diff options
Diffstat (limited to 'arch/alpha/lib/copy_user.S')
| -rw-r--r-- | arch/alpha/lib/copy_user.S | 53 |
1 files changed, 38 insertions, 15 deletions
diff --git a/arch/alpha/lib/copy_user.S b/arch/alpha/lib/copy_user.S index da57fd6d1..aa309b9f5 100644 --- a/arch/alpha/lib/copy_user.S +++ b/arch/alpha/lib/copy_user.S @@ -27,11 +27,18 @@ */ /* Allow an exception for an insn; exit if we get one. */ -#define EX(x,y...) \ +#define EXI(x,y...) \ 99: x,##y; \ .section __ex_table,"a"; \ .gprel32 99b; \ - lda $31, $exit-99b($31); \ + lda $31, $exitin-99b($31); \ + .previous + +#define EXO(x,y...) \ + 99: x,##y; \ + .section __ex_table,"a"; \ + .gprel32 99b; \ + lda $31, $exitout-99b($31); \ .previous .set noat @@ -45,14 +52,14 @@ __copy_user: subq $3,8,$3 .align 5 $37: - EX( ldq_u $1,0($7) ) - EX( ldq_u $2,0($6) ) + EXI( ldq_u $1,0($7) ) + EXO( ldq_u $2,0($6) ) extbl $1,$7,$1 mskbl $2,$6,$2 insbl $1,$6,$1 addq $3,1,$3 bis $1,$2,$1 - EX( stq_u $1,0($6) ) + EXO( stq_u $1,0($6) ) subq $0,1,$0 addq $6,1,$6 addq $7,1,$7 @@ -63,10 +70,10 @@ $36: bic $0,7,$4 beq $1,$43 beq $4,$48 - EX( ldq_u $3,0($7) ) + EXI( ldq_u $3,0($7) ) .align 5 $50: - EX( ldq_u $2,8($7) ) + EXI( ldq_u $2,8($7) ) subq $4,8,$4 extql $3,$7,$3 extqh $2,$7,$1 @@ -81,13 +88,13 @@ $48: beq $0,$41 .align 5 $57: - EX( ldq_u $1,0($7) ) - EX( ldq_u $2,0($6) ) + EXI( ldq_u $1,0($7) ) + EXO( ldq_u $2,0($6) ) extbl $1,$7,$1 mskbl $2,$6,$2 insbl $1,$6,$1 bis $1,$2,$1 - EX( stq_u $1,0($6) ) + EXO( stq_u $1,0($6) ) subq $0,1,$0 addq $6,1,$6 addq $7,1,$7 @@ -98,7 +105,7 @@ $43: beq $4,$65 .align 5 $66: - EX( ldq $1,0($7) ) + EXI( ldq $1,0($7) ) subq $4,8,$4 stq $1,0($6) addq $7,8,$7 @@ -107,15 +114,31 @@ $66: bne $4,$66 $65: beq $0,$41 - EX( ldq $2,0($7) ) - EX( ldq $1,0($6) ) + EXI( ldq $2,0($7) ) + EXO( ldq $1,0($6) ) mskql $2,$0,$2 mskqh $1,$0,$1 bis $2,$1,$2 - EX( stq $2,0($6) ) + EXO( stq $2,0($6) ) bis $31,$31,$0 $41: $35: -$exit: +$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 + ret $31,($28),1 + .end __copy_user |