user/sven/linux.git/init/version.c, branch v5.18.3

kbuild: add an elfnote for whether vmlinux is built with lto

2021-04-24T20:25:42Z

Currently, clang LTO built vmlinux won't work with pahole. LTO introduced cross-cu dwarf tag references and broke current pahole model which handles one cu as a time. The solution is to merge all cu's as one pahole cu as in [1]. We would like to do this merging only if cross-cu dwarf references happens. The LTO build mode is a pretty good indication for that. In earlier version of this patch ([2]), clang flag -grecord-gcc-switches is proposed to add to compilation flags so pahole could detect "-flto" and then merging cu's. This will increate the binary size of 1% without LTO though. Arnaldo suggested to use a note to indicate the vmlinux is built with LTO. Such a cheap way to get whether the vmlinux is built with LTO or not helps pahole but is also useful for tracing as LTO may inline/delete/demote global functions, promote static functions, etc. So this patch added an elfnote with a new type LINUX_ELFNOTE_LTO_INFO. The owner of the note is "Linux". With gcc 8.4.1 and clang trunk, without LTO, I got $ readelf -n vmlinux Displaying notes found in: .notes Owner Data size Description ... Linux 0x00000004 func description data: 00 00 00 00 ... With "readelf -x ".notes" vmlinux", I can verify the above "func" with type code 0x101. With clang thin-LTO, I got the same as above except the following: description data: 01 00 00 00 which indicates the vmlinux is built with LTO. [1] https://lore.kernel.org/bpf/20210325065316.3121287-1-yhs@fb.com/ [2] https://lore.kernel.org/bpf/20210331001623.2778934-1-yhs@fb.com/ Suggested-by: Arnaldo Carvalho de Melo Signed-off-by: Yonghong Song Reviewed-by: Nick Desaulniers Tested-by: Sedat Dilek # LLVM/Clang v12.0.0-rc4 (x86-64) Tested-by: Arnaldo Carvalho de Melo Signed-off-by: Masahiro Yamada

init/version.c: remove Version_ symbol

2021-02-26T17:41:04Z

This code hunk creates a Version_ symbol if CONFIG_KALLSYMS is disabled. For example, building the kernel v5.10 for allnoconfig creates the following symbol: $ nm vmlinux | grep Version_ c116b028 B Version_330240 There is no in-tree user of this symbol. Commit 197dcffc8ba0 ("init/version.c: define version_string only if CONFIG_KALLSYMS is not defined") mentions that Version_* is only used with ksymoops. However, a commit in the pre-git era [1] had added the statement, "ksymoops is useless on 2.6. Please use the Oops in its original format". That statement existed until commit 4eb9241127a0 ("Documentation: admin-guide: update bug-hunting.rst") finally removed the stale ksymoops information. This symbol is no longer needed. [1] https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=ad68b2f085f5c79e4759ca2d13947b3c885ee831 Link: https://lkml.kernel.org/r/20210120033452.2895170-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Cc: Mauro Carvalho Chehab Cc: Randy Dunlap Cc: Daniel Guilak Cc: Lee Revell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uts: Use generic ns_common::count

2020-08-19T12:13:20Z

Switch over uts namespaces to use the newly introduced common lifetime counter. Currently every namespace type has its own lifetime counter which is stored in the specific namespace struct. The lifetime counters are used identically for all namespaces types. Namespaces may of course have additional unrelated counters and these are not altered. This introduces a common lifetime counter into struct ns_common. The ns_common struct encompasses information that all namespaces share. That should include the lifetime counter since its common for all of them. It also allows us to unify the type of the counters across all namespaces. Most of them use refcount_t but one uses atomic_t and at least one uses kref. Especially the last one doesn't make much sense since it's just a wrapper around refcount_t since 2016 and actually complicates cleanup operations by having to use container_of() to cast the correct namespace struct out of struct ns_common. Having the lifetime counter for the namespaces in one place reduces maintenance cost. Not just because after switching all namespaces over we will have removed more code than we added but also because the logic is more easily understandable and we indicate to the user that the basic lifetime requirements for all namespaces are currently identical. Signed-off-by: Kirill Tkhai Reviewed-by: Kees Cook Acked-by: Christian Brauner Link: https://lore.kernel.org/r/159644978167.604812.1773586504374412107.stgit@localhost.localdomain Signed-off-by: Christian Brauner

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45Z

Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

kbuild: Add build salt to the kernel and modules

2018-07-17T16:18:05Z

In Fedora, the debug information is packaged separately (foo-debuginfo) and can be installed separately. There's been a long standing issue where only one version of a debuginfo info package can be installed at a time. There's been an effort for Fedora for parallel debuginfo to rectify this problem. Part of the requirement to allow parallel debuginfo to work is that build ids are unique between builds. The existing upstream rpm implementation ensures this by re-calculating the build-id using the version and release as a seed. This doesn't work 100% for the kernel because of the vDSO which is its own binary and doesn't get updated when embedded. Fix this by adding some data in an ELF note for both the kernel and modules. The data is controlled via a Kconfig option so distributions can set it to an appropriate value to ensure uniqueness between builds. Suggested-by: Masahiro Yamada Signed-off-by: Laura Abbott Signed-off-by: Masahiro Yamada

init/version.c: include instead of

2017-11-18T00:10:02Z

init/version.c has nothing to do with modules, so remove the . Instead, include for EXPORT_SYMBOL_GPL. This cuts off a lot of unnecessary header parsing. Link: http://lkml.kernel.org/r/1505920984-8523-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Cc: Paul Gortmaker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

locking/atomic, kref: Add KREF_INIT()

2017-01-14T10:37:18Z

Since we need to change the implementation, stop exposing internals. Provide KREF_INIT() to allow static initialization of struct kref. Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

copy address of proc_ns_ops into ns_common

2014-12-04T19:34:47Z

Signed-off-by: Al Viro

common object embedded into various struct ....ns

2014-12-04T19:31:00Z

for now - just move corresponding ->proc_inum instances over there Acked-by: "Eric W. Biederman" Signed-off-by: Al Viro

proc: Split the namespace stuff out into linux/proc_ns.h

2013-05-01T21:29:39Z

Split the proc namespace stuff out into linux/proc_ns.h. Signed-off-by: David Howells cc: netdev@vger.kernel.org cc: Serge E. Hallyn cc: Eric W. Biederman Signed-off-by: Al Viro