[PATCH 1/2] ARC: uaccess: dont use "l" inline as constraint

[PATCH 1/2] ARC: uaccess: dont use "l" inline as constraint

[Vineet Gupta]

This constraint has been removed from gcc

There was an earlier fix 3c7c7a2fc8811 which fixed this in delay.h but
somehow missed this one as gcc change had not made its way into
production toolchains

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/include/asm/uaccess.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h
index f35974ee7264..c9173c02081c 100644
--- a/arch/arc/include/asm/uaccess.h
+++ b/arch/arc/include/asm/uaccess.h
@@ -668,6 +668,7 @@ __arc_strncpy_from_user(char *dst, const char __user *src, long count)
 		return 0;
 
 	__asm__ __volatile__(
+	"	mov	lp_count, %5		\n"
 	"	lp	3f			\n"
 	"1:	ldb.ab  %3, [%2, 1]		\n"
 	"	breq.d	%3, 0, 3f               \n"
@@ -684,8 +685,8 @@ __arc_strncpy_from_user(char *dst, const char __user *src, long count)
 	"	.word   1b, 4b			\n"
 	"	.previous			\n"
 	: "+r"(res), "+r"(dst), "+r"(src), "=r"(val)
-	: "g"(-EFAULT), "l"(count)
-	: "memory");
+	: "g"(-EFAULT), "r"(count)
+	: "lp_count", "lp_start", "lp_end", "memory");
 
 	return res;
 }
-- 
2.7.4

[PATCH 2/2] ARC: provide for gcc "isolate path" induced generated abort calls

[Vineet Gupta]

gcc toggle -fisolate-erroneous-paths-dereference (default at -O2
onwards) isolates faulty code paths such as null pointer access, divide
by zero etc. If gcc port doesnt implement __builtin_trap, an abort() is
generated which causes kernel link error hence this patch.

FWIW ARC gcc now has the builtin, but we need to handle this error for
older toolchains.

The code in question triggering gcc is in lib/mpi/mpih-div.o

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/kernel/setup.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 9d27331fe69a..5e180090b17f 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -19,6 +19,7 @@
 #include <linux/of_fdt.h>
 #include <linux/of.h>
 #include <linux/cache.h>
+#include <linux/reboot.h>
 #include <asm/sections.h>
 #include <asm/arcregs.h>
 #include <asm/tlb.h>
@@ -637,3 +638,8 @@ static int __init topology_init(void)
 }
 
 subsys_initcall(topology_init);
+
+void __weak abort(void)
+{
+	machine_halt();
+}
-- 
2.7.4