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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-06-30 23:34:49 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-06-30 23:34:49 -0400 |
| commit | b223f4e215b32849b841e750e83a915b670070f5 (patch) | |
| tree | 75340f6305028de331a17255018869822b3886d2 /arch/arm64/mm/context.c | |
| parent | f4e6d844bdc142322905d137a9e44e07eee43c5c (diff) | |
| parent | 0cac643c102c0632dc2cc81e2490b0fec1cac0af (diff) | |
Merge branch 'd_real' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into work.misc
Diffstat (limited to 'arch/arm64/mm/context.c')
| -rw-r--r-- | arch/arm64/mm/context.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index b7b397802088..efcf1f7ef1e4 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -179,7 +179,7 @@ static u64 new_context(struct mm_struct *mm, unsigned int cpu) &asid_generation); flush_context(cpu); - /* We have at least 1 ASID per CPU, so this will always succeed */ + /* We have more ASIDs than CPUs, so this will always succeed */ asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, 1); set_asid: @@ -227,8 +227,11 @@ switch_mm_fastpath: static int asids_init(void) { asid_bits = get_cpu_asid_bits(); - /* If we end up with more CPUs than ASIDs, expect things to crash */ - WARN_ON(NUM_USER_ASIDS < num_possible_cpus()); + /* + * Expect allocation after rollover to fail if we don't have at least + * one more ASID than CPUs. ASID #0 is reserved for init_mm. + */ + WARN_ON(NUM_USER_ASIDS - 1 <= num_possible_cpus()); atomic64_set(&asid_generation, ASID_FIRST_VERSION); asid_map = kzalloc(BITS_TO_LONGS(NUM_USER_ASIDS) * sizeof(*asid_map), GFP_KERNEL); |