klamer@mi.eltn.utwente.nl (Klamer Schutte) (04/08/91)
As i already announced in an earlier message, there is a bug in
kernel/stfloppy.c which produces a kernel panic. The bug is that
there is divided through a possible-zero number. The fix is to check
for this and give a proper error. (return EINVAL).
Fix is relative to minix 1.5.10#3. Don't apply it to plain 1.5.10.
Don't think about 1.1 ;-)
Both plaintext and uud version follow.
Klamer
echo x - stfloppy.c.cdi
sed '/^X/s///' > stfloppy.c.cdi << '/'
X*** 1.1 1991/04/08 10:37:42
X--- stfloppy.c 1991/04/08 11:06:14
X***************
X*** 538,552 ****
X if (ret != SECTOR_SIZE)
X return(ret);
X nr_sec[d] = sh88tosh68(block0.b0_spt);
X- nr_cyl[d] = sh88tosh68(block0.b0_nsects) / nr_sec[d];
X nr_hds[d] = sh88tosh68(block0.b0_nsides);
X /* safety first: check for plausible values */
X /* assume that #sectors is between 8 (old dos) and 18 (hd diskettes) */
X if ((nr_sec[d] < 8) || (nr_sec[d] > 18)) return(EINVAL);
X- /* assume that #cylinders is either 40 (5 1/4" dos) or between 78 and 85 */
X- if ((nr_cyl[d] != 40) && (nr_cyl[d] < 78) || (nr_cyl[d] > 85)) return(EINVAL);
X /* definitely must have either one or two heads */
X if ((nr_hds[d] != 1) && (nr_hds[d] != 2)) return(EINVAL);
X return(0);
X }
X #endif
X--- 538,553 ----
X if (ret != SECTOR_SIZE)
X return(ret);
X nr_sec[d] = sh88tosh68(block0.b0_spt);
X nr_hds[d] = sh88tosh68(block0.b0_nsides);
X /* safety first: check for plausible values */
X /* assume that #sectors is between 8 (old dos) and 18 (hd diskettes) */
X if ((nr_sec[d] < 8) || (nr_sec[d] > 18)) return(EINVAL);
X /* definitely must have either one or two heads */
X if ((nr_hds[d] != 1) && (nr_hds[d] != 2)) return(EINVAL);
X+ /* now is know that nr_sec and nr_hds are not zero there can de divided */
X+ nr_cyl[d] = sh88tosh68(block0.b0_nsects) / (nr_sec[d]*nr_hds[d]);
X+ /* assume that #cylinders is either 40 (5 1/4" dos) or between 78 and 85 */
X+ if ((nr_cyl[d] != 40) && (nr_cyl[d] < 78) || (nr_cyl[d] > 85)) return(EINVAL);
X return(0);
X }
X #endif
/
echo x - stfloppy.uue
sed '/^X/s///' > stfloppy.uue << '/'
Xtable
X !"#$%&'()*+,-./0123456789:;<=>?
X@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_
Xbegin 644 stfloppy.c.cdi.Z
XM'YV-*@*"B.$B1H(8.7+$> &#!D,< V'HF'%#!PT9"EIH!#&'CADV;^# R>-Bz
XMS,&$"QL^'!A#!PP;.F+04!"PILV;*F@*K#$#!XL:-62 L*D A%$0:<R 0"&Gy
XM#!T0(7J F%)D")4G4KY,2:*E2(JB1Q,TI5-'CANF3E/L &O4C9PO<\J,V4*Fx
XM"PBI<]#@P$'G35X;.%"( 3EF#0P78F# A4-';<:C;K^,R<.&KEV\>OGZ10-8w
XM,&'#B!6[B3N&SIP4(%Z B$S:\MJCJ]^B(3/'\EV.F?O^#3SX3>'#B;^,3D.Fv
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XM&&X\&,."LT&8QAQK.$6'<:BI\!YL22V% FMRV<:#@JCQP<=2*,Y5%P@^#(1#s
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XML9.NM4*1J[UQ1X @K.&&X"<K&5O38^1<X>*WYMQ4X$_I :6KIIXW!H67:F@'i
XM<64\^.;?_AY:6<!Y#;R;9[Z!%MQH+..L6M%.=Z$"W !WX1CI5\]7<I(IC\"Dh
XMD\5%*6"I9.>Y99=?AHDSF3 ;B*"@:C[>YJR\O_WGZ7;AF27=AMHYXXJ#*EUHg
X79.+;I6@->;-+==_P+=LL6,\:%6V%U +>f
X e
Xend
/
--
Klamer Schutte
Faculty of electrical engineering -- University of Twente, The Netherlands
klamer@mi.eltn.utwente.nl {backbone}!mcsun!mi.eltn.utwente.nl!klamer