Re: svn commit: r990537 - /subversion/branches/performance/subversion/libsvn_subr/svn_temp_ser ializer.c
Johan Corveleyn wrote on Tue, Aug 31, 2010 at 22:07:59 +0200: (I hope the attachments (file svn-crash...log.txt and svn-crash...dmp) get through; if not, let me know and I'll zip them or something) I see svn-crash-log20100831213059.log.txt only. By the way, please send as plain text, if possible. (you sent multipart/alternative with an html part)
RE: svn commit: r990537 - /subversion/branches/performance/subversion/libsvn_subr/svn_temp_ser ializer.c
-Original Message- From: Daniel Shahaf [mailto:d...@daniel.shahaf.name] Sent: zondag 29 augustus 2010 16:36 To: Johan Corveleyn Cc: dev@subversion.apache.org; stef...@apache.org Subject: Re: svn commit: r990537 - /subversion/branches/performance/subversion/libsvn_subr/svn_temp_ser ializer.c Johan Corveleyn wrote on Sun, Aug 29, 2010 at 16:24:24 +0200: Hi Stefan, On Sun, Aug 29, 2010 at 12:32 PM, stef...@apache.org wrote: Author: stefan2 Date: Sun Aug 29 10:32:08 2010 New Revision: 990537 URL: http://svn.apache.org/viewvc?rev=990537view=rev Log: Looking for the cause of Johan Corveleyn's crash (see http://svn.haxx.se/dev/archive-2010-08/0652.shtml), it seems that wrong / corrupted data contains backward pointers, i.e. negative offsets. That cannot happen if everything works as intended. I've just retried my test after this change (actually with performance-bra...@990579, so updated just 10 minutes ago). Now I get the assertion error, after running log or blame on that particular file: [[[ $ svnserve -d -r c:/research/svn/experiment/repos Assertion failed: *ptr buffer, file ..\..\..\subversion\libsvn_subr\svn_temp_serializer.c, line 282 This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. ]]] Is there any way I can find more information about this failure, so I can help you diagnose the problem? s/assert/SVN_ERR_MALFUNCTION_NO_RETURN/ assert and SVN_ERR_MALFUNCTION() have their own use. assert() is only evaluated in Maintainer/DEBUG mode and isn't evaluated at runtime for normal users. So this assertion is good for tests that are too slow for general use or for things that shouldn't happen but are not really an error. E.g. it is used through svn_dirent_*(), svn_uri_*(), etc. [A url is really just a valid unix path which can be canonicalized by removing double slashes, but using it is in almost every case a user error. So this triggers a maintainer/debug only assertion] This allows easier debugging of these errors. SVN_ERR_MALFUNCTION() and SVN_ERR_ASSERT() are for tests that also need evaluation in release mode. The fatal error is avoidable by installing a error callback. The SVN_ERR_MALFUNCTION_NO_RETURN and SVN_ERR_ASSERT_NO_RETURN() function should be avoided (real fix: Make the function return svn_error_t*) as these will trigger an error and then an abort at runtime. So it will CRASH third party application when this error occurs there. Bert
Re: svn commit: r990537 - /subversion/branches/performance/subversion/libsvn_subr/svn_temp_ser ializer.c
Bert Huijben wrote: -Original Message- From: Daniel Shahaf [mailto:d...@daniel.shahaf.name] Sent: zondag 29 augustus 2010 16:36 To: Johan Corveleyn Cc: dev@subversion.apache.org; stef...@apache.org Subject: Re: svn commit: r990537 - /subversion/branches/performance/subversion/libsvn_subr/svn_temp_ser ializer.c Johan Corveleyn wrote on Sun, Aug 29, 2010 at 16:24:24 +0200: Hi Stefan, On Sun, Aug 29, 2010 at 12:32 PM, stef...@apache.org wrote: Author: stefan2 Date: Sun Aug 29 10:32:08 2010 New Revision: 990537 URL: http://svn.apache.org/viewvc?rev=990537view=rev Log: Looking for the cause of Johan Corveleyn's crash (see http://svn.haxx.se/dev/archive-2010-08/0652.shtml), it seems that wrong / corrupted data contains backward pointers, i.e. negative offsets. That cannot happen if everything works as intended. I've just retried my test after this change (actually with performance-bra...@990579, so updated just 10 minutes ago). Now I get the assertion error, after running log or blame on that particular file: [[[ $ svnserve -d -r c:/research/svn/experiment/repos Assertion failed: *ptr buffer, file ..\..\..\subversion\libsvn_subr\svn_temp_serializer.c, line 282 This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. ]]] Is there any way I can find more information about this failure, so I can help you diagnose the problem? s/assert/SVN_ERR_MALFUNCTION_NO_RETURN/ assert and SVN_ERR_MALFUNCTION() have their own use. assert() is only evaluated in Maintainer/DEBUG mode and isn't evaluated at runtime for normal users. So this assertion is good for tests that are too slow for general use or for things that shouldn't happen but are not really an error. E.g. it is used through svn_dirent_*(), svn_uri_*(), etc. [A url is really just a valid unix path which can be canonicalized by removing double slashes, but using it is in almost every case a user error. So this triggers a maintainer/debug only assertion] This allows easier debugging of these errors. SVN_ERR_MALFUNCTION() and SVN_ERR_ASSERT() are for tests that also need evaluation in release mode. The fatal error is avoidable by installing a error callback. The SVN_ERR_MALFUNCTION_NO_RETURN and SVN_ERR_ASSERT_NO_RETURN() function should be avoided (real fix: Make the function return svn_error_t*) as these will trigger an error and then an abort at runtime. So it will CRASH third party application when this error occurs there. I'm a bit torn what the ultimate solution would be here. For the time being, I only need that as debug code. Depending on the root cause of the problem, I might promote it to general threat and then use one of the NO_RETURN errors because it is still better than a PF. But it would never be a good choice to just continue operations (e.g. disable the cache and retry) because the server may already operate on or even have handed out on corrupted data. -- Stefan^2.
Re: svn commit: r990537 - /subversion/branches/performance/subversion/libsvn_subr/svn_temp_ser ializer.c
On Sun, Aug 29, 2010 at 4:36 PM, Daniel Shahaf d...@daniel.shahaf.namewrote: Johan Corveleyn wrote on Sun, Aug 29, 2010 at 16:24:24 +0200: Hi Stefan, On Sun, Aug 29, 2010 at 12:32 PM, stef...@apache.org wrote: Author: stefan2 Date: Sun Aug 29 10:32:08 2010 New Revision: 990537 URL: http://svn.apache.org/viewvc?rev=990537view=rev Log: Looking for the cause of Johan Corveleyn's crash (see http://svn.haxx.se/dev/archive-2010-08/0652.shtml), it seems that wrong / corrupted data contains backward pointers, i.e. negative offsets. That cannot happen if everything works as intended. I've just retried my test after this change (actually with performance-bra...@990579, so updated just 10 minutes ago). Now I get the assertion error, after running log or blame on that particular file: [[[ $ svnserve -d -r c:/research/svn/experiment/repos Assertion failed: *ptr buffer, file ..\..\..\subversion\libsvn_subr\svn_temp_serializer.c, line 282 This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. ]]] Is there any way I can find more information about this failure, so I can help you diagnose the problem? s/assert/SVN_ERR_MALFUNCTION_NO_RETURN/ I think you meant SVN_ERR_ASSERT_NO_RETURN. If I do that, I get: [[[ $ svnserve -d -r c:/research/svn/experiment/repos ..\..\..\subversion\libsvn_fs_fs\fs_fs.c:2363: (apr_err=235000) svn: In file '..\..\..\subversion\libsvn_subr\svn_temp_serializer.c' line 282: assertion failed (*ptr buffer) This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. ]]] -- Johan
