Re: Strange segmentation fault
Ralf Mattes ha scritto: On Mon, 2007-07-30 at 18:49 +0200, [EMAIL PROTECTED] wrote: I found that a similar problem was this: http://mail-archives.apache.org/mod_mbox/httpd-modules-dev/200703.mbox/[EMAIL PROTECTED] Similar? In what way? Abusing libxml2 interna? Are you doing this? Iff xmlFreeDoc triggers a segmentation violation than the most likely case is that you pass it a document pointer that's not (a valid libxml document any more). So what part of the module did invalidate that doc pointer? Is it more likely to be Apache or your module code? BTW - one shure way to f^h^hk up you document is messing (i.e. releasing) nodes still refered to from the document. Does your module copy/move/delete nodes? The violation is inside my module,near the end. When I'm at the end of my module I reply to the client and I free the xml documents I used: . ap_add_output_filter(SV_XSLT_FILTER_NAME, NULL, r, r-connection); mod_transform_set_XSLT(r, xslfilename); xmlDocDumpMemoryEnc(doc, bufptr, size, UTF-8); putXML(r, (char*)bufptr); if (size 0) xmlFree(bufptr); if (docinter != NULL) xmlFreeDoc(docinter); if (docs != NULL) xmlFreeDoc(docs); xmlFreeDoc(doc); xmlCleanupParser(); return OK; where: void putXML(request_rec *r, char* xml) { ap_set_content_type(r, text/xml); ap_rwrite(xml, strlen(xml), r); ap_rflush(r); } My final xml document is doc which is built in the module getting information from docinter and docs. Yes my module copies some nodes from docs to doc with xmlCopyNode. I think that my code is correct. Am I doing some mistakes? Best regards Marco So it seems that it's possibile. I don't understand how to solve it. Could you give me some hints? Unless your module replaced libxml2's allocator the library uses malloc/free - you can use all the glorious GNU tools to debug. I guess you already set MALLOC_CHECK_ to 1, did you? HTH Ralf Mattes Best regards Marco Sorry I don't understand the reply. You are telling me that it should be possibile or not? I always use r-pool to allocate memory in my module, but not for libxml2. It has it's memory allocation and looking at source it uses malloc and free. Best regards Marco On Mon, Jul 30, 2007 at 06:04:27PM +0200, [EMAIL PROTECTED] wrote: I isolated my problem. It seems that sometimes during xmlFreeDoc(doc) I get a Segmentation fault. xmlFreeDoc is a function of libxml2 which I use inside my module. I suppose that libxml2 uses malloc/free to alloc and free memory: is it possibile that there is some overlap of memory with apr poll (r-poll)? Not an option. Unless you use somewhat pools to allocate memory for libxml. If you do so, stop it. Either use apr pools or malloc/free. Kind regards. -- Software Engineer - Spinetti Marco Direzione Sviluppo Servizi, Sistemi e Piattaforme Tel. +39 050 618.4264 Fax. +39 050 618.4244 Mob. +39 329 4424216 E-Mail: [EMAIL PROTECTED] ItaliaOnLine S.p.A. Direzione e coordinamento di Weather Investments S.p.A. Via G. Malagoli, 12 56124 PISA The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer. Any term contained in this email is intended solely as a basis for further discussion and is not intended to be and does not constitute a legally binding obligation. No legally binding obligations will be created, implied or inferred until a definitive agreement in final form is executed in writing and delivered by both parties. Without limiting the generality of the foregoing, the parties intend that there shall be no ligations based on such things as parol evidence, extended negotiations, oral understandings or courses of conduct (including without limitation reliance and changes of position).
Re: Strange segmentation fault
I tried what Nick advised yesterday. I register all my cleanup with apr_pool_cleanup_register: this is for xml documents and bufptr. So after the creation or parsing of xml documents: apr_pool_cleanup_register(r-pool, doc, liberaDoc, apr_pool_cleanup_null); and after dump xml doc: xmlDocDumpMemoryEnc(doc, bufptr, size, UTF-8); apr_pool_cleanup_register(r-pool, bufptr, liberaBuff, apr_pool_cleanup_null); where: apr_status_t liberaDoc(void *d) { xmlDocPtr doc = d; if (doc != NULL) xmlFreeDoc(doc); return APR_SUCCESS; } apr_status_t liberaBuff(void *b) { xmlChar *bufptr = b; if (bufptr != NULL) xmlFree(bufptr); return APR_SUCCESS; } then I inserted two print at the start and end of my module: ap_log_perror(APLOG_MARK, APLOG_ERR, 0, r-pool, I:[%ld]%s, (long)getpid(), q); ap_log_perror(APLOG_MARK, APLOG_ERR, 0, r-pool, F:[%ld]%s, (long)getpid(), q); where the last print if before the last instruction of my module (return OK). Sometimes I get in the error_log: [Tue Jul 31 10:03:31 2007] [error] I:[15560]CASCINA DEI FAGIOLARI [Tue Jul 31 10:03:31 2007] [error] F:[15560]CASCINA DEI FAGIOLARI [Tue Jul 31 10:03:32 2007] [notice] child pid 15560 exit signal Segmentation fault (11) This is very strange. I use mod_transform (Nick is one of the authors ;-) ) to reply to the client. So I inserted this two print at the start and end of transform_filter: ap_log_perror(APLOG_MARK, APLOG_ERR, 0, f-r-pool, II:[%ld], (long)getpid()); ap_log_perror(APLOG_MARK, APLOG_ERR, 0, f-r-pool, FF:[%ld], (long)getpid()); Then I repeated the test and in the error log I get: [Tue Jul 31 10:52:19 2007] [error] I:[7307]CASCINA DEI FAGIOLARI [Tue Jul 31 10:52:20 2007] [error] II:[7307] [Tue Jul 31 10:52:20 2007] [error] FF:[7307] [Tue Jul 31 10:52:20 2007] [error] F:[7307]CASCINA DEI FAGIOLARI [Tue Jul 31 10:52:20 2007] [error] II:[7307] [Tue Jul 31 10:52:20 2007] [error] FF:[7307] [Tue Jul 31 10:52:20 2007] [notice] child pid 7307 exit signal Segmentation fault (11) I don't know why I have two times the prints of mod_transform (???) but the segmentation fault is after the end of mod_transform. So it seems that the error is in the mod_transform. What do you think? Best regards Marco Marco Spinetti ha scritto: Ralf Mattes ha scritto: On Mon, 2007-07-30 at 18:49 +0200, [EMAIL PROTECTED] wrote: I found that a similar problem was this: http://mail-archives.apache.org/mod_mbox/httpd-modules-dev/200703.mbox/[EMAIL PROTECTED] Similar? In what way? Abusing libxml2 interna? Are you doing this? Iff xmlFreeDoc triggers a segmentation violation than the most likely case is that you pass it a document pointer that's not (a valid libxml document any more). So what part of the module did invalidate that doc pointer? Is it more likely to be Apache or your module code? BTW - one shure way to f^h^hk up you document is messing (i.e. releasing) nodes still refered to from the document. Does your module copy/move/delete nodes? The violation is inside my module,near the end. When I'm at the end of my module I reply to the client and I free the xml documents I used: . ap_add_output_filter(SV_XSLT_FILTER_NAME, NULL, r, r-connection); mod_transform_set_XSLT(r, xslfilename); xmlDocDumpMemoryEnc(doc, bufptr, size, UTF-8); putXML(r, (char*)bufptr); if (size 0) xmlFree(bufptr); if (docinter != NULL) xmlFreeDoc(docinter); if (docs != NULL) xmlFreeDoc(docs); xmlFreeDoc(doc); xmlCleanupParser(); return OK; where: void putXML(request_rec *r, char* xml) { ap_set_content_type(r, text/xml); ap_rwrite(xml, strlen(xml), r); ap_rflush(r); } My final xml document is doc which is built in the module getting information from docinter and docs. Yes my module copies some nodes from docs to doc with xmlCopyNode. I think that my code is correct. Am I doing some mistakes? Best regards Marco So it seems that it's possibile. I don't understand how to solve it. Could you give me some hints? Unless your module replaced libxml2's allocator the library uses malloc/free - you can use all the glorious GNU tools to debug. I guess you already set MALLOC_CHECK_ to 1, did you? HTH Ralf Mattes Best regards Marco Sorry I don't understand the reply. You are telling me that it should be possibile or not? I always use r-pool to allocate memory in my module, but not for libxml2. It has it's memory allocation and looking at source it uses malloc and free. Best regards Marco On Mon, Jul 30, 2007 at 06:04:27PM +0200, [EMAIL PROTECTED] wrote: I isolated my problem. It seems that sometimes during xmlFreeDoc(doc) I get a Segmentation fault. xmlFreeDoc is a function of libxml2 which I use inside my module. I suppose that libxml2 uses malloc/free to alloc and free memory: is it possibile that there is some overlap of memory with apr poll (r-poll)? Not an option.
Re: Strange segmentation fault
Any news :'( ? Marco Marco Spinetti ha scritto: I tried what Nick advised yesterday. I register all my cleanup with apr_pool_cleanup_register: this is for xml documents and bufptr. So after the creation or parsing of xml documents: apr_pool_cleanup_register(r-pool, doc, liberaDoc, apr_pool_cleanup_null); and after dump xml doc: xmlDocDumpMemoryEnc(doc, bufptr, size, UTF-8); apr_pool_cleanup_register(r-pool, bufptr, liberaBuff, apr_pool_cleanup_null); where: apr_status_t liberaDoc(void *d) { xmlDocPtr doc = d; if (doc != NULL) xmlFreeDoc(doc); return APR_SUCCESS; } apr_status_t liberaBuff(void *b) { xmlChar *bufptr = b; if (bufptr != NULL) xmlFree(bufptr); return APR_SUCCESS; } then I inserted two print at the start and end of my module: ap_log_perror(APLOG_MARK, APLOG_ERR, 0, r-pool, I:[%ld]%s, (long)getpid(), q); ap_log_perror(APLOG_MARK, APLOG_ERR, 0, r-pool, F:[%ld]%s, (long)getpid(), q); where the last print if before the last instruction of my module (return OK). Sometimes I get in the error_log: [Tue Jul 31 10:03:31 2007] [error] I:[15560]CASCINA DEI FAGIOLARI [Tue Jul 31 10:03:31 2007] [error] F:[15560]CASCINA DEI FAGIOLARI [Tue Jul 31 10:03:32 2007] [notice] child pid 15560 exit signal Segmentation fault (11) This is very strange. I use mod_transform (Nick is one of the authors ;-) ) to reply to the client. So I inserted this two print at the start and end of transform_filter: ap_log_perror(APLOG_MARK, APLOG_ERR, 0, f-r-pool, II:[%ld], (long)getpid()); ap_log_perror(APLOG_MARK, APLOG_ERR, 0, f-r-pool, FF:[%ld], (long)getpid()); Then I repeated the test and in the error log I get: [Tue Jul 31 10:52:19 2007] [error] I:[7307]CASCINA DEI FAGIOLARI [Tue Jul 31 10:52:20 2007] [error] II:[7307] [Tue Jul 31 10:52:20 2007] [error] FF:[7307] [Tue Jul 31 10:52:20 2007] [error] F:[7307]CASCINA DEI FAGIOLARI [Tue Jul 31 10:52:20 2007] [error] II:[7307] [Tue Jul 31 10:52:20 2007] [error] FF:[7307] [Tue Jul 31 10:52:20 2007] [notice] child pid 7307 exit signal Segmentation fault (11) I don't know why I have two times the prints of mod_transform (???) but the segmentation fault is after the end of mod_transform. So it seems that the error is in the mod_transform. What do you think? Best regards Marco Marco Spinetti ha scritto: Ralf Mattes ha scritto: On Mon, 2007-07-30 at 18:49 +0200, [EMAIL PROTECTED] wrote: I found that a similar problem was this: http://mail-archives.apache.org/mod_mbox/httpd-modules-dev/200703.mbox/[EMAIL PROTECTED] Similar? In what way? Abusing libxml2 interna? Are you doing this? Iff xmlFreeDoc triggers a segmentation violation than the most likely case is that you pass it a document pointer that's not (a valid libxml document any more). So what part of the module did invalidate that doc pointer? Is it more likely to be Apache or your module code? BTW - one shure way to f^h^hk up you document is messing (i.e. releasing) nodes still refered to from the document. Does your module copy/move/delete nodes? The violation is inside my module,near the end. When I'm at the end of my module I reply to the client and I free the xml documents I used: . ap_add_output_filter(SV_XSLT_FILTER_NAME, NULL, r, r-connection); mod_transform_set_XSLT(r, xslfilename); xmlDocDumpMemoryEnc(doc, bufptr, size, UTF-8); putXML(r, (char*)bufptr); if (size 0) xmlFree(bufptr); if (docinter != NULL) xmlFreeDoc(docinter); if (docs != NULL) xmlFreeDoc(docs); xmlFreeDoc(doc); xmlCleanupParser(); return OK; where: void putXML(request_rec *r, char* xml) { ap_set_content_type(r, text/xml); ap_rwrite(xml, strlen(xml), r); ap_rflush(r); } My final xml document is doc which is built in the module getting information from docinter and docs. Yes my module copies some nodes from docs to doc with xmlCopyNode. I think that my code is correct. Am I doing some mistakes? Best regards Marco So it seems that it's possibile. I don't understand how to solve it. Could you give me some hints? Unless your module replaced libxml2's allocator the library uses malloc/free - you can use all the glorious GNU tools to debug. I guess you already set MALLOC_CHECK_ to 1, did you? HTH Ralf Mattes Best regards Marco Sorry I don't understand the reply. You are telling me that it should be possibile or not? I always use r-pool to allocate memory in my module, but not for libxml2. It has it's memory allocation and looking at source it uses malloc and free. Best regards Marco On Mon, Jul 30, 2007 at 06:04:27PM +0200, [EMAIL PROTECTED] wrote: I isolated my problem. It seems that sometimes during xmlFreeDoc(doc) I get a Segmentation fault. xmlFreeDoc is a function of libxml2 which I use inside my module. I suppose that libxml2 uses malloc/free to alloc and free memory: is it possibile that there is some overlap of memory with apr poll
Re: Strange segmentation fault
On Mon, Jul 30, 2007 at 06:04:27PM +0200, [EMAIL PROTECTED] wrote: I isolated my problem. It seems that sometimes during xmlFreeDoc(doc) I get a Segmentation fault. xmlFreeDoc is a function of libxml2 which I use inside my module. I suppose that libxml2 uses malloc/free to alloc and free memory: is it possibile that there is some overlap of memory with apr poll (r-poll)? Not an option. Unless you use somewhat pools to allocate memory for libxml. If you do so, stop it. Either use apr pools or malloc/free. Kind regards.
Re: Strange segmentation fault
On Mon, 2007-07-30 at 20:22 +0200, Mike wrote: On Mon, Jul 30, 2007 at 06:31:58PM +0200, [EMAIL PROTECTED] wrote: Sorry I don't understand the reply. You are telling me that it should be possibile or not? I always use r-pool to allocate memory in my module, but not for libxml2. It has it's memory allocation and looking at source it uses malloc and free. So maybe it is libxml2 problem? Dream on ;-) Cheers, RalfD