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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 | |
| parent | d94760f944cebf05b239dd0b65c3b40a5577013b (diff) | |
| download | glibc-22bc5239e1c7d97b0642af6c135af994586f8e82.tar.gz glibc-22bc5239e1c7d97b0642af6c135af994586f8e82.tar.xz glibc-22bc5239e1c7d97b0642af6c135af994586f8e82.zip | |
Fix wrap-around in memusage.
| -rw-r--r-- | ChangeLog | 5 | ||||
| -rw-r--r-- | malloc/memusage.c | 9 |
2 files changed, 10 insertions, 4 deletions
diff --git a/ChangeLog b/ChangeLog index 25bb3255df..99088df6ad 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2009-10-29 Andreas Schwab <schwab@redhat.com> + + * malloc/memusage.c (update_data): Fix index wraparound handling + so that buffer_cnt is actually reset. + 2009-10-29 Ulrich Drepper <drepper@redhat.com> [BZ #10784] diff --git a/malloc/memusage.c b/malloc/memusage.c index fcd58dc684..382261c1c4 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); |