kernel/linux.git/include/asm-generic/vmlinux.lds.h, branch v4.9.209

earlycon: Use a pointer table to fix __earlycon_table stride

2018-05-01T22:13:09+00:00

commit dd709e72cb934eefd44de8d9969097173fbf45dc upstream. Commit 99492c39f39f ("earlycon: Fix __earlycon_table stride") tried to fix __earlycon_table stride by forcing the earlycon_id struct alignment to 32 and asking the linker to 32-byte align the __earlycon_table symbol. This fix was based on commit 07fca0e57fca92 ("tracing: Properly align linker defined symbols") which tried a similar fix for the tracing subsystem. However, this fix doesn't quite work because there is no guarantee that gcc will place structures packed into an array format. In fact, gcc 4.9 chooses to 64-byte align these structs by inserting additional padding between the entries because it has no clue that they are supposed to be in an array. If we are unlucky, the linker will assign symbol "__earlycon_table" to a 32-byte aligned address which does not correspond to the 64-byte aligned contents of section "__earlycon_table". To address this same problem, the fix to the tracing system was subsequently re-implemented using a more robust table of pointers approach by commits: 3d56e331b653 ("tracing: Replace syscall_meta_data struct array with pointer array") 654986462939 ("tracepoints: Fix section alignment using pointer array") e4a9ea5ee7c8 ("tracing: Replace trace_event struct array with pointer array") Let's use this same "array of pointers to structs" approach for EARLYCON_TABLE. Fixes: 99492c39f39f ("earlycon: Fix __earlycon_table stride") Signed-off-by: Daniel Kurtz Suggested-by: Aaron Durbin Reviewed-by: Rob Herring Tested-by: Guenter Roeck Reviewed-by: Guenter Roeck Cc: stable Signed-off-by: Greg Kroah-Hartman

kaiser: cleanups while trying for gold link

2018-01-05T14:46:33+00:00

While trying to get our gold link to work, four cleanups: matched the gdt_page declaration to its definition; in fiddling unsuccessfully with PERCPU_INPUT(), lined up backslashes; lined up the backslashes according to convention in percpu-defs.h; deleted the unused irq_stack_pointer addition to irq_stack_union. Sad to report that aligning backslashes does not appear to help gold align to 8192: but while these did not help, they are worth keeping. Signed-off-by: Hugh Dickins Signed-off-by: Greg Kroah-Hartman

KAISER: Kernel Address Isolation

2018-01-05T14:46:32+00:00

This patch introduces our implementation of KAISER (Kernel Address Isolation to have Side-channels Efficiently Removed), a kernel isolation technique to close hardware side channels on kernel address information. More information about the patch can be found on: https://github.com/IAIK/KAISER From: Richard Fellner From: Daniel Gruss Subject: [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode Date: Thu, 4 May 2017 14:26:50 +0200 Link: http://marc.info/?l=linux-kernel&m=149390087310405&w=2 Kaiser-4.10-SHA1: c4b1831d44c6144d3762ccc72f0c4e71a0c713e5 To: To: Cc: Cc: Cc: Michael Schwarz Cc: Richard Fellner Cc: Ingo Molnar Cc: Cc: After several recent works [1,2,3] KASLR on x86_64 was basically considered dead by many researchers. We have been working on an efficient but effective fix for this problem and found that not mapping the kernel space when running in user mode is the solution to this problem [4] (the corresponding paper [5] will be presented at ESSoS17). With this RFC patch we allow anybody to configure their kernel with the flag CONFIG_KAISER to add our defense mechanism. If there are any questions we would love to answer them. We also appreciate any comments! Cheers, Daniel (+ the KAISER team from Graz University of Technology) [1] http://www.ieee-security.org/TC/SP2013/papers/4977a191.pdf [2] https://www.blackhat.com/docs/us-16/materials/us-16-Fogh-Using-Undocumented-CPU-Behaviour-To-See-Into-Kernel-Mode-And-Break-KASLR-In-The-Process.pdf [3] https://www.blackhat.com/docs/us-16/materials/us-16-Jang-Breaking-Kernel-Address-Space-Layout-Randomization-KASLR-With-Intel-TSX.pdf [4] https://github.com/IAIK/KAISER [5] https://gruss.cc/files/kaiser.pdf [patch based also on https://raw.githubusercontent.com/IAIK/KAISER/master/KAISER/0001-KAISER-Kernel-Address-Isolation.patch] Signed-off-by: Richard Fellner Signed-off-by: Moritz Lipp Signed-off-by: Daniel Gruss Signed-off-by: Michael Schwarz Acked-by: Jiri Kosina Signed-off-by: Hugh Dickins Signed-off-by: Greg Kroah-Hartman

kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured

2017-08-30T08:21:49+00:00

commit cb87481ee89dbd6609e227afbf64900fb4e5c930 upstream. The .data and .bss sections were modified in the generic linker script to pull in sections named .data., which are generated by gcc with -ffunction-sections and -fdata-sections options. The problem with this pattern is it can also match section names that Linux defines explicitly, e.g., .data.unlikely. This can cause Linux sections to get moved into the wrong place. The way to avoid this is to use ".." separators for explicit section names (the dot character is valid in a section name but not a C identifier). However currently there are sections which don't follow this rule, so for now just disable the wild card by default. Example: http://marc.info/?l=linux-arm-kernel&m=150106824024221&w=2 Fixes: b67067f1176df ("kbuild: allow archs to select link dead code/data elimination") Signed-off-by: Nicholas Piggin Signed-off-by: Masahiro Yamada Signed-off-by: Greg Kroah-Hartman

mm: kmemleak: scan .data.ro_after_init

2016-11-11T16:12:37+00:00

Limit the number of kmemleak false positives by including .data.ro_after_init in memory scanning. To achieve this we need to add symbols for start and end of the section to the linker scripts. The problem was been uncovered by commit 56989f6d8568 ("genetlink: mark families as __ro_after_init"). Link: http://lkml.kernel.org/r/1478274173-15218-1-git-send-email-jakub.kicinski@netronome.com Reviewed-by: Catalin Marinas Signed-off-by: Jakub Kicinski Cc: Arnd Bergmann Cc: Cong Wang Cc: Johannes Berg Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2016-10-14T21:26:58+00:00

Pull kbuild updates from Michal Marek: - EXPORT_SYMBOL for asm source by Al Viro. This does bring a regression, because genksyms no longer generates checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is working on a patch to fix this. Plus, we are talking about functions like strcpy(), which rarely change prototypes. - Fixes for PPC fallout of the above by Stephen Rothwell and Nick Piggin - fixdep speedup by Alexey Dobriyan. - preparatory work by Nick Piggin to allow architectures to build with -ffunction-sections, -fdata-sections and --gc-sections - CONFIG_THIN_ARCHIVES support by Stephen Rothwell - fix for filenames with colons in the initramfs source by me. * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits) initramfs: Escape colons in depfile ppc: there is no clear_pages to export powerpc/64: whitelist unresolved modversions CRCs kbuild: -ffunction-sections fix for archs with conflicting sections kbuild: add arch specific post-link Makefile kbuild: allow archs to select link dead code/data elimination kbuild: allow architectures to use thin archives instead of ld -r kbuild: Regenerate genksyms lexer kbuild: genksyms fix for typeof handling fixdep: faster CONFIG_ search ia64: move exports to definitions sparc32: debride memcpy.S a bit [sparc] unify 32bit and 64bit string.h sparc: move exports to definitions ppc: move exports to definitions arm: move exports to definitions s390: move exports to definitions m68k: move exports to definitions alpha: move exports to actual definitions x86: move exports to actual definitions ...

nmi_backtrace: generate one-line reports for idle cpus

2016-10-08T01:46:30+00:00

When doing an nmi backtrace of many cores, most of which are idle, the output is a little overwhelming and very uninformative. Suppress messages for cpus that are idling when they are interrupted and just emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN". We do this by grouping all the cpuidle code together into a new .cpuidle.text section, and then checking the address of the interrupted PC to see if it lies within that section. This commit suitably tags x86 and tile idle routines, and only adds in the minimal framework for other architectures. Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com Signed-off-by: Chris Metcalf Acked-by: Peter Zijlstra (Intel) Tested-by: Peter Zijlstra (Intel) Tested-by: Daniel Thompson [arm] Tested-by: Petr Mladek Cc: Aaron Tomlin Cc: Peter Zijlstra (Intel) Cc: "Rafael J. Wysocki" Cc: Russell King Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kbuild: -ffunction-sections fix for archs with conflicting sections

2016-09-22T12:37:14+00:00

Enabling -ffunction-sections modified the generic linker script to pull .text.* sections into regular TEXT_TEXT section, conflicting with some architectures. Revert that change and require archs that enable the option to ensure they have no conflicting section names, and do the appropriate merging. Reported-by: Guenter Roeck Tested-by: Guenter Roeck Fixes: b67067f1176d ("kbuild: allow archs to select link dead code/data elimination") Signed-off-by: Nicholas Piggin Signed-off-by: Michal Marek

kbuild: allow archs to select link dead code/data elimination

2016-09-09T08:47:00+00:00

Introduce LD_DEAD_CODE_DATA_ELIMINATION option for architectures to select to build with -ffunction-sections, -fdata-sections, and link with --gc-sections. It requires some work (documented) to ensure all unreferenced entrypoints are live, and requires toolchain and build verification, so it is made a per-arch option for now. On a random powerpc64le build, this yelds a significant size saving, it boots and runs fine, but there is a lot I haven't tested as yet, so these savings may be reduced if there are bugs in the link. text data bss dec filename 11169741 1180744 1923176 14273661 vmlinux 10445269 1004127 1919707 13369103 vmlinux.dce ~700K text, ~170K data, 6% removed from kernel image size. Signed-off-by: Nicholas Piggin Signed-off-by: Michal Marek

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2016-08-02T20:37:12+00:00

Pull kbuild updates from Michal Marek: - GCC plugin support by Emese Revfy from grsecurity, with a fixup from Kees Cook. The plugins are meant to be used for static analysis of the kernel code. Two plugins are provided already. - reduction of the gcc commandline by Arnd Bergmann. - IS_ENABLED / IS_REACHABLE macro enhancements by Masahiro Yamada - bin2c fix by Michael Tautschnig - setlocalversion fix by Wolfram Sang * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: gcc-plugins: disable under COMPILE_TEST kbuild: Abort build on bad stack protector flag scripts: Fix size mismatch of kexec_purgatory_size kbuild: make samples depend on headers_install Kbuild: don't add obj tree in additional includes Kbuild: arch: look for generated headers in obtree Kbuild: always prefix objtree in LINUXINCLUDE Kbuild: avoid duplicate include path Kbuild: don't add ../../ to include path vmlinux.lds.h: replace config_enabled() with IS_ENABLED() kconfig.h: allow to use IS_{ENABLE,REACHABLE} in macro expansion kconfig.h: use already defined macros for IS_REACHABLE() define export.h: use __is_defined() to check if __KSYM_* is defined kconfig.h: use __is_defined() to check if MODULE is defined kbuild: setlocalversion: print error to STDERR Add sancov plugin Add Cyclomatic complexity GCC plugin GCC plugin infrastructure Shared library support