powerpc: Do not assign thread.tidr if already assigned

If set_thread_tidr() is called twice for same task_struct then it will
allocate a new tidr value to it leaving the previous value still
dangling in the vas_thread_ida table.

To fix this the patch changes set_thread_tidr() to check if a tidr
value is already assigned to the task_struct and if yes then returns
zero.

Fixes: ec233ede4c86("powerpc: Add support for setting SPRN_TIDR")
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
[mpe: Modify to return 0 in the success case, not the TID value]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This commit is contained in:

Vaibhav Jain

2017-11-24 14:03:38 +05:30

committed by

Michael Ellerman

parent aca7573fde

commit 7e4d423326

1 changed files with 3 additions and 0 deletions

									
										arch/powerpc/kernel/process.c
									
		+3
		
												View File
												
				@@ -1577,6 +1577,9 @@ int set_thread_tidr(struct task_struct *t)

					if (t != current)

						return -EINVAL;

					if (t->thread.tidr)

						return 0;

					rc = assign_thread_tidr();

					if (rc < 0)

						return rc;