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[Qemu-devel] [PATCH] oslib-posix: Fix new compiler error with -Wclobbere
From: |
Stefan Weil |
Subject: |
[Qemu-devel] [PATCH] oslib-posix: Fix new compiler error with -Wclobbered |
Date: |
Tue, 24 Jun 2014 22:52:29 +0200 |
Newer versions of gcc report a warning (or an error with -Werror) when
compiler option -Wclobbered (or -Wextra) is active:
util/oslib-posix.c:372:12: error:
variable ‘hpagesize’ might be clobbered by ‘longjmp’ or ‘vfork’
[-Werror=clobbered]
The rewritten code fixes this warning: variable 'hpagesize' is now set and
used in a block without any call of sigsetjmp or similar functions.
Signed-off-by: Stefan Weil <address@hidden>
---
util/oslib-posix.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 1524ead..cdbfb2e 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -366,10 +366,9 @@ static size_t fd_getpagesize(int fd)
void os_mem_prealloc(int fd, char *area, size_t memory)
{
- int ret, i;
+ int ret;
struct sigaction act, oldact;
sigset_t set, oldset;
- size_t hpagesize = fd_getpagesize(fd);
memset(&act, 0, sizeof(act));
act.sa_handler = &sigbus_handler;
@@ -389,19 +388,22 @@ void os_mem_prealloc(int fd, char *area, size_t memory)
if (sigsetjmp(sigjump, 1)) {
fprintf(stderr, "os_mem_prealloc: failed to preallocate pages\n");
exit(1);
- }
+ } else {
+ int i;
+ size_t hpagesize = fd_getpagesize(fd);
- /* MAP_POPULATE silently ignores failures */
- memory = (memory + hpagesize - 1) & -hpagesize;
- for (i = 0; i < (memory/hpagesize); i++) {
- memset(area + (hpagesize*i), 0, 1);
- }
+ /* MAP_POPULATE silently ignores failures */
+ memory = (memory + hpagesize - 1) & -hpagesize;
+ for (i = 0; i < (memory / hpagesize); i++) {
+ memset(area + (hpagesize * i), 0, 1);
+ }
- ret = sigaction(SIGBUS, &oldact, NULL);
- if (ret) {
- perror("os_mem_prealloc: failed to reinstall signal handler");
- exit(1);
- }
+ ret = sigaction(SIGBUS, &oldact, NULL);
+ if (ret) {
+ perror("os_mem_prealloc: failed to reinstall signal handler");
+ exit(1);
+ }
- pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+ pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+ }
}
--
1.7.10.4
- [Qemu-devel] [PATCH] oslib-posix: Fix new compiler error with -Wclobbered,
Stefan Weil <=