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1da42d7c5f
commit a4d62babf988fe5dfde24437fa135ef147bc7aa0 upstream.
Hardware:
CPU: XLP832,the 64-bit OS
NOR Flash:S29GL128S 128M
Software:
Kernel:2.6.32.41
Filesystem:JFFS2
When writing files, errors appear:
Write len 182 but return retlen 180
Write of 182 bytes at 0x072c815c failed. returned -5, retlen 180
Write len 186 but return retlen 184
Write of 186 bytes at 0x072caff4 failed. returned -5, retlen 184
These errors exist only in 64-bit systems,not in 32-bit systems. After analysis, we
found that the left shift operation is wrong in map_word_load_partial. For instance:
unsigned char buf[3] ={0x9e,0x3a,0xea};
map_bankwidth(map) is 4;
for (i=0; i < 3; i++) {
int bitpos;
bitpos = (map_bankwidth(map)-1-i)*8;
orig.x[0] &= ~(0xff << bitpos);
orig.x[0] |= buf[i] << bitpos;
}
The value of orig.x[0] is expected to be 0x9e3aeaff, but in this situation(64-bit
System) we'll get the wrong value of 0xffffffff9e3aeaff due to the 64-bit sign
extension:
buf[i] is defined as "unsigned char" and the left-shift operation will convert it
to the type of "signed int", so when left-shift buf[i] by 24 bits, the final result
will get the wrong value: 0xffffffff9e3aeaff.
If the left-shift bits are less than 24, then sign extension will not occur. Whereas
the bankwidth of the nor flash we used is 4, therefore this BUG emerges.
Signed-off-by: Pang Xunlei <pang.xunlei@zte.com.cn>
Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn>
Signed-off-by: Lu Zhongjun <lu.zhongjun@zte.com.cn>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|---|---|---|
| .. | ||
| bbm.h | ||
| blktrans.h | ||
| cfi.h | ||
| cfi_endian.h | ||
| concat.h | ||
| doc2000.h | ||
| flashchip.h | ||
| fsmc.h | ||
| ftl.h | ||
| gen_probe.h | ||
| inftl.h | ||
| latch-addr-flash.h | ||
| lpc32xx_mlc.h | ||
| lpc32xx_slc.h | ||
| map.h | ||
| mtd.h | ||
| mtdram.h | ||
| nand-gpio.h | ||
| nand.h | ||
| nand_bch.h | ||
| nand_ecc.h | ||
| ndfc.h | ||
| nftl.h | ||
| onenand.h | ||
| onenand_regs.h | ||
| partitions.h | ||
| pfow.h | ||
| physmap.h | ||
| pismo.h | ||
| plat-ram.h | ||
| qinfo.h | ||
| sh_flctl.h | ||
| sharpsl.h | ||
| spear_smi.h | ||
| super.h | ||
| ubi.h | ||
| xip.h | ||