On Fri, 2014-06-06 at 11:58 +0800, Tang Chen wrote:
> We use the following command to online a memory_block:
>
> echo online|online_kernel|online_movable > /sys/devices/system/memory/memoryXXX/state
>
> But, if we do the following:
>
> echo online_fhsjkghfkd > /sys/devices/system/memory/memoryXXX/state
>
> the block will also be onlined.
>
> This is because the following code in store_mem_state() does not compare the whole string,
> but only the prefix of the string.
>
> store_mem_state()
> {
> ......
> 328 if (!strncmp(buf, "online_kernel", min_t(int, count, 13)))
>
> Here, only compare the first 13 letters of the string. If we give "online_kernelXXXXXX",
> it will be recognized as online_kernel, which is incorrect.
>
> 329 online_type = ONLINE_KERNEL;
> 330 else if (!strncmp(buf, "online_movable", min_t(int, count, 14)))
>
> We have the same problem here,
>
> 331 online_type = ONLINE_MOVABLE;
> 332 else if (!strncmp(buf, "online", min_t(int, count, 6)))
>
> here,
>
> (Here is more problematic. If we give online_movalbe, which is a typo of online_movable,
> it will be recognized as online without noticing the author.)
>
> 333 online_type = ONLINE_KEEP;
> 334 else if (!strncmp(buf, "offline", min_t(int, count, 7)))
>
> and here.
>
> 335 online_type = -1;
> 336 else {
> 337 ret = -EINVAL;
> 338 goto err;
> 339 }
> ......
> }
>
> This patch fix this problem by using sysfs_streq() to compare the whole string.
>
> Reported-by: Hu Tao <hutao@xxxxxxxxxxxxxx>
> Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Acked-by: Toshi Kani <toshi.kani@xxxxxx>
Thanks,
-Toshi
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