From: Sonny Rao <sonny@burdell.org>
Date: Tue, 27 Jun 2006 12:46:09 +0000 (-0400)
Subject: [POWERPC] Fix idr locking in init_new_context
X-Git-Tag: archive/raspbian/4.9.13-1+rpi1~10^2~43124^2~5
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/www.github.com/%22bookmarks:///%22http:/www.example.com/cgi/%22https:/www.github.com/%22bookmarks:/?a=commitdiff_plain;h=f86c9747fe1cd72b2c5c6bdf72d17aeb2a3c6cb0;p=linux-4.9.git

[POWERPC] Fix idr locking in init_new_context

We always need to serialize accesses to mmu_context_idr.

I hit this bug when testing with a small number of mmu contexts.

Signed-off-by: Sonny Rao <sonny@burdell.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---

diff --git a/arch/powerpc/mm/mmu_context_64.c b/arch/powerpc/mm/mmu_context_64.c
index 65d18dca266f..e2051efa09c5 100644
--- a/arch/powerpc/mm/mmu_context_64.c
+++ b/arch/powerpc/mm/mmu_context_64.c
@@ -44,7 +44,9 @@ again:
 		return err;
 
 	if (index > MAX_CONTEXT) {
+		spin_lock(&mmu_context_lock);
 		idr_remove(&mmu_context_idr, index);
+		spin_unlock(&mmu_context_lock);
 		return -ENOMEM;
 	}