Searched hist:187223 (Results 1 - 2 of 2) sorted by relevance
| /freebsd-11.0-release/sys/arm/ti/omap4/ | ||
| H A D | omap4_prcm_clks.c | diff 262870 Thu Mar 06 21:07:57 MST 2014 cognet When calculating the MPU freq, make sure not to overflow by using a uint64_t. PR: arm/187223 Submitted by: Svatopluk Kraus <onwahe@gmail.com> |
| /freebsd-11.0-release/sys/kern/ | ||
| H A D | sysv_sem.c | diff 187223 Wed Jan 14 15:26:14 MST 2009 kib It seems that there are at least three issues with IPC_RMID operation on SysV semaphores. The squeeze of the semaphore array in the kern_semctl() modifies sem_base for the semaphores with sem_base greater then sem_base of the removed semaphore, as well as the values of the semaphores, without locking their mutex. This can lead to (killable) hangs or unexpected behaviour of the processes performing any sem operations while other process does IPC_RMID. The semexit_myhook() eventhandler unlocks SEMUNDO_LOCK() while accessing *suptr. This allows for IPC_RMID for the sem id to be performed in parallel with undo hook referenced by the current undo structure. This leads to the panic("semexit - semid not allocated") [1]. The semaphore creation is protected by Giant, while IPC_RMID is done while only semaphore mutex is held. This seems to result in invalid values for semtot, causing random ENOSPC error returns [2]. Redo the locking of the semaphores lifetime cycle. Delegate the sem_mtx to the sole purpose of protecting semget() and semctl(IPC_RMID). Introduce new sem_undo_mtx to protect SEM_UNDO handling. Remove the Giant remnants from the code. Note that mac_sysvsem_check_semget() and mac_sysvsem_create() are now called while sem_mtx is held, as well as mac_sysvsem_cleanup() [3]. When semaphore is removed, acquire semaphore locks for all semaphores with sem_base that is going to be changed by squeeze of the sema array. The lock order is not important there, because the region is protected by sem_mtx. Organize both used and free sem_undo structures into the lists, protected by sem_undo_mtx. In semexit_myhook(), remove sem_undo structure that is being processed, from used list, without putting it onto the free to prevent modifications by other threads. This allows for sem_undo_lock to be dropped to acquire individial semaphore locks without violating lock order. Since IPC_RMID may no longer find this sem_undo, do tolerate references to unallocated semaphores in undo structure, and check sequential number to not undo unrelated semaphore with the same id. While there, convert functions definitions to ANSI C and fix small style(9) glitches. Reported by: Omer Faruk Sen <omerfsen gmail com> [1], pho [2] Reviewed by: rwatson [3] Tested by: pho MFC after: 1 month |
Completed in 198 milliseconds