Public bug reported: == Comment: #0 - Stefan Liebler <[email protected]> - 2016-04-01 08:33:44 == On s390, no fpr/vrs were saved while resolving a symbol via _dl_runtime_resolve/_dl_runtime_profile.
According to the abi, the fpr-arguments are defined as call clobbered. In leaf-functions, gcc 4.9 and newer can use fprs for saving/restoring gprs instead of saving them to the stack. If gcc do this in one of the resolver-functions, then the floating point arguments of a library-function are invalid for the first library-function-call. Thus, this patch (see below) saves/restores the fprs around the resolving code. The same could occur for vector registers. Furthermore an ifunc-resolver could also clobber the vector/floating point argument registers. Thus this patch provides the further variants _dl_runtime_resolve_vx/ _dl_runtime_profile_vx, which are used if the kernel claims, that we run on a machine with vector registers. Furthermore, if _dl_runtime_profile calls _dl_call_pltexit, the pointers to inregs-/outregs-structs were setup invalid. Now they point to the correct location in the stack-frame. Before branching back to the caller, the return values are now restored instead of containing the return values of the _dl_call_pltexit() call. On s390-32, an endless loop occurs if _dl_call_pltexit() should be called. Now, this code-path branches to this function instead of just after the preceding basr-instruction. (Picked from upstream commits 4603c51ef7989d7eb800cdd6f42aab206f891077 and d8a012c5c9e4bfc1b8db2bc6deacb85b44a2e1eb) Starting with z13, vector registers can also occur as argument registers. Thus the passed input/output register structs for la_s390_[32|64]_gnu_plt[enter|exit] functions should reflect those new registers. This patch extends these structs La_s390_regs and La_s390_retval and adjusts _dl_runtime_profile() to handle those fields in case of running on a z13 machine. (picked from upstream commit 5cdd1989d1d2f135d02e66250f37ba8e767f9772) These upstream patches are also backported to glibc 2.23 release branch: S390: Save and restore fprs/vrs while resolving symbols. https://sourceware.org/git/?p=glibc.git;a=commit;h=d93f04543c68c461bd90294751f5fa532a24680c S390: Extend structs La_s390_regs / La_s390_retval with vector-registers. https://sourceware.org/git/?p=glibc.git;a=commit;h=0eb234232eaf925fe4dca3bd60a3e1b4a7ab2882 Please pull both and add it to ubuntu glibc package. ** Affects: glibc (Ubuntu) Importance: Undecided Assignee: Skipper Bug Screeners (skipper-screen-team) Status: New ** Tags: architecture-s39064 bugnameltc-139912 severity-high targetmilestone-inin1604 ** Tags added: architecture-s39064 bugnameltc-139912 severity-high targetmilestone-inin1604 ** Changed in: ubuntu Assignee: (unassigned) => Skipper Bug Screeners (skipper-screen-team) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1564918 Title: glibc/s390: Save and restore fprs/vrs while resolving symbols. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1564918/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
