Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
2014-05-17 8:09 GMT+09:00, Greg KH gre...@linuxfoundation.org: On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: - alloc_tty_driver() is deprecated so it is changed to tty_alloc_driver() - Pointers which are allocated by alloc_tty_driver() and kzalloc() can be NULL so it need to check NULL for them. - If one of those is failed, it need to add proper handler for avoiding memory leak. Signed-off-by: Daeseok Youn daeseok.y...@gmail.com --- drivers/staging/dgap/dgap.c | 49 +++ 1 files changed, 40 insertions(+), 9 deletions(-) This doesn't apply at all to my tree anymore, please refresh it and resend. Yes. It need to rebase on staging-next branch. I will rebase and resend this. Thanks Daeseok Youn. thanks, greg k-h ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
Hi, This patch haven't been updated over the past 3 weeks. Will you check for me? Regards, Daeseok Youn. 2014-04-28 8:21 GMT+09:00 DaeSeok Youn daeseok.y...@gmail.com: OK. I'll make my patch based on Mark's patch. Thanks. Daeseok Youn. 2014-04-27 3:48 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: On Sat, Apr 26, 2014 at 11:39:38AM +0900, DaeSeok Youn wrote: Hi, please check below my comments. 2014-04-25 23:41 GMT+09:00 Mark Hounschell ma...@compro.net: On 04/25/2014 08:59 AM, Dan Carpenter wrote: On Fri, Apr 25, 2014 at 08:29:41AM -0400, Mark Hounschell wrote: On 04/25/2014 07:02 AM, DaeSeok Youn wrote: Hi, Dan. 2014-04-25 18:26 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: Mark, maybe you should add yourself to the MAINTAINERS entry for this driver? I'll look into this. I am clueless on what that would actually mean. Just add your name with Lidza in the MAINTAINERS file so that people will CC you on all the patches. DIGI EPCA PCI PRODUCTS M: Lidza Louina lidza.lou...@gmail.com L: driverdev-devel@linuxdriverproject.org S: Maintained F: drivers/staging/dgap/ You don't have to do it if you don't want to, but you seem to be working on this driver and I'm going to refer questions to you either way. :P On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: @@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd) /* Register tty devices */ rc = tty_register_driver(brd-SerialDriver); if (rc 0) - return rc; + goto free_print_ttys; + brd-dgap_Major_Serial_Registered = TRUE; dgap_BoardsByMajor[brd-SerialDriver-major] = brd; brd-dgap_Serial_Major = brd-SerialDriver-major; @@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd) /* Register Transparent Print devices */ rc = tty_register_driver(brd-PrintDriver); if (rc 0) - return rc; + goto unregister_serial_drv; + brd-dgap_Major_TransparentPrint_Registered = TRUE; dgap_BoardsByMajor[brd-PrintDriver-major] = brd; brd-dgap_TransparentPrint_Major = brd-PrintDriver-major; } return rc; + +unregister_serial_drv: + tty_unregister_driver(brd-SerialDriver); We only register the -SerialDriver if someone else hasn't registered it first? So this should be: if (we_were_the_ones_who_registered_the_serial_driver) tty_unregister_driver(brd-SerialDriver); I haven't followed looked at this. Who else is registering the serial driver? You have looked at this, what do you think? Or Mark. registering the brd-XDriver is only done when a board is detected and only during the firmware_load process. If we fail to tty_register_driver do we _need_ to tty_unregister_driver? Isn't that like freeing after an alloc failure? The allocation is conditional so the free should be conditional. If we didn't allocate it, then we shouldn't free it. It wouldn't have even been a question except I'm not sure the allocation is *really* conditional because brd-dgap_Major_Serial_Registered might always be false like you guys seem to be saying. I think brd struct is from dgap_Board array as global static variable when this function is called. So brd-dgap_Major_Serial_Registered is always false. If dgap_NumBoards is less than MAXBOARDS, brd-SerialDriver should be registered. I'm not sure.. I don't see any check for (dgap_NumBoards MAXBOARDS), which I think I probably should, but I do see we are calling dgap_tty_register, which can fail, without actually checking the return value. Also, yes, dgap_Major_Xxxx_Registered seems to be always false until registered, and it looks like dgap_Major_X_Registered flags could be removed because the only places we can unregister is at module_cleanup or after it is already registered. What is the driver _supposed_ to do if we fail something on the second or later board? Is the driver supposed to cleanup and exit or are we supposed to stay loaded for the board/boards that are usable? Stay loaded. Then these tests on brd-dgap_Major_Serial_Registered need to stay in there. If I have 3 boards and the second fails in some way, if I rmmod the driver they will protect from unregistering a never registered one. At least in the unregister code path. There is probably no need for them in the register code path. I'll work up a patch for this. Should I update my patch? I think if (!brd-dgap_Major_XXX_Registered) line can be removed in this function, because if tty_register_driver() is failed just set false to dgap_Major_XXX_Registered. Mark sent a patch to remove the check. Could
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
On Fri, May 16, 2014 at 06:40:28PM +0900, DaeSeok Youn wrote: Hi, This patch haven't been updated over the past 3 weeks. Will you check for me? Greg was trying to travel around the world in one month like Jackie Chan. http://www.imdb.com/title/tt0327437/ He is back to work since yesterday. regards, dan carpenter ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
2014-05-16 18:52 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: On Fri, May 16, 2014 at 06:40:28PM +0900, DaeSeok Youn wrote: Hi, This patch haven't been updated over the past 3 weeks. Will you check for me? Greg was trying to travel around the world in one month like Jackie Chan. http://www.imdb.com/title/tt0327437/ He is back to work since yesterday. Oh, good notice :-), but I'm not asking why my patch is not pushed. I knew this patch should be re-based on Mark's patch. You said that I waited his patch and it need to redo based on his. And I checked staging-next branch and linux-next branch but I didn't found his patch. He did already send that patch, let me know. Thanks. Daeseok Youn. regards, dan carpenter ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
On Fri, May 16, 2014 at 12:52:47PM +0300, Dan Carpenter wrote: On Fri, May 16, 2014 at 06:40:28PM +0900, DaeSeok Youn wrote: Hi, This patch haven't been updated over the past 3 weeks. Will you check for me? Greg was trying to travel around the world in one month like Jackie Chan. http://www.imdb.com/title/tt0327437/ He is back to work since yesterday. Well, I'm home for a day or so before I leave again for a week, so I'm having to prioritize things (patches or laundry) and dealing with a pet vet emergency, so my ability to get to cleanup patches is way down the list... greg k-h ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: - alloc_tty_driver() is deprecated so it is changed to tty_alloc_driver() - Pointers which are allocated by alloc_tty_driver() and kzalloc() can be NULL so it need to check NULL for them. - If one of those is failed, it need to add proper handler for avoiding memory leak. Signed-off-by: Daeseok Youn daeseok.y...@gmail.com --- drivers/staging/dgap/dgap.c | 49 +++ 1 files changed, 40 insertions(+), 9 deletions(-) This doesn't apply at all to my tree anymore, please refresh it and resend. thanks, greg k-h ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
OK. I'll make my patch based on Mark's patch. Thanks. Daeseok Youn. 2014-04-27 3:48 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: On Sat, Apr 26, 2014 at 11:39:38AM +0900, DaeSeok Youn wrote: Hi, please check below my comments. 2014-04-25 23:41 GMT+09:00 Mark Hounschell ma...@compro.net: On 04/25/2014 08:59 AM, Dan Carpenter wrote: On Fri, Apr 25, 2014 at 08:29:41AM -0400, Mark Hounschell wrote: On 04/25/2014 07:02 AM, DaeSeok Youn wrote: Hi, Dan. 2014-04-25 18:26 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: Mark, maybe you should add yourself to the MAINTAINERS entry for this driver? I'll look into this. I am clueless on what that would actually mean. Just add your name with Lidza in the MAINTAINERS file so that people will CC you on all the patches. DIGI EPCA PCI PRODUCTS M: Lidza Louina lidza.lou...@gmail.com L: driverdev-devel@linuxdriverproject.org S: Maintained F: drivers/staging/dgap/ You don't have to do it if you don't want to, but you seem to be working on this driver and I'm going to refer questions to you either way. :P On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: @@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd) /* Register tty devices */ rc = tty_register_driver(brd-SerialDriver); if (rc 0) - return rc; + goto free_print_ttys; + brd-dgap_Major_Serial_Registered = TRUE; dgap_BoardsByMajor[brd-SerialDriver-major] = brd; brd-dgap_Serial_Major = brd-SerialDriver-major; @@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd) /* Register Transparent Print devices */ rc = tty_register_driver(brd-PrintDriver); if (rc 0) - return rc; + goto unregister_serial_drv; + brd-dgap_Major_TransparentPrint_Registered = TRUE; dgap_BoardsByMajor[brd-PrintDriver-major] = brd; brd-dgap_TransparentPrint_Major = brd-PrintDriver-major; } return rc; + +unregister_serial_drv: + tty_unregister_driver(brd-SerialDriver); We only register the -SerialDriver if someone else hasn't registered it first? So this should be: if (we_were_the_ones_who_registered_the_serial_driver) tty_unregister_driver(brd-SerialDriver); I haven't followed looked at this. Who else is registering the serial driver? You have looked at this, what do you think? Or Mark. registering the brd-XDriver is only done when a board is detected and only during the firmware_load process. If we fail to tty_register_driver do we _need_ to tty_unregister_driver? Isn't that like freeing after an alloc failure? The allocation is conditional so the free should be conditional. If we didn't allocate it, then we shouldn't free it. It wouldn't have even been a question except I'm not sure the allocation is *really* conditional because brd-dgap_Major_Serial_Registered might always be false like you guys seem to be saying. I think brd struct is from dgap_Board array as global static variable when this function is called. So brd-dgap_Major_Serial_Registered is always false. If dgap_NumBoards is less than MAXBOARDS, brd-SerialDriver should be registered. I'm not sure.. I don't see any check for (dgap_NumBoards MAXBOARDS), which I think I probably should, but I do see we are calling dgap_tty_register, which can fail, without actually checking the return value. Also, yes, dgap_Major_Xxxx_Registered seems to be always false until registered, and it looks like dgap_Major_X_Registered flags could be removed because the only places we can unregister is at module_cleanup or after it is already registered. What is the driver _supposed_ to do if we fail something on the second or later board? Is the driver supposed to cleanup and exit or are we supposed to stay loaded for the board/boards that are usable? Stay loaded. Then these tests on brd-dgap_Major_Serial_Registered need to stay in there. If I have 3 boards and the second fails in some way, if I rmmod the driver they will protect from unregistering a never registered one. At least in the unregister code path. There is probably no need for them in the register code path. I'll work up a patch for this. Should I update my patch? I think if (!brd-dgap_Major_XXX_Registered) line can be removed in this function, because if tty_register_driver() is failed just set false to dgap_Major_XXX_Registered. Mark sent a patch to remove the check. Could you redo your patch based on his? regards, dan carpenter ___ devel mailing list de...@linuxdriverproject.org
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
On Sat, Apr 26, 2014 at 11:39:38AM +0900, DaeSeok Youn wrote: Hi, please check below my comments. 2014-04-25 23:41 GMT+09:00 Mark Hounschell ma...@compro.net: On 04/25/2014 08:59 AM, Dan Carpenter wrote: On Fri, Apr 25, 2014 at 08:29:41AM -0400, Mark Hounschell wrote: On 04/25/2014 07:02 AM, DaeSeok Youn wrote: Hi, Dan. 2014-04-25 18:26 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: Mark, maybe you should add yourself to the MAINTAINERS entry for this driver? I'll look into this. I am clueless on what that would actually mean. Just add your name with Lidza in the MAINTAINERS file so that people will CC you on all the patches. DIGI EPCA PCI PRODUCTS M: Lidza Louina lidza.lou...@gmail.com L: driverdev-devel@linuxdriverproject.org S: Maintained F: drivers/staging/dgap/ You don't have to do it if you don't want to, but you seem to be working on this driver and I'm going to refer questions to you either way. :P On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: @@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd) /* Register tty devices */ rc = tty_register_driver(brd-SerialDriver); if (rc 0) - return rc; + goto free_print_ttys; + brd-dgap_Major_Serial_Registered = TRUE; dgap_BoardsByMajor[brd-SerialDriver-major] = brd; brd-dgap_Serial_Major = brd-SerialDriver-major; @@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd) /* Register Transparent Print devices */ rc = tty_register_driver(brd-PrintDriver); if (rc 0) - return rc; + goto unregister_serial_drv; + brd-dgap_Major_TransparentPrint_Registered = TRUE; dgap_BoardsByMajor[brd-PrintDriver-major] = brd; brd-dgap_TransparentPrint_Major = brd-PrintDriver-major; } return rc; + +unregister_serial_drv: + tty_unregister_driver(brd-SerialDriver); We only register the -SerialDriver if someone else hasn't registered it first? So this should be: if (we_were_the_ones_who_registered_the_serial_driver) tty_unregister_driver(brd-SerialDriver); I haven't followed looked at this. Who else is registering the serial driver? You have looked at this, what do you think? Or Mark. registering the brd-XDriver is only done when a board is detected and only during the firmware_load process. If we fail to tty_register_driver do we _need_ to tty_unregister_driver? Isn't that like freeing after an alloc failure? The allocation is conditional so the free should be conditional. If we didn't allocate it, then we shouldn't free it. It wouldn't have even been a question except I'm not sure the allocation is *really* conditional because brd-dgap_Major_Serial_Registered might always be false like you guys seem to be saying. I think brd struct is from dgap_Board array as global static variable when this function is called. So brd-dgap_Major_Serial_Registered is always false. If dgap_NumBoards is less than MAXBOARDS, brd-SerialDriver should be registered. I'm not sure.. I don't see any check for (dgap_NumBoards MAXBOARDS), which I think I probably should, but I do see we are calling dgap_tty_register, which can fail, without actually checking the return value. Also, yes, dgap_Major_Xxxx_Registered seems to be always false until registered, and it looks like dgap_Major_X_Registered flags could be removed because the only places we can unregister is at module_cleanup or after it is already registered. What is the driver _supposed_ to do if we fail something on the second or later board? Is the driver supposed to cleanup and exit or are we supposed to stay loaded for the board/boards that are usable? Stay loaded. Then these tests on brd-dgap_Major_Serial_Registered need to stay in there. If I have 3 boards and the second fails in some way, if I rmmod the driver they will protect from unregistering a never registered one. At least in the unregister code path. There is probably no need for them in the register code path. I'll work up a patch for this. Should I update my patch? I think if (!brd-dgap_Major_XXX_Registered) line can be removed in this function, because if tty_register_driver() is failed just set false to dgap_Major_XXX_Registered. Mark sent a patch to remove the check. Could you redo your patch based on his? regards, dan carpenter ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
[PATCH] staging: dgap: implement error handling in dgap_tty_register()
- alloc_tty_driver() is deprecated so it is changed to
tty_alloc_driver()
- Pointers which are allocated by alloc_tty_driver() and kzalloc()
can be NULL so it need to check NULL for them.
- If one of those is failed, it need to add proper handler for
avoiding memory leak.
Signed-off-by: Daeseok Youn daeseok.y...@gmail.com
---
drivers/staging/dgap/dgap.c | 49 +++
1 files changed, 40 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/dgap/dgap.c b/drivers/staging/dgap/dgap.c
index 3c9278a..5c8823a 100644
--- a/drivers/staging/dgap/dgap.c
+++ b/drivers/staging/dgap/dgap.c
@@ -875,7 +875,11 @@ static int dgap_firmware_load(struct pci_dev *pdev, int
card_type)
return -EINVAL;
}
- dgap_tty_register(brd);
+ ret = dgap_tty_register(brd);
+ if (ret) {
+ pr_err(dgap: failed to register tty driver\n);
+ return ret;
+ }
dgap_finalize_board_init(brd);
if (fw_info[card_type].bios_name) {
@@ -1200,7 +1204,9 @@ static int dgap_tty_register(struct board_t *brd)
{
int rc = 0;
- brd-SerialDriver = alloc_tty_driver(MAXPORTS);
+ brd-SerialDriver = tty_alloc_driver(MAXPORTS, 0);
+ if (IS_ERR(brd-SerialDriver))
+ return PTR_ERR(brd-SerialDriver);
snprintf(brd-SerialName, MAXTTYNAMELEN, tty_dgap_%d_, brd-boardnum);
brd-SerialDriver-name = brd-SerialName;
@@ -1218,8 +1224,10 @@ static int dgap_tty_register(struct board_t *brd)
/* The kernel wants space to store pointers to tty_structs */
brd-SerialDriver-ttys =
kzalloc(MAXPORTS * sizeof(struct tty_struct *), GFP_KERNEL);
- if (!brd-SerialDriver-ttys)
- return -ENOMEM;
+ if (!brd-SerialDriver-ttys) {
+ rc = -ENOMEM;
+ goto free_serial_drv;
+ }
/*
* Entry points for driver. Called by the kernel from
@@ -1232,7 +1240,11 @@ static int dgap_tty_register(struct board_t *brd)
* again, separately so we don't get the LD confused about what major
* we are when we get into the dgap_tty_open() routine.
*/
- brd-PrintDriver = alloc_tty_driver(MAXPORTS);
+ brd-PrintDriver = tty_alloc_driver(MAXPORTS, 0);
+ if (IS_ERR(brd-PrintDriver)) {
+ rc = PTR_ERR(brd-PrintDriver);
+ goto free_serial_ttys;
+ }
snprintf(brd-PrintName, MAXTTYNAMELEN, pr_dgap_%d_, brd-boardnum);
brd-PrintDriver-name = brd-PrintName;
@@ -1250,8 +1262,10 @@ static int dgap_tty_register(struct board_t *brd)
/* The kernel wants space to store pointers to tty_structs */
brd-PrintDriver-ttys =
kzalloc(MAXPORTS * sizeof(struct tty_struct *), GFP_KERNEL);
- if (!brd-PrintDriver-ttys)
- return -ENOMEM;
+ if (!brd-PrintDriver-ttys) {
+ rc = -ENOMEM;
+ goto free_print_drv;
+ }
/*
* Entry points for driver. Called by the kernel from
@@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd)
/* Register tty devices */
rc = tty_register_driver(brd-SerialDriver);
if (rc 0)
- return rc;
+ goto free_print_ttys;
+
brd-dgap_Major_Serial_Registered = TRUE;
dgap_BoardsByMajor[brd-SerialDriver-major] = brd;
brd-dgap_Serial_Major = brd-SerialDriver-major;
@@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd)
/* Register Transparent Print devices */
rc = tty_register_driver(brd-PrintDriver);
if (rc 0)
- return rc;
+ goto unregister_serial_drv;
+
brd-dgap_Major_TransparentPrint_Registered = TRUE;
dgap_BoardsByMajor[brd-PrintDriver-major] = brd;
brd-dgap_TransparentPrint_Major = brd-PrintDriver-major;
}
return rc;
+
+unregister_serial_drv:
+ tty_unregister_driver(brd-SerialDriver);
+free_print_ttys:
+ kfree(brd-PrintDriver-ttys);
+ brd-PrintDriver-ttys = NULL;
+free_print_drv:
+ put_tty_driver(brd-PrintDriver);
+free_serial_ttys:
+ kfree(brd-SerialDriver-ttys);
+ brd-SerialDriver-ttys = NULL;
+free_serial_drv:
+ put_tty_driver(brd-SerialDriver);
+
+ return rc;
}
/*
--
1.7.4.4
___
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Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
On Fri, Apr 25, 2014 at 08:29:41AM -0400, Mark Hounschell wrote: On 04/25/2014 07:02 AM, DaeSeok Youn wrote: Hi, Dan. 2014-04-25 18:26 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: Mark, maybe you should add yourself to the MAINTAINERS entry for this driver? I'll look into this. I am clueless on what that would actually mean. Just add your name with Lidza in the MAINTAINERS file so that people will CC you on all the patches. DIGI EPCA PCI PRODUCTS M: Lidza Louina lidza.lou...@gmail.com L: driverdev-devel@linuxdriverproject.org S: Maintained F: drivers/staging/dgap/ You don't have to do it if you don't want to, but you seem to be working on this driver and I'm going to refer questions to you either way. :P On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: @@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd) /* Register tty devices */ rc = tty_register_driver(brd-SerialDriver); if (rc 0) - return rc; + goto free_print_ttys; + brd-dgap_Major_Serial_Registered = TRUE; dgap_BoardsByMajor[brd-SerialDriver-major] = brd; brd-dgap_Serial_Major = brd-SerialDriver-major; @@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd) /* Register Transparent Print devices */ rc = tty_register_driver(brd-PrintDriver); if (rc 0) - return rc; + goto unregister_serial_drv; + brd-dgap_Major_TransparentPrint_Registered = TRUE; dgap_BoardsByMajor[brd-PrintDriver-major] = brd; brd-dgap_TransparentPrint_Major = brd-PrintDriver-major; } return rc; + +unregister_serial_drv: + tty_unregister_driver(brd-SerialDriver); We only register the -SerialDriver if someone else hasn't registered it first? So this should be: if (we_were_the_ones_who_registered_the_serial_driver) tty_unregister_driver(brd-SerialDriver); I haven't followed looked at this. Who else is registering the serial driver? You have looked at this, what do you think? Or Mark. registering the brd-XDriver is only done when a board is detected and only during the firmware_load process. If we fail to tty_register_driver do we _need_ to tty_unregister_driver? Isn't that like freeing after an alloc failure? The allocation is conditional so the free should be conditional. If we didn't allocate it, then we shouldn't free it. It wouldn't have even been a question except I'm not sure the allocation is *really* conditional because brd-dgap_Major_Serial_Registered might always be false like you guys seem to be saying. I think brd struct is from dgap_Board array as global static variable when this function is called. So brd-dgap_Major_Serial_Registered is always false. If dgap_NumBoards is less than MAXBOARDS, brd-SerialDriver should be registered. I'm not sure.. I don't see any check for (dgap_NumBoards MAXBOARDS), which I think I probably should, but I do see we are calling dgap_tty_register, which can fail, without actually checking the return value. Also, yes, dgap_Major_Xxxx_Registered seems to be always false until registered, and it looks like dgap_Major_X_Registered flags could be removed because the only places we can unregister is at module_cleanup or after it is already registered. What is the driver _supposed_ to do if we fail something on the second or later board? Is the driver supposed to cleanup and exit or are we supposed to stay loaded for the board/boards that are usable? Stay loaded. regards, dan carpenter ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
On 04/25/2014 08:59 AM, Dan Carpenter wrote: On Fri, Apr 25, 2014 at 08:29:41AM -0400, Mark Hounschell wrote: On 04/25/2014 07:02 AM, DaeSeok Youn wrote: Hi, Dan. 2014-04-25 18:26 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: Mark, maybe you should add yourself to the MAINTAINERS entry for this driver? I'll look into this. I am clueless on what that would actually mean. Just add your name with Lidza in the MAINTAINERS file so that people will CC you on all the patches. DIGI EPCA PCI PRODUCTS M: Lidza Louina lidza.lou...@gmail.com L: driverdev-devel@linuxdriverproject.org S: Maintained F: drivers/staging/dgap/ You don't have to do it if you don't want to, but you seem to be working on this driver and I'm going to refer questions to you either way. :P On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: @@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd) /* Register tty devices */ rc = tty_register_driver(brd-SerialDriver); if (rc 0) - return rc; + goto free_print_ttys; + brd-dgap_Major_Serial_Registered = TRUE; dgap_BoardsByMajor[brd-SerialDriver-major] = brd; brd-dgap_Serial_Major = brd-SerialDriver-major; @@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd) /* Register Transparent Print devices */ rc = tty_register_driver(brd-PrintDriver); if (rc 0) - return rc; + goto unregister_serial_drv; + brd-dgap_Major_TransparentPrint_Registered = TRUE; dgap_BoardsByMajor[brd-PrintDriver-major] = brd; brd-dgap_TransparentPrint_Major = brd-PrintDriver-major; } return rc; + +unregister_serial_drv: + tty_unregister_driver(brd-SerialDriver); We only register the -SerialDriver if someone else hasn't registered it first? So this should be: if (we_were_the_ones_who_registered_the_serial_driver) tty_unregister_driver(brd-SerialDriver); I haven't followed looked at this. Who else is registering the serial driver? You have looked at this, what do you think? Or Mark. registering the brd-XDriver is only done when a board is detected and only during the firmware_load process. If we fail to tty_register_driver do we _need_ to tty_unregister_driver? Isn't that like freeing after an alloc failure? The allocation is conditional so the free should be conditional. If we didn't allocate it, then we shouldn't free it. It wouldn't have even been a question except I'm not sure the allocation is *really* conditional because brd-dgap_Major_Serial_Registered might always be false like you guys seem to be saying. I think brd struct is from dgap_Board array as global static variable when this function is called. So brd-dgap_Major_Serial_Registered is always false. If dgap_NumBoards is less than MAXBOARDS, brd-SerialDriver should be registered. I'm not sure.. I don't see any check for (dgap_NumBoards MAXBOARDS), which I think I probably should, but I do see we are calling dgap_tty_register, which can fail, without actually checking the return value. Also, yes, dgap_Major_Xxxx_Registered seems to be always false until registered, and it looks like dgap_Major_X_Registered flags could be removed because the only places we can unregister is at module_cleanup or after it is already registered. What is the driver _supposed_ to do if we fail something on the second or later board? Is the driver supposed to cleanup and exit or are we supposed to stay loaded for the board/boards that are usable? Stay loaded. Then these tests on brd-dgap_Major_Serial_Registered need to stay in there. If I have 3 boards and the second fails in some way, if I rmmod the driver they will protect from unregistering a never registered one. At least in the unregister code path. There is probably no need for them in the register code path. I'll work up a patch for this. I need to look at the (dgap_NumBoards MAXBOARDS) thing too. Mark ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: [PATCH] staging: dgap: implement error handling in dgap_tty_register()
Hi, please check below my comments. 2014-04-25 23:41 GMT+09:00 Mark Hounschell ma...@compro.net: On 04/25/2014 08:59 AM, Dan Carpenter wrote: On Fri, Apr 25, 2014 at 08:29:41AM -0400, Mark Hounschell wrote: On 04/25/2014 07:02 AM, DaeSeok Youn wrote: Hi, Dan. 2014-04-25 18:26 GMT+09:00 Dan Carpenter dan.carpen...@oracle.com: Mark, maybe you should add yourself to the MAINTAINERS entry for this driver? I'll look into this. I am clueless on what that would actually mean. Just add your name with Lidza in the MAINTAINERS file so that people will CC you on all the patches. DIGI EPCA PCI PRODUCTS M: Lidza Louina lidza.lou...@gmail.com L: driverdev-devel@linuxdriverproject.org S: Maintained F: drivers/staging/dgap/ You don't have to do it if you don't want to, but you seem to be working on this driver and I'm going to refer questions to you either way. :P On Fri, Apr 25, 2014 at 04:04:59PM +0900, Daeseok Youn wrote: @@ -1263,7 +1277,8 @@ static int dgap_tty_register(struct board_t *brd) /* Register tty devices */ rc = tty_register_driver(brd-SerialDriver); if (rc 0) - return rc; + goto free_print_ttys; + brd-dgap_Major_Serial_Registered = TRUE; dgap_BoardsByMajor[brd-SerialDriver-major] = brd; brd-dgap_Serial_Major = brd-SerialDriver-major; @@ -1273,13 +1288,29 @@ static int dgap_tty_register(struct board_t *brd) /* Register Transparent Print devices */ rc = tty_register_driver(brd-PrintDriver); if (rc 0) - return rc; + goto unregister_serial_drv; + brd-dgap_Major_TransparentPrint_Registered = TRUE; dgap_BoardsByMajor[brd-PrintDriver-major] = brd; brd-dgap_TransparentPrint_Major = brd-PrintDriver-major; } return rc; + +unregister_serial_drv: + tty_unregister_driver(brd-SerialDriver); We only register the -SerialDriver if someone else hasn't registered it first? So this should be: if (we_were_the_ones_who_registered_the_serial_driver) tty_unregister_driver(brd-SerialDriver); I haven't followed looked at this. Who else is registering the serial driver? You have looked at this, what do you think? Or Mark. registering the brd-XDriver is only done when a board is detected and only during the firmware_load process. If we fail to tty_register_driver do we _need_ to tty_unregister_driver? Isn't that like freeing after an alloc failure? The allocation is conditional so the free should be conditional. If we didn't allocate it, then we shouldn't free it. It wouldn't have even been a question except I'm not sure the allocation is *really* conditional because brd-dgap_Major_Serial_Registered might always be false like you guys seem to be saying. I think brd struct is from dgap_Board array as global static variable when this function is called. So brd-dgap_Major_Serial_Registered is always false. If dgap_NumBoards is less than MAXBOARDS, brd-SerialDriver should be registered. I'm not sure.. I don't see any check for (dgap_NumBoards MAXBOARDS), which I think I probably should, but I do see we are calling dgap_tty_register, which can fail, without actually checking the return value. Also, yes, dgap_Major_Xxxx_Registered seems to be always false until registered, and it looks like dgap_Major_X_Registered flags could be removed because the only places we can unregister is at module_cleanup or after it is already registered. What is the driver _supposed_ to do if we fail something on the second or later board? Is the driver supposed to cleanup and exit or are we supposed to stay loaded for the board/boards that are usable? Stay loaded. Then these tests on brd-dgap_Major_Serial_Registered need to stay in there. If I have 3 boards and the second fails in some way, if I rmmod the driver they will protect from unregistering a never registered one. At least in the unregister code path. There is probably no need for them in the register code path. I'll work up a patch for this. Should I update my patch? I think if (!brd-dgap_Major_XXX_Registered) line can be removed in this function, because if tty_register_driver() is failed just set false to dgap_Major_XXX_Registered. dgap_Major_XXX_Registered only is used in cleaup function, right? So code like below rc = tty_register_driver(brd-PrintDriver); if (rc 0) goto unregister_serial_drv; brd-dgap_Major_TransparentPrint_Registered = TRUE; ... unregister_serial_drv; brd-dgap_Major_Serial_Registered = false; tty_unregister_driver(brd-SerialDriver); Thanks. Regards, Daeseok Youn. I need to look at the (dgap_NumBoards MAXBOARDS) thing too. Mark
