From: Sitsofe Wheeler <sitsofe@yahoo.com>
Date: Sat, 20 May 2017 17:41:35 +0000 (+0100)
Subject: fio: fix some struct alignment issues
X-Git-Tag: fio-2.21~47
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=dbf285f75b4a447390a94a45b4c6091ac0c9f604;ds=sidebyside

fio: fix some struct alignment issues

Fix unaligned/misaligned accesses related to struct thread_stat and
struct jobs_eta seen when running a build produced by
CC=~/clang-3.9/build/bin/clang ./configure --disable-optimizations \
   --extra-cflags="-D__compiler_offsetof=__builtin_offsetof \
   -fsanitize=undefined"

and add to the compile time asserts to make these problems more visible.

Signed-off-by: Sitsofe Wheeler <sitsofe@yahoo.com>
---

diff --git a/fio.h b/fio.h
index e11a0390..ed631bc7 100644
--- a/fio.h
+++ b/fio.h
@@ -149,7 +149,7 @@ struct thread_data {
 	unsigned int thread_number;
 	unsigned int subjob_number;
 	unsigned int groupid;
-	struct thread_stat ts;
+	struct thread_stat ts __attribute__ ((aligned));
 
 	int client_type;
 
diff --git a/libfio.c b/libfio.c
index 83107084..da22456e 100644
--- a/libfio.c
+++ b/libfio.c
@@ -353,14 +353,17 @@ int initialize_fio(char *envp[])
 	 * can run into problems on archs that fault on unaligned fp
 	 * access (ARM).
 	 */
+	compiletime_assert((offsetof(struct thread_data, ts) % sizeof(void *)) == 0, "ts");
 	compiletime_assert((offsetof(struct thread_stat, percentile_list) % 8) == 0, "stat percentile_list");
 	compiletime_assert((offsetof(struct thread_stat, total_run_time) % 8) == 0, "total_run_time");
 	compiletime_assert((offsetof(struct thread_stat, total_err_count) % 8) == 0, "total_err_count");
 	compiletime_assert((offsetof(struct thread_stat, latency_percentile) % 8) == 0, "stat latency_percentile");
+	compiletime_assert((offsetof(struct thread_data, ts.clat_stat) % 8) == 0, "ts.clat_stat");
 	compiletime_assert((offsetof(struct thread_options_pack, zipf_theta) % 8) == 0, "zipf_theta");
 	compiletime_assert((offsetof(struct thread_options_pack, pareto_h) % 8) == 0, "pareto_h");
 	compiletime_assert((offsetof(struct thread_options_pack, percentile_list) % 8) == 0, "percentile_list");
 	compiletime_assert((offsetof(struct thread_options_pack, latency_percentile) % 8) == 0, "latency_percentile");
+	compiletime_assert((offsetof(struct jobs_eta, m_rate) % 8) == 0, "m_rate");
 
 	err = endian_check();
 	if (err) {
diff --git a/stat.h b/stat.h
index aa4ad806..d8a08034 100644
--- a/stat.h
+++ b/stat.h
@@ -242,17 +242,17 @@ struct jobs_eta {
 	uint32_t nr_pending;
 	uint32_t nr_setting_up;
 
-	uint32_t files_open;
-
 	uint64_t m_rate[DDIR_RWDIR_CNT], t_rate[DDIR_RWDIR_CNT];
-	uint32_t m_iops[DDIR_RWDIR_CNT], t_iops[DDIR_RWDIR_CNT];
 	uint64_t rate[DDIR_RWDIR_CNT];
+	uint32_t m_iops[DDIR_RWDIR_CNT], t_iops[DDIR_RWDIR_CNT];
 	uint32_t iops[DDIR_RWDIR_CNT];
 	uint64_t elapsed_sec;
 	uint64_t eta_sec;
 	uint32_t is_pow2;
 	uint32_t unit_base;
 
+	uint32_t files_open;
+
 	/*
 	 * Network 'copy' of run_str[]
 	 */