gcc warning:
/qemu/util/oslib-posix.c:304:11: error:
variable ‘addr’ might be clobbered by ‘longjmp’ or ‘vfork’
[-Werror=clobbered]
Fix also some related data types:
numpages, hpagesize are used as pointer offset.
Always use size_t for them and for the derived numpages_per_thread.
Avoid a type cast by declaring addr volatile.
Signed-off-by: Stefan Weil <s...@weilnetz.de>
---
v2: Fix more data types (partially as discussed with Richard)
Please note that checkpatch.pl raises an error:
ERROR: Use of volatile is usually wrong: see
Documentation/volatile-considered-harmful.txt
This error is wrong in the current context.
It also refers to a file which exists in the Linux sources
but not in the QEMU source.
Regards
Stefan
util/oslib-posix.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 80086c549f..beef148c96 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -59,8 +59,8 @@
struct MemsetThread {
char *addr;
- uint64_t numpages;
- uint64_t hpagesize;
+ size_t numpages;
+ size_t hpagesize;
QemuThread pgthread;
sigjmp_buf env;
};
@@ -301,11 +301,7 @@ static void sigbus_handler(int signal)
static void *do_touch_pages(void *arg)
{
MemsetThread *memset_args = (MemsetThread *)arg;
- char *addr = memset_args->addr;
- uint64_t numpages = memset_args->numpages;
- uint64_t hpagesize = memset_args->hpagesize;
sigset_t set, oldset;
- int i = 0;
/* unblock SIGBUS */
sigemptyset(&set);
@@ -315,6 +311,10 @@ static void *do_touch_pages(void *arg)
if (sigsetjmp(memset_args->env, 1)) {
memset_thread_failed = true;
} else {
+ volatile char *addr = memset_args->addr;
+ size_t numpages = memset_args->numpages;
+ size_t hpagesize = memset_args->hpagesize;
+ size_t i;
for (i = 0; i < numpages; i++) {
/*
* Read & write back the same value, so we don't
@@ -328,7 +328,7 @@ static void *do_touch_pages(void *arg)
* don't need to write at all so we don't cause
* wear on the storage backing the region...
*/
- *(volatile char *)addr = *addr;
+ *addr = *addr;
addr += hpagesize;
}
}
@@ -351,7 +351,8 @@ static inline int get_memset_num_threads(int smp_cpus)
static bool touch_all_pages(char *area, size_t hpagesize, size_t numpages,
int smp_cpus)
{
- uint64_t numpages_per_thread, size_per_thread;
+ size_t numpages_per_thread;
+ size_t size_per_thread;
char *addr = area;
int i = 0;
--
2.11.0
