Bug 2998 - tde-devels - Trinity Desktop Environment

David C. Rankin

7 Feb 7 Feb

6:21 p.m.

New subject: [trinity-devel] Bug 2998

On 02/07/2019 09:52 AM, Russell Brown wrote:

As the code I posted on bugzilla used a crude fixed buffer, here's a cleaned up version that uses malloc. *** /tmp/tdebase-trinity-14.0.6~pre38/kdesktop/lock/main.cc Thu Feb 7 15:48:21 2019 --- /usr/tmp/tdebase-trinity-14.0.6~pre38/kdesktop/lock/main.cc Sun May 20 19:41:55 2018 *************** *** 325,336 **** #endif } ! char *locknameroot="kdesktop_lock_lockfile."; ! char *lockfilename = (char*)malloc(strlen(locknameroot) + strlen(getenv("DISPLAY")) + 1);

I haven't followed the issue too closely, but in the past, there was an issue that would cause high CPU usage caused by a security addition to either KDM or the lockscreen itself. I would ensure this wasn't a regression (Slavek may recall, it was in the 2012-14 timeframe) Regarding the proposed code, only one quandary -- where is lockfilename freed? (if this is allocated in a forked process that later dies and releases the memory then you are fine, but if not, it seems this would leak memory each time lockfilename is allocated -- unless there is a free later not shown in the code posted) -- David C. Rankin, J.D.,P.E.

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Fat-Zer

11:10 p.m.

New subject: [trinity-devel] Bug 2998

Hi, Note that this is essentially a lighter version of the issue in bug 1766. I'm digging it right now, but a simple adding of the DISPLAY won't fix it for me because as for now there are actually 2 instances for each of two screens (4 in total, see the bug for details) are fighting over control. Having a squared-number-of-screen kdesktop_lock running all the time just looks messed up. Also they conflict with each other when locking a desktop from a «wrong screen». So, I'd rather get rid of all of those constantly running kdesktop_lock(s) and leave only one or one-for-each-screen at most. But it requires some thine and gentle tweaking to achieve it and not compromise the security/stability. I've tried to rearrange things in the `main()` at first (to lock and wait for a signal from kdesktop before forking), but it didn't gone specifically well, actually I've got caught up into some sort of cabbage-goat-wolf puzzle but with a flesh-eating cabbage this time... As for now I'm looking forward for some changes in kdesktop/kdesktop_lock or inter-kdesktop communications. Also I was going to commit some refactoring on the kdesktop/lock/main.cc because as for now that mess is unmodifiable (on rather high level)... чт, 7 февр. 2019 г. в 22:41, Slávek Banko <slavek.banko(a)axis.cz>cz>:

...

On Thursday 07 of February 2019 16:52:21 Russell Brown wrote:

Hi, I don't know how closely the devs watch the Bug list but I believe I've fixed Bug 2998. As this bug results in kdesktop/kdesktop_lock eating CPU and going unresponsive; might I humbly request that the fix is incorporated in the next possible/dev version. As the code I posted on bugzilla used a crude fixed buffer, here's a cleaned up version that uses malloc. *** /tmp/tdebase-trinity-14.0.6~pre38/kdesktop/lock/main.cc Thu Feb 7 15:48:21 2019 --- /usr/tmp/tdebase-trinity-14.0.6~pre38/kdesktop/lock/main.cc Sun May 20 19:41:55 2018 *************** *** 325,336 **** #endif } ! char *locknameroot="kdesktop_lock_lockfile."; ! char *lockfilename = (char*)malloc(strlen(locknameroot) + strlen(getenv("DISPLAY")) + 1); ! strcpy(lockfilename,locknameroot); ! strcat(lockfilename,getenv("DISPLAY")); ! ! TDELockFile lock(locateLocal("tmp", lockfilename)); lock.setStaleTime(0); TDELockFile::LockResult lockRet = lock.lock(); if (lockRet != TDELockFile::LockOK) { --- 325,331 ---- #endif } ! TDELockFile lock(locateLocal("tmp", "kdesktop_lock_lockfile")); lock.setStaleTime(0); TDELockFile::LockResult lockRet = lock.lock(); if (lockRet != TDELockFile::LockOK) {

Hi Russell, your observation gives a very clear sense. The name of the lock does not distinguish between $DISPLAY and therefore two separate kdesktop_lock processes struggles for one file. Good conclusion! Because locateLocal expects a TQString value as argument, I suggest using this fact and make the patch simpler: --- a/kdesktop/lock/main.cc +++ b/kdesktop/lock/main.cc @@ -325,7 +325,7 @@ #endif } - TDELockFile lock(locateLocal("tmp", "kdesktop_lock_lockfile")); + TDELockFile lock(locateLocal("tmp", TQString("kdesktop_lock_lockfile.%1").arg(getenv("DISPLAY")))); lock.setStaleTime(0); TDELockFile::LockResult lockRet = lock.lock(); if (lockRet != TDELockFile::LockOK) { If you want to get involved, the best way is to register on TDE Gitea Workspace and create a pull-request. See: https://wiki.trinitydesktop.org/TDE_Gitea_Workspace Note: Pull-requests should always be on the master branch. Core developers then take care of a backport patch into a stable branch. Note1: By the way, in your proposed code is missing free, so this would leads to memory leaks. Cheers -- Slávek

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Slávek Banko

9 Feb 9 Feb

6:41 p.m.

New subject: [trinity-devel] Bug 2998

Hi Fat-Zer, although it is clear that Russell's patch will not be able to solve all of the problems mentioned in 1766, it is a good step forward - quickly and simply solving one particular problem. Therefore, there is good reason to merge it. Cheers -- Slávek On Friday 08 of February 2019 00:10:24 Fat-Zer wrote:

...

Hi, Note that this is essentially a lighter version of the issue in bug 1766. I'm digging it right now, but a simple adding of the DISPLAY won't fix it for me because as for now there are actually 2 instances for each of two screens (4 in total, see the bug for details) are fighting over control. Having a squared-number-of-screen kdesktop_lock running all the time just looks messed up. Also they conflict with each other when locking a desktop from a «wrong screen». So, I'd rather get rid of all of those constantly running kdesktop_lock(s) and leave only one or one-for-each-screen at most. But it requires some thine and gentle tweaking to achieve it and not compromise the security/stability. I've tried to rearrange things in the `main()` at first (to lock and wait for a signal from kdesktop before forking), but it didn't gone specifically well, actually I've got caught up into some sort of cabbage-goat-wolf puzzle but with a flesh-eating cabbage this time... As for now I'm looking forward for some changes in kdesktop/kdesktop_lock or inter-kdesktop communications. Also I was going to commit some refactoring on the kdesktop/lock/main.cc because as for now that mess is unmodifiable (on rather high level)... чт, 7 февр. 2019 г. в 22:41, Slávek Banko <slavek.banko(a)axis.cz>cz>:

On Thursday 07 of February 2019 16:52:21 Russell Brown wrote:

Hi, I don't know how closely the devs watch the Bug list but I believe I've fixed Bug 2998. As this bug results in kdesktop/kdesktop_lock eating CPU and going unresponsive; might I humbly request that the fix is incorporated in the next possible/dev version. As the code I posted on bugzilla used a crude fixed buffer, here's a cleaned up version that uses malloc. *** /tmp/tdebase-trinity-14.0.6~pre38/kdesktop/lock/main.cc Thu Feb 7 15:48:21 2019 --- /usr/tmp/tdebase-trinity-14.0.6~pre38/kdesktop/lock/main.cc Sun May 20 19:41:55 2018 *************** *** 325,336 **** #endif } ! char *locknameroot="kdesktop_lock_lockfile."; ! char *lockfilename = (char*)malloc(strlen(locknameroot) + strlen(getenv("DISPLAY")) + 1); ! strcpy(lockfilename,locknameroot); ! strcat(lockfilename,getenv("DISPLAY")); ! ! TDELockFile lock(locateLocal("tmp", lockfilename)); lock.setStaleTime(0); TDELockFile::LockResult lockRet = lock.lock(); if (lockRet != TDELockFile::LockOK) { --- 325,331 ---- #endif } ! TDELockFile lock(locateLocal("tmp", "kdesktop_lock_lockfile")); lock.setStaleTime(0); TDELockFile::LockResult lockRet = lock.lock(); if (lockRet != TDELockFile::LockOK) {

Hi Russell, your observation gives a very clear sense. The name of the lock does not distinguish between $DISPLAY and therefore two separate kdesktop_lock processes struggles for one file. Good conclusion! Because locateLocal expects a TQString value as argument, I suggest using this fact and make the patch simpler: --- a/kdesktop/lock/main.cc +++ b/kdesktop/lock/main.cc @@ -325,7 +325,7 @@ #endif } - TDELockFile lock(locateLocal("tmp", "kdesktop_lock_lockfile")); + TDELockFile lock(locateLocal("tmp", TQString("kdesktop_lock_lockfile.%1").arg(getenv("DISPLAY")))); lock.setStaleTime(0); TDELockFile::LockResult lockRet = lock.lock(); if (lockRet != TDELockFile::LockOK) { If you want to get involved, the best way is to register on TDE Gitea Workspace and create a pull-request. See: https://wiki.trinitydesktop.org/TDE_Gitea_Workspace Note: Pull-requests should always be on the master branch. Core developers then take care of a backport patch into a stable branch. Note1: By the way, in your proposed code is missing free, so this would leads to memory leaks. Cheers -- Slávek

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Russell Brown

8 Feb 8 Feb

9:17 a.m.

New subject: [trinity-devel] Bug 2998

Quoth Sl�vek Banko.....

...

Because locateLocal expects a TQString value as argument, I suggest using this fact and make the patch simpler: - TDELockFile lock(locateLocal("tmp", "kdesktop_lock_lockfile")); + TDELockFile lock(locateLocal("tmp", TQString("kdesktop_lock_lockfile.%1").arg(getenv("DISPLAY"))));

Thank you Sl�vek, I thought there would be a TDE/TQT way of doing this. I'll change my in-use version to this. -- Regards, Russell -------------------------------------------------------------------- | Russell Brown | MAIL: russell(a)lls.com PHONE: 01780 471800 | | Lady Lodge Systems | WWW Work: http://www.lls.com | | Peterborough, England | WWW Play: http://www.ruffle.me.uk | --------------------------------------------------------------------

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Russell Brown

11 Feb 11 Feb

9:14 a.m.

New subject: [trinity-devel] Bug 2998

Hi Sl�vek, Quoth Sl�vek Banko.....

...

>Because locateLocal expects a TQString value as argument, I suggest >using this fact and make the patch simpler: > >- TDELockFile lock(locateLocal("tmp", > "kdesktop_lock_lockfile")); + TDELockFile > lock(locateLocal("tmp", > TQString("kdesktop_lock_lockfile.%1").arg(getenv("DISPLAY"))));

what next step will be? Are you interested in joining TGW and entering pull request? Or do I push a patch?

Can you do the honours and push the patch. Thanks. -- Regards, Russell -------------------------------------------------------------------- | Russell Brown | MAIL: russell(a)lls.com PHONE: 01780 471800 | | Lady Lodge Systems | WWW Work: http://www.lls.com | | Peterborough, England | WWW Play: http://www.ruffle.me.uk | --------------------------------------------------------------------

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