From 085354f907969fb3ee33f236368f6e1dd4c74d62 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 10 Sep 2016 16:21:34 -0400 Subject: alpha: get rid of tail-zeroing in __copy_user() ... and adjust copy_from_user() accordingly Signed-off-by: Al Viro --- arch/alpha/lib/copy_user.S | 16 +--------------- arch/alpha/lib/ev6-copy_user.S | 23 +---------------------- 2 files changed, 2 insertions(+), 37 deletions(-) (limited to 'arch/alpha/lib') diff --git a/arch/alpha/lib/copy_user.S b/arch/alpha/lib/copy_user.S index 6f3fab9eb434..ac9c3766ba8c 100644 --- a/arch/alpha/lib/copy_user.S +++ b/arch/alpha/lib/copy_user.S @@ -124,22 +124,8 @@ $65: bis $31,$31,$0 $41: $35: -$exitout: - ret $31,($28),1 - $exitin: - /* A stupid byte-by-byte zeroing of the rest of the output - buffer. This cures security holes by never leaving - random kernel data around to be copied elsewhere. */ - - mov $0,$1 -$101: - EXO ( ldq_u $2,0($6) ) - subq $1,1,$1 - mskbl $2,$6,$2 - EXO ( stq_u $2,0($6) ) - addq $6,1,$6 - bgt $1,$101 +$exitout: ret $31,($28),1 .end __copy_user diff --git a/arch/alpha/lib/ev6-copy_user.S b/arch/alpha/lib/ev6-copy_user.S index db42ffe9c350..c4d0689c3d26 100644 --- a/arch/alpha/lib/ev6-copy_user.S +++ b/arch/alpha/lib/ev6-copy_user.S @@ -227,33 +227,12 @@ $dirtyentry: bgt $0,$onebyteloop # U .. .. .. : U L U L $zerolength: +$exitin: $exitout: # Destination for exception recovery(?) nop # .. .. .. E nop # .. .. E .. nop # .. E .. .. ret $31,($28),1 # L0 .. .. .. : L U L U -$exitin: - - /* A stupid byte-by-byte zeroing of the rest of the output - buffer. This cures security holes by never leaving - random kernel data around to be copied elsewhere. */ - - nop - nop - nop - mov $0,$1 - -$101: - EXO ( stb $31,0($6) ) # L - subq $1,1,$1 # E - addq $6,1,$6 # E - bgt $1,$101 # U - - nop - nop - nop - ret $31,($28),1 # L0 - .end __copy_user -- cgit v1.2.3