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authorBart Van Assche <bvanassche@acm.org>2023-02-10 21:52:00 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2023-02-22 04:00:51 +0100
commitfc663711b94468f4e1427ebe289c9f05669699c9 (patch)
tree56a1c90dc59b8f2c6770e27a2ef4869350284d17
parentscsi: core: Fix a source code comment (diff)
downloadlinux-fc663711b94468f4e1427ebe289c9f05669699c9.tar.xz
linux-fc663711b94468f4e1427ebe289c9f05669699c9.zip
scsi: core: Remove the /proc/scsi/${proc_name} directory earlier
Remove the /proc/scsi/${proc_name} directory earlier to fix a race condition between unloading and reloading kernel modules. This fixes a bug introduced in 2009 by commit 77c019768f06 ("[SCSI] fix /proc memory leak in the SCSI core"). Fix the following kernel warning: proc_dir_entry 'scsi/scsi_debug' already registered WARNING: CPU: 19 PID: 27986 at fs/proc/generic.c:376 proc_register+0x27d/0x2e0 Call Trace: proc_mkdir+0xb5/0xe0 scsi_proc_hostdir_add+0xb5/0x170 scsi_host_alloc+0x683/0x6c0 sdebug_driver_probe+0x6b/0x2d0 [scsi_debug] really_probe+0x159/0x540 __driver_probe_device+0xdc/0x230 driver_probe_device+0x4f/0x120 __device_attach_driver+0xef/0x180 bus_for_each_drv+0xe5/0x130 __device_attach+0x127/0x290 device_initial_probe+0x17/0x20 bus_probe_device+0x110/0x130 device_add+0x673/0xc80 device_register+0x1e/0x30 sdebug_add_host_helper+0x1a7/0x3b0 [scsi_debug] scsi_debug_init+0x64f/0x1000 [scsi_debug] do_one_initcall+0xd7/0x470 do_init_module+0xe7/0x330 load_module+0x122a/0x12c0 __do_sys_finit_module+0x124/0x1a0 __x64_sys_finit_module+0x46/0x50 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Link: https://lore.kernel.org/r/20230210205200.36973-3-bvanassche@acm.org Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Yi Zhang <yi.zhang@redhat.com> Cc: stable@vger.kernel.org Fixes: 77c019768f06 ("[SCSI] fix /proc memory leak in the SCSI core") Reported-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/hosts.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index b28375f9e019..f7f62e56afca 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -181,6 +181,7 @@ void scsi_remove_host(struct Scsi_Host *shost)
scsi_forget_host(shost);
mutex_unlock(&shost->scan_mutex);
scsi_proc_host_rm(shost);
+ scsi_proc_hostdir_rm(shost->hostt);
/*
* New SCSI devices cannot be attached anymore because of the SCSI host
@@ -340,6 +341,7 @@ static void scsi_host_dev_release(struct device *dev)
struct Scsi_Host *shost = dev_to_shost(dev);
struct device *parent = dev->parent;
+ /* In case scsi_remove_host() has not been called. */
scsi_proc_hostdir_rm(shost->hostt);
/* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */