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authorDavid S. Miller <davem@davemloft.net>2018-10-12 21:38:46 -0700
committerDavid S. Miller <davem@davemloft.net>2018-10-12 21:38:46 -0700
commitd864991b220b7c62e81d21209e1fd978fd67352c (patch)
treeb570a1ad6fc1b959c5bcda6ceca0b321319c01e0 /arch/arc/kernel/process.c
parenta688c53a0277d8ea21d86a5c56884892e3442c5e (diff)
parentbab5c80b211035739997ebd361a679fa85b39465 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts were easy to resolve using immediate context mostly, except the cls_u32.c one where I simply too the entire HEAD chunk. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/arc/kernel/process.c')
-rw-r--r--arch/arc/kernel/process.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index 4674541eba3f..8ce6e7235915 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -241,6 +241,26 @@ int copy_thread(unsigned long clone_flags,
task_thread_info(current)->thr_ptr;
}
+
+ /*
+ * setup usermode thread pointer #1:
+ * when child is picked by scheduler, __switch_to() uses @c_callee to
+ * populate usermode callee regs: this works (despite being in a kernel
+ * function) since special return path for child @ret_from_fork()
+ * ensures those regs are not clobbered all the way to RTIE to usermode
+ */
+ c_callee->r25 = task_thread_info(p)->thr_ptr;
+
+#ifdef CONFIG_ARC_CURR_IN_REG
+ /*
+ * setup usermode thread pointer #2:
+ * however for this special use of r25 in kernel, __switch_to() sets
+ * r25 for kernel needs and only in the final return path is usermode
+ * r25 setup, from pt_regs->user_r25. So set that up as well
+ */
+ c_regs->user_r25 = c_callee->r25;
+#endif
+
return 0;
}