On Thu, 10 Aug 2023 15:45:50 +0800 Jijie Shao wrote: > on 2023/8/9 15:03, Leon Romanovsky wrote: > > On Wed, Aug 09, 2023 at 10:09:02AM +0800, Jijie Shao wrote: > >> From: Hao Chen <chenhao418@xxxxxxxxxx> > >> > >> hns3_dbg_fill_content()/hclge_dbg_fill_content() is aim to integrate some > >> items to a string for content, and we add '\n' and '\0' in the last > >> two bytes of content. > >> > >> strscpy() will add '\0' in the last byte of destination buffer(one of > >> items), it result in finishing content print ahead of schedule and some > >> dump content truncation. > >> > >> One Error log shows as below: > >> cat mac_list/uc > >> UC MAC_LIST: > >> > >> Expected: > >> UC MAC_LIST: > >> FUNC_ID MAC_ADDR STATE > >> pf 00:2b:19:05:03:00 ACTIVE > >> > >> The destination buffer is length-bounded and not required to be > >> NUL-terminated, so just change strscpy() to memcpy() to fix it. > > I think that you should change to strtomem() and not use plain memcpy(). > > > > Thanks > > Hi: > > We tried to replace memcpy with strtomem, but errors was reported during > compilation: > /kernel/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c: In > function ‘hclge_dbg_fill_content.part.0’: > /kernel/include/linux/compiler_types.h:397:38: error: call to > ‘__compiletime_assert_519’ declared with attribute error: BUILD_BUG_ON > failed: !__builtin_constant_p(_dest_len) || _dest_len == (size_t)-1 > 397 | _compiletime_assert(condition, msg, __compiletime_assert_, > __COUNTER__) > | ^ > /kernel/include/linux/compiler_types.h:378:4: note: in definition of > macro ‘__compiletime_assert’ > 378 | prefix ## suffix(); \ > | ^~~~~~ > /kernel/include/linux/compiler_types.h:397:2: note: in expansion of > macro ‘_compiletime_assert’ > 397 | _compiletime_assert(condition, msg, __compiletime_assert_, > __COUNTER__) > | ^~~~~~~~~~~~~~~~~~~ > /kernel/include/linux/build_bug.h:39:37: note: in expansion of macro > ‘compiletime_assert’ > 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), > msg) > | ^~~~~~~~~~~~~~~~~~ > /kernel/include/linux/build_bug.h:50:2: note: in expansion of macro > ‘BUILD_BUG_ON_MSG’ > 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) > | ^~~~~~~~~~~~~~~~ > /kernel/include/linux/string.h:302:2: note: in expansion of macro > ‘BUILD_BUG_ON’ > 302 | BUILD_BUG_ON(!__builtin_constant_p(_dest_len) || \ > | ^~~~~~~~~~~~ > /kernel/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:115:4: > note: in expansion of macro ‘strtomem’ > 115 | strtomem(pos, result[i]); > | ^~~~~~~~ > > In the strtomem macro, __builtin_object_size is used to calculate the > _dest_len. > We tried to print the _dest_len directly, and the result was -1. > How can we solve this? Let's add Kees in case he has a immediate recommendation on use of strtomem() vs memcpy() for this case..
