Commit 3c7f6221 authored May 09, 2017 by Dave Aldridge Committed by David S. Miller May 09, 2017

sparc64: fix fault handling in NGbzero.S and GENbzero.S



When any of the functions contained in NGbzero.S and GENbzero.S
vector through *bzero_from_clear_user, we may end up taking a
fault when executing one of the store alternate address space
instructions. If this happens, the exception handler does not
restore the %asi register.

This commit fixes the issue by introducing a new exception
handler that ensures the %asi register is restored when
a fault is handled.

Orabug: 25577560

Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Reviewed-by: Rob Gardner <rob.gardner@oracle.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent aed74ea0

arch/sparc/kernel/head_64.S

+6 −0

Original line number	Diff line number	Diff line
		@@ -939,3 +939,9 @@ ENTRY(__retl_o1)
		retl
		mov %o1, %o0
		ENDPROC(__retl_o1)

		ENTRY(__retl_o1_asi)
		wr %o5, 0x0, %asi
		retl
		mov %o1, %o0
		ENDPROC(__retl_o1_asi)

arch/sparc/lib/GENbzero.S

+1 −1

Original line number	Diff line number	Diff line
		@@ -8,7 +8,7 @@
		98: x,y; \
		.section __ex_table,"a";\
		.align 4; \
		.word 98b, __retl_o1; \
		.word 98b, __retl_o1_asi;\
		.text; \
		.align 4;

arch/sparc/lib/NGbzero.S

+1 −1

Original line number	Diff line number	Diff line
		@@ -8,7 +8,7 @@
		98: x,y; \
		.section __ex_table,"a";\
		.align 4; \
		.word 98b, __retl_o1; \
		.word 98b, __retl_o1_asi;\
		.text; \
		.align 4;