Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

18 files changed, 116 insertions, 76 deletions

diff --git a/kernel/arch/parisc/include/asm/bitops.h b/kernel/arch/parisc/include/asm/bitops.h
index 3f9406d9b..da8794332 100644
--- a/kernel/arch/parisc/include/asm/bitops.h
+++ b/kernel/arch/parisc/include/asm/bitops.h
@@ -6,7 +6,7 @@
 #endif
 
 #include <linux/compiler.h>
-#include <asm/types.h>		/* for BITS_PER_LONG/SHIFT_PER_LONG */
+#include <asm/types.h>
 #include <asm/byteorder.h>
 #include <asm/barrier.h>
 #include <linux/atomic.h>
@@ -17,6 +17,12 @@
  * to include/asm-i386/bitops.h or kerneldoc
  */
 
+#if __BITS_PER_LONG == 64
+#define SHIFT_PER_LONG 6
+#else
+#define SHIFT_PER_LONG 5
+#endif
+
 #define CHOP_SHIFTCOUNT(x) (((unsigned long) (x)) & (BITS_PER_LONG - 1))
 
 
diff --git a/kernel/arch/parisc/include/asm/pgtable.h b/kernel/arch/parisc/include/asm/pgtable.h
index 291cee28c..3a4ed9f91 100644
--- a/kernel/arch/parisc/include/asm/pgtable.h
+++ b/kernel/arch/parisc/include/asm/pgtable.h
@@ -65,9 +65,9 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
 		unsigned long flags;				\
 		spin_lock_irqsave(&pa_tlb_lock, flags);		\
 		old_pte = *ptep;				\
-		set_pte(ptep, pteval);				\
 		if (pte_inserted(old_pte))			\
 			purge_tlb_entries(mm, addr);		\
+		set_pte(ptep, pteval);				\
 		spin_unlock_irqrestore(&pa_tlb_lock, flags);	\
 	} while (0)
 
@@ -83,10 +83,10 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
 	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, (unsigned long)pgd_val(e))
 
 /* This is the size of the initially mapped kernel memory */
-#ifdef CONFIG_64BIT
-#define KERNEL_INITIAL_ORDER	25	/* 1<<25 = 32MB */
+#if defined(CONFIG_64BIT)
+#define KERNEL_INITIAL_ORDER	26	/* 1<<26 = 64MB */
 #else
-#define KERNEL_INITIAL_ORDER	24	/* 1<<24 = 16MB */
+#define KERNEL_INITIAL_ORDER	25	/* 1<<25 = 32MB */
 #endif
 #define KERNEL_INITIAL_SIZE	(1 << KERNEL_INITIAL_ORDER)
 
@@ -478,8 +478,8 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned
 		spin_unlock_irqrestore(&pa_tlb_lock, flags);
 		return 0;
 	}
-	set_pte(ptep, pte_mkold(pte));
 	purge_tlb_entries(vma->vm_mm, addr);
+	set_pte(ptep, pte_mkold(pte));
 	spin_unlock_irqrestore(&pa_tlb_lock, flags);
 	return 1;
 }
@@ -492,9 +492,9 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 
 	spin_lock_irqsave(&pa_tlb_lock, flags);
 	old_pte = *ptep;
-	set_pte(ptep, __pte(0));
 	if (pte_inserted(old_pte))
 		purge_tlb_entries(mm, addr);
+	set_pte(ptep, __pte(0));
 	spin_unlock_irqrestore(&pa_tlb_lock, flags);
 
 	return old_pte;
@@ -504,8 +504,8 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
 {
 	unsigned long flags;
 	spin_lock_irqsave(&pa_tlb_lock, flags);
-	set_pte(ptep, pte_wrprotect(*ptep));
 	purge_tlb_entries(mm, addr);
+	set_pte(ptep, pte_wrprotect(*ptep));
 	spin_unlock_irqrestore(&pa_tlb_lock, flags);
 }
 
diff --git a/kernel/arch/parisc/include/asm/uaccess.h b/kernel/arch/parisc/include/asm/uaccess.h
index 0abdd4c60..4ad514658 100644
--- a/kernel/arch/parisc/include/asm/uaccess.h
+++ b/kernel/arch/parisc/include/asm/uaccess.h
@@ -10,6 +10,7 @@
 #include <asm-generic/uaccess-unaligned.h>
 
 #include <linux/bug.h>
+#include <linux/string.h>
 
 #define VERIFY_READ 0
 #define VERIFY_WRITE 1
@@ -76,6 +77,7 @@ struct exception_table_entry {
  */
 struct exception_data {
 	unsigned long fault_ip;
+	unsigned long fault_gp;
 	unsigned long fault_space;
 	unsigned long fault_addr;
 };
@@ -244,13 +246,14 @@ static inline unsigned long __must_check copy_from_user(void *to,
                                           unsigned long n)
 {
         int sz = __compiletime_object_size(to);
-        int ret = -EFAULT;
+        unsigned long ret = n;
 
         if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
                 ret = __copy_from_user(to, from, n);
         else
                 copy_from_user_overflow();
-
+	if (unlikely(ret))
+		memset(to + (n - ret), 0, ret);
         return ret;
 }
 
diff --git a/kernel/arch/parisc/include/uapi/asm/bitsperlong.h b/kernel/arch/parisc/include/uapi/asm/bitsperlong.h
index e0a23c7bd..07fa7e50b 100644
--- a/kernel/arch/parisc/include/uapi/asm/bitsperlong.h
+++ b/kernel/arch/parisc/include/uapi/asm/bitsperlong.h
@@ -3,10 +3,8 @@
 
 #if defined(__LP64__)
 #define __BITS_PER_LONG 64
-#define SHIFT_PER_LONG 6
 #else
 #define __BITS_PER_LONG 32
-#define SHIFT_PER_LONG 5
 #endif
 
 #include <asm-generic/bitsperlong.h>
diff --git a/kernel/arch/parisc/include/uapi/asm/errno.h b/kernel/arch/parisc/include/uapi/asm/errno.h
index c0ae62520..274d5bc6e 100644
--- a/kernel/arch/parisc/include/uapi/asm/errno.h
+++ b/kernel/arch/parisc/include/uapi/asm/errno.h
@@ -97,10 +97,10 @@
 #define	ENOTCONN	235	/* Transport endpoint is not connected */
 #define	ESHUTDOWN	236	/* Cannot send after transport endpoint shutdown */
 #define	ETOOMANYREFS	237	/* Too many references: cannot splice */
-#define EREFUSED	ECONNREFUSED	/* for HP's NFS apparently */
 #define	ETIMEDOUT	238	/* Connection timed out */
 #define	ECONNREFUSED	239	/* Connection refused */
-#define EREMOTERELEASE	240	/* Remote peer released connection */
+#define	EREFUSED	ECONNREFUSED	/* for HP's NFS apparently */
+#define	EREMOTERELEASE	240	/* Remote peer released connection */
 #define	EHOSTDOWN	241	/* Host is down */
 #define	EHOSTUNREACH	242	/* No route to host */
 
diff --git a/kernel/arch/parisc/include/uapi/asm/swab.h b/kernel/arch/parisc/include/uapi/asm/swab.h
index e78403b12..928e1bbac 100644
--- a/kernel/arch/parisc/include/uapi/asm/swab.h
+++ b/kernel/arch/parisc/include/uapi/asm/swab.h
@@ -1,6 +1,7 @@
 #ifndef _PARISC_SWAB_H
 #define _PARISC_SWAB_H
 
+#include <asm/bitsperlong.h>
 #include <linux/types.h>
 #include <linux/compiler.h>
 
@@ -38,7 +39,7 @@ static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
 }
 #define __arch_swab32 __arch_swab32
 
-#if BITS_PER_LONG > 32
+#if __BITS_PER_LONG > 32
 /*
 ** From "PA-RISC 2.0 Architecture", HP Professional Books.
 ** See Appendix I page 8 , "Endian Byte Swapping".
@@ -61,6 +62,6 @@ static inline __attribute_const__ __u64 __arch_swab64(__u64 x)
 	return x;
 }
 #define __arch_swab64 __arch_swab64
-#endif /* BITS_PER_LONG > 32 */
+#endif /* __BITS_PER_LONG > 32 */
 
 #endif /* _PARISC_SWAB_H */
diff --git a/kernel/arch/parisc/kernel/asm-offsets.c b/kernel/arch/parisc/kernel/asm-offsets.c
index d2f62570a..78d30d2ea 100644
--- a/kernel/arch/parisc/kernel/asm-offsets.c
+++ b/kernel/arch/parisc/kernel/asm-offsets.c
@@ -299,6 +299,7 @@ int main(void)
 #endif
 	BLANK();
 	DEFINE(EXCDATA_IP, offsetof(struct exception_data, fault_ip));
+	DEFINE(EXCDATA_GP, offsetof(struct exception_data, fault_gp));
 	DEFINE(EXCDATA_SPACE, offsetof(struct exception_data, fault_space));
 	DEFINE(EXCDATA_ADDR, offsetof(struct exception_data, fault_addr));
 	BLANK();
diff --git a/kernel/arch/parisc/kernel/cache.c b/kernel/arch/parisc/kernel/cache.c
index cda6dbbe9..6857a104b 100644
--- a/kernel/arch/parisc/kernel/cache.c
+++ b/kernel/arch/parisc/kernel/cache.c
@@ -351,6 +351,7 @@ void __init parisc_setup_cache_timing(void)
 {
 	unsigned long rangetime, alltime;
 	unsigned long size, start;
+	unsigned long threshold;
 
 	alltime = mfctl(16);
 	flush_data_cache();
@@ -364,26 +365,30 @@ void __init parisc_setup_cache_timing(void)
 	printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
 		alltime, size, rangetime);
 
-	/* Racy, but if we see an intermediate value, it's ok too... */
-	parisc_cache_flush_threshold = size * alltime / rangetime;
-
-	parisc_cache_flush_threshold = L1_CACHE_ALIGN(parisc_cache_flush_threshold);
-	if (!parisc_cache_flush_threshold)
-		parisc_cache_flush_threshold = FLUSH_THRESHOLD;
-
-	if (parisc_cache_flush_threshold > cache_info.dc_size)
-		parisc_cache_flush_threshold = cache_info.dc_size;
-
-	printk(KERN_INFO "Setting cache flush threshold to %lu kB\n",
+	threshold = L1_CACHE_ALIGN(size * alltime / rangetime);
+	if (threshold > cache_info.dc_size)
+		threshold = cache_info.dc_size;
+	if (threshold)
+		parisc_cache_flush_threshold = threshold;
+	printk(KERN_INFO "Cache flush threshold set to %lu KiB\n",
 		parisc_cache_flush_threshold/1024);
 
 	/* calculate TLB flush threshold */
 
+	/* On SMP machines, skip the TLB measure of kernel text which
+	 * has been mapped as huge pages. */
+	if (num_online_cpus() > 1 && !parisc_requires_coherency()) {
+		threshold = max(cache_info.it_size, cache_info.dt_size);
+		threshold *= PAGE_SIZE;
+		threshold /= num_online_cpus();
+		goto set_tlb_threshold;
+	}
+
 	alltime = mfctl(16);
 	flush_tlb_all();
 	alltime = mfctl(16) - alltime;
 
-	size = PAGE_SIZE;
+	size = 0;
 	start = (unsigned long) _text;
 	rangetime = mfctl(16);
 	while (start < (unsigned long) _end) {
@@ -396,13 +401,12 @@ void __init parisc_setup_cache_timing(void)
 	printk(KERN_DEBUG "Whole TLB flush %lu cycles, flushing %lu bytes %lu cycles\n",
 		alltime, size, rangetime);
 
-	parisc_tlb_flush_threshold = size * alltime / rangetime;
-	parisc_tlb_flush_threshold *= num_online_cpus();
-	parisc_tlb_flush_threshold = PAGE_ALIGN(parisc_tlb_flush_threshold);
-	if (!parisc_tlb_flush_threshold)
-		parisc_tlb_flush_threshold = FLUSH_TLB_THRESHOLD;
+	threshold = PAGE_ALIGN(num_online_cpus() * size * alltime / rangetime);
 
-	printk(KERN_INFO "Setting TLB flush threshold to %lu kB\n",
+set_tlb_threshold:
+	if (threshold)
+		parisc_tlb_flush_threshold = threshold;
+	printk(KERN_INFO "TLB flush threshold set to %lu KiB\n",
 		parisc_tlb_flush_threshold/1024);
 }
 
diff --git a/kernel/arch/parisc/kernel/pacache.S b/kernel/arch/parisc/kernel/pacache.S
index b743a80ea..a4761b772 100644
--- a/kernel/arch/parisc/kernel/pacache.S
+++ b/kernel/arch/parisc/kernel/pacache.S
@@ -96,7 +96,7 @@ fitmanyloop:					/* Loop if LOOP >= 2 */
 
 fitmanymiddle:					/* Loop if LOOP >= 2 */
 	addib,COND(>)		-1, %r31, fitmanymiddle	/* Adjusted inner loop decr */
-	pitlbe		0(%sr1, %r28)
+	pitlbe		%r0(%sr1, %r28)
 	pitlbe,m	%arg1(%sr1, %r28)	/* Last pitlbe and addr adjust */
 	addib,COND(>)		-1, %r29, fitmanymiddle	/* Middle loop decr */
 	copy		%arg3, %r31		/* Re-init inner loop count */
@@ -139,7 +139,7 @@ fdtmanyloop:					/* Loop if LOOP >= 2 */
 
 fdtmanymiddle:					/* Loop if LOOP >= 2 */
 	addib,COND(>)		-1, %r31, fdtmanymiddle	/* Adjusted inner loop decr */
-	pdtlbe		0(%sr1, %r28)
+	pdtlbe		%r0(%sr1, %r28)
 	pdtlbe,m	%arg1(%sr1, %r28)	/* Last pdtlbe and addr adjust */
 	addib,COND(>)		-1, %r29, fdtmanymiddle	/* Middle loop decr */
 	copy		%arg3, %r31		/* Re-init inner loop count */
@@ -620,12 +620,12 @@ ENTRY(copy_user_page_asm)
 	/* Purge any old translations */
 
 #ifdef CONFIG_PA20
-	pdtlb,l		0(%r28)
-	pdtlb,l		0(%r29)
+	pdtlb,l		%r0(%r28)
+	pdtlb,l		%r0(%r29)
 #else
 	tlb_lock	%r20,%r21,%r22
-	pdtlb		0(%r28)
-	pdtlb		0(%r29)
+	pdtlb		%r0(%r28)
+	pdtlb		%r0(%r29)
 	tlb_unlock	%r20,%r21,%r22
 #endif
 
@@ -768,10 +768,10 @@ ENTRY(clear_user_page_asm)
 	/* Purge any old translation */
 
 #ifdef CONFIG_PA20
-	pdtlb,l		0(%r28)
+	pdtlb,l		%r0(%r28)
 #else
 	tlb_lock	%r20,%r21,%r22
-	pdtlb		0(%r28)
+	pdtlb		%r0(%r28)
 	tlb_unlock	%r20,%r21,%r22
 #endif
 
@@ -852,10 +852,10 @@ ENTRY(flush_dcache_page_asm)
 	/* Purge any old translation */
 
 #ifdef CONFIG_PA20
-	pdtlb,l		0(%r28)
+	pdtlb,l		%r0(%r28)
 #else
 	tlb_lock	%r20,%r21,%r22
-	pdtlb		0(%r28)
+	pdtlb		%r0(%r28)
 	tlb_unlock	%r20,%r21,%r22
 #endif
 
@@ -886,19 +886,10 @@ ENTRY(flush_dcache_page_asm)
 	fdc,m		r31(%r28)
 	fdc,m		r31(%r28)
 	fdc,m		r31(%r28)
-	cmpb,COND(<<)		%r28, %r25,1b
+	cmpb,COND(<<)	%r28, %r25,1b
 	fdc,m		r31(%r28)
 
 	sync
-
-#ifdef CONFIG_PA20
-	pdtlb,l		0(%r25)
-#else
-	tlb_lock	%r20,%r21,%r22
-	pdtlb		0(%r25)
-	tlb_unlock	%r20,%r21,%r22
-#endif
-
 	bv		%r0(%r2)
 	nop
 	.exit
@@ -925,13 +916,18 @@ ENTRY(flush_icache_page_asm)
 	depwi		0, 31,PAGE_SHIFT, %r28	/* Clear any offset bits */
 #endif
 
-	/* Purge any old translation */
+	/* Purge any old translation.  Note that the FIC instruction
+	 * may use either the instruction or data TLB.  Given that we
+	 * have a flat address space, it's not clear which TLB will be
+	 * used.  So, we purge both entries.  */
 
 #ifdef CONFIG_PA20
+	pdtlb,l		%r0(%r28)
 	pitlb,l         %r0(%sr4,%r28)
 #else
 	tlb_lock        %r20,%r21,%r22
-	pitlb           (%sr4,%r28)
+	pdtlb		%r0(%r28)
+	pitlb           %r0(%sr4,%r28)
 	tlb_unlock      %r20,%r21,%r22
 #endif
 
@@ -968,15 +964,6 @@ ENTRY(flush_icache_page_asm)
 	fic,m		%r31(%sr4,%r28)
 
 	sync
-
-#ifdef CONFIG_PA20
-	pitlb,l         %r0(%sr4,%r25)
-#else
-	tlb_lock        %r20,%r21,%r22
-	pitlb           (%sr4,%r25)
-	tlb_unlock      %r20,%r21,%r22
-#endif
-
 	bv		%r0(%r2)
 	nop
 	.exit
diff --git a/kernel/arch/parisc/kernel/parisc_ksyms.c b/kernel/arch/parisc/kernel/parisc_ksyms.c
index 568b2c61e..3cad8aadc 100644
--- a/kernel/arch/parisc/kernel/parisc_ksyms.c
+++ b/kernel/arch/parisc/kernel/parisc_ksyms.c
@@ -47,11 +47,11 @@ EXPORT_SYMBOL(__cmpxchg_u64);
 EXPORT_SYMBOL(lclear_user);
 EXPORT_SYMBOL(lstrnlen_user);
 
-/* Global fixups */
-extern void fixup_get_user_skip_1(void);
-extern void fixup_get_user_skip_2(void);
-extern void fixup_put_user_skip_1(void);
-extern void fixup_put_user_skip_2(void);
+/* Global fixups - defined as int to avoid creation of function pointers */
+extern int fixup_get_user_skip_1;
+extern int fixup_get_user_skip_2;
+extern int fixup_put_user_skip_1;
+extern int fixup_put_user_skip_2;
 EXPORT_SYMBOL(fixup_get_user_skip_1);
 EXPORT_SYMBOL(fixup_get_user_skip_2);
 EXPORT_SYMBOL(fixup_put_user_skip_1);
diff --git a/kernel/arch/parisc/kernel/pci-dma.c b/kernel/arch/parisc/kernel/pci-dma.c
index b9402c9b3..af0d7fae7 100644
--- a/kernel/arch/parisc/kernel/pci-dma.c
+++ b/kernel/arch/parisc/kernel/pci-dma.c
@@ -95,8 +95,8 @@ static inline int map_pte_uncached(pte_t * pte,
 
 		if (!pte_none(*pte))
 			printk(KERN_ERR "map_pte_uncached: page already exists\n");
-		set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
 		purge_tlb_start(flags);
+		set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
 		pdtlb_kernel(orig_vaddr);
 		purge_tlb_end(flags);
 		vaddr += PAGE_SIZE;
diff --git a/kernel/arch/parisc/kernel/setup.c b/kernel/arch/parisc/kernel/setup.c
index f7ea626e2..2e66a8877 100644
--- a/kernel/arch/parisc/kernel/setup.c
+++ b/kernel/arch/parisc/kernel/setup.c
@@ -38,6 +38,7 @@
 #include <linux/export.h>
 
 #include <asm/processor.h>
+#include <asm/sections.h>
 #include <asm/pdc.h>
 #include <asm/led.h>
 #include <asm/machdep.h>	/* for pa7300lc_init() proto */
@@ -140,6 +141,13 @@ void __init setup_arch(char **cmdline_p)
 #endif
 	printk(KERN_CONT ".\n");
 
+	/*
+	 * Check if initial kernel page mappings are sufficient.
+	 * panic early if not, else we may access kernel functions
+	 * and variables which can't be reached.
+	 */
+	if (__pa((unsigned long) &_end) >= KERNEL_INITIAL_SIZE)
+		panic("KERNEL_INITIAL_ORDER too small!");
 
 	pdc_console_init();
 
@@ -326,6 +334,10 @@ static int __init parisc_init(void)
 	/* tell PDC we're Linux. Nevermind failure. */
 	pdc_stable_write(0x40, &osid, sizeof(osid));
 	
+	/* start with known state */
+	flush_cache_all_local();
+	flush_tlb_all_local(NULL);
+
 	processor_init();
 #ifdef CONFIG_SMP
 	pr_info("CPU(s): %d out of %d %s at %d.%06d MHz online\n",
diff --git a/kernel/arch/parisc/kernel/syscall.S b/kernel/arch/parisc/kernel/syscall.S
index fbafa0d0e..a86b19fcc 100644
--- a/kernel/arch/parisc/kernel/syscall.S
+++ b/kernel/arch/parisc/kernel/syscall.S
@@ -106,8 +106,6 @@ linux_gateway_entry:
 	mtsp	%r0,%sr4			/* get kernel space into sr4 */
 	mtsp	%r0,%sr5			/* get kernel space into sr5 */
 	mtsp	%r0,%sr6			/* get kernel space into sr6 */
-	mfsp    %sr7,%r1                        /* save user sr7 */
-	mtsp    %r1,%sr3                        /* and store it in sr3 */
 
 #ifdef CONFIG_64BIT
 	/* for now we can *always* set the W bit on entry to the syscall
@@ -133,6 +131,14 @@ linux_gateway_entry:
 	depdi	0, 31, 32, %r21
 1:	
 #endif
+
+	/* We use a rsm/ssm pair to prevent sr3 from being clobbered
+	 * by external interrupts.
+	 */
+	mfsp    %sr7,%r1                        /* save user sr7 */
+	rsm	PSW_SM_I, %r0			/* disable interrupts */
+	mtsp    %r1,%sr3                        /* and store it in sr3 */
+
 	mfctl   %cr30,%r1
 	xor     %r1,%r30,%r30                   /* ye olde xor trick */
 	xor     %r1,%r30,%r1
@@ -147,6 +153,7 @@ linux_gateway_entry:
 	 */
 
 	mtsp	%r0,%sr7			/* get kernel space into sr7 */
+	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
diff --git a/kernel/arch/parisc/kernel/traps.c b/kernel/arch/parisc/kernel/traps.c
index 553b09855..77e2262c9 100644
--- a/kernel/arch/parisc/kernel/traps.c
+++ b/kernel/arch/parisc/kernel/traps.c
@@ -798,6 +798,9 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 
 	    if (fault_space == 0 && !faulthandler_disabled())
 	    {
+		/* Clean up and return if in exception table. */
+		if (fixup_exception(regs))
+			return;
 		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
 		parisc_terminate("Kernel Fault", regs, code, fault_address);
 	    }
diff --git a/kernel/arch/parisc/kernel/unaligned.c b/kernel/arch/parisc/kernel/unaligned.c
index d7c0acb35..8d49614d6 100644
--- a/kernel/arch/parisc/kernel/unaligned.c
+++ b/kernel/arch/parisc/kernel/unaligned.c
@@ -666,7 +666,7 @@ void handle_unaligned(struct pt_regs *regs)
 		break;
 	}
 
-	if (modify && R1(regs->iir))
+	if (ret == 0 && modify && R1(regs->iir))
 		regs->gr[R1(regs->iir)] = newbase;
 
 
@@ -677,6 +677,14 @@ void handle_unaligned(struct pt_regs *regs)
 
 	if (ret)
 	{
+		/*
+		 * The unaligned handler failed.
+		 * If we were called by __get_user() or __put_user() jump
+		 * to it's exception fixup handler instead of crashing.
+		 */
+		if (!user_mode(regs) && fixup_exception(regs))
+			return;
+
 		printk(KERN_CRIT "Unaligned handler failed, ret = %d\n", ret);
 		die_if_kernel("Unaligned data reference", regs, 28);
 
diff --git a/kernel/arch/parisc/kernel/vmlinux.lds.S b/kernel/arch/parisc/kernel/vmlinux.lds.S
index 308f29081..60771df10 100644
--- a/kernel/arch/parisc/kernel/vmlinux.lds.S
+++ b/kernel/arch/parisc/kernel/vmlinux.lds.S
@@ -88,8 +88,9 @@ SECTIONS
 	/* Start of data section */
 	_sdata = .;
 
-	RO_DATA_SECTION(8)
-
+	/* Architecturally we need to keep __gp below 0x1000000 and thus
+	 * in front of RO_DATA_SECTION() which stores lots of tracepoint
+	 * and ftrace symbols. */
 #ifdef CONFIG_64BIT
 	. = ALIGN(16);
 	/* Linkage tables */
@@ -104,6 +105,8 @@ SECTIONS
 	}
 #endif
 
+	RO_DATA_SECTION(8)
+
 	/* unwind info */
 	.PARISC.unwind : {
 		__start___unwind = .;
diff --git a/kernel/arch/parisc/lib/fixup.S b/kernel/arch/parisc/lib/fixup.S
index 536ef66bb..1052b747e 100644
--- a/kernel/arch/parisc/lib/fixup.S
+++ b/kernel/arch/parisc/lib/fixup.S
@@ -26,6 +26,7 @@
 
 #ifdef CONFIG_SMP
 	.macro  get_fault_ip t1 t2
+	loadgp
 	addil LT%__per_cpu_offset,%r27
 	LDREG RT%__per_cpu_offset(%r1),\t1
 	/* t2 = smp_processor_id() */
@@ -40,14 +41,19 @@
 	LDREG RT%exception_data(%r1),\t1
 	/* t1 = this_cpu_ptr(&exception_data) */
 	add,l \t1,\t2,\t1
+	/* %r27 = t1->fault_gp - restore gp */
+	LDREG EXCDATA_GP(\t1), %r27
 	/* t1 = t1->fault_ip */
 	LDREG EXCDATA_IP(\t1), \t1
 	.endm
 #else
 	.macro  get_fault_ip t1 t2
+	loadgp
 	/* t1 = this_cpu_ptr(&exception_data) */
 	addil LT%exception_data,%r27
 	LDREG RT%exception_data(%r1),\t2
+	/* %r27 = t2->fault_gp - restore gp */
+	LDREG EXCDATA_GP(\t2), %r27
 	/* t1 = t2->fault_ip */
 	LDREG EXCDATA_IP(\t2), \t1
 	.endm
diff --git a/kernel/arch/parisc/mm/fault.c b/kernel/arch/parisc/mm/fault.c
index a762864ec..f90644499 100644
--- a/kernel/arch/parisc/mm/fault.c
+++ b/kernel/arch/parisc/mm/fault.c
@@ -151,6 +151,7 @@ int fixup_exception(struct pt_regs *regs)
 		struct exception_data *d;
 		d = this_cpu_ptr(&exception_data);
 		d->fault_ip = regs->iaoq[0];
+		d->fault_gp = regs->gr[27];
 		d->fault_space = regs->isr;
 		d->fault_addr = regs->ior;