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| author | Matthew Wilcox <mawilcox@microsoft.com> | 2018-02-26 14:39:30 -0500 |
|---|---|---|
| committer | Matthew Wilcox <mawilcox@microsoft.com> | 2018-02-26 14:39:30 -0500 |
| commit | 4b0ad07653ee94182e2d8f21404242c9e83ad0b4 (patch) | |
| tree | 88d581f08d2eac9d8b5d933c2740b91003e44401 /lib | |
| parent | 3d4d5d618639c3155cfce57101d619a0935434d2 (diff) | |
| download | lwn-4b0ad07653ee94182e2d8f21404242c9e83ad0b4.tar.gz lwn-4b0ad07653ee94182e2d8f21404242c9e83ad0b4.zip | |
idr: Fix handling of IDs above INT_MAX
Khalid reported that the kernel selftests are currently failing:
selftests: test_bpf.sh
========================================
test_bpf: [FAIL]
not ok 1..8 selftests: test_bpf.sh [FAIL]
He bisected it to 6ce711f2750031d12cec91384ac5cfa0a485b60a ("idr: Make
1-based IDRs more efficient").
The root cause is doing a signed comparison in idr_alloc_u32() instead
of an unsigned comparison. I went looking for any similar problems and
found a couple (which would each result in the failure to warn in two
situations that aren't supposed to happen).
I knocked up a few test-cases to prove that I was right and added them
to the test-suite.
Reported-by: Khalid Aziz <khalid.aziz@oracle.com>
Tested-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/idr.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/lib/idr.c b/lib/idr.c index 99ec5bc89d25..823b813f08f8 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -36,8 +36,8 @@ int idr_alloc_u32(struct idr *idr, void *ptr, u32 *nextid, { struct radix_tree_iter iter; void __rcu **slot; - int base = idr->idr_base; - int id = *nextid; + unsigned int base = idr->idr_base; + unsigned int id = *nextid; if (WARN_ON_ONCE(radix_tree_is_internal_node(ptr))) return -EINVAL; @@ -204,10 +204,11 @@ int idr_for_each(const struct idr *idr, radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, 0) { int ret; + unsigned long id = iter.index + base; - if (WARN_ON_ONCE(iter.index > INT_MAX)) + if (WARN_ON_ONCE(id > INT_MAX)) break; - ret = fn(iter.index + base, rcu_dereference_raw(*slot), data); + ret = fn(id, rcu_dereference_raw(*slot), data); if (ret) return ret; } @@ -230,8 +231,8 @@ void *idr_get_next(struct idr *idr, int *nextid) { struct radix_tree_iter iter; void __rcu **slot; - int base = idr->idr_base; - int id = *nextid; + unsigned long base = idr->idr_base; + unsigned long id = *nextid; id = (id < base) ? 0 : id - base; slot = radix_tree_iter_find(&idr->idr_rt, &iter, id); |