devel June 2022

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F37 proposal: RPM Macros for Build Flags (System-Wide Change proposal)
by Ben Cotton 10 Feb '23

10 Feb '23

https://fedoraproject.org/wiki/Changes/RPMMacrosForBuildFlags This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee. == Summary == Create a corresponding macro for each compiler flag in the redhat-rpm-config macro file and create "extra flag" macros to make it easier for packages to add and remove compiler flags. == Owner == * Name: [[User:tstellar| Tom Stellard]] * Email: <tstellar(a)redhat.com> == Detailed Description == The macros file in the redhat-rpm-config package contains a list of default compiler flags for packages to use when compiling C, C++, and Fortran packages. There is currently no standard way to remove or add to the set of default flags. Most packages use a combination of echo and sed to remove unwanted flags or add new ones. Some examples: compiler-rt: [https://src.fedoraproject.org/rpms/compiler-rt/blob/rawhide/f/compiler-rt.s… global optflags %(echo %{optflags} -D_DEFAULT_SOURCE)] julia: [https://src.fedoraproject.org/rpms/julia/blob/rawhide/f/julia.spec#_267 %global optflags %(echo %{optflags} | sed 's/-Wp,-D_GLIBCXX_ASSERTIONS //')] This change will add new macros which will make it easier for packages to add and remove their own compiler flags. This strategy is already used to some extent with feature macros like %{_lto_cflags}, %{_hardening_cflags}, etc, but these new macros will give packagers even more fine-grained control over the options. The proposed macros for adding new flags are: %_pkg_extra_cflags %_pkg_extra_cxxflags %_pkg_extra_fflags %_pkg_extra_ldflags These will be added to %{build_cflags}, %{build_cxxflags}, %{build_fflags}, and %{build_ldflags} respectively to allow packges to add their own flags to the default list: e.g. %build_cflags %{optflags} %{_pkg_extra_cflags} The proposed new macros to represent existing flags are: %_flag_fstack_protector_strong -fstack-protector-strong %_flag_z_now -Wl,-z,now %_flag_z_defs -Wl,-z,defs %_flag_flto_auto -flto=auto %_flag_ffat_lto_objects -ffat-lto-objects %_flag_o -O2 %_flag_f_exceptions -fexceptions %_flag_g -g %_flag_grecord_gcc_switches -grecord-gcc-switches %_flag_pipe -pipe %_flag_wall -Wall %_flag_werror_format_security -Werror=format-security %_flag_fortify_source -Wp,-D_FORTIFY_SOURCE=2 %_flag_glibcxx_assertions -Wp,-D_GLIBCXX_ASSERTIONS %_flag_asynchronous_unwind_tables -fasynchronous-unwind-tables %_flag_fstack_clash_protection -fstack-clash-protection %_flag_fcf_protection -fcf-protection %_flag_mbranch_protection_standard -mbranch-protection=standard With these new macros, the examples from above could be re-written as: compiler-rt: %global _pkg_extra_cflags -D_DEFAULT_SOURCE julia: %global _flag_glibcxx_assertions %{nil} For more details see the [https://src.fedoraproject.org/fork/tstellar/rpms/redhat-rpm-config/c/0ee9a8… Prototype Implementation]. In addition to adding these new macros, the packaging guidelines will be updated to require that all new flags added to redhat-rpm-config have their own RPM macro. == Benefit to Fedora == * It will provide a standard way to disable existing compiler flags or enable new ones that is more simple and robust than the existing echo + sed solution. * It will make it easier to determine which packages disable or add compiler flags by doing a simple grep of the spec files. * It will make it easier for toolchain developers to experiment with adding new flags to the distribution as this can be done with a simple macro definition instead of patching redhat-rpm-config. == Scope == * Proposal owners: ** Proposal owners will update the redhat-rpm-config package and add the new macros. ** Proposal owners will test the changes to ensure that the correct flags are still being used. * Other developers: ** Other developers may, but are not required to, update their packages to use the new macros. * Release engineering: [https://pagure.io/releng/issues/10819 #10819] * Policies and guidelines: ** The Fedora packaging policy will be updated to require that new flags added to redhat-rpm-config come with their own RPM macro. * Trademark approval: N/A (not needed for this Change) * Alignment with Objectives: == Upgrade/compatibility impact == None. == How To Test == * This can be tested by inspecting the value of the %{build_cflags}, %{build_cxxflags}, %{build_fflags}, and %{build_ldflags} and ensuring they are the same before and after the change. * This can be tested by modifying some of the new macros in a spec file and ensuring that the changes appear in the appropriate macro mentioned above. == User Experience == This is a change for developers and will have no impact to the user experience. == Dependencies == None. == Contingency Plan == * Contingency mechanism: (What to do? Who will do it?) Change owner will revert the update to redhat-rpm-config. * Contingency deadline: Mass Rebuild * Blocks release? N/A (not a System Wide Change), No == Documentation == None. == Release Notes == None. -- Ben Cotton He / Him / His Fedora Program Manager Red Hat TZ=America/Indiana/Indianapolis

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F37 Change Proposal: MAC Address Policy none (System-Wide Change)
by Vipul Siddharth 07 Feb '23

07 Feb '23

This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee. == Summary == The `systemd-udev` package installs `"/usr/lib/systemd/network/99-default.link"`, which sets `Link.MACAddressPolicy=persistent`. This proposal is to change it to set `Link.MACAddressPolicy=none` to stop changing the MAC address. This is particularly important for bridge and bond devices. This change can either only apply to bridge/bond devices, or to various software devices. That is to be discussed. == Owner == * Name: [[User:thaller|Thomas Haller]] (NetworkManager) * Email: <thaller(a)redhat.com> * Name: [[User:dustymabe| Dusty Mabe]] (Fedora CoreOS) * Email: <dmabe(a)redhat.com> == Detailed Description == On Fedora, udev by default changes the MAC address of a wide range of software devices. This was introduced by systemd 242 in early 2019 (Fedora 31), when `MACAddressPolicy=` was extended to affect more types of devices. With `MACAddressPolicy=persistent` udev's aim is to provide a stable MAC address, otherwise the kernel will assign a random one. However, that can cause problems: Firstly, software devices are always created by some tool that has plans for the device. The tool may not expect that udev is going to change the MAC address and races against that. The best solution for the tool is to set the MAC address when creating an interface. This will prevent udev from changing the MAC address according to the MACAddressPolicy. Otherwise, the tool should wait for udev to initialize the device to avoid the race. In theory, a tool is always advised to wait for udev to initialize the device. However, if it were not for MACAddressPolicy, in common scenarios udev doesn't do anything relevant for software devices to make that necessary. Secondly, for interface types bridge and bond, an unset MAC address has a special meaning to the kernel and the MAC address of the first port is used. If udev changes the MAC address, that no longer works. Now the generated MAC address is not directly discoverable as it is based on `/etc/machine-id` ([https://www.man7.org/linux/man-pages/man5/machine-id.5.html machine-id(5)]), among other data. Even if there were a tool to easily calculate the MAC address, it could be cumbersome to use it without logging into the machine first. The MAC address can directly affect the assigned IP address, for example when using DHCP. When booting a new virtual machine, the user might know the MAC address of the (virtual) "physical" interfaces. When bonding/bridging those interfaces, the bond/bridge would get one of the well known MAC addresses. `MACAddressPolicy=persistent` interferes with that. The goal of persistent policy is to provide a stable MAC address. Note that if the tool or user who created the interface would want a certain MAC address, they have all the means to set it already. That applies regardless whether the tool is iproute2, NetworkManager, systemd-networkd. Neither NetworkManager nor systemd-networkd rely on udev's MACAddressPolicy for setting the MAC address. This behavior is mostly useful for plain `ip link add`, but it's unclear which real world user wants this behavior. Of course, the user is welcome to configure the MAC address in any way they want. Including, dropping a link file that sets `MACAddressPolicy=persistent`. The problem is once udev sets a MAC address, it cannot be unset. Which makes this problematic to do by default. While Fedora inherited this behavior from upstream systemd, RHEL-9 does not follow this behavior ([https://gitlab.com/redhat/centos-stream/rpms/systemd/-/blob/c8953519504bf2e… centos9], [https://bugzilla.redhat.com/show_bug.cgi?id=1921094 rh#1921094]). For RHEL-8, this doesn't apply because the systemd there is too old to change the MAC address of most software devices. This could be either implemented by patching `/usr/lib/systemd/network/99-default.link` to have a different policy, or by dropping a link file with higher priority. In the latter case, that override could be shipped either by udev or even by NetworkManager. Another option is to change the scope of this proposal to only change to `MACAddressPolicy=none` for the device types where this causes the most issues (bridge/bond/team). == Feedback == This was also discussed on upstream systemd mailing list [https://lists.freedesktop.org/archives/systemd-devel/2022-May/047893.html here]. The upstream systemd maintainers' opinion is that the current udev behavior is desirable, but accepts that distributions (or network stacks such as NetworkManager) may choose to change the default depending on their needs ([https://lists.freedesktop.org/archives/systemd-devel/2022-May/047943.html reference]). The goal here is to find out what the Fedora community thinks is the most appropriate default. The RHEL-9 bug is [https://bugzilla.redhat.com/show_bug.cgi?id=1921094 [rh#1921094]]. == Benefit to Fedora == Pros: - Consistent behavior with RHEL8 and RHEL9. - Avoid race of udev and the tool that creates the interface. - Bridge and bond interfaces can get the MAC addresses from their first port. In the case of `MACAddressPolicy=none` for a bond (or bridge) the bond will get a MAC related to one of its physical NIC devices. In the case of provisioning new systems (especially in a large datacenter) information about the server can be used to configure the network environment (DHCP, Firewall, etc) before the server is ever even powered on. This does mean that you may have to update your network environment configuration if you replace a NIC (con), but that you won't have to update your network environment configuration if you re-install your server (pro), which is what you'd have to do now with `MACAddressPolicy=persistent`. Cons: - Deviate from upstream systemd. It is desirable that RHEL and Fedora behaves similar. A possible outcome could be the current behavior stays and RHEL 10 would change behavior. On the other hand, different distributions (or even Fedora spins) have different uses and needs. Deviating might be fine. In the same vein, there is also a desire to stay close to upstream systemd behavior. But the uses of systemd project go beyond Fedora/RHEL, so deviating here may also be fine. == Scope == * Proposal owners: The main goal of this request is to generate productive discussion and find the desired behavior. The implementation/changes are either way very simple. * Other developers: Other projects that wish a certain MAC address are welcome to set it for their devices. Including using udev's MACAddressPolicy. * Release engineering: Not needed for this change. * Policies and guidelines: N/A (not needed for this Change) * Trademark approval: N/A (not needed for this Change) * Alignment with Objectives: == Upgrade/compatibility impact == After the change, the MAC address for the affected device types changes. == How To Test == 1) Create a software device two times, for example `ip link add type bridge`. Note that the MAC address is either stable or random, depending on the `MACAddressPolicy=`. 2) Note that if the software device has the MAC address set initially, udev does not change it (`ip link add address aa:aa:aa:aa:aa:aa type bridge`). That depends on `/sys/class/net/$dev/addr_assign_type`. 3) Create a bridge/bond interface without setting the MAC address. Note that if `MACAddressPolicy=none`, the MAC address is random at first. Note that attaching the first port will update the controller's MAC address. On the other hand, with `MACAddressPolicy=persistent`, the MAC address of the controller is fixed and not inherited from the port. 4) Run ip monitor link & while : ; do ip link del xxx ip link add name xxx type dummy \ && ip link set xxx addr aa:00:00:00:00:00 \ && ip link show xxx | grep -q aa:00:00:00:00:00 \ || break done to reproduce the race between a simple tool and udev changing the MAC address. == User Experience == Bond/bridge devices would again get assigned the MAC address of the first NIC added to the device. If we chose to not limit the scope of this change to just bonds/bridges then all software devices would get randomly assigned MAC addresses. == Dependencies == None. == Contingency Plan == If the change is rejected, nothing needs to be done. The change itself will be simple to implement. Contingency deadline: beta freeze Blocks release? No == Documentation == TODO. == Release Notes == -- Vipul Siddharth He/His/Him FPgM team member

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x86_64-v2 in Fedora
by Neal Gompa 02 Feb '23

02 Feb '23

Hey all, Earlier this week, I was helping with processing features for openSUSE Leap 15.4[1] and I discovered that they're planning on introducing x86_64-v2 to openSUSE soon. The reference for this change was that RHEL 9 is going to use x86_64-v2[2]. Additionally, other distributions have been considering bumping up to v2 or v3[3][4]. Some cursory examination of the new x86_64 sublevels seem to indicate that x86_64-v2 goes back to roughly 2007~2008, merely cutting off the first couple of generations of x86_64 CPUs from Intel and AMD. I personally don't have any computers that don't have support for x86_64-v2 anymore. Does anyone know if anyone is planning to propose this for Fedora anytime soon, either as an addon architecture (like what Arch is doing) or an upgrade of our x86_64 baseline like RHEL is doing? [1]: https://en.opensuse.org/Feature_Planning_15.4 [2]: https://developers.redhat.com/blog/2021/01/05/building-red-hat-enterprise-l… [3]: https://ml.mageia.org/l/arc/dev/2021-02/msg00583.html [4]: https://www.phoronix.com/scan.php?page=news_item&px=Arch-Linux-x86-64-v3-Po… -- 真実はいつも一つ！/ Always, there's only one truth!

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FESCo wants to know what you use i686 packages for
by David Cantrell 17 Jan '23

17 Jan '23

Hi, Our most recent FESCo meeting involved discussing the proposal to drop i686 builds of jdk8,11,17 from Fedora 37 onward. The topic quickly changed to the larger question of "what do people use i686 packages for?" Rather than guess, we wanted to ask the community what you use i686 packages for in Fedora. There are no wrong answers here. We are seeking information. Why? Since the removal of the i686 kernel in Fedora, we want to reduce the number of i686 packages provided in the repo. As time marches on, the ability to build a lot of things for i686 becomes unrealistic or even impossible. Remember it goes beyond providing builds...providing support, bug fixes, and security fixes for those packages too. Maybe some things using i686 packages now can move to x86_64 packages. We do not know yet, but a goal is to figure out what packages, if anything, can drop their i686 builds. NOTE: Nothing is changing now. We are in an information gathering phase. ~~~~~~~~~~~~~~~~~~~~~~~~ If you use i686 packages for something now, please respond to this thread. Thanks, -- David Cantrell <dcantrell(a)redhat.com> Red Hat, Inc. | Boston, MA | EST5EDT

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"rescue" boot entry files are not updated on OS upgrades
by Chris Murphy 04 Jan '23

04 Jan '23

Summary---------- Most all Fedora variants (except Cloud) have a GRUB menu entry containing the word "rescue". This kernel+initramfs pair are never updated for the life of a Fedora installation. And they quickly become stale as a Fedora installation ages. This kernel's modules are eventually deleted, and if selected at boot time, the typical user experience is a dracut shell. Basic background------------- (skip this section if you know how it works) During a new installation, a single kernel version is installed. e.g. vmlinuz-5.17.0-0.rc4.96.fc36.x86_64 which is then duplicated as e.g. vmlinuz-0-rescue-3a86878de5d649a983916543ece7bb7e. Each of those (identical) kernels has an initramfs file: initramfs-5.17.0-0.rc4.96.fc36.x86_64.img initramfs-0-rescue-3a86878de5d649a983916543ece7bb7e.img The sole difference is the first one is a smaller host-only initramfs, the second one is a larger no host-only initramfs created with `dracut -N`. The bigger one just contains a bunch of extra kernel modules and dracut scripts, ostensibly to make it more likely to boot a system with some change in hardware that the host-only initramfs doesn't contain. The size of this rescue initramfs is around 100 MiB, with the common day to day "host only" initramfs being around 33 MiB. [1] As the system is updated, additional kernel versions are installed. dnf.conf contains installonly_limit=3, which results in a maximum of three kernel versions being installed at a time. Once a fourth kernel is installed, the first kernel and its modules are removed from /usr/lib/modules. The rescue kernel+initramfs pair are never updated or upgraded, even during system upgrades. Observations------------ This has been discussed by the Workstation working group [2] but since this functionality is present in all of Fedora, we're moving the discussion for greater visibility. There's two separate complaints, if you will: (a) that the kernel+initramfs pair are never update or upgraded for the life of the installation; and (b) that even during one release cycle, the user experience when booting the rescue entry, changes, i.e. when the matching /usr/lib/modules for the rescue entry are present early on, you do get a full runtime behavior, you will get to a graphical environment. But then once the version matched /usr/lib/modules are removed, you get a completely different behavior when booting the rescue entry. An important note from that ticket from Justin Forbes, the Fedora kernel maintainer: " Remember, the only real purpose of the rescue kernel is to get your system out of something completely unusable. It isn't meant to be a full runtime." Questions------------ * Considering the very narrow purpose of the entry, maybe the current behavior is adequate? * Does the rescue entry reliably get users to a dracut prompt, rather than indefinite hang? I don't know whether it does. * Is there any way to improve the situation without increasing the risk that the rescue entry becomes totally non-functional? * The chosen kernel version needs to be based on one that is known to boot. Currently we know the kernel+initramfs pair work because it's the same version used to boot the installation media when doing the initial provisioning. We don't actually know an updated replacement "no host-only" initramfs will work until it's tried. Is it possible to automate this? And is it worth the risk, or even figuring out how to assess the risk? * At Flock 2021, Zbyszek proposed "Building Initrd Images from RPMs" to reduce the complexity of building initramfs, maybe there's a role for it here? More: https://www.youtube.com/watch?v=GATg_bqmASc * What happens if we accept some scope creep, and go for many improvements that make the extra work worth it? * What about the unsigned nature of the initramfs? Should we be creating initramfs's in Fedora infra and signing them? * Stuff a graphical rescue environment into the initramfs? (This might be ten leaps too far, but it's intended to encourage thinking with a vivid imagination.) [1] both values from a recent Fedora 36 Workstation installation [2] https://pagure.io/fedora-workstation/issue/259 -- Chris Murphy

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Orphaned X11 packages
by Adam Jackson 24 Dec '22

24 Dec '22

The following packages, previously owned by xgl-maint, are now up for grabs: xorg-x11-xfs xorg-sgml-doctools xorg-x11-drv-v4l xorg-x11-xsm xorg-x11-twm xorg-x11-drv-sisusb xorg-x11-xdm xorg-x11-docs Upstream development on all of these is pretty much nil, so if you're serious about picking up any of these you may also wish to take on the module upstream: https://gitlab.freedesktop.org/xorg - ajax

3 2

[apt-cacher-ng] Resurrect dead package
by Frédéric Pierret 24 Dec '22

24 Dec '22

Hi, I've resurrected `apt-cacher-ng` on my fork: https://src.fedoraproject.org/fork/fepitre/rpms/apt-cacher-ng/c/06340bafbb2… with successful builds on my testing COPR repository for F32+ and EPEL8: https://copr.fedorainfracloud.org/coprs/fepitre/fedora/build/1879178/. I plan to (already) use this package for my current work on reproducible builds. Is the procedure described in https://fedoraproject.org/wiki/Orphaned_package_that_need_new_maintainers?r… still available for such case? Thank you. Best regards, Frédéric Pierret

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F37 proposal: Add -fno-omit-frame-pointer to default compilation flags (System-Wide Change proposal)
by Ben Cotton 29 Nov '22

29 Nov '22

https://fedoraproject.org/wiki/Changes/fno-omit-frame-pointer This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee. == Summary == Fedora will add -fno-omit-frame-pointer to the default C/C++ compilation flags, which will improve the effectiveness of profiling and debugging tools. == Owner == * Name: [[User:daandemeyer| Daan De Meyer]], [[User:Dcavalca| Davide Cavalca]], [[ Andrii Nakryiko]] * Email: daandemeyer(a)fb.com, dcavalca(a)fb.com, andriin(a)fb.com == Detailed Description == Credits to Mirek Klimos, whose internal note on stacktrace unwinding formed the basis for this change proposal (myreggg(a)gmail.com) Any performance or efficiency work relies on accurate profiling data. Sampling profilers probe the target program's call stack at regular intervals and store the stack traces. If we collect enough of them, we can closely approximate the real cost of a library or function with minimal runtime overhead. Stack trace capture what’s running on a thread. It should start with clone - if the thread was created via clone syscall - or with _start - if it’s the main thread of the process. The last function in the stack trace is code that CPU is currently executing. If a stack starts with [unknown] or any other symbol, it means it's not complete. === Unwinding === How does the profiler get the list of function names? There are two parts of it: # Unwinding the stack - getting a list of virtual addresses pointing to the executable code # Symbolization - translating virtual addresses into human-readable information, like function name, inlined functions at the address, or file name and line number. Unwinding is what we're interested in for the purpose of this proposal. The important things are: * Data on stack is split into frames, each frame belonging to one function. * Right before each function call, the return address is put on the stack. This is the instruction address in the caller to which we will eventually return — and that's what we care about. * One register, called the "frame pointer" or "base pointer" register (RBP), is traditionally used to point to the beginning of the current frame. Every function should back up RBP onto the stack and set it properly at the very beginning. The “frame pointer” part is achieved by adding push %rbp, mov %rsp,%rbp to the beginning of every function and by adding pop %rbp before returning. Using this knowledge, stack unwinding boils down to traversing a linked list: https://i.imgur.com/P6pFdPD.png === Where’s the catch? === The frame pointer register is not necessary to run a compiled binary. It makes it easy to unwind the stack, and some debugging tools rely on frame pointers, but the compiler knows how much data it put on the stack, so it can generate code that doesn't need the RBP. Not using the frame pointer register can make a program more efficient: * We don’t need to back up the value of the register onto the stack, which saves 3 instructions per function. * We can treat the RBP as a general-purpose register and use it for something else. Whether the compiler sets frame pointer or not is controlled by the -fomit-frame-pointer flag and the default is "omit", meaning we can’t use this method of stack unwinding by default. To make it possible to rely on the frame pointer being available, we'll add -fno-omit-frame-pointer to the default C/C++ compilation flags. This will instruct the compiler to make sure the frame pointer is always available. This will in turn allow profiling tools to provide accurate performance data which can drive performance improvements in core libraries and executables. == Feedback == === Potential performance impact === * Meta builds all its libraries and executables with -fno-omit-frame-pointer by default. Internal benchmarks did not show significant impact on performance when omitting the frame pointer for two of our most performance intensive applications. * Firefox recently landed a change to preserve the frame pointer in all jitted code (https://bugzilla.mozilla.org/show_bug.cgi?id=1426134) No significant decrease in performance was observed. * Kernel 4.8 frame pointer benchmarks by Suse showed 5%-10% regressions in some benchmarks (https://lore.kernel.org/all/20170602104048.jkkzssljsompjdwy@suse.de/T/#u) Should individual libraries or executables notice a significant performance degradation caused by including the frame pointer everywhere, these packages can opt-out on an individual basis as described in https://docs.fedoraproject.org/en-US/packaging-guidelines/#_compiler_flags. === Alternatives to frame pointers === There are a few alternative ways to unwind stacks instead of using the frame pointer: * [https://dwarfstd.org DWARF] data - The compiler can emit extra information that allows us to find the beginning of the frame without the frame pointer, which means we can walk the stack exactly as before. The problem is that we need to unwind the stack in kernel space which isn't implemented in the kernel. Given that the kernel implemented it's own format (ORC) instead of using DWARF, it's unlikely that we'll see a DWARF unwinder in the kernel any time soon. The perf tool allows you to use the DWARF data with --call-graph=dwarf, but this means that it copies the full stack on every event and unwinds in user space. This has very high overhead. * [https://www.kernel.org/doc/html/v5.3/x86/orc-unwinder.html ORC] (undwarf) - problems with unwinding in kernel led to creation of another format with the same purpose as DWARF, just much simpler. This can only be used to unwind kernel stack traces; it doesn't help us with userspace stacks. More information on ORC can be found [https://lwn.net/Articles/728339 here]. * [https://lwn.net/Articles/680985 LBR] - New Intel CPUs have a feature that gives you source and target addresses for the last 16 (or 32, in newer CPUs) branches with no overhead. It can be configured to record only function calls and to be used as a stack, which means it can be used to get the stack trace. Sadly, you only get the last X calls, and not the full stack trace, so the data can be very incomplete. On top of that, many Fedora users might still be using CPUs without LBR support which means we wouldn't be able to assume working profilers on a Fedora system by default. To summarize, if we want complete stacks with reasonably low overhead (which we do, there's no other way to get accurate profiling data from running services), frame pointers are currently the best option. == Benefit to Fedora == Implementing this change will provide profiling tools with easy access to stacktraces of installed libraries and executables which will lead to more accurate profiling data in general. This in turn can be used to implement optimizations to core libraries and executables which will improve the overall performance of Fedora itself and the wider Linux ecosystem. Various debugging tools can also make use of the frame pointer to access the current stacktrace, although tools like gdb can already do this to some degree via embedded dwarf debugging info. == Scope == * Proposal owners: Put up a PR to change the rpm macros to build packages by default with -fno-omit-frame-pointer by default. * Other developers: Review and merge the PR implementing the Change. * Release engineering: [https://pagure.io/releng/issues #Releng issue number]. A mass rebuild is required. * Policies and guidelines: N/A (not needed for this Change) * Trademark approval: N/A (not needed for this Change) * Alignment with Objectives: N/A == Upgrade/compatibility impact == This should not impact upgrades in any way. == How To Test == # Build the package with the updated rpm macros # Profile the binary with `perf record -g <binary>` # Inspect the perf data with `perf report -g 'graph,0.5,caller'` # When expanding hot functions in the perf report, perf should show the full call graph of the hot function (at least for all functions that are part of the binary compiled with -fno-omit-frame-pointer) == User Experience == Fedora users will be more likely to have a streamlined experience when trying to debug/profile system executables/libraries. Tools such as perf will work out of the box instead of requiring to users to provide extra options (e.g. --call-graph=dwarf/LBR) or requiring users to recompile all relevant packages with -fno-omit-frame-pointer. == Dependencies == The rpm macros for Fedora need to be adjusted to include -fno-omit-frame-pointer in the default C/C++ compilation flags. == Contingency Plan == * Contingency mechanism: The new version can be released without every package being rebuilt with fno-omit-frame-pointer. Profiling will only work perfectly once all packages have been rebuilt but there will be no regression in behavior if not all packages have been rebuilt by the time of the release. If the Change is found to introduce unacceptable regressions, the PR implementing it can be reverted and affected packages can be rebuilt. * Contingency deadline: Final freeze * Blocks release? No == Documentation == * Original proposal for in-kernel DWARF unwinder (rejected): https://lkml.org/lkml/2017/5/5/571 == Release Notes == Packages are now compiled with frame pointers included by default. This will enable a variety of profiling and debugging tools to show more information out of the box. -- Ben Cotton He / Him / His Fedora Program Manager Red Hat TZ=America/Indiana/Indianapolis

39 142

fedpkg clone fails with Permission denied (publickey).
by Richard Shaw 26 Nov '22

26 Nov '22

Long story short I lost my home directory where I do all of my packager activities (separate from my main user) so I'm setting things up from scratch. I created new ssh keys and uploaded the public key to admin.fedoraproject.org and pasted into pagure.io. It's been over an hour and I'm still getting: $ fedpkg clone hamlib Cloning into 'hamlib'... hobbes1069(a)pkgs.fedoraproject.org: Permission denied (publickey). fatal: Could not read from remote repository. Please make sure you have the correct access rights and the repository exists. Could not execute clone: Failed to execute command. I've also updated my API tokens, which is STILL not well documented. I pasted them in the appropriate spot in "/etc/rpkg/fedpkg.conf" which isn't real intuitive. Thanks, Richard

5 10

F38 Proposal: SPDX License Phase 1 (Self-Contained Change proposal)
by Ben Cotton 05 Oct '22

05 Oct '22

https://fedoraproject.org/wiki/Changes/SPDX_Licenses_Phase_1 This document represents a proposed Change. As part of the Changes process, proposals are publicly announced in order to receive community feedback. This proposal will only be implemented if approved by the Fedora Engineering Steering Committee. == Summary == Transition from Fedora's short name of licenses to standardized [https://spdx.org/licenses/ SPDX license] [https://spdx.dev/specifications/ formula]. == Owner == * Name: [[User:msuchy| Miroslav Suchý]] * Name: [[User:jlovejoy| Jilayne Lovejoy]] * Name: [[User:ngompa| Neal Gompa]] * Name: [[User:dcantrell| David Cantrell]] * Name: [[User:rfontanaref| Richard Fontana]] * Name: [[User:mattdm| Matthew Miller]]  * Email: msuchy(a)redhat.com, dcantrell(a)redhat.com, jlovejoy(a)redhat.com, ngompa13(a)gmail.com, rfontana(a)redhat.com == Detailed Description == In the past, Fedora decided to use short names for licenses. Although we documented the short names very well. The identifiers were never standard. In the meantime, SPDX identifiers become standard, and [https://wiki.spdx.org/view/Business_Team/Adoption other SW vendors start using it]. In this phase, we want to provide documentation and tooling to allow maintainers to begin using SPDX license ids instead of the old Fedora short names. This move is opt-in. There will be [[Changes/SPDX_Licenses_Phase_2|Phase 2]], where we identify the remaining packages and help them to migrate to the SPDX formula. == Feedback == Ancient [https://lists.fedoraproject.org/archives/list/legal@lists.fedoraproject.org… feedback from SPDX organization]. Summary from [https://lists.fedoraproject.org/archives/search?q=spdx&page=1&mlist=legal%4… fedora-legal mailing list]: we want this to happen, but this is big scope and likely will happen over more than one release. Summary from packaging-committee: * [https://pagure.io/packaging-committee/pull-request/971#] older PR to change packaging guidelines * [https://pagure.io/packaging-committee/pull-request/1142] present PR that needs more updating Summary from devel-list: TBD == Benefit to Fedora == The use of a standardized identifier for license will align Fedora with other distributions. And allows efficient and reliable identification of licenses. == Scope == * Proposal owners (things sorted by done/todo and by priorities): ** Miroslav Suchý: license-fedora2spdx - done ** Jilayne Lovejoy: map rest of Fedora licenses to SPDX ids - done ** David Cantrell: create machine-readable format and new repo - done ** David Cantrell: merge mapping of Fedora licenses to SPDX ids to new data format/repo - done ** Richard Fontana & Jilayne Lovejoy: review update all licensing info and legal pages in wiki - in process ** Jilayne Lovejoy & Richard Fontana: create and populate new Docs pages for legal and licensing info - in process ** Miroslav Suchy - create [https://gitlab.com/fedora/legal/fedora-license-data fedora-license-data package] (with data from rpminspect-data-fedora) - TODO ** David Cantrell: separate licenses from rpminspect-data-fedora [https://bugzilla.redhat.com/show_bug.cgi?id=2077914 BZ 2077914] - TODO ** Miroslav Suchý: allow `license-validate` to use spdx - TODO ** David Cantrell: generate from license data to new Docs page similar to [https://fedoraproject.org/wiki/Licensing:Main#Software_License_List Licensing:Main] ** SOMEBODY: create a webhook that updates Docs page after the merge to fedora-license-data - TODO ** Jilayne Lovejoy: prepare PR for updates to packaging guidelines - in the process [https://pagure.io/packaging-committee/pull-request/1142] ** SOMEBODY: help maintainers who want to change license string to SPDX identifiers proactively. * Out of Scope: In this phase, we do not target to move **all** packages to SPDX identifiers. That will be done in [[Changes/SPDX_Licenses_Phase_2|Phase 2]]. In [[Changes/SPDX_Licenses_Phase_2|Phase 2]] we will identify the remaining packages and open BZ or PR. * Other developers: Early adopters can migrate their License tag to the SPDX identifiers. Proposal owners will gather feedback and will work on potential problems. We want to have all bits ready so that maintainers can start changing the spec files just after Fedora 37 branching (summer 2022). * Release engineering: * Policies and guidelines: Licensing page, packaging guidelines has to be altered. * Trademark approval: N/A (not needed for this Change) * Alignment with Objectives: == Upgrade/compatibility impact == License strings are not used anything in run time. This change will not affect the upgrade or runtime of Fedora. During the transition period, developer tools like rpminspect, licensecheck, etc. may produce false negatives. And we have to define a date where we flip these tools from old Fedora's short names to the SPDX formula. == How To Test == Users should not need any testing. These steps are for package maintainers: * Fetch your license string from `License` tag in SPEC file. * Test that your current Fedora's short name is correct. E.g. $ license-validate -v 'MIT or GPLv1' Approved license * Convert license string to SPDX formula: $ license-fedora2spdx 'MIT or GPLv1' Warning: more options how to interpret MIT. Possible options: ['Adobe-Glyph', 'MIT-CMU', 'MIT-CMU', 'HPND', 'HPND', 'no-spdx-yet (MIT license (also X11))', 'SGI-B-2.0', 'SGI-B-2.0', 'SMLNJ', 'MIT-enna', 'MIT-feh', 'mpich2'] mpich2 or GPL-1.0-only In this example, the short name `GPLv1` can be converted straight to `GPL-1.0-only`. But short name `MIT` stands for several licenses with different [https://spdx.org/licenses/ SPDX identifiers]. You have to examine what license is package actually using. `license-fedora2spdx` will try to convert the formula and use one of the options but without any heuristics. You need to manually review the license. You can check if SPDX formula is correct using: $ license-validate -v --file FIXME "MIT-CMU or GPL-1.0-only" == User Experience == Users should be able to use standard software tools that audit licenses. E.g. for Software Bills of Materials. == Dependencies == No other dependencies. == Contingency Plan == * Contingency mechanism: In this first phase, if something goes wrong, we can 'git revert' each change in dist-git. It is expected that in the first phase, there will be only a few packages altered. It may be a few hundred, but it is still doable to revert. * Contingency deadline: Beta freeze. But it is expected that not all packages will be converted by that time and the change will continue in the next release. * Blocks release? No. This change has no impact on runtime of any package. == Documentation == N/A (not a System Wide Change) == Release Notes == -- Ben Cotton He / Him / His Fedora Program Manager Red Hat TZ=America/Indiana/Indianapolis

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devel June 2022