADDR_PHYS_MASK;
+		if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) &&
+			addr >= initrd_start && addr < initrd_end)
+			pr_crit("CRITICAL: initrd possibly broken "
+				"due to bad memory!\n");
+
 		/* mark memory page bad */
 		memblock_reserve(pdt_entry[i] & PAGE_MASK, PAGE_SIZE);
 	}
diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
index a778bd3c107c..e120d63c1b28 100644
--- a/arch/parisc/kernel/processor.c
+++ b/arch/parisc/kernel/processor.c
@@ -317,7 +317,7 @@ void __init collect_boot_cpu_data(void)
  *
  * o Enable CPU profiling hooks.
  */
-int init_per_cpu(int cpunum)
+int __init init_per_cpu(int cpunum)
 {
 	int ret;
 	struct pdc_coproc_cfg coproc_cfg;
diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c
index dee6f9d6a153..f7d0c3b33d70 100644
--- a/arch/parisc/kernel/setup.c
+++ b/arch/parisc/kernel/setup.c
@@ -38,6 +38,7 @@
 #include <linux/export.h>
 #include <linux/sched.h>
 #include <linux/sched/clock.h>
+#include <linux/start_kernel.h>
 
 #include <asm/processor.h>
 #include <asm/sections.h>
@@ -48,6 +49,7 @@
 #include <asm/io.h>
 #include <asm/setup.h>
 #include <asm/unwind.h>
+#include <asm/smp.h>
 
 static char __initdata command_line[COMMAND_LINE_SIZE];
 
@@ -115,7 +117,6 @@ void __init dma_ops_init(void)
 }
 #endif
 
-extern int init_per_cpu(int cpuid);
 extern void collect_boot_cpu_data(void);
 
 void __init setup_arch(char **cmdline_p)
@@ -398,9 +399,8 @@ static int __init parisc_init(void)
 }
 arch_initcall(parisc_init);
 
-void start_parisc(void)
+void __init start_parisc(void)
 {
-	extern void start_kernel(void);
 	extern void early_trap_init(void);
 
 	int ret, cpunum;
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 63365106ea19..30c28ab14540 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -255,12 +255,11 @@ void arch_send_call_function_single_ipi(int cpu)
 static void __init
 smp_cpu_init(int cpunum)
 {
-	extern int init_per_cpu(int);  /* arch/parisc/kernel/processor.c */
 	extern void init_IRQ(void);    /* arch/parisc/kernel/irq.c */
 	extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
 
 	/* Set modes and Enable floating point coprocessor */
-	(void) init_per_cpu(cpunum);
+	init_per_cpu(cpunum);
 
 	disable_sr_hashing();
 
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 991654c88eec..230333157fe3 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -817,7 +817,7 @@ void __init initialize_ivt(const void *iva)
 	u32 check = 0;
 	u32 *ivap;
 	u32 *hpmcp;
-	u32 length;
+	u32 length, instr;
 
 	if (strcmp((const char *)iva, "cows can fly"))
 		panic("IVT invalid");
@@ -827,6 +827,14 @@ void __init initialize_ivt(const void *iva)
 	for (i = 0; i < 8; i++)
 	    *ivap++ = 0;
 
+	/*
+	 * Use PDC_INSTR firmware function to get instruction that invokes
+	 * PDCE_CHECK in HPMC handler.  See programming note at page 1-31 of
+	 * the PA 1.1 Firmware Architecture document.
+	 */
+	if (pdc_instr(&instr) == PDC_OK)
+		ivap[0] = instr;
+
 	/* Compute Checksum for HPMC handler */
 	length = os_hpmc_size;
 	ivap[7] = length;
diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c
index 48dc7d4d20bb..caab39dfa95d 100644
--- a/arch/parisc/kernel/unwind.c
+++ b/arch/parisc/kernel/unwind.c
@@ -14,6 +14,7 @@
 #include <linux/slab.h>
 #include <linux/kallsyms.h>
 #include <linux/sort.h>
+#include <linux/sched.h>
 
 #include <linux/uaccess.h>
 #include <asm/assembly.h>
@@ -279,6 +280,17 @@ 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)) {
+				info->prev_sp = 0;
+				break;
+			}
+
 			if (get_user(tmp, (unsigned long *)(info->prev_sp - RP_OFFSET))) 
 				break;
 			info->prev_ip = tmp;