nvExit() never returns #701

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1. TristanIsrael commented on Dec 19, 2025

   

   TristanIsrael

   on Dec 19, 2025

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   I precise I use TransferMemory (tmemCreateFromMemory()) and I call tmemClose() before calling framebufferClose()
2. masagrator commented on Dec 19, 2025

   

   masagrator

   on Dec 19, 2025

   Last edited by masagrator

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    and I call tmemClose() before calling framebufferClose()
   

   You are not supposed to do that. Remove tmemClose() call. nvExit gets stuck because passed TransferMemory is not RW anymore and it expects it to be RW before closing it on its own and returning.

   void _nvCleanup(void) {
       serviceClose(&g_nvSrvClone);
       serviceClose(&g_nvSrv);
       tmemWaitForPermission(&g_nvTransfermem, Perm_Rw);
       tmemClose(&g_nvTransfermem);
   }

   tmemWaitForPermission() is there because passing ownership of Transfermem is async. So in default conditions you cannot be 100% sure it is immediately available after closing service (there were already confirmed cases of race condition). If it can't detect that passed Transfermem is RW, it waits infinitely.

   👍React with 👍1Reacted by Tristan Israël
3. TristanIsrael commented on Dec 19, 2025

   

   TristanIsrael

   on Dec 19, 2025

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   Great thank you. I'll fix that.
4. TristanIsrael commented on Dec 19, 2025

   

   TristanIsrael

   on Dec 19, 2025

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   I'm sorry but I removed the call to tmemClose() and the call to framebufferClose() still blocks at the same place. I am using the 4.10.0-1 version of libnx.
5. TristanIsrael commented on Dec 19, 2025

   

   TristanIsrael

   on Dec 19, 2025

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   An additional information, I declared this function

   TransferMemory* g_transfertMemory = nullptr;
   alignas(ams::os::MemoryPageSize) constinit u8 g_nv_transfer_memory[0x80000];
   extern "C" ::Result __nx_nv_create_tmem(TransferMemory *t, u32 *out_size, Permission perm) {
       *out_size = sizeof(g_nv_transfer_memory);
   
       Result rc = tmemCreateFromMemory(t, g_nv_transfer_memory, sizeof(g_nv_transfer_memory), perm);
       
       if(R_SUCCEEDED(rc)) {
           g_transfertMemory = t;
           logDebug("[Renderer] Successfully created transfer memory with permission %i\n", perm);
       } else {
           logError("[Renderer] Could not create transfer memory of size %i and permission %i\n", sizeof(g_nv_transfer_memory), perm);
       }
   
       return rc;
   }
   

   and in my log I can see that Permission == 0, which means Perm_None, maybe that is a problem?
6. TristanIsrael commented on Dec 19, 2025

   

   TristanIsrael

   on Dec 19, 2025

   Last edited by TristanIsrael

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   Well I fixed this issue by not allocating the Transfer memory by myself and setting u32 __nx_nv_transfermem_size = 0x15000;.

   But now I have different problem... The second time I call framebufferCreate() after the call to framebufferClose(), the result is R_MODULE=345, R_DESCRIPTION=2

   Let me give you more context: I am developing a sysmodule that shows popups and it supposed to work with Tesla overlay for control. But the problem is that both sysmodules can't use VI at the same time. When I don't close the framebuffer and VI Tesla don't show up anymore. That's the reason why I need to close the framebuffer and VI to let Tesla work, and later take it back, and so on.