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| author | Simo Sorce <simo@redhat.com> | 2012-12-05 16:40:32 -0500 |
|---|---|---|
| committer | Jakub Hrozek <jhrozek@redhat.com> | 2012-12-05 23:24:50 +0100 |
| commit | ddd46c1308d3acfded4b48b620b1b59ee0271b13 (patch) | |
| tree | 32cea684eec8ec22c1bea7c42b6c1f8e5f3ccace | |
| parent | b9d9832829aae62aed1a4f76abf2f88d25133dca (diff) | |
| download | sssd-ddd46c1308d3acfded4b48b620b1b59ee0271b13.tar.gz sssd-ddd46c1308d3acfded4b48b620b1b59ee0271b13.tar.xz sssd-ddd46c1308d3acfded4b48b620b1b59ee0271b13.zip | |
Add memory barrier to mmap cache client code loop
Fixes https://fedorahosted.org/sssd/ticket/1694
| -rw-r--r-- | src/sss_client/nss_mc_common.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/sss_client/nss_mc_common.c b/src/sss_client/nss_mc_common.c index 39a00f86f..a361f57b9 100644 --- a/src/sss_client/nss_mc_common.c +++ b/src/sss_client/nss_mc_common.c @@ -46,6 +46,9 @@ errno_t sss_nss_check_header(struct sss_cli_mc_ctx *ctx) /* retry barrier protected reading max 5 times then give up */ for (count = 5; count > 0; count--) { memcpy(&h, ctx->mmap_base, sizeof(struct sss_mc_header)); + /* we need a barrier here to make sure the compiler does not optimize + * too much and avoids updating the register for the next check */ + __sync_synchronize(); if (MC_VALID_BARRIER(h.b1) && h.b1 == h.b2) { /* record is consistent so we can proceed */ break; |