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| author | Andreas Schwab <schwab@redhat.com> | 2009-10-29 11:25:20 -0700 |
|---|---|---|
| committer | Ulrich Drepper <drepper@redhat.com> | 2009-10-29 11:25:20 -0700 |
| commit | 22bc5239e1c7d97b0642af6c135af994586f8e82 (patch) | |
| tree | 5a239a09214ad5b6a058e49f7a8c87f3136ad66a /malloc/memusage.c | |
| parent | d94760f944cebf05b239dd0b65c3b40a5577013b (diff) | |
| download | glibc-22bc5239e1c7d97b0642af6c135af994586f8e82.zip glibc-22bc5239e1c7d97b0642af6c135af994586f8e82.tar.gz glibc-22bc5239e1c7d97b0642af6c135af994586f8e82.tar.bz2 | |
Fix wrap-around in memusage.
Diffstat (limited to 'malloc/memusage.c')
| -rw-r--r-- | malloc/memusage.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/malloc/memusage.c b/malloc/memusage.c index fcd58dc..382261c 100644 --- a/malloc/memusage.c +++ b/malloc/memusage.c @@ -163,15 +163,16 @@ update_data (struct header *result, size_t len, size_t old_len) if (fd != -1) { uatomic32_t idx = catomic_exchange_and_add (&buffer_cnt, 1); - if (idx >= 2 * buffer_size) + if (idx + 1 >= 2 * buffer_size) { /* We try to reset the counter to the correct range. If this fails because of another thread increasing the counter it does not matter since that thread will take care of the correction. */ - uatomic32_t reset = idx % (2 * buffer_size); - catomic_compare_and_exchange_val_acq (&buffer_cnt, reset, idx); - idx = reset; + uatomic32_t reset = (idx + 1) % (2 * buffer_size); + catomic_compare_and_exchange_val_acq (&buffer_cnt, reset, idx + 1); + if (idx >= 2 * buffer_size) + idx = reset - 1; } assert (idx < 2 * DEFAULT_BUFFER_SIZE); |