Commit 4c0cae48 authored by Pavel Tatashin's avatar Pavel Tatashin Committed by Greg Kroah-Hartman

sparc64: reset mm cpumask after wrap


[ Upstream commit 58897485 ]

After a wrap (getting a new context version) a process must get a new
context id, which means that we would need to flush the context id from
the TLB before running for the first time with this ID on every CPU. But,
we use mm_cpumask to determine if this process has been running on this CPU
before, and this mask is not reset after a wrap. So, there are two possible
fixes for this issue:

1. Clear mm cpumask whenever mm gets a new context id
2. Unconditionally flush context every time process is running on a CPU

This patch implements the first solution
Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: default avatarBob Picco <bob.picco@oracle.com>
Reviewed-by: default avatarSteven Sistare <steven.sistare@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7047c200
......@@ -708,6 +708,8 @@ void get_new_mmu_context(struct mm_struct *mm)
goto out;
}
}
if (mm->context.sparc64_ctx_val)
cpumask_clear(mm_cpumask(mm));
mmu_context_bmap[new_ctx>>6] |= (1UL << (new_ctx & 63));
new_ctx |= (tlb_context_cache & CTX_VERSION_MASK);
out:
......
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