@@ -362,7 +362,7 @@ static inline map_word map_word_load_partial(struct map_info *map, map_word orig
bitpos = (map_bankwidth(map)-1-i)*8;
#endif
orig.x[0] &= ~(0xff << bitpos);
- orig.x[0] |= buf[i-start] << bitpos;
+ orig.x[0] |= (unsigned long)buf[i-start] << bitpos;
}
}
return orig;
@@ -381,7 +381,7 @@ static inline map_word map_word_ff(struct map_info *map)
if (map_bankwidth(map) < MAP_FF_LIMIT) {
int bw = 8 * map_bankwidth(map);
- r.x[0] = (1 << bw) - 1;
+ r.x[0] = (1UL << bw) - 1;
} else {
for (i=0; i<map_words(map); i++)
r.x[i] = ~0UL;
This is a note to let you know that I have just added a patch titled mtd: map: fixed bug in 64-bit systems to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.14. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From e35c5f4401577705a5c8b76d84e45a9ac742f67e Mon Sep 17 00:00:00 2001 From: Wang Haitao <wang.haitao1@zte.com.cn> Date: Thu, 22 Aug 2013 19:32:38 +0800 Subject: mtd: map: fixed bug in 64-bit systems 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: Kamal Mostafa <kamal@canonical.com> --- include/linux/mtd/map.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 1.8.3.2