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* Merge branch 'for-5.12' of ↵Linus Torvalds2021-02-232-15/+27
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu Pull percpu updates from Dennis Zhou: "Percpu had a cleanup come in that makes use of the cpu bitmask helpers instead of the current iterative approach. This clean up then had an adverse interaction when clang's inlining sensitivity is changed such that not all sites are inlined resulting in modpost being upset with section mismatch due to percpu setup being marked __init. That was fixed by introducing __flatten to compiler_attributes.h" * 'for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu: percpu: fix clang modpost section mismatch percpu: reduce the number of cpu distance comparisons
| * percpu: fix clang modpost section mismatchDennis Zhou2021-02-142-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pcpu_build_alloc_info() is an __init function that makes a call to cpumask_clear_cpu(). With CONFIG_GCOV_PROFILE_ALL enabled, the inline heuristics are modified and such cpumask_clear_cpu() which is marked inline doesn't get inlined. Because it works on mask in __initdata, modpost throws a section mismatch error. Arnd sent a patch with the flatten attribute as an alternative [2]. I've added it to compiler_attributes.h. modpost complaint: WARNING: modpost: vmlinux.o(.text+0x735425): Section mismatch in reference from the function cpumask_clear_cpu() to the variable .init.data:pcpu_build_alloc_info.mask The function cpumask_clear_cpu() references the variable __initdata pcpu_build_alloc_info.mask. This is often because cpumask_clear_cpu lacks a __initdata annotation or the annotation of pcpu_build_alloc_info.mask is wrong. clang output: mm/percpu.c:2724:5: remark: cpumask_clear_cpu not inlined into pcpu_build_alloc_info because too costly to inline (cost=725, threshold=325) [-Rpass-missed=inline] [1] https://lore.kernel.org/linux-mm/202012220454.9F6Bkz9q-lkp@intel.com/ [2] https://lore.kernel.org/lkml/CAK8P3a2ZWfNeXKSm8K_SUhhwkor17jFo3xApLXjzfPqX0eUDUA@mail.gmail.com/ Reported-by: kernel test robot <lkp@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Dennis Zhou <dennis@kernel.org>
| * percpu: reduce the number of cpu distance comparisonsWonhyuk Yang2021-02-141-14/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To build group_map[] and group_cnt[], we find out which group CPUs belong to by comparing the distance of the cpu. However, this includes cases where comparisons are not required. This patch uses a bitmap to record CPUs that is not classified in the group. CPUs that we know which group they belong to should be cleared from the bitmap. In result, we can reduce the number of unnecessary comparisons. Signed-off-by: Wonhyuk Yang <vvghjk1234@gmail.com> Signed-off-by: Dennis Zhou <dennis@kernel.org> [Dennis: added cpumask_clear() call and #include cpumask.h.]
* | Kbuild: disable TRIM_UNUSED_KSYMS optionLinus Torvalds2021-02-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The removal of EXPORT_UNUSED_SYMBOL() in commit 367948220fce looks like (and was sold as) a no-op, but it actually had a rather serious and subtle side effect: the UNUSED_SYMBOLS option not only enabled the removed (unused) functionality, it also _disabled_ the TRIM_UNUSED_KSYMS functionality. And it turns out that TRIM_UNUSED_KSYMS is a huge time waste, and takes up a third of the kernel build time for me. For no actual upside, since no distro is likely to ever be able to enable it (because they all support external kernel modules). Rather than re-enable EXPORT_UNUSED_SYMBOL, this just disables the TRIM_UNUSED_KSYMS option by marking it broken. I'm tempted to just remove the support entirely, but maybe somebody has a use-case and can fix the behavior of it. I could have just disabled it for COMPILE_TEST, but it really smells like the TRIM_UNUSED_KSYMS option is badly done and not really useful, so this takes the more direct approach - let's see if anybody ever actually notices or complains. Cc: Miroslav Benes <mbenes@suse.cz> Cc: Emil Velikov <emil.l.velikov@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jessica Yu <jeyu@kernel.org> Fixes: 367948220fce ("module: remove EXPORT_UNUSED_SYMBOL*") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'modules-for-v5.12' of ↵Linus Torvalds2021-02-2335-516/+287
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module updates from Jessica Yu: - Retire EXPORT_UNUSED_SYMBOL() and EXPORT_SYMBOL_GPL_FUTURE(). These export types were introduced between 2006 - 2008. All the of the unused symbols have been long removed and gpl future symbols were converted to gpl quite a long time ago, and I don't believe these export types have been used ever since. So, I think it should be safe to retire those export types now (Christoph Hellwig) - Refactor and clean up some aged code cruft in the module loader (Christoph Hellwig) - Build {,module_}kallsyms_on_each_symbol only when livepatching is enabled, as it is the only caller (Christoph Hellwig) - Unexport find_module() and module_mutex and fix the last module callers to not rely on these anymore. Make module_mutex internal to the module loader (Christoph Hellwig) - Harden ELF checks on module load and validate ELF structures before checking the module signature (Frank van der Linden) - Fix undefined symbol warning for clang (Fangrui Song) - Fix smatch warning (Dan Carpenter) * tag 'modules-for-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: potential uninitialized return in module_kallsyms_on_each_symbol() module: remove EXPORT_UNUSED_SYMBOL* module: remove EXPORT_SYMBOL_GPL_FUTURE module: move struct symsearch to module.c module: pass struct find_symbol_args to find_symbol module: merge each_symbol_section into find_symbol module: remove each_symbol_in_section module: mark module_mutex static kallsyms: only build {,module_}kallsyms_on_each_symbol when required kallsyms: refactor {,module_}kallsyms_on_each_symbol module: use RCU to synchronize find_module module: unexport find_module and module_mutex drm: remove drm_fb_helper_modinit powerpc/powernv: remove get_cxl_module module: harden ELF info handling module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols
| * | module: potential uninitialized return in module_kallsyms_on_each_symbol()Dan Carpenter2021-02-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Smatch complains that: kernel/module.c:4472 module_kallsyms_on_each_symbol() error: uninitialized symbol 'ret'. This warning looks like it could be correct if the &modules list is empty. Fixes: 013c1667cf78 ("kallsyms: refactor {,module_}kallsyms_on_each_symbol") Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: remove EXPORT_UNUSED_SYMBOL*Christoph Hellwig2021-02-0824-193/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | EXPORT_UNUSED_SYMBOL* is not actually used anywhere. Remove the unused functionality as we generally just remove unused code anyway. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: remove EXPORT_SYMBOL_GPL_FUTUREChristoph Hellwig2021-02-089-65/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As far as I can tell this has never been used at all, and certainly not any time recently. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: move struct symsearch to module.cChristoph Hellwig2021-02-082-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct symsearch is only used inside of module.h, so move the definition out of module.h. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: pass struct find_symbol_args to find_symbolChristoph Hellwig2021-02-081-61/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify the calling convention by passing the find_symbol_args structure to find_symbol instead of initializing it inside the function. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: merge each_symbol_section into find_symbolChristoph Hellwig2021-02-081-79/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | each_symbol_section is only called by find_symbol, so merge the two functions. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: remove each_symbol_in_sectionChristoph Hellwig2021-02-081-22/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | each_symbol_in_section just contains a trivial loop over its arguments. Just open code the loop in the two callers. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: mark module_mutex staticChristoph Hellwig2021-02-083-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Except for two lockdep asserts module_mutex is only used in module.c. Remove the two asserts given that the functions they are in are not exported and just called from the module code, and mark module_mutex static. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | kallsyms: only build {,module_}kallsyms_on_each_symbol when requiredChristoph Hellwig2021-02-084-25/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kallsyms_on_each_symbol and module_kallsyms_on_each_symbol are only used by the livepatching code, so don't build them if livepatching is not enabled. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | kallsyms: refactor {,module_}kallsyms_on_each_symbolChristoph Hellwig2021-02-083-12/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Require an explicit call to module_kallsyms_on_each_symbol to look for symbols in modules instead of the call from kallsyms_on_each_symbol, and acquire module_mutex inside of module_kallsyms_on_each_symbol instead of leaving that up to the caller. Note that this slightly changes the behavior for the livepatch code in that the symbols from vmlinux are not iterated anymore if objname is set, but that actually is the desired behavior in this case. Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: use RCU to synchronize find_moduleChristoph Hellwig2021-02-084-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow for a RCU-sched critical section around find_module, following the lower level find_module_all helper, and switch the two callers outside of module.c to use such a RCU-sched critical section instead of module_mutex. Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: unexport find_module and module_mutexChristoph Hellwig2021-02-081-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | find_module is not used by modular code any more, and random driver code has no business calling it to start with. Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | drm: remove drm_fb_helper_modinitChristoph Hellwig2021-02-083-44/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | drm_fb_helper_modinit has a lot of boilerplate for what is not very simple functionality. Just open code it in the only caller using IS_ENABLED and IS_MODULE, and skip the find_module check as a request_module is harmless if the module is already loaded (and not other caller has this find_module check either). Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | powerpc/powernv: remove get_cxl_moduleChristoph Hellwig2021-02-081-22/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The static inline get_cxl_module function is entirely unused since commit 8bf6b91a5125a ("Revert "powerpc/powernv: Add support for the cxl kernel api on the real phb"), so remove it. Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: harden ELF info handlingFrank van der Linden2021-01-193-21/+126
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 5fdc7db644 ("module: setup load info before module_sig_check()") moved the ELF setup, so that it was done before the signature check. This made the module name available to signature error messages. However, the checks for ELF correctness in setup_load_info are not sufficient to prevent bad memory references due to corrupted offset fields, indices, etc. So, there's a regression in behavior here: a corrupt and unsigned (or badly signed) module, which might previously have been rejected immediately, can now cause an oops/crash. Harden ELF handling for module loading by doing the following: - Move the signature check back up so that it comes before ELF initialization. It's best to do the signature check to see if we can trust the module, before using the ELF structures inside it. This also makes checks against info->len more accurate again, as this field will be reduced by the length of the signature in mod_check_sig(). The module name is now once again not available for error messages during the signature check, but that seems like a fair tradeoff. - Check if sections have offset / size fields that at least don't exceed the length of the module. - Check if sections have section name offsets that don't fall outside the section name table. - Add a few other sanity checks against invalid section indices, etc. This is not an exhaustive consistency check, but the idea is to at least get through the signature and blacklist checks without crashing because of corrupted ELF info, and to error out gracefully for most issues that would have caused problems later on. Fixes: 5fdc7db6448a ("module: setup load info before module_sig_check()") Signed-off-by: Frank van der Linden <fllinden@amazon.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
| * | module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbolsFangrui Song2021-01-181-2/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clang-12 -fno-pic (since https://github.com/llvm/llvm-project/commit/a084c0388e2a59b9556f2de0083333232da3f1d6) can emit `call __stack_chk_fail@PLT` instead of `call __stack_chk_fail` on x86. The two forms should have identical behaviors on x86-64 but the former causes GNU as<2.37 to produce an unreferenced undefined symbol _GLOBAL_OFFSET_TABLE_. (On x86-32, there is an R_386_PC32 vs R_386_PLT32 difference but the linker behavior is identical as far as Linux kernel is concerned.) Simply ignore _GLOBAL_OFFSET_TABLE_ for now, like what scripts/mod/modpost.c:ignore_undef_symbol does. This also fixes the problem for gcc/clang -fpie and -fpic, which may emit `call foo@PLT` for external function calls on x86. Note: ld -z defs and dynamic loaders do not error for unreferenced undefined symbols so the module loader is reading too much. If we ever need to ignore more symbols, the code should be refactored to ignore unreferenced symbols. Cc: <stable@vger.kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1250 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27178 Reported-by: Marco Elver <elver@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Marco Elver <elver@google.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
* | | Merge tag 'microblaze-v5.12' of git://git.monstr.eu/linux-2.6-microblazeLinus Torvalds2021-02-233-28/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull microblaze updates from Michal Simek: - Fix DTB alignment - Remove code for very old GCC versions - Remove TRACING_SUPPORT selection * tag 'microblaze-v5.12' of git://git.monstr.eu/linux-2.6-microblaze: microblaze: Fix built-in DTB alignment to be 8-byte aligned microblaze: Remove support for gcc < 4 microblaze: do not select TRACING_SUPPORT directly
| * | | microblaze: Fix built-in DTB alignment to be 8-byte alignedRob Herring2021-02-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9") broke booting on Microblaze systems depending on the build. The problem is libfdt gained an 8-byte starting alignment check, but the Microblaze built-in DTB area is only 4-byte aligned. This affected not just built-in DTBs as bootloader passed DTBs are copied into the built-in DTB region. Other arches using built-in DTBs use a common linker macro which has sufficient alignment. Fixes: 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9") Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Michal Simek <monstr@monstr.eu> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20210213011624.251838-1-robh@kernel.org Signed-off-by: Michal Simek <michal.simek@xilinx.com>
| * | | microblaze: Remove support for gcc < 4Geert Uytterhoeven2021-02-111-26/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit cafa0010cd51fb71 ("Raise the minimum required gcc version to 4.6") , the kernel can no longer be compiled using gcc-3. Hence drop support code for gcc-3. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20210210141140.1506212-5-geert+renesas@glider.be Signed-off-by: Michal Simek <michal.simek@xilinx.com>
| * | | microblaze: do not select TRACING_SUPPORT directlyMasahiro Yamada2021-01-041-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Microblaze is the only architecture that selects TRACING_SUPPORT. In my understanding, it is computed by kernel/trace/Kconfig: config TRACING_SUPPORT bool depends on TRACE_IRQFLAGS_SUPPORT depends on STACKTRACE_SUPPORT default y Microblaze enables both TRACE_IRQFLAGS_SUPPORT and STACKTRACE_SUPPORT, so there is no change in the resulted configuration. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20201223152947.698744-1-masahiroy@kernel.org Signed-off-by: Michal Simek <michal.simek@xilinx.com>
* | | | Merge tag 'objtool-core-2021-02-23' of ↵Linus Torvalds2021-02-2349-597/+962
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Thomas Gleixner: - Make objtool work for big-endian cross compiles - Make stack tracking via stack pointer memory operations match push/pop semantics to prepare for architectures w/o PUSH/POP instructions. - Add support for analyzing alternatives - Improve retpoline detection and handling - Improve assembly code coverage on x86 - Provide support for inlined stack switching * tag 'objtool-core-2021-02-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) objtool: Support stack-swizzle objtool,x86: Additionally decode: mov %rsp, (%reg) x86/unwind/orc: Change REG_SP_INDIRECT x86/power: Support objtool validation in hibernate_asm_64.S x86/power: Move restore_registers() to top of the file x86/power: Annotate indirect branches as safe x86/acpi: Support objtool validation in wakeup_64.S x86/acpi: Annotate indirect branch as safe x86/ftrace: Support objtool vmlinux.o validation in ftrace_64.S x86/xen/pvh: Annotate indirect branch as safe x86/xen: Support objtool vmlinux.o validation in xen-head.S x86/xen: Support objtool validation in xen-asm.S objtool: Add xen_start_kernel() to noreturn list objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNC objtool: Add asm version of STACK_FRAME_NON_STANDARD objtool: Assume only ELF functions do sibling calls x86/ftrace: Add UNWIND_HINT_FUNC annotation for ftrace_stub objtool: Support retpoline jump detection for vmlinux.o objtool: Fix ".cold" section suffix check for newer versions of GCC objtool: Fix retpoline detection in asm code ...
| * | | | objtool: Support stack-swizzlePeter Zijlstra2021-02-101-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Natively support the stack swizzle pattern: mov %rsp, (%[tos]) mov %[tos], %rsp ... pop %rsp It uses the vals[] array to link the first two stack-ops, and detect the SP to SP_INDIRECT swizzle. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
| * | | | objtool,x86: Additionally decode: mov %rsp, (%reg)Peter Zijlstra2021-02-101-8/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Where we already decode: mov %rsp, %reg, also decode mov %rsp, (%reg). Nothing should match for this new stack-op. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
| * | | | x86/unwind/orc: Change REG_SP_INDIRECTPeter Zijlstra2021-02-102-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently REG_SP_INDIRECT is unused but means (%rsp + offset), change it to mean (%rsp) + offset. The reason is that we're going to swizzle stack in the middle of a C function with non-trivial stack footprint. This means that when the unwinder finds the ToS, it needs to dereference it (%rsp) and then add the offset to the next frame, resulting in: (%rsp) + offset This is somewhat unfortunate, since REG_BP_INDIRECT is used (by DRAP) and thus needs to retain the current (%rbp + offset). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
| * | | | x86/power: Support objtool validation in hibernate_asm_64.SJosh Poimboeuf2021-01-262-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The OBJECT_FILES_NON_STANDARD annotation is used to tell objtool to ignore a file. File-level ignores won't work when validating vmlinux.o. Instead, convert restore_image() and core_restore_code() to be ELF functions. Their code is conventional enough for objtool to be able to understand them. Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/974f8ceb5385e470f72e93974c70ab5c894bb0dc.1611263462.git.jpoimboe@redhat.com
| * | | | x86/power: Move restore_registers() to top of the fileJosh Poimboeuf2021-01-261-46/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because restore_registers() is page-aligned, the assembler inexplicably adds an unreachable jump from after the end of the previous function to the beginning of restore_registers(). That confuses objtool, understandably. It also creates significant text fragmentation. As a result, most of the object file is wasted text (nops). Move restore_registers() to the beginning of the file to both prevent the text fragmentation and avoid the dead jump instruction. $ size /tmp/hibernate_asm_64.before.o /tmp/hibernate_asm_64.after.o text data bss dec hex filename 4415 0 0 4415 113f /tmp/hibernate_asm_64.before.o 524 0 0 524 20c /tmp/hibernate_asm_64.after.o Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/8c7f634201d26453d73fe55032cbbdc05d004387.1611263462.git.jpoimboe@redhat.com
| * | | | x86/power: Annotate indirect branches as safeJosh Poimboeuf2021-01-261-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These indirect jumps are harmless; annotate them to make objtool's retpoline validation happy. Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/ba7a141c98f2c09c255b19bf78ee4a5f45d4ecb6.1611263462.git.jpoimboe@redhat.com
| * | | | x86/acpi: Support objtool validation in wakeup_64.SJosh Poimboeuf2021-01-262-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The OBJECT_FILES_NON_STANDARD annotation is used to tell objtool to ignore a file. File-level ignores won't work when validating vmlinux.o. Instead, tell objtool to ignore do_suspend_lowlevel() directly with the STACK_FRAME_NON_STANDARD annotation. Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/269eda576c53bc9ecc8167c211989111013a67aa.1611263462.git.jpoimboe@redhat.com
| * | | | x86/acpi: Annotate indirect branch as safeJosh Poimboeuf2021-01-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This indirect jump is harmless; annotate it to keep objtool's retpoline validation happy. Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/a7288e7043265d95c1a5d64f9fd751ead4854bdc.1611263462.git.jpoimboe@redhat.com
| * | | | x86/ftrace: Support objtool vmlinux.o validation in ftrace_64.SJosh Poimboeuf2021-01-261-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With objtool vmlinux.o validation of return_to_handler(), now that objtool has visibility inside the retpoline, jumping from EMPTY state to a proper function state results in a stack state mismatch. return_to_handler() is actually quite normal despite the underlying magic. Just annotate it as a normal function. Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/14f48e623f61dbdcd84cf27a56ed8ccae73199ef.1611263462.git.jpoimboe@redhat.com
| * | | | x86/xen/pvh: Annotate indirect branch as safeJosh Poimboeuf2021-01-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This indirect jump is harmless; annotate it to keep objtool's retpoline validation happy. Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/4797c72a258b26e06741c58ccd4a75c42db39c1d.1611263462.git.jpoimboe@redhat.com
| * | | | x86/xen: Support objtool vmlinux.o validation in xen-head.SJosh Poimboeuf2021-01-261-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Xen hypercall page is filled with zeros, causing objtool to fall through all the empty hypercall functions until it reaches a real function, resulting in a stack state mismatch. The build-time contents of the hypercall page don't matter because the page gets rewritten by the hypervisor. Make it more palatable to objtool by making each hypervisor function a true empty function, with nops and a return. Cc: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/0883bde1d7a1fb3b6a4c952bc0200e873752f609.1611263462.git.jpoimboe@redhat.com
| * | | | x86/xen: Support objtool validation in xen-asm.SJosh Poimboeuf2021-01-262-11/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The OBJECT_FILES_NON_STANDARD annotation is used to tell objtool to ignore a file. File-level ignores won't work when validating vmlinux.o. Tweak the ELF metadata and unwind hints to allow objtool to follow the code. Cc: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/8b042a09c69e8645f3b133ef6653ba28f896807d.1611263462.git.jpoimboe@redhat.com
| * | | | objtool: Add xen_start_kernel() to noreturn listJosh Poimboeuf2021-01-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | xen_start_kernel() doesn't return. Annotate it as such so objtool can follow the code flow. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/930deafa89256c60b180442df59a1bbae48f30ab.1611263462.git.jpoimboe@redhat.com
| * | | | objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNCJosh Poimboeuf2021-01-268-40/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ORC metadata generated for UNWIND_HINT_FUNC isn't actually very func-like. With certain usages it can cause stack state mismatches because it doesn't set the return address (CFI_RA). Also, users of UNWIND_HINT_RET_OFFSET no longer need to set a custom return stack offset. Instead they just need to specify a func-like situation, so the current ret_offset code is hacky for no good reason. Solve both problems by simplifying the RET_OFFSET handling and converting it into a more useful UNWIND_HINT_FUNC. If we end up needing the old 'ret_offset' functionality again in the future, we should be able to support it pretty easily with the addition of a custom 'sp_offset' in UNWIND_HINT_FUNC. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/db9d1f5d79dddfbb3725ef6d8ec3477ad199948d.1611263462.git.jpoimboe@redhat.com
| * | | | objtool: Add asm version of STACK_FRAME_NON_STANDARDJosh Poimboeuf2021-01-262-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To be used for adding asm functions to the ignore list. The "aw" is needed to help the ELF section metadata match GCC-created sections. Otherwise the linker creates duplicate sections instead of combining them. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/8faa476f9a5ac89af27944ec184c89f95f3c6c49.1611263462.git.jpoimboe@redhat.com
| * | | | objtool: Assume only ELF functions do sibling callsJosh Poimboeuf2021-01-261-14/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's an inconsistency in how sibling calls are detected in non-function asm code, depending on the scope of the object. If the target code is external to the object, objtool considers it a sibling call. If the target code is internal but not a function, objtool *doesn't* consider it a sibling call. This can cause some inconsistencies between per-object and vmlinux.o validation. Instead, assume only ELF functions can do sibling calls. This generally matches existing reality, and makes sibling call validation consistent between vmlinux.o and per-object. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/0e9ab6f3628cc7bf3bde7aa6762d54d7df19ad78.1611263461.git.jpoimboe@redhat.com
| * | | | x86/ftrace: Add UNWIND_HINT_FUNC annotation for ftrace_stubJosh Poimboeuf2021-01-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prevent an unreachable objtool warning after the sibling call detection gets improved. ftrace_stub() is basically a function, annotate it as such. Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/6845e1b2fb0723a95740c6674e548ba38c5ea489.1611263461.git.jpoimboe@redhat.com
| * | | | objtool: Support retpoline jump detection for vmlinux.oJosh Poimboeuf2021-01-261-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Objtool converts direct retpoline jumps to type INSN_JUMP_DYNAMIC, since that's what they are semantically. That conversion doesn't work in vmlinux.o validation because the indirect thunk function is present in the object, so the intra-object jump check succeeds before the retpoline jump check gets a chance. Rearrange the checks: check for a retpoline jump before checking for an intra-object jump. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/4302893513770dde68ddc22a9d6a2a04aca491dd.1611263461.git.jpoimboe@redhat.com
| * | | | objtool: Fix ".cold" section suffix check for newer versions of GCCJosh Poimboeuf2021-01-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With my version of GCC 9.3.1 the ".cold" subfunctions no longer have a numbered suffix, so the trailing period is no longer there. Presumably this doesn't yet trigger a user-visible bug since most of the subfunction detection logic is duplicated. I only found it when testing vmlinux.o validation. Fixes: 54262aa28301 ("objtool: Fix sibling call detection") Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/ca0b5a57f08a2fbb48538dd915cc253b5edabb40.1611263461.git.jpoimboe@redhat.com
| * | | | objtool: Fix retpoline detection in asm codeJosh Poimboeuf2021-01-263-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The JMP_NOSPEC macro branches to __x86_retpoline_*() rather than the __x86_indirect_thunk_*() wrappers used by C code. Detect jumps to __x86_retpoline_*() as retpoline dynamic jumps. Presumably this doesn't trigger a user-visible bug. I only found it when testing vmlinux.o validation. Fixes: 39b735332cb8 ("objtool: Detect jumps to retpoline thunks") Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/31f5833e2e4f01e3d755889ac77e3661e906c09f.1611263461.git.jpoimboe@redhat.com
| * | | | objtool: Fix error handling for STD/CLD warningsJosh Poimboeuf2021-01-261-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Actually return an error (and display a backtrace, if requested) for directional bit warnings. Fixes: 2f0f9e9ad7b3 ("objtool: Add Direction Flag validation") Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/dc70f2adbc72f09526f7cab5b6feb8bf7f6c5ad4.1611263461.git.jpoimboe@redhat.com
| * | | | objtool: Support stack layout changes in alternativesJosh Poimboeuf2021-01-144-111/+159
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ORC unwinder showed a warning [1] which revealed the stack layout didn't match what was expected. The problem was that paravirt patching had replaced "CALL *pv_ops.irq.save_fl" with "PUSHF;POP". That changed the stack layout between the PUSHF and the POP, so unwinding from an interrupt which occurred between those two instructions would fail. Part of the agreed upon solution was to rework the custom paravirt patching code to use alternatives instead, since objtool already knows how to read alternatives (and converging runtime patching infrastructure is always a good thing anyway). But the main problem still remains, which is that runtime patching can change the stack layout. Making stack layout changes in alternatives was disallowed with commit 7117f16bf460 ("objtool: Fix ORC vs alternatives"), but now that paravirt is going to be doing it, it needs to be supported. One way to do so would be to modify the ORC table when the code gets patched. But ORC is simple -- a good thing! -- and it's best to leave it alone. Instead, support stack layout changes by "flattening" all possible stack states (CFI) from parallel alternative code streams into a single set of linear states. The only necessary limitation is that CFI conflicts are disallowed at all possible instruction boundaries. For example, this scenario is allowed: Alt1 Alt2 Alt3 0x00 CALL *pv_ops.save_fl CALL xen_save_fl PUSHF 0x01 POP %RAX 0x02 NOP ... 0x05 NOP ... 0x07 <insn> The unwind information for offset-0x00 is identical for all 3 alternatives. Similarly offset-0x05 and higher also are identical (and the same as 0x00). However offset-0x01 has deviating CFI, but that is only relevant for Alt3, neither of the other alternative instruction streams will ever hit that offset. This scenario is NOT allowed: Alt1 Alt2 0x00 CALL *pv_ops.save_fl PUSHF 0x01 NOP6 ... 0x07 NOP POP %RAX The problem here is that offset-0x7, which is an instruction boundary in both possible instruction patch streams, has two conflicting stack layouts. [ The above examples were stolen from Peter Zijlstra. ] The new flattened CFI array is used both for the detection of conflicts (like the second example above) and the generation of linear ORC entries. BTW, another benefit of these changes is that, thanks to some related cleanups (new fake nops and alt_group struct) objtool can finally be rid of fake jumps, which were a constant source of headaches. [1] https://lkml.kernel.org/r/20201111170536.arx2zbn4ngvjoov7@treble Cc: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
| * | | | objtool: Add 'alt_group' structJosh Poimboeuf2021-01-142-7/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create a new struct associated with each group of alternatives instructions. This will help with the removal of fake jumps, and more importantly with adding support for stack layout changes in alternatives. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
| * | | | objtool: Refactor ORC section generationJosh Poimboeuf2021-01-147-159/+140
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Decouple ORC entries from instructions. This simplifies the control/data flow, and is going to make it easier to support alternative instructions which change the stack layout. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-30 12:18:18 +0000