From 3c7f62212018b904ae17f5636ead18a4dca3a88f Mon Sep 17 00:00:00 2001 From: Dave Aldridge <david.j.aldridge@oracle.com> Date: Tue, 9 May 2017 02:57:35 -0600 Subject: [PATCH] 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> --- arch/sparc/kernel/head_64.S | 6 ++++++ arch/sparc/lib/GENbzero.S | 2 +- arch/sparc/lib/NGbzero.S | 2 +- 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/sparc/kernel/head_64.S b/arch/sparc/kernel/head_64.S index 44101196d02b5..41a4073286671 100644 --- a/arch/sparc/kernel/head_64.S +++ b/arch/sparc/kernel/head_64.S @@ -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) diff --git a/arch/sparc/lib/GENbzero.S b/arch/sparc/lib/GENbzero.S index 8e7a843ddd883..2fbf6297d57cf 100644 --- a/arch/sparc/lib/GENbzero.S +++ b/arch/sparc/lib/GENbzero.S @@ -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; diff --git a/arch/sparc/lib/NGbzero.S b/arch/sparc/lib/NGbzero.S index beab29bf419b6..33053bdf3766b 100644 --- a/arch/sparc/lib/NGbzero.S +++ b/arch/sparc/lib/NGbzero.S @@ -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; -- GitLab