Hi, Some time ago I tried to fix this with https://github.com/apache/nuttx/pull/6376 but it ended-up nowhere as I didn't find time for a proper solution.
Best regards, Petro ср, 26 квіт. 2023 р. о 12:50 Ville JUven <ville.ju...@gmail.com> пише: > Hi, > > I'm in the process of trying to fix this issue: > https://github.com/apache/nuttx/issues/8917 > > TL;DR semaphores are unusable when MMU is in use, because the kernel > private data of struct sem_s exists in user space and is not always > visible to the kernel when it needs it. So I'm trying to separate / move > the kernel private data to kernel space (for CONFIG_BUILD_KERNEL only > btw.). > > > > I have a question about using mutex_t / struct mutex_s inside libs/libc. > The mutex_t definition is kernel internal but some modules inside the > libs folder use it directly. My question is, is this intentional ? I > don't think such modules should be using mutex_t. > > Why not ? libc is userspace code (even though we use it inside the > kernel as well as I guess nothing prohibits this) > > What is the problem ? Using NXMUTEX_INITIALIZER uses the kernel private > NXSEM_INITIALIZER macro. I'm trying to separate kernel private data from > semaphores like stated above but there are some corner cases where this > becomes impossible, mutex_t is one example. > > The locations where mutex_t is used (there might be others, using > nxrmutex for example): > ./libs/libnx/nxmu/nx_connect.c:55:static mutex_t g_nxliblock = > NXMUTEX_INITIALIZER; > ./libs/libnx/nxfonts/nxfonts_cache.c:79:static mutex_t g_cachelock = > NXMUTEX_INITIALIZER; > ./libs/libc/locale/lib_gettext.c:87:static mutex_t g_lock = > NXMUTEX_INITIALIZER; > ./libs/libc/wqueue/work_usrthread.c:65: NXMUTEX_INITIALIZER, > ./libs/libc/userfs/lib_userfs.c:73:static mutex_t g_userfs_lock = > NXMUTEX_INITIALIZER; > ./libs/libc/stdlib/lib_mktemp.c:68:static mutex_t g_b62lock = > NXMUTEX_INITIALIZER; > > My question ? Should these be sem_t or perhaps pthread_mutex_t ? Both of > which are valid user APIs. > > Anyone have any idea / suggestions on how to fix this ? > > Br, > > Ville Juven / pussuw > >
