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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?psxkiicw2NAxWvaWj6Vp508/NPehl+D5rINOseGKIHGIi31SDwGr3dCy1B/x?= =?us-ascii?Q?R0KZ6vHCWZLzF2jmjptXceqN7QWyl1p099r0pvXhezkgKNjaUslvlp3RvUF1?= =?us-ascii?Q?cmOn+MzogDs0mkOGstp+zFFk9dSuTju6RhxslqbDLARBJDWguJVPQa9W1rkj?= =?us-ascii?Q?m+HO2VYFcF7260+6G1sTxOOZvEMadHewb8BHvhH3J7tzEA24Bf0JrZm77ChL?= =?us-ascii?Q?ns4nDpNWHmsmb99/wxKSnU7bJs8aZ2OGXQblBawp1Vw3i6QjvoOVBkN9iMyc?= =?us-ascii?Q?yMEq6lwaDVfDAZsXvLNxQfOMlmC0V78QAdnTt7ZR8vphATF+s/yH1Se7pX13?= =?us-ascii?Q?aPOHDp6gXtDQJMdTdgnaS/ytpdrRQcwDwOxVK7AcOR95g9ujxxNX/Mbr1YE3?= =?us-ascii?Q?IMpOX1dWKVQWm/FLJyhls4uj+Ahs+5B7QTSdhdEGFCJ5TRpsTT/Vcj2akFES?= =?us-ascii?Q?qqRj/c41xvCYAgFehsOjqfVCkfJIsfgkCp0WWA6pHmYIG/8uXrPl0NeU3wr0?= =?us-ascii?Q?C5+5XyODf1I78hU0evz2+01MZumsflWNf/eFD9TZMJSYKqz5oDGI2N5CEsui?= =?us-ascii?Q?G5BcM+y17sa7rwZj4lW73uALm3Mc1EquqK+NC2FVxPHt44CgfT8tVasfZiN1?= =?us-ascii?Q?Ls3/M/MU/6oN5tJclFgs+jvJLJG+MU4+SJEdNK7uApi7YnQG050MPs6JBf7a?= =?us-ascii?Q?3+XCppXe1wCz23WSlbsHbaji970uYGCDMYFYwfeuxC/d2fMa3ZfM1/0WJGGe?= =?us-ascii?Q?bz6R0XRV6l5KI7i8Wybb5qcrvBmGpY8yhdnia/6Tqx5cT49DYFOI3FW1r+7R?= =?us-ascii?Q?o94edEcgP69z0MQiPkAs3v9jFbS/2CKtUsYKKjtuRWHOvslqf4GVnM4fZnMQ?= =?us-ascii?Q?02TVu4NjiD+Ert8+Gx97IO54zy2QickxTAGKY50aQA4QxAD7BBtrpLA7t8rk?= =?us-ascii?Q?4svE+y0r11IALmKi9j2J8wOW1tvN3s10YIztJpOrw2/omxCsIM5lMBT3BJ6m?= =?us-ascii?Q?dBJcwOBMqyy+EitN3W8m7EJtfk3RXUUuVkEFwdDFZPb+BY7OumJ1EtiwigDG?= =?us-ascii?Q?aELO0sT+Gh5ywsaP0z4GrZQ0GucCtsP9vAUPI5QJVYtBtkvTzBweAgebSKj8?= =?us-ascii?Q?PlttwTdY+XoCuEPURufX48+GIyuYmA1QyusWkI9LuZ4p14g04SxVZM6h/WNp?= =?us-ascii?Q?RXQwj6k/1TxIgK1MG21cAO6bAo4/OmRR7fGoikl4ldV9D9JHAMR/Q7MYAKWe?= =?us-ascii?Q?i3l3X6Gx75jzsQGEatB9AmMyHfpi7ig1WqvbYctGPbd4StJZHA+pZFPfSeTD?= =?us-ascii?Q?Bsna+gh8tTGXiNmODqM+03DdMnU32a4CycwiMlCNONg1iemIC+BoEVJyWkWw?= =?us-ascii?Q?uXdfgjHyMhTWCJnDVcEqaeiD8MTPkw40M5OwH7UWzD8T6XWGqpq3wNj+EROT?= =?us-ascii?Q?S+SFTPGqnG6IBOWwrYHH5yHj/fBg8b6+X46wCTPdmXgxjmBUAGdBsTCXP2DJ?= =?us-ascii?Q?nBGdYQYB81sKnkFxK089IihyAI8MXQFAFV1yXqALjYc5AxzaYoPqEViBNfqr?= =?us-ascii?Q?TFFhSoVJNflnTkQwYJgVRwTjdZlqkceaVGd+heQeaqRBBHh8naOorirpOY9i?= =?us-ascii?Q?lnvx4cMNHlrT3581Rwc6gNqWItv55kaPYbg9Q+efnEIiU/txN4gWuWs/GxDY?= =?us-ascii?Q?wokFgUjMYVhpZcq/xZemGjv+BGScD74esUYuY8kq2o6Ei1qpqInmOjYs/ml1?= =?us-ascii?Q?I+VCJb9woA=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 8ca06aae-ff38-40db-eed4-08da221f98ee X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Apr 2022 16:13:53.7553 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: O43KGgTL4BUNpV6t7m/5/BLV3uTGncGMnDtk4t+ycgdU13ywEsu4qJjpSGuiyh7U X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR12MB3906 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 18, 2022 at 11:33:22PM +0800, Duoming Zhou wrote: > There is a deadlock in irdma_cleanup_cm_core(), which is shown > below: > > (Thread 1) | (Thread 2) > | irdma_schedule_cm_timer() > irdma_cleanup_cm_core() | add_timer() > spin_lock_irqsave() //(1) | (wait a time) > ... | irdma_cm_timer_tick() > del_timer_sync() | spin_lock_irqsave() //(2) > (wait timer to stop) | ... > > We hold cm_core->ht_lock in position (1) of thread 1 and > use del_timer_sync() to wait timer to stop, but timer handler > also need cm_core->ht_lock in position (2) of thread 2. > As a result, irdma_cleanup_cm_core() will block forever. > > This patch removes the check of timer_pending() in > irdma_cleanup_cm_core(), because the del_timer_sync() > function will just return directly if there isn't a > pending timer. As a result, the lock is redundant, > because there is no resource it could protect. > > Signed-off-by: Duoming Zhou > --- > Changes in V6: > - Change subject line prefixed with "RDMA/irdma: ". > > drivers/infiniband/hw/irdma/cm.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) I fixed the compile warning. Applied to for-rc, thanks Jason