On Wed, Sep 14, 2011 at 10:21:53AM -0300, Davidlohr Bueso wrote:
> On Tue, 2011-09-13 at 23:13 +0200, Sami Kerola wrote:
> Please try the following patch, it fixed it for me. In the case when the
> errors were shown, the msgctl(2) was returning 0 (success), so errno
> shouldn't be checked. Remember, this isn't reseted afterwards, so we are
> running into bogus messages (the msgid's are being correctly deleted).
>
> Thanks,
> Davidlohr
>
> From 952d6100c28505005c0a335e3e64f384bd941859 Mon Sep 17 00:00:00 2001
> From: Davidlohr Bueso <dave@xxxxxxx>
> Date: Wed, 14 Sep 2011 10:17:15 -0300
> Subject: [PATCH] ipcrm: check IPC syscalls
>
> It's not enough to check errno for errors as the variable is not reset, we also need to check the last syscall return value to verify a problem.
> This addresses bogus msgqueue errors when deleting keys.
>
> Signed-off-by: Davidlohr Bueso <dave@xxxxxxx>
> ---
> sys-utils/ipcrm.c | 9 +++++----
> 1 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/sys-utils/ipcrm.c b/sys-utils/ipcrm.c
> index a8d6623..c794cbe 100644
> --- a/sys-utils/ipcrm.c
> +++ b/sys-utils/ipcrm.c
> @@ -65,6 +65,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
>
> int remove_id(int type, int iskey, int id)
> {
> + int ret;
> char *errmsg;
> /* needed to delete semaphores */
> union semun arg;
> @@ -75,24 +76,24 @@ int remove_id(int type, int iskey, int id)
> case SHM:
> if (verbose)
> printf(_("removing shared memory segment id `%d'\n"), id);
> - shmctl(id, IPC_RMID, NULL);
> + ret = shmctl(id, IPC_RMID, NULL);
> break;
> case MSG:
> if (verbose)
> printf(_("removing message queue id `%d'\n"), id);
> - msgctl(id, IPC_RMID, NULL);
> + ret = msgctl(id, IPC_RMID, NULL);
> break;
> case SEM:
> if (verbose)
> printf(_("removing semaphore id `%d'\n"), id);
> - semctl(id, 0, IPC_RMID, arg);
> + ret = semctl(id, 0, IPC_RMID, arg);
> break;
> default:
> errx(EXIT_FAILURE, "impossible occurred");
> }
>
> /* how did the removal go? */
> - switch (errno) {
> + switch (errno && ret) {
so true/false only ... why we need the "case EACCES" (etc.)?
> case 0:
> return 0;
> case EACCES:
why we cannot use:
if (ret < 0)
switch(errno) {
case EACCES:
...
break;
....
}
Karel
--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
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