Attached a short program which can be compiled in order to see the problem. Compile with
bcc -ansi -S struct_pass.c Then scroll down the resulting assembly file struct_pass.s to get past the comments. On my system the errant code began at line 235. ** Attachment added: "Source code struct_pass.c to help show the bug" https://bugs.launchpad.net/ubuntu/+source/linux86/+bug/1407521/+attachment/4292104/+files/struct_pass.c -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux86 in Ubuntu. https://bugs.launchpad.net/bugs/1407521 Title: C compiler bcc struct passing fails Status in linux86 package in Ubuntu: New Bug description: C compiler bcc copies structs and returns structs correctly but fails to pass them to functions. From checking it turns out that the generated code calls _memcpy with the wrong parameters. For example, this is the generated assembly which should pass a 6-byte struct to a function. ! Debug: list struct composite original = [S+$14-$C] (used reg = ) add sp,*-6 mov ax,sp <--- presumably the target address mov ax,*6 <--- gets overwritten by the size of the struct push ax <--- push the size of the struct lea bx,-$A[bp] push bx <--- push the source address push ax <--- should be the target address call _memcpy add sp,*6 ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: bcc 0.16.17-3.1ubuntu3 ProcVersionSignature: Ubuntu 3.13.0-30.54-generic 3.13.11.2 Uname: Linux 3.13.0-30-generic i686 ApportVersion: 2.14.1-0ubuntu3.2 Architecture: i386 Date: Sun Jan 4 22:58:22 2015 ProcEnviron: SHELL=/bin/bash TERM=ansi PATH=(custom, user) LANG=en_GB.utf8 XDG_RUNTIME_DIR=<set> SourcePackage: linux86 UpgradeStatus: Upgraded to trusty on 2014-06-20 (198 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux86/+bug/1407521/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
