Commit Graph

142 Commits

Author SHA1 Message Date
d55571c008 Merge tag 'kbuild-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Refactor scripts/kallsyms to make it faster and easier to maintain

 - Clean up menuconfig

 - Provide Clang with hard-coded target triple instead of CROSS_COMPILE

 - Use -z pack-relative-relocs flags instead of --use-android-relr-tags
   for arm64 CONFIG_RELR

 - Add srcdeb-pkg target to build only a Debian source package

 - Add KDEB_SOURCE_COMPRESS option to specify the compression for a
   Debian source package

 - Misc cleanups and fixes

* tag 'kbuild-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: deb-pkg: specify targets in debian/rules as .PHONY
  sparc: unify sparc32/sparc64 archhelp
  kbuild: rpm-pkg: remove kernel-drm PROVIDES
  kbuild: deb-pkg: add KDEB_SOURCE_COMPRESS to specify source compression
  kbuild: add srcdeb-pkg target
  Makefile: use -z pack-relative-relocs
  kbuild: clang: do not use CROSS_COMPILE for target triple
  kconfig: menuconfig: reorder functions to remove forward declarations
  kconfig: menuconfig: remove unused M_EVENT macro
  kconfig: menuconfig: remove OLD_NCURSES macro
  kbuild: builddeb: Eliminate debian/arch use
  scripts/kallsyms: update the usage in the comment block
  scripts/kallsyms: decrease expand_symbol() / cleanup_symbol_name() calls
  scripts/kallsyms: change the output order
  scripts/kallsyms: move compiler-generated symbol patterns to mksysmap
  scripts/kallsyms: exclude symbols generated by itself dynamically
  scripts/mksysmap: use sed with in-line comments
  scripts/mksysmap: remove comments described in nm(1)
  scripts/kallsyms: remove redundant code for omitting U and N
  kallsyms: expand symbol name into comment for debugging
2023-04-30 11:32:53 -07:00
ca09bf48f9 scripts/kallsyms: exclude symbols generated by itself dynamically
Drop the symbols generated by scripts/kallsyms itself automatically
instead of maintaining the symbol list manually.

Pass the kallsyms object from the previous kallsyms step (if it exists)
as the third parameter of scripts/mksysmap, which will weed out the
generated symbols from the input to the next kallsyms step.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-04-17 11:03:56 +09:00
4b3d049f1c scripts/link-vmlinux.sh: fix error message presentation
This comes out as

   Try make KALLSYMS_EXTRA_PASS=1 as a workaround

but we want quotes:

   Try "make KALLSYMS_EXTRA_PASS=1" as a workaround

Link: https://lkml.kernel.org/r/202303042034.Cjc7JTd0-lkp@intel.com
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-08 13:45:37 -07:00
010a0aad39 kallsyms: Correctly sequence symbols when CONFIG_LTO_CLANG=y
LLVM appends various suffixes for local functions and variables, suffixes
observed:
 - foo.llvm.[0-9a-f]+
 - foo.[0-9a-f]+

Therefore, when CONFIG_LTO_CLANG=y, kallsyms_lookup_name() needs to
truncate the suffix of the symbol name before comparing the local function
or variable name.

Old implementation code:
-	if (strcmp(namebuf, name) == 0)
-		return kallsyms_sym_address(i);
-	if (cleanup_symbol_name(namebuf) && strcmp(namebuf, name) == 0)
-		return kallsyms_sym_address(i);

The preceding process is traversed by address from low to high. That is,
for those with the same name after the suffix is removed, the one with
the smallest address is returned first. Therefore, when sorting in the
tool, if the raw names are the same, they should be sorted by address in
ascending order.

ASCII[.]   = 2e
ASCII[0-9] = 30,39
ASCII[A-Z] = 41,5a
ASCII[_]   = 5f
ASCII[a-z] = 61,7a

According to the preceding ASCII code values, the following sorting result
is strictly followed.
 ---------------------------------
|    main-key     |    sub-key    |
|---------------------------------|
|                 |  addr_lowest  |
| <name>          |      ...      |
| <name>.<suffix> |      ...      |
|                 |  addr_highest |
|---------------------------------|
| <name>?<others> |               |   //? is [_A-Za-z0-9]
 ---------------------------------

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2022-11-12 18:47:36 -08:00
5d4aeffbf7 kbuild: rebuild .vmlinux.export.o when its prerequisite is updated
When include/linux/export-internal.h is updated, .vmlinux.export.o
must be rebuilt, but it does not happen because its rule is hidden
behind scripts/link-vmlinux.sh.

Move it out of the shell script, so that Make can see the dependency
between vmlinux and .vmlinux.export.o.

Move the vmlinux rule to scripts/Makefile.vmlinux.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-10-03 03:52:58 +09:00
7a342e6c77 kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o
Do not build modules.builtin(.modinfo) as a side-effect of vmlinux.

There are no good reason to rebuild them just because any of vmlinux's
prerequistes (vmlinux.lds, .vmlinux.export.c, etc.) has been updated.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-10-03 03:52:58 +09:00
aa221f2ea5 kallsyms: take the input file instead of reading stdin
This gets rid of the pipe operator connected with 'cat'.

Also use getopt_long() to parse the command line.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-10-02 18:06:05 +09:00
94ff2f63d6 kbuild: reuse mksysmap output for kallsyms
scripts/mksysmap internally runs ${NM} (dropping some symbols).

When CONFIG_KALLSYMS=y, mksysmap creates .tmp_System.map, but it is
almost the same as the output from the ${NM} invocation in kallsyms().
It is true scripts/mksysmap drops some symbols, but scripts/kallsyms.c
ignores more anyway.

Keep the mksysmap output as *.syms, and reuse it for kallsyms and
'cmp -s'. It saves one ${NM} invocation.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-10-02 18:06:05 +09:00
3216484550 kbuild: use obj-y instead extra-y for objects placed at the head
The objects placed at the head of vmlinux need special treatments:

 - arch/$(SRCARCH)/Makefile adds them to head-y in order to place
   them before other archives in the linker command line.

 - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of
   obj-y to avoid them going into built-in.a.

This commit gets rid of the latter.

Create vmlinux.a to collect all the objects that are unconditionally
linked to vmlinux. The objects listed in head-y are moved to the head
of vmlinux.a by using 'ar m'.

With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y
for builtin objects.

There is no *.o that is directly linked to vmlinux. Drop unneeded code
in scripts/clang-tools/gen_compile_commands.py.

$(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested
by Nathan Chancellor [1].

[1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-10-02 18:04:05 +09:00
f73edc8951 kbuild: unify two modpost invocations
Currently, modpost is executed twice; first for vmlinux, second
for modules.

This commit merges them.

Current build flow
==================

  1) build obj-y and obj-m objects
    2) link vmlinux.o
      3) modpost for vmlinux
        4) link vmlinux
          5) modpost for modules
            6) link modules (*.ko)

The build steps 1) through 6) are serialized, that is, modules are
built after vmlinux. You do not get benefits of parallel builds when
scripts/link-vmlinux.sh is being run.

New build flow
==============

  1) build obj-y and obj-m objects
    2) link vmlinux.o
      3) modpost for vmlinux and modules
        4a) link vmlinux
        4b) link modules (*.ko)

In the new build flow, modpost is invoked just once.

vmlinux and modules are built in parallel. One exception is
CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-09-29 06:07:58 +09:00
9c5a0ac3c3 kbuild: move vmlinux.o rule to the top Makefile
Move the build rules of vmlinux.o out of scripts/link-vmlinux.sh to
clearly separate 1) pre-modpost, 2) modpost, 3) post-modpost stages.
This will make further refactoring possible.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-09-29 04:42:34 +09:00
26ef40de5c kbuild: move .vmlinux.objs rule to Makefile.modpost
.vmlinux.objs is used by modpost, so scripts/Makefile.modpost is
a better place to generate it.

It is used only when CONFIG_MODVERSIONS=y. It should be guarded
by "ifdef CONFIG_MODVERSIONS".

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-09-29 04:42:00 +09:00
2df8220cc5 kbuild: build init/built-in.a just once
Kbuild builds init/built-in.a twice; first during the ordinary
directory descending, second from scripts/link-vmlinux.sh.

We do this because UTS_VERSION contains the build version and the
timestamp. We cannot update it during the normal directory traversal
since we do not yet know if we need to update vmlinux. UTS_VERSION is
temporarily calculated, but omitted from the update check. Otherwise,
vmlinux would be rebuilt every time.

When Kbuild results in running link-vmlinux.sh, it increments the
version number in the .version file and takes the timestamp at that
time to really fix UTS_VERSION.

However, updating the same file twice is a footgun. To avoid nasty
timestamp issues, all build artifacts that depend on init/built-in.a
are atomically generated in link-vmlinux.sh, where some of them do not
need rebuilding.

To fix this issue, this commit changes as follows:

[1] Split UTS_VERSION out to include/generated/utsversion.h from
    include/generated/compile.h

    include/generated/utsversion.h is generated just before the
    vmlinux link. It is generated under include/generated/ because
    some decompressors (s390, x86) use UTS_VERSION.

[2] Split init_uts_ns and linux_banner out to init/version-timestamp.c
    from init/version.c

    init_uts_ns and linux_banner contain UTS_VERSION. During the ordinary
    directory descending, they are compiled with __weak and used to
    determine if vmlinux needs relinking. Just before the vmlinux link,
    they are compiled without __weak to embed the real version and
    timestamp.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-09-29 04:40:15 +09:00
b42d230650 kbuild: factor out the common objtool arguments
scripts/Makefile.build and scripts/link-vmlinux.sh have similar setups
for the objtool arguments.

It was difficult to factor out them because all the vmlinux build rules
were written in a shell script. It is somewhat tedious to touch the two
files every time a new objtool option is supported.

To reduce the code duplication, move the objtool for vmlinux.o into
scripts/Makefile.vmlinux_o. Then, move the common macros to Makefile.lib
so they are shared between Makefile.build and Makefile.vmlinux_o.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-06-05 06:20:57 +09:00
5d45950dfb kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o
This is a preparation for moving the objtool rule in the next commit.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-06-05 06:20:57 +09:00
b0d6207bad kbuild: clean .tmp_* pattern by make clean
Change the "make clean" rule to remove all the .tmp_* files.

.tmp_objdiff is the only exception, which should be removed by
"make mrproper".

Rename the record directory of objdiff, .tmp_objdiff to .objdiff to
avoid the removal by "make clean".

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-06-05 06:20:57 +09:00
a78b6afa99 kbuild: remove redundant cleanups in scripts/link-vmlinux.sh
These are cleaned by the top Makefile.

vmlinux.o and .vmlinux.d matches the '*.[aios]' and '.*.d' patterns
respectively.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-06-01 23:07:29 +09:00
0aa24a79ee kbuild: do not try to parse *.cmd files for objects provided by compiler
Guenter Roeck reported the build breakage for parisc and csky.
I confirmed nios2 and openrisc are broken as well.

The reason is that they borrow libgcc.a from the toolchains.

For example, see this line in arch/parisc/Makefile:

    LIBGCC          := $(shell $(CC) -print-libgcc-file-name)

Some objects in libgcc.a are linked to vmlinux.o, but they do not have
.*.cmd files.

Obviously, there is no EXPORT_SYMBOL in external objects. Ignore them.

(Most of the architectures import library code into the kernel tree.
Perhaps those 4 architectures can do similar, but I do not know how
challenging it is.)

Fixes: f292d875d0 ("modpost: extract symbol versions from *.cmd files")
Link: https://lore.kernel.org/linux-kbuild/20220528224745.GA2501857@roeck-us.net/T/#mac65c20c71c3e272db0350ecfba53fcd8905b0a0
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
2022-05-29 18:36:41 +09:00
df202b452f Merge tag 'kbuild-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Add HOSTPKG_CONFIG env variable to allow users to override pkg-config

 - Support W=e as a shorthand for KCFLAGS=-Werror

 - Fix CONFIG_IKHEADERS build to support toybox cpio

 - Add scripts/dummy-tools/pahole to ease distro packagers' life

 - Suppress false-positive warnings from checksyscalls.sh for W=2 build

 - Factor out the common code of arch/*/boot/install.sh into
   scripts/install.sh

 - Support 'kernel-install' tool in scripts/prune-kernel

 - Refactor module-versioning to link the symbol versions at the final
   link of vmlinux and modules

 - Remove CONFIG_MODULE_REL_CRCS because module-versioning now works in
   an arch-agnostic way

 - Refactor modpost, Makefiles

* tag 'kbuild-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (56 commits)
  genksyms: adjust the output format to modpost
  kbuild: stop merging *.symversions
  kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
  modpost: extract symbol versions from *.cmd files
  modpost: add sym_find_with_module() helper
  modpost: change the license of EXPORT_SYMBOL to bool type
  modpost: remove left-over cross_compile declaration
  kbuild: record symbol versions in *.cmd files
  kbuild: generate a list of objects in vmlinux
  modpost: move *.mod.c generation to write_mod_c_files()
  modpost: merge add_{intree_flag,retpoline,staging_flag} to add_header
  scripts/prune-kernel: Use kernel-install if available
  kbuild: factor out the common installation code into scripts/install.sh
  modpost: split new_symbol() to symbol allocation and hash table addition
  modpost: make sym_add_exported() always allocate a new symbol
  modpost: make multiple export error
  modpost: dump Module.symvers in the same order of modules.order
  modpost: traverse the namespace_list in order
  modpost: use doubly linked list for dump_lists
  modpost: traverse unresolved symbols in order
  ...
2022-05-26 12:09:50 -07:00
22922deae1 Merge tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:

 - Comprehensive interface overhaul:
   =================================

   Objtool's interface has some issues:

     - Several features are done unconditionally, without any way to
       turn them off. Some of them might be surprising. This makes
       objtool tricky to use, and prevents porting individual features
       to other arches.

     - The config dependencies are too coarse-grained. Objtool
       enablement is tied to CONFIG_STACK_VALIDATION, but it has several
       other features independent of that.

     - The objtool subcmds ("check" and "orc") are clumsy: "check" is
       really a subset of "orc", so it has all the same options.

       The subcmd model has never really worked for objtool, as it only
       has a single purpose: "do some combination of things on an object
       file".

     - The '--lto' and '--vmlinux' options are nonsensical and have
       surprising behavior.

   Overhaul the interface:

      - get rid of subcmds

      - make all features individually selectable

      - remove and/or clarify confusing/obsolete options

      - update the documentation

      - fix some bugs found along the way

 - Fix x32 regression

 - Fix Kbuild cleanup bugs

 - Add scripts/objdump-func helper script to disassemble a single
   function from an object file.

 - Rewrite scripts/faddr2line to be section-aware, by basing it on
   'readelf', moving it away from 'nm', which doesn't handle multiple
   sections well, which can result in decoding failure.

 - Rewrite & fix symbol handling - which had a number of bugs wrt.
   object files that don't have global symbols - which is rare but
   possible. Also fix a bunch of symbol handling bugs found along the
   way.

* tag 'objtool-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  objtool: Fix objtool regression on x32 systems
  objtool: Fix symbol creation
  scripts/faddr2line: Fix overlapping text section failures
  scripts: Create objdump-func helper script
  objtool: Remove libsubcmd.a when make clean
  objtool: Remove inat-tables.c when make clean
  objtool: Update documentation
  objtool: Remove --lto and --vmlinux in favor of --link
  objtool: Add HAVE_NOINSTR_VALIDATION
  objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"
  objtool: Make noinstr hacks optional
  objtool: Make jump label hack optional
  objtool: Make static call annotation optional
  objtool: Make stack validation frame-pointer-specific
  objtool: Add CONFIG_OBJTOOL
  objtool: Extricate sls from stack validation
  objtool: Rework ibt and extricate from stack validation
  objtool: Make stack validation optional
  objtool: Add option to print section addresses
  objtool: Don't print parentheses in function addresses
  ...
2022-05-24 10:36:38 -07:00
7375cbcf23 kbuild: stop merging *.symversions
Now modpost reads symbol versions from .*.cmd files.

The merged *.symversions are no longer needed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-24 16:33:20 +09:00
7b4537199a kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
include/{linux,asm-generic}/export.h defines a weak symbol, __crc_*
as a placeholder.

Genksyms writes the version CRCs into the linker script, which will be
used for filling the __crc_* symbols. The linker script format depends
on CONFIG_MODULE_REL_CRCS. If it is enabled, __crc_* holds the offset
to the reference of CRC.

It is time to get rid of this complexity.

Now that modpost parses text files (.*.cmd) to collect all the CRCs,
it can generate C code that will be linked to the vmlinux or modules.

Generate a new C file, .vmlinux.export.c, which contains the CRCs of
symbols exported by vmlinux. It is compiled and linked to vmlinux in
scripts/link-vmlinux.sh.

Put the CRCs of symbols exported by modules into the existing *.mod.c
files. No additional build step is needed for modules. As before,
*.mod.c are compiled and linked to *.ko in scripts/Makefile.modfinal.

No linker magic is used here. The new C implementation works in the
same way, whether CONFIG_RELOCATABLE is enabled or not.
CONFIG_MODULE_REL_CRCS is no longer needed.

Previously, Kbuild invoked additional $(LD) to update the CRCs in
objects, but this step is unneeded too.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nicolas Schier <nicolas@fjasle.eu>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)
2022-05-24 16:33:20 +09:00
c5a3d3c01e Merge tag 'x86_cpu_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 CPU feature updates from Borislav Petkov:

 - Remove a bunch of chicken bit options to turn off CPU features which
   are not really needed anymore

 - Misc fixes and cleanups

* tag 'x86_cpu_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation: Add missing prototype for unpriv_ebpf_notify()
  x86/pm: Fix false positive kmemleak report in msr_build_context()
  x86/speculation/srbds: Do not try to turn mitigation off when not supported
  x86/cpu: Remove "noclflush"
  x86/cpu: Remove "noexec"
  x86/cpu: Remove "nosmep"
  x86/cpu: Remove CONFIG_X86_SMAP and "nosmap"
  x86/cpu: Remove "nosep"
  x86/cpu: Allow feature bit names from /proc/cpuinfo in clearcpuid=
2022-05-23 18:01:31 -07:00
e493f47275 kbuild: generate a list of objects in vmlinux
A *.mod file lists the member objects of a module, but vmlinux does
not have such a file.

Generate this list to allow modpost to know all the member objects.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
2022-05-11 21:46:39 +09:00
753da4179d objtool: Remove --lto and --vmlinux in favor of --link
The '--lto' option is a confusing way of telling objtool to do stack
validation despite it being a linked object.  It's no longer needed now
that an explicit '--stackval' option exists.  The '--vmlinux' option is
also redundant.

Remove both options in favor of a straightforward '--link' option which
identifies a linked object.

Also, implicitly set '--link' with a warning if the user forgets to do
so and we can tell that it's a linked object.  This makes it easier for
manual vmlinux runs.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/dcd3ceffd15a54822c6183e5766d21ad06082b45.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:05 +02:00
0f620cefd7 objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"
CONFIG_VMLINUX_VALIDATION is just the validation of the "noinstr" rules.
That name is a misnomer, because now objtool actually does vmlinux
validation for other reasons.

Rename CONFIG_VMLINUX_VALIDATION to CONFIG_NOINSTR_VALIDATION.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/173f07e2d6d1afc0874aed975a61783207c6a531.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:04 +02:00
22102f4559 objtool: Make noinstr hacks optional
Objtool has some hacks in place to workaround toolchain limitations
which otherwise would break no-instrumentation rules.  Make the hacks
explicit (and optional for other arches) by turning it into a cmdline
option and kernel config option.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/b326eeb9c33231b9dfbb925f194ed7ee40edcd7c.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:04 +02:00
4ab7674f59 objtool: Make jump label hack optional
Objtool secretly does a jump label hack to overcome the limitations of
the toolchain.  Make the hack explicit (and optional for other arches)
by turning it into a cmdline option and kernel config option.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/3bdcbfdd27ecb01ddec13c04bdf756a583b13d24.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:04 +02:00
26e176896a objtool: Make static call annotation optional
As part of making objtool more modular, put the existing static call
code behind a new '--static-call' option.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/d59ac57ef3d6d8380cdce20322314c9e2e556750.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:03 +02:00
7206447496 objtool: Make stack validation frame-pointer-specific
Now that CONFIG_STACK_VALIDATION is frame-pointer specific, do the same
for the '--stackval' option.  Now the '--no-fp' option is redundant and
can be removed.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/f563fa064b3b63d528de250c72012d49e14742a3.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:03 +02:00
03f16cd020 objtool: Add CONFIG_OBJTOOL
Now that stack validation is an optional feature of objtool, add
CONFIG_OBJTOOL and replace most usages of CONFIG_STACK_VALIDATION with
it.

CONFIG_STACK_VALIDATION can now be considered to be frame-pointer
specific.  CONFIG_UNWINDER_ORC is already inherently valid for live
patching, so no need to "validate" it.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/939bf3d85604b2a126412bf11af6e3bd3b872bcb.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:03 +02:00
7dce62041a objtool: Make stack validation optional
Make stack validation an explicit cmdline option so that individual
objtool features can be enabled individually by other arches.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/52da143699574d756e65ca4c9d4acaffe9b0fe5f.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:02 +02:00
b51277eb97 objtool: Ditch subcommands
Objtool has a fairly singular focus.  It runs on object files and does
validations and transformations which can be combined in various ways.
The subcommand model has never been a good fit, making it awkward to
combine and remove options.

Remove the "check" and "orc" subcommands in favor of a more traditional
cmdline option model.  This makes it much more flexible to use, and
easier to port individual features to other arches.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/5c61ebf805e90aefc5fa62bc63468ffae53b9df6.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:01 +02:00
2daf7faba7 objtool: Reorganize cmdline options
Split the existing options into two groups: actions, which actually do
something; and options, which modify the actions in some way.

Also there's no need to have short flags for all the non-action options.
Reserve short flags for the more important actions.

While at it:

- change a few of the short flags to be more intuitive

- make option descriptions more consistently descriptive

- sort options in the source like they are when printed

- move options to a global struct

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/9dcaa752f83aca24b1b21f0b0eeb28a0c181c0b0.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:01 +02:00
4a5de9b76f objtool: Enable unreachable warnings for CLANG LTO
With IBT support in, objtool is now fully capable of following vmlinux
code flow in LTO mode.  Start reporting unreachable warnings for Clang
LTO as well.

Fixes: ed53a0d971 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/7b12df54bceeb0761fe9fc8269ea0c00501214a9.1650300597.git.jpoimboe@redhat.com
2022-04-19 21:58:48 +02:00
dbae0a934f x86/cpu: Remove CONFIG_X86_SMAP and "nosmap"
Those were added as part of the SMAP enablement but SMAP is currently
an integral part of kernel proper and there's no need to disable it
anymore.

Rip out that functionality. Leave --uaccess default on for objtool as
this is what objtool should do by default anyway.

If still needed - clearcpuid=smap.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127115626.14179-4-bp@alien8.de
2022-04-04 10:16:57 +02:00
099c22bdca kbuild: fix empty ${PYTHON} in scripts/link-vmlinux.sh
The two commits

  d8d2d38275 ("kbuild: remove PYTHON variable")
  a8cccdd954 ("init: lto: ensure initcall ordering")

were applied in the same development cycle, into two different trees.

After they were merged together, this ${PYTHON} expands to an empty
string.

Therefore, ${srctree}/scripts/jobserver-exec is executed directly.
(it has the executable bit set)

This is working but let's fix the code into the intended form.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
2022-04-02 00:04:42 +09:00
ed53a0d971 x86/alternative: Use .ibt_endbr_seal to seal indirect calls
Objtool's --ibt option generates .ibt_endbr_seal which lists
superfluous ENDBR instructions. That is those instructions for which
the function is never indirectly called.

Overwrite these ENDBR instructions with a NOP4 such that these
function can never be indirect called, reducing the number of viable
ENDBR targets in the kernel.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.822545231@infradead.org
2022-03-15 10:32:47 +01:00
53f7109ef9 objtool: Rename --duplicate to --lto
In order to prepare for LTO like objtool runs for modules, rename the
duplicate argument to lto.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.172584233@infradead.org
2022-03-15 10:32:42 +01:00
fd6f57bfda Merge tag 'kbuild-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Add new kconfig target 'make mod2noconfig', which will be useful to
   speed up the build and test iteration.

 - Raise the minimum supported version of LLVM to 11.0.0

 - Refactor certs/Makefile

 - Change the format of include/config/auto.conf to stop double-quoting
   string type CONFIG options.

 - Fix ARCH=sh builds in dash

 - Separate compression macros for general purposes (cmd_bzip2 etc.) and
   the ones for decompressors (cmd_bzip2_with_size etc.)

 - Misc Makefile cleanups

* tag 'kbuild-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
  kbuild: add cmd_file_size
  arch: decompressor: remove useless vmlinux.bin.all-y
  kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22}
  kbuild: drop $(size_append) from cmd_zstd
  sh: rename suffix-y to suffix_y
  doc: kbuild: fix default in `imply` table
  microblaze: use built-in function to get CPU_{MAJOR,MINOR,REV}
  certs: move scripts/extract-cert to certs/
  kbuild: do not quote string values in include/config/auto.conf
  kbuild: do not include include/config/auto.conf from shell scripts
  certs: simplify $(srctree)/ handling and remove config_filename macro
  kbuild: stop using config_filename in scripts/Makefile.modsign
  certs: remove misleading comments about GCC PR
  certs: refactor file cleaning
  certs: remove unneeded -I$(srctree) option for system_certificates.o
  certs: unify duplicated cmd_extract_certs and improve the log
  certs: use $< and $@ to simplify the key generation rule
  kbuild: remove headers_check stub
  kbuild: move headers_check.pl to usr/include/
  certs: use if_changed to re-generate the key when the key type is changed
  ...
2022-01-19 11:15:19 +02:00
4d66020dce Merge tag 'trace-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
 "New:

   - The Real Time Linux Analysis (RTLA) tool is added to the tools
     directory.

   - Can safely filter on user space pointers with: field.ustring ~
     "match-string"

   - eprobes can now be filtered like any other event.

   - trace_marker(_raw) now uses stream_open() to allow multiple threads
     to safely write to it. Note, this could possibly break existing
     user space, but we will not know until we hear about it, and then
     can revert the change if need be.

   - New field in events to display when bottom halfs are disabled.

   - Sorting of the ftrace functions are now done at compile time
     instead of at bootup.

  Infrastructure changes to support future efforts:

   - Added __rel_loc type for trace events. Similar to __data_loc but
     the offset to the dynamic data is based off of the location of the
     descriptor and not the beginning of the event. Needed for user
     defined events.

   - Some simplification of event trigger code.

   - Make synthetic events process its callback better to not hinder
     other event callbacks that are registered. Needed for user defined
     events.

  And other small fixes and cleanups"

* tag 'trace-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (50 commits)
  tracing: Add ustring operation to filtering string pointers
  rtla: Add rtla timerlat hist documentation
  rtla: Add rtla timerlat top documentation
  rtla: Add rtla timerlat documentation
  rtla: Add rtla osnoise hist documentation
  rtla: Add rtla osnoise top documentation
  rtla: Add rtla osnoise man page
  rtla: Add Documentation
  rtla/timerlat: Add timerlat hist mode
  rtla: Add timerlat tool and timelart top mode
  rtla/osnoise: Add the hist mode
  rtla/osnoise: Add osnoise top mode
  rtla: Add osnoise tool
  rtla: Helper functions for rtla
  rtla: Real-Time Linux Analysis tool
  tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails
  tracing: Remove duplicate warnings when calling trace_create_file()
  tracing/kprobes: 'nmissed' not showed correctly for kretprobe
  tracing: Add test for user space strings when filtering on string pointers
  tracing: Have syscall trace events use trace_event_buffer_lock_reserve()
  ...
2022-01-16 10:15:32 +02:00
72b3942a17 scripts: ftrace - move the sort-processing in ftrace_init
When the kernel starts, the initialization of ftrace takes
up a portion of the time (approximately 6~8ms) to sort mcount
addresses. We can save this time by moving mcount-sorting to
compile time.

Link: https://lkml.kernel.org/r/20211212113358.34208-2-yinan@linux.alibaba.com

Signed-off-by: Yinan Liu <yinan@linux.alibaba.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2022-01-13 16:23:04 -05:00
7d153696e5 kbuild: do not include include/config/auto.conf from shell scripts
Richard Weinberger pointed out the risk of sourcing the kernel config
from shell scripts [1], and proposed some patches [2], [3]. It is a good
point, but it took a long time because I was wondering how to fix this.

This commit goes with simple grep approach because there are only a few
scripts including the kernel configuration.

scripts/link_vmlinux.sh has references to a bunch of CONFIG options,
all of which are boolean. I added is_enabled() helper as
scripts/package/{mkdebian,builddeb} do.

scripts/gen_autoksyms.sh uses 'eval', stating "to expand the whitelist
path". I removed it since it is the issue we are trying to fix.

I was a bit worried about the cost of invoking the grep command over
again. I extracted the grep parts from it, and measured the cost. It
was approximately 0.03 sec, which I hope is acceptable.

[test code]

  $ cat test-grep.sh
  #!/bin/sh

  is_enabled() {
          grep -q "^$1=y" include/config/auto.conf
  }

  is_enabled CONFIG_LTO_CLANG
  is_enabled CONFIG_LTO_CLANG
  is_enabled CONFIG_STACK_VALIDATION
  is_enabled CONFIG_UNWINDER_ORC
  is_enabled CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
  is_enabled CONFIG_VMLINUX_VALIDATION
  is_enabled CONFIG_FRAME_POINTER
  is_enabled CONFIG_GCOV_KERNEL
  is_enabled CONFIG_LTO_CLANG
  is_enabled CONFIG_RETPOLINE
  is_enabled CONFIG_X86_SMAP
  is_enabled CONFIG_LTO_CLANG
  is_enabled CONFIG_VMLINUX_MAP
  is_enabled CONFIG_KALLSYMS_ALL
  is_enabled CONFIG_KALLSYMS_ABSOLUTE_PERCPU
  is_enabled CONFIG_KALLSYMS_BASE_RELATIVE
  is_enabled CONFIG_DEBUG_INFO_BTF
  is_enabled CONFIG_KALLSYMS
  is_enabled CONFIG_DEBUG_INFO_BTF
  is_enabled CONFIG_BPF
  is_enabled CONFIG_BUILDTIME_TABLE_SORT
  is_enabled CONFIG_KALLSYMS

  $ time ./test-grep.sh
  real    0m0.036s
  user    0m0.027s
  sys     m0.009s

[1]: https://lore.kernel.org/all/1919455.eZKeABUfgV@blindfold/
[2]: https://lore.kernel.org/all/20180219092245.26404-1-richard@nod.at/
[3]: https://lore.kernel.org/all/20210920213957.1064-2-richard@nod.at/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-01-08 17:46:36 +09:00
e463a09af2 x86: Add straight-line-speculation mitigation
Make use of an upcoming GCC feature to mitigate
straight-line-speculation for x86:

  https://gcc.gnu.org/g:53a643f8568067d7700a9f2facc8ba39974973d3
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952
  https://bugs.llvm.org/show_bug.cgi?id=52323

It's built tested on x86_64-allyesconfig using GCC-12 and GCC-11.

Maintenance overhead of this should be fairly low due to objtool
validation.

Size overhead of all these additional int3 instructions comes to:

     text	   data	    bss	    dec	    hex	filename
  22267751	6933356	2011368	31212475	1dc43bb	defconfig-build/vmlinux
  22804126	6933356	1470696	31208178	1dc32f2	defconfig-build/vmlinux.sls

Or roughly 2.4% additional text.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134908.140103474@infradead.org
2021-12-09 13:32:25 +01:00
1e9ed9360f Merge tag 'kbuild-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Remove the global -isystem compiler flag, which was made possible by
   the introduction of <linux/stdarg.h>

 - Improve the Kconfig help to print the location in the top menu level

 - Fix "FORCE prerequisite is missing" build warning for sparc

 - Add new build targets, tarzst-pkg and perf-tarzst-src-pkg, which
   generate a zstd-compressed tarball

 - Prevent gen_init_cpio tool from generating a corrupted cpio when
   KBUILD_BUILD_TIMESTAMP is set to 2106-02-07 or later

 - Misc cleanups

* tag 'kbuild-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
  kbuild: use more subdir- for visiting subdirectories while cleaning
  sh: remove meaningless archclean line
  initramfs: Check timestamp to prevent broken cpio archive
  kbuild: split DEBUG_CFLAGS out to scripts/Makefile.debug
  gen_init_cpio: add static const qualifiers
  kbuild: Add make tarzst-pkg build option
  scripts: update the comments of kallsyms support
  sparc: Add missing "FORCE" target when using if_changed
  kconfig: refactor conf_touch_dep()
  kconfig: refactor conf_write_dep()
  kconfig: refactor conf_write_autoconf()
  kconfig: add conf_get_autoheader_name()
  kconfig: move sym_escape_string_value() to confdata.c
  kconfig: refactor listnewconfig code
  kconfig: refactor conf_write_symbol()
  kconfig: refactor conf_write_heading()
  kconfig: remove 'const' from the return type of sym_escape_string_value()
  kconfig: rename a variable in the lexer to a clearer name
  kconfig: narrow the scope of variables in the lexer
  kconfig: Create links to main menu items in search
  ...
2021-11-08 09:15:45 -08:00
9741e07ece kbuild: Unify options for BTF generation for vmlinux and modules
Using new PAHOLE_FLAGS variable to pass extra arguments to
pahole for both vmlinux and modules BTF data generation.

Adding new scripts/pahole-flags.sh script that detect and
prints pahole options.

[ fixed issues found by kernel test robot ]

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211029125729.70002-1-jolsa@kernel.org
2021-11-01 18:09:58 -07:00
2216cf68cf scripts: update the comments of kallsyms support
update the comments of kallsyms support.

Fixes: af73d78bd3 ("kbuild: Remove debug info from kallsyms linking")
Signed-off-by: Hui Su <suhui_kernel@163.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-10-12 11:50:46 +09:00
5df77ad61f kbuild: merge vmlinux_link() between ARCH=um and other architectures
For ARCH=um, ${CC} is used as the linker driver. Hence, the linker
options are prefixed with -Wl, .

Merge the similar code.

I replaced the -T option with the long option --script= so that it
works well with/without ${wl}.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
2021-09-03 08:17:21 +09:00
d40aecd108 kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
arch/um/Makefile passes the -f option to the ln command:

  linux: vmlinux
          @echo '  LINK $@'
          $(Q)ln -f $< $@

So, the hard link is always re-created, and the old one is removed
anyway.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
2021-09-03 08:17:21 +09:00
8f1305124e kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
When Clang LTO is enabled, vmlinux_link() reuses vmlinux.o instead of
re-linking ${KBUILD_VMLINUX_OBJS} and ${KBUILD_VMLINUX_LIBS}.

That is the only difference here, so merge the similar code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
2021-09-03 08:17:20 +09:00