Created attachment 1374983 [details] unwind.i Description of problem: The attached program, when compiled using gcc -fPIC -O2 -fgnu89-inline-fstack-clash-protection -c unwind.i produces invalid CFI instructions for __GI___pthread_unwind: __GI___pthread_unwind: .LFB55: .cfi_startproc pushl %esi .cfi_def_cfa_offset 8 .cfi_offset 6, -8 pushl %ebx .cfi_def_cfa_offset 12 .cfi_offset 3, -12 pushl %esi .cfi_def_cfa_offset 16 .cfi_offset 6, -16 popl %esi .cfi_restore 6 .cfi_def_cfa_offset 12 call __x86.get_pc_thunk.bx addl $_GLOBAL_OFFSET_TABLE_, %ebx subl $8, %esp .cfi_def_cfa_offset 20 movl %eax, %esi The problem is that the .cfi_restore for %esi does not restore the original location at offset 8, but essentially declares that the register will not be clobbered further below, while in fact it is used to store the function argument (__pthread_unwind is compiled with __attribute__ ((regparm (1)))). As a result, the libgcc unwinder restores the wrong value for %esi, leading to bug 1529549. Version-Release number of selected component (if applicable): gcc-7.2.1-4.fc28.i686
Mine, obviously. I'll be on it first thing tomorrow.
This bug appears to have been reported against 'rawhide' during the Fedora 28 development cycle. Changing version to '28'.
This message is a reminder that Fedora 28 is nearing its end of life. On 2019-May-28 Fedora will stop maintaining and issuing updates for Fedora 28. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '28'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 28 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete.
Fedora 28 changed to end-of-life (EOL) status on 2019-05-28. Fedora 28 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.