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authorVaibhav Jain <vaibhav@linux.vnet.ibm.com>2017-11-24 09:33:38 +0100
committerMichael Ellerman <mpe@ellerman.id.au>2017-11-29 09:56:18 +0100
commit7e4d4233260be0611c7fbdb2730c12731c4b8dc0 (patch)
tree52eab6d31594903d88d7dd68f547d16bf873106c /arch
parentpowerpc: Avoid signed to unsigned conversion in set_thread_tidr() (diff)
downloadlinux-7e4d4233260be0611c7fbdb2730c12731c4b8dc0.tar.xz
linux-7e4d4233260be0611c7fbdb2730c12731c4b8dc0.zip
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/process.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index d205b52e3850..5acb5a176dbe 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -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;