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2022-05-08scripts: dummy-tools, add paholeJiri Slaby
CONFIG_PAHOLE_VERSION is a part of a config since the commit below. And when multiple people update the config, this value constantly changes. Even if they use dummy scripts. To fix this, add a pahole dummy script returning v99.99. (This is translated into 9999 later in the process.) Thereafter, this script can be invoked easily for example as: make PAHOLE=scripts/dummy-tools/pahole oldconfig Fixes: 613fe1692377 (kbuild: Add CONFIG_PAHOLE_VERSION) Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-05-08kbuild: support W=e to make build abort in case of warningYann Droneaud
When developing new code/feature, CONFIG_WERROR is most often turned off, especially for people using make W=12 to get more warnings. In such case, turning on -Werror temporarily would require switching on CONFIG_WERROR in the configuration, building, then switching off CONFIG_WERROR. For this use case, this patch introduces a new 'e' modifier to W= as a short hand for KCFLAGS+=-Werror" so that -Werror got added to the kernel (built-in) and modules' CFLAGS. Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-05-08kbuild: read *.mod to get objects passed to $(LD) or $(AR)Masahiro Yamada
ld and ar support @file, which command-line options are read from. Now that *.mod lists the member objects in the correct order, without duplication, it is ready to be passed to ld and ar. By using the @file syntax, people will not be worried about the pitfall described in the NOTE. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08kbuild: make *.mod not depend on *.oMasahiro Yamada
The dependency $(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o ... exists because *.mod files previously contained undefined symbols, which are computed from *.o files when CONFIG_TRIM_UNUSED_KSYMS=y. Now that the undefined symbols are put into separate *.usyms files, there is no reason to make *.mod depend on *.o files. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-05-08kbuild: get rid of duplication in *.mod filesMasahiro Yamada
It is allowed to add the same objects multiple times to obj-y / obj-m: obj-y += foo.o foo.o foo.o obj-m += bar.o bar.o bar.o It is also allowed to add the same objects multiple times to a composite module: obj-m += foo.o foo-y := foo1.o foo2.o foo2.o foo1.o This flexibility is useful because the same object might be selected by different CONFIG options, like this: obj-m += foo.o foo-y := foo1.o foo-$(CONFIG_FOO_X) += foo2.o foo-$(CONFIG_FOO_Y) += foo2.o The duplicated objects are omitted at link time. It works naturally in Makefiles because GNU Make removes duplication in $^ without changing the order. It is working well, almost... A small flaw I notice is, *.mod contains duplication in such a case. This is probably not a big deal. As far as I know, the only small problem is scripts/mod/sumversion.c parses the same file multiple times. I am fixing this because I plan to reuse *.mod for other purposes, where the duplication can be problematic. The code change is quite simple. We already use awk to drop duplicated lines in modules.order (see cmd_modules_order in the same file). I copied the code, but changed RS to use spaces as record separators. I also changed the file format to list one object per line. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-05-08kbuild: split the second line of *.mod into *.usymsMasahiro Yamada
The *.mod files have two lines; the first line lists the member objects of the module, and the second line, if CONFIG_TRIM_UNUSED_KSYMS=y, lists the undefined symbols. Currently, we generate *.mod after constructing composite modules, otherwise, we cannot compute the second line. No prerequisite is required to print the first line. They are orthogonal. Splitting them into separate commands will ease further cleanups. This commit splits the list of undefined symbols out to *.usyms files. Previously, the list of undefined symbols ended up with a very long line, but now it has one symbol per line. Use sed like we did before commit 7d32358be8ac ("kbuild: avoid split lines in .mod files"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-05-08kbuild: reuse real-search to simplify cmd_modMasahiro Yamada
The first command in cmd_mod is similar to the real-search macro. Reuse it. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08kbuild: make multi_depend work with targets in subdirectoryMasahiro Yamada
Precisely speaking, when you get the stem of the path, you should use $(patsubst $(obj)/%,%,...) instead of $(notdir ...). I do not see this usecase, but if you create a composite object in a subdirectory, the Makefile should look like this: obj-$(CONFIG_FOO) += dir/foo.o dir/foo-objs := dir/foo1.o dir/foo2.o The member objects should be assigned to dir/foo-objs instead of foo-objs. This syntax is more consistent with commit 54b8ae66ae1a ("kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08kbuild: reuse suffix-search to refactor multi_dependMasahiro Yamada
The complicated part of multi_depend is the same as suffix-search. Reuse it. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08kbuild: refactor cmd_modversions_SMasahiro Yamada
Split the code into two macros, cmd_gen_symversions_S for running genksyms, and cmd_modversions for running $(LD) to update the object with CRCs. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08kbuild: refactor cmd_modversions_cMasahiro Yamada
cmd_modversions_c implements two parts; run genksyms to calculate CRCs of exported symbols, run $(LD) to update the object with the CRCs. The latter is not executed for CONFIG_LTO_CLANG=y since the object is not ELF but LLVM bit code at this point. The first part can be unified because we can always use $(NM) instead of "$(OBJDUMP) -h" to dump the symbols. Split the code into the two macros, cmd_gen_symversions_c and cmd_modversions. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08modpost: remove annoying namespace_from_kstrtabns()Masahiro Yamada
There are two call sites for sym_update_namespace(). When the symbol has no namespace, s->namespace is set to NULL, but the conversion from "" to NULL is done in two different places. [1] read_symbols() This gets the namespace from __kstrtabns_<symbol>. If the symbol has no namespace, sym_get_data(info, sym) returns the empty string "". namespace_from_kstrtabns() converts it to NULL before it is passed to sym_update_namespace(). [2] read_dump() This gets the namespace from the dump file, *.symvers. If the symbol has no namespace, the 'namespace' is the empty string "", which is directly passed into sym_update_namespace(). The conversion from "" to NULL is done in sym_update_namespace(). namespace_from_kstrtabns() exists only for creating this inconsistency. Remove namespace_from_kstrtabns() so that sym_update_namespace() is consistently passed with "" instead of NULL. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08modpost: remove redundant initializes for static variablesMasahiro Yamada
These are initialized with zeros without explicit initializers. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08modpost: move export_from_secname() call to more relevant placeMasahiro Yamada
The assigned 'export' is only used when if (strstarts(symname, "__ksymtab_")) is met. The else-part of the assignment is the dead code. Move the export_from_secname() call to where it is used. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-08modpost: remove useless export_from_sec()Masahiro Yamada
With commit 1743694eb235 ("modpost: stop symbol preloading for modversion CRC") applied, now export_from_sec() is useless. handle_symbol() is called for every symbol in the ELF. When 'symname' does not start with "__ksymtab", export_from_sec() is called, and the returned value is stored in 'export'. It is used in the last part of handle_symbol(): if (strstarts(symname, "__ksymtab_")) { name = symname + strlen("__ksymtab_"); sym_add_exported(name, mod, export); } 'export' is used only when 'symname' starts with "__ksymtab_". So, the value returned by export_from_sec() is never used. Remove useless export_from_sec(). This makes further cleanups possible. I put the temporary code: export = export_unknown; Otherwise, I would get the compiler warning: warning: 'export' may be used uninitialized in this function [-Wmaybe-uninitialized] This is apparently false positive because if (strstarts(symname, "__ksymtab_") ... is a stronger condition than: if (strstarts(symname, "__ksymtab") Anyway, this part will be cleaned up by the next commit. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-05-04Merge branch kvm-arm64/hyp-stack-guard into kvmarm-master/nextMarc Zyngier
* kvm-arm64/hyp-stack-guard: : . : Harden the EL2 stack by providing stack guards, courtesy of : Kalesh Singh. : . KVM: arm64: Symbolize the nVHE HYP addresses KVM: arm64: Detect and handle hypervisor stack overflows KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack KVM: arm64: Add guard pages for KVM nVHE hypervisor stack KVM: arm64: Introduce pkvm_alloc_private_va_range() KVM: arm64: Introduce hyp_alloc_private_va_range() Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-03selinux: declare data arrays constChristian Göttsche
The arrays for the policy capability names, the initial sid identifiers and the class and permission names are not changed at runtime. Declare them const to avoid accidental modification. Do not override the classmap and the initial sid list in the build time script genheaders. Check flose(3) is successful in genheaders.c, otherwise the written data might be corrupted or incomplete. Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: manual merge due to fuzz, minor style tweaks] Signed-off-by: Paul Moore <paul@paul-moore.com>
2022-05-02Merge 5.18-rc5 into driver-core-nextGreg Kroah-Hartman
We need the kernfs/driver core fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-02Merge 5.18-rc5 into char-misc-nextGreg Kroah-Hartman
We need the char-misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-29get_maintainer: Honor mailmap for in file emailsRob Herring
Add support to also use the mailmap for 'in file' email addresses. Link: https://lkml.kernel.org/r/20220323193645.317514-1-robh@kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Reported-by: Marc Zyngier <maz@kernel.org> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-29scripts/bloat-o-meter: filter out vermagic as it is not relevantPaul Gortmaker
Seeing it as a false positive increase at the top is just noise: linux-head$./scripts/bloat-o-meter ../pre/vmlinux ../post/vmlinux add/remove: 0/571 grow/shrink: 1/9 up/down: 20/-64662 (-64642) Function old new delta vermagic 49 69 +20 Since it really doesn't "grow", it makes sense to filter it out. Link: https://lkml.kernel.org/r/20220428035824.7934-1-paul.gortmaker@windriver.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-29scripts/decode_stacktrace.sh: support old bash versionSchspa Shi
Old bash version don't support associative array variables. Avoid to use associative array variables to avoid error. Without this, old bash version will report error as fellowing [ 15.954042] Kernel panic - not syncing: sysrq triggered crash [ 15.955252] CPU: 1 PID: 167 Comm: sh Not tainted 5.18.0-rc1-00208-gb7d075db2fd5 #4 [ 15.956472] Hardware name: Hobot J5 Virtual development board (DT) [ 15.957856] Call trace: ./scripts/decode_stacktrace.sh: line 128: ,dump_backtrace: syntax error: operand expected (error token is ",dump_backtrace") Link: https://lkml.kernel.org/r/20220409180331.24047-1-schspa@gmail.com Signed-off-by: Schspa Shi <schspa@gmail.com> Cc: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-28KVM: arm64: Symbolize the nVHE HYP addressesKalesh Singh
Reintroduce the __kvm_nvhe_ symbols in kallsyms, ignoring the local symbols in this namespace. The local symbols are not informative and can cause aliasing issues when symbolizing the addresses. With the necessary symbols now in kallsyms we can symbolize nVHE addresses using the %p print format specifier: [ 98.916444][ T426] kvm [426]: nVHE hyp panic at: [<ffffffc0096156fc>] __kvm_nvhe_overflow_stack+0x8/0x34! Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Tested-by: Fuad Tabba <tabba@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220420214317.3303360-7-kaleshsingh@google.com
2022-04-26bus: mhi: ep: Add uevent support for module autoloadingManivannan Sadhasivam
Add uevent support to MHI endpoint bus so that the client drivers can be autoloaded by udev when the MHI endpoint devices gets created. The client drivers are expected to provide MODULE_DEVICE_TABLE with the MHI id_table struct so that the alias can be exported. The MHI endpoint reused the mhi_device_id structure of the MHI bus. Reviewed-by: Alex Elder <elder@linaro.org> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Link: https://lore.kernel.org/r/20220405135754.6622-19-manivannan.sadhasivam@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-26checkpatch: add new alloc functions to alloc with multiplies checkGustavo A. R. Silva
kvmalloc() and kvzalloc() functions have now 2-factor multiplication argument forms kvmalloc_array() and kvcalloc(), correspondingly. Add alloc-with-multiplies checks for these new functions. Link: https://github.com/KSPP/linux/issues/187 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2022-04-24scripts/get_abi: Fix wrong script file name in the help messageSeongJae Park
The help message of 'get_abi.pl' is mistakenly saying it's 'abi_book.pl'. This commit fixes the wrong name in the help message. Fixes: bbc249f2b859 ("scripts: add an script to parse the ABI files") Signed-off-by: SeongJae Park <sj@kernel.org> Link: https://lore.kernel.org/r/20220419121636.290407-1-sj@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-22objtool: Remove --lto and --vmlinux in favor of --linkJosh Poimboeuf
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
2022-04-22objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"Josh Poimboeuf
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
2022-04-22objtool: Make noinstr hacks optionalJosh Poimboeuf
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
2022-04-22objtool: Make jump label hack optionalJosh Poimboeuf
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
2022-04-22objtool: Make static call annotation optionalJosh Poimboeuf
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
2022-04-22objtool: Make stack validation frame-pointer-specificJosh Poimboeuf
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
2022-04-22objtool: Add CONFIG_OBJTOOLJosh Poimboeuf
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
2022-04-22objtool: Make stack validation optionalJosh Poimboeuf
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
2022-04-22objtool: Ditch subcommandsJosh Poimboeuf
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
2022-04-22objtool: Reorganize cmdline optionsJosh Poimboeuf
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
2022-04-19objtool: Enable unreachable warnings for CLANG LTOJosh Poimboeuf
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: ed53a0d97192 ("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
2022-04-13security: don't treat structure as an array of struct hlist_headBill Wendling
The initialization of "security_hook_heads" is done by casting it to another structure pointer type, and treating it as an array of "struct hlist_head" objects. This requires an exception be made in "randstruct", because otherwise it will emit an error, reducing the effectiveness of the hardening technique. Instead of using a cast, initialize the individual struct hlist_head elements in security_hook_heads explicitly. This removes the need for the cast and randstruct exception. Signed-off-by: Bill Wendling <morbo@google.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220407175930.471870-1-morbo@google.com
2022-04-12Merge tag 'hardening-v5.18-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening fixes from Kees Cook: - latent_entropy: Use /dev/urandom instead of small GCC seed (Jason Donenfeld) - uapi/stddef.h: add missed include guards (Tadeusz Struk) * tag 'hardening-v5.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: gcc-plugins: latent_entropy: use /dev/urandom uapi/linux/stddef.h: Add include guards
2022-04-12gcc-plugins: latent_entropy: use /dev/urandomJason A. Donenfeld
While the latent entropy plugin mostly doesn't derive entropy from get_random_const() for measuring the call graph, when __latent_entropy is applied to a constant, then it's initialized statically to output from get_random_const(). In that case, this data is derived from a 64-bit seed, which means a buffer of 512 bits doesn't really have that amount of compile-time entropy. This patch fixes that shortcoming by just buffering chunks of /dev/urandom output and doling it out as requested. At the same time, it's important that we don't break the use of -frandom-seed, for people who want the runtime benefits of the latent entropy plugin, while still having compile-time determinism. In that case, we detect whether gcc's set_random_seed() has been called by making a call to get_random_seed(noinit=true) in the plugin init function, which is called after set_random_seed() is called but before anything that calls get_random_seed(noinit=false), and seeing if it's zero or not. If it's not zero, we're in deterministic mode, and so we just generate numbers with a basic xorshift prng. Note that we don't detect if -frandom-seed is being used using the documented local_tick variable, because it's assigned via: local_tick = (unsigned) tv.tv_sec * 1000 + tv.tv_usec / 1000; which may well overflow and become -1 on its own, and so isn't reliable: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105171 [kees: The 256 byte rnd_buf size was chosen based on average (250), median (64), and std deviation (575) bytes of used entropy for a defconfig x86_64 build] Fixes: 38addce8b600 ("gcc-plugins: Add latent_entropy plugin") Cc: stable@vger.kernel.org Cc: PaX Team <pageexec@freemail.hu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220405222815.21155-1-Jason@zx2c4.com
2022-04-06kbuild: do not remove empty *.symtypes explicitlyMasahiro Yamada
Presumably, 'test -s $@ || rm -f $@' intends to remove the output when the genksyms command fails. It is unneeded because .DELETE_ON_ERROR automatically removes the output on failure. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-04-06kbuild: factor out genksyms command from cmd_gensymtypes_{c,S}Masahiro Yamada
The genksyms command part in cmd_gensymtypes_{c,S} is duplicated. Factor it out into the 'genksyms' macro. For the readability, I slightly refactor the arguments to genksyms. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-04-05kbuild: Allow kernel installation packaging to override pkg-configChun-Tse Shao
Add HOSTPKG_CONFIG to allow tooling that builds the kernel to override what pkg-config and parameters are used. Signed-off-by: Chun-Tse Shao <ctshao@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-04-04x86/cpu: Remove CONFIG_X86_SMAP and "nosmap"Borislav Petkov
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
2022-04-03modpost: restore the warning message for missing symbol versionsMasahiro Yamada
This log message was accidentally chopped off. I was wondering why this happened, but checking the ML log, Mark precisely followed my suggestion [1]. I just used "..." because I was too lazy to type the sentence fully. Sorry for the confusion. [1]: https://lore.kernel.org/all/CAK7LNAR6bXXk9-ZzZYpTqzFqdYbQsZHmiWspu27rtsFxvfRuVA@mail.gmail.com/ Fixes: 4a6795933a89 ("kbuild: modpost: Explicitly warn about unprototyped symbols") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Mark Brown <broonie@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2022-04-02kbuild: fix empty ${PYTHON} in scripts/link-vmlinux.shMasahiro Yamada
The two commits d8d2d38275c1 ("kbuild: remove PYTHON variable") a8cccdd95473 ("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>
2022-04-02kconfig: remove stale comment about removed kconfig_print_symbol()Masahiro Yamada
This comment is about kconfig_print_symbol(), which was removed by commit 6ce45a91a982 ("kconfig: refactor conf_write_symbol()"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2022-03-31Merge tag 'docs-5.18-2' of git://git.lwn.net/linuxLinus Torvalds
Pull more documentation updates from Jonathan Corbet: "Some late-arriving documentation improvements. This is mostly build-system fixes from Mauro and Akira; I also took the liberty of dropping in my 'messy diffstat' document" * tag 'docs-5.18-2' of git://git.lwn.net/linux: docs: Add a document on how to fix a messy diffstat docs: sphinx/requirements: Limit jinja2<3.1 Documentation: kunit: Fix cross-referencing warnings scripts/kernel-doc: change the line number meta info scripts/get_abi: change the file/line number meta info docs: kernel_include.py: add sphinx build dependencies docs: kernel_abi.py: add sphinx build dependencies docs: kernel_feat.py: add build dependencies scripts/get_feat.pl: allow output the parsed file names docs: kfigure.py: Don't warn of missing PDF converter in 'make htmldocs' Documentation: Fix duplicate statement about raw_spinlock_t type
2022-03-31Merge tag 'kbuild-v5.18-v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add new environment variables, USERCFLAGS and USERLDFLAGS to allow additional flags to be passed to user-space programs. - Fix missing fflush() bugs in Kconfig and fixdep - Fix a minor bug in the comment format of the .config file - Make kallsyms ignore llvm's local labels, .L* - Fix UAPI compile-test for cross-compiling with Clang - Extend the LLVM= syntax to support LLVM=<suffix> form for using a particular version of LLVm, and LLVM=<prefix> form for using custom LLVM in a particular directory path. - Clean up Makefiles * tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: Make $(LLVM) more flexible kbuild: add --target to correctly cross-compile UAPI headers with Clang fixdep: use fflush() and ferror() to ensure successful write to files arch: syscalls: simplify uapi/kapi directory creation usr/include: replace extra-y with always-y certs: simplify empty certs creation in certs/Makefile certs: include certs/signing_key.x509 unconditionally kallsyms: ignore all local labels prefixed by '.L' kconfig: fix missing '# end of' for empty menu kconfig: add fflush() before ferror() check kbuild: replace $(if A,A,B) with $(or A,B) kbuild: Add environment variables for userprogs flags kbuild: unify cmd_copy and cmd_shipped
2022-03-31fixdep: use fflush() and ferror() to ensure successful write to filesMasahiro Yamada
Currently, fixdep checks the return value from (v)printf(), but it does not ensure the complete write to the .cmd file. printf() just writes data to the internal buffer, which usually succeeds. (Of course, it may fail for another reason, for example when the file descriptor is closed, but that is another story.) When the buffer (4k?) is full, an actual write occurs, and printf() may really fail. One of typical cases is "No space left on device" when the disk is full. The data remaining in the buffer will be pushed out to the file when the program exits, but we never know if it is successful. One straight-forward fix would be to add the following code at the end of the program. ret = fflush(stdout); if (ret < 0) { /* error handling */ } However, it is tedious to check the return code in all the call sites of printf(), fflush(), fclose(), and whatever can cause actual writes to the end device. Doing that lets the program bail out at the first failure but is usually not worth the effort. Instead, let's check the error status from ferror(). This is 'sticky', so you need to check it just once. You still need to call fflush(). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: David Laight <david.laight@aculab.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
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