#7 modem_run reports error only by first run

[Lukasz Mach]

If there is some error, for example bad path to
firmware, modem_run reports error to syslog only once.

reproduce:
1. launch linux (be sure that modem_run isn't called in
boot time)
2. run
modem_run -v 1 -f /some/fake/path

modem run will report that /some/fake/path doesn't
exists in /var/log/syslog

3. now, every launch of modem_run will only do such
line in syslog

Aug 20 10:23:22 tereska modem_run[3687]: modem_run
version 1.3 started by root uid 0

and nothing more, no matter if is proper path or not.

I have PLD with glibc 2.3.4 snapshot 20040707, kernel
2.6.7, ppp 2.4.2
speedtouch 1.3. I tried yesterdays cvs snapshot, but
the same result.

[RichB]

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user_id=1114158

This problem seems to be due to the semaphore stuff used to
prevent more than one simultaneous instance of modem_run. If
an instance ends prematurely it leaves the semaphore behind
so that any subsequent instance thinks that there's already
a copy running.

I would try and fix it myself, but I don't know enough about
Linux semaphores...

[RichB]

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user_id=1114158

Put the following program in the 'src' directory and compile
it - I called it "deshag.c".

try: gcc -o deshag deshag.c

Run it as root with no command line:
./deshag
and it will tell you if the semaphore exists

Run it again with -d to delete it:
./deshag -d

This should remove the rogue semaphore so that you can try
running modem_run again without rebooting.

#include "mutex.h"
union semun {
int val; /* value for SETVAL */
struct semid_ds *buf; /* buffer for IPC_STAT,
IPC_SET */
unsigned short int *array; /* array for GETALL, SETALL */
struct seminfo *__buf; /* buffer for IPC_INFO */
};

int main(int argc, char *argv[]) {
int semid;
union semun un;

semid=semget\(0xdeadbeef, 2, 0666\);
if \(semid < 0\) \{
    printf\("No modem\_run semaphore found\n"\);
\} else \{
    if\(argc>1 && \!strcmp\(argv\[1\], "-d"\)\) \{
    printf\("Here goes: %d\n", semctl\(semid, 0, IPC\_RMID, un\)\);
    \} else \{
    printf\("Semaphore seems to exist. Rerun with '-d' to fix.\n"\);
    \}
\}
return 0;

}

[Lukasz Mach]

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user_id=617333

smart solution. I'll try it.

I think better will be if modem_run clean it's semaphores
when retrning with error.

anyway do you mind if I add this package to speedtouch rpm
in PLD Linux Distribution?. if yes, what license, GPL?

[RichB]

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user_id=1114158

If you're referring to my code snippet, I have no objection
to you adding it to anything. I hereby renounce any
copyright in the code. Do with it as you will under whatever
licence terms suit you.

[Paweł Gl]

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user_id=1121185

the problem is that modem_run allocates system-wide
semaphore and when it crashes it does not free this
resource. I had same problem and I solved this adding option
to force reload of firmware. Diff for modem_run.c from
release 1.3 and my changed file is:
$diff -b modem_run.c modem_run.c.new
150a151
> int reload = 0;
202a204,205
> } else if (strcmp(argv[i], "-g") == 0) {
> reload = 1;
277a281,283
> if (reload)
> do_exit = 0; // force reload of microcode
> else

option to force reload as you see is: -g it is very usefull
for testing purpose.

Or as root:
#ipcs
look for semaphore with key: 0xdeadbeef
and remove it with:
ipcrm -s id_of_semaphore

then restart modem_run.

[Lukasz Mach]

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user_id=617333

great.

could you sent this patch as unified diff?

have you sent this patch to developers?

[Paweł Gl]

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user_id=1121185

As you wish:

--- modem_run.c 2004-06-10 18:36:35.000000000 +0200
+++ modem_run.c.new 2004-09-14 01:32:05.000000000 +0200
@@ -148,6 +148,7 @@
char *devicename = NULL;
const char *user;
int timeout = 120; /* Wait for 120s before giving up */
+ int reload = 0;
int polling_interval = 10; /* Polling device state
interval in seconds */
int upload_tries = 10;
stusb_firmware_t *firmware = NULL;
@@ -200,6 +201,8 @@
revision = atoi(argv[++i]);
} else if (strcmp(argv[i], "-s") == 0) {
dl_512_first = 0;
+ } else if (strcmp(argv[i], "-g") == 0) {
+ reload = 1;
} else if (strcmp(argv[i], "-t") == 0 &&
i+1<argc) {
timeout = atoi(argv[++i]);
} else if (strcmp(argv[i], "-v") == 0 &&
i+1<argc) {
@@ -275,6 +278,9 @@
break;

case S_LINE_OK:
+ if (reload)
+ do_exit = 0; /* force reload of microcode */
+ else
do_exit = 1;
do_exit_code = 0;
break;

I'm quite new on sourceforge so I leave developers for you. :-)