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2025-02-21s390/vdso: Switch to generic storage implementationThomas Weißschuh
The generic storage implementation provides the same features as the custom one. However it can be shared between architectures, making maintenance easier. Co-developed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-12-13a4669dfc8c@linutronix.de
2025-02-21vdso: Rename included MakefileThomas Weißschuh
As the Makefile is included into other Makefiles it can not be used to define objects to be built from the current source directory. However the generic datastore will introduce such a local source file. Rename the included Makefile so it is clear how it is to be used and to make room for a regular Makefile in lib/vdso/. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-4-13a4669dfc8c@linutronix.de
2024-12-10s390/Kconfig: Select VMAP_STACK unconditionallyHeiko Carstens
There is no point in supporting !VMAP_STACK kernel builds. VMAP_STACK has proven to work since many years. Also, since KASAN_VMALLOC is supported, kernels built with !VMAP_STACK are completely untested. Therefore select VMAP_STACK unconditionally and remove all config options and code required for !VMAP_STACK builds. Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-11-02s390/vdso: Drop LBASE_VDSOThomas Weißschuh
This constant is always "0", providing no value and making the logic harder to understand. Also prepare for a consolidation of the vdso linkerscript logic by aligning it with other architectures. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-3-b64f0842d512@linutronix.de
2024-09-23s390/vdso: Use one large alternative instead of an alternative branchHeiko Carstens
Replace the alternative branch with a larger alternative that contains both paths. That way the two paths are closer together and it is easier to change both paths if the need should arise. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-09-23s390/vdso: Use SYM_DATA_START_LOCAL()/SYM_DATA_END() for data objectsHeiko Carstens
Use SYM_DATA_START_LOCAL()/SYM_DATA_END() in vgetrandom-chacha.S so that the constants end up in an object with correct size: readelf -Ws vgetrandom-chacha.o Num: Value Size Type Bind Vis Ndx Name ... 5: 0000000000000000 32 OBJECT LOCAL DEFAULT 5 chacha20_constants Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-09-23s390/vdso: Use macros for annotation of asm functionsJens Remus
Use the macros SYM_FUNC_START() and SYM_FUNC_END() to annotate the functions in assembly. Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-09-23s390/vdso: Add CFI annotations to __arch_chacha20_blocks_nostack()Jens Remus
This allows proper unwinding, for instance when using a debugger such as GDB. Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-09-23s390/vdso: Fix comment within __arch_chacha20_blocks_nostack()Heiko Carstens
Fix comment within __arch_chacha20_blocks_nostack() so the comment reflects what the code is doing. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-09-23s390/vdso: Get rid of permutation constantsHeiko Carstens
The three byte masks for VECTOR PERMUTE are not needed, since the instruction VECTOR SHIFT LEFT DOUBLE BY BYTE can be used to implement the required "rotate left" easily. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-09-13s390/vdso: Wire up getrandom() vdso implementationHeiko Carstens
Provide the s390 specific vdso getrandom() architecture backend. _vdso_rng_data required data is placed within the _vdso_data vvar page, by using a hardcoded offset larger than vdso_data. As required the chacha20 implementation does not write to the stack. The implementation follows more or less the arm64 implementations and makes use of vector instructions. It has a fallback to the getrandom() system call for machines where the vector facility is not installed. The check if the vector facility is installed, as well as an optimization for machines with the vector-enhancements facility 2, is implemented with alternatives, avoiding runtime checks. Note that __kernel_getrandom() is implemented without the vdso user wrapper which would setup a stack frame for odd cases (aka very old glibc variants) where the caller has not done that. All callers of __kernel_getrandom() are required to setup a stack frame, like the C ABI requires it. The vdso testcases vdso_test_getrandom and vdso_test_chacha pass. Benchmark on a z16: $ ./vdso_test_getrandom bench-single vdso: 25000000 times in 0.493703559 seconds syscall: 25000000 times in 6.584025337 seconds Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-09-13s390/vdso: Allow alternatives in vdso codeHeiko Carstens
Implement the infrastructure required to allow alternatives in vdso code. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-05-21Merge tag 's390-6.10-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Alexander Gordeev: - Switch read and write software bits for PUDs - Add missing hardware bits for PUDs and PMDs - Generate unwind information for C modules to fix GDB unwind error for vDSO functions - Create .build-id links for unstripped vDSO files to enable vDSO debugging with symbols - Use standard stack frame layout for vDSO generated stack frames to manually walk stack frames without DWARF information - Rework perf_callchain_user() and arch_stack_walk_user() functions to reduce code duplication - Skip first stack frame when walking user stack - Add basic checks to identify invalid instruction pointers when walking stack frames - Introduce and use struct stack_frame_vdso_wrapper within vDSO user wrapper code to automatically generate an asm-offset define. Also use STACK_FRAME_USER_OVERHEAD instead of STACK_FRAME_OVERHEAD to document that the code works with user space stack - Clear the backchain of the extra stack frame added by the vDSO user wrapper code. This allows the user stack walker to detect and skip the non-standard stack frame. Without this an incorrect instruction pointer would be added to stack traces. - Rewrite psw_idle() function in C to ease maintenance and further enhancements - Remove get_vtimer() function and use get_cpu_timer() instead - Mark psw variable in __load_psw_mask() as __unitialized to avoid superfluous clearing of PSW - Remove obsolete and superfluous comment about removed TIF_FPU flag - Replace memzero_explicit() and kfree() with kfree_sensitive() to fix warnings reported by Coccinelle - Wipe sensitive data and all copies of protected- or secure-keys from stack when an IOCTL fails - Both do_airq_interrupt() and do_io_interrupt() functions set CIF_NOHZ_DELAY flag. Move it in do_io_irq() to simplify the code - Provide iucv_alloc_device() and iucv_release_device() helpers, which can be used to deduplicate more or less identical IUCV device allocation and release code in four different drivers - Make use of iucv_alloc_device() and iucv_release_device() helpers to get rid of quite some code and also remove a cast to an incompatible function (clang W=1) - There is no user of iucv_root outside of the core IUCV code left. Therefore remove the EXPORT_SYMBOL - __apply_alternatives() contains a runtime check which verifies that the size of the to be patched code area is even. Convert this to a compile time check - Increase size of buffers for sending z/VM CP DIAGNOSE X'008' commands from 128 to 240 - Do not accept z/VM CP DIAGNOSE X'008' commands longer than maximally allowed - Use correct defines IPL_BP_NVME_LEN and IPL_BP0_NVME_LEN instead of IPL_BP_FCP_LEN and IPL_BP0_FCP_LEN ones to initialize NVMe reIPL block on 'scp_data' sysfs attribute update - Initialize the correct fields of the NVMe dump block, which were confused with FCP fields - Refactor macros for 'scp_data' (re-)IPL sysfs attribute to reduce code duplication - Introduce 'scp_data' sysfs attribute for dump IPL to allow tools such as dumpconf passing additional kernel command line parameters to a stand-alone dumper - Rework the CPACF query functions to use the correct RRE or RRF instruction formats and set instruction register fields correctly - Instead of calling BUG() at runtime force a link error during compile when a unsupported opcode is used with __cpacf_query() or __cpacf_check_opcode() functions - Fix a crash in ap_parse_bitmap_str() function on /sys/bus/ap/apmask or /sys/bus/ap/aqmask sysfs file update with a relative mask value - Fix "bindings complete" udev event which should be sent once all AP devices have been bound to device drivers and again when unbind/bind actions take place and all AP devices are bound again - Facility list alt_stfle_fac_list is nowhere used in the decompressor, therefore remove it there - Remove custom kprobes insn slot allocator in favour of the standard module_alloc() one, since kernel image and module areas are located within 4GB - Use kvcalloc() instead of kvmalloc_array() in zcrypt driver to avoid calling memset() with a large byte count and get rid of the sparse warning as result * tag 's390-6.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits) s390/zcrypt: Use kvcalloc() instead of kvmalloc_array() s390/kprobes: Remove custom insn slot allocator s390/boot: Remove alt_stfle_fac_list from decompressor s390/ap: Fix bind complete udev event sent after each AP bus scan s390/ap: Fix crash in AP internal function modify_bitmap() s390/cpacf: Make use of invalid opcode produce a link error s390/cpacf: Split and rework cpacf query functions s390/ipl: Introduce sysfs attribute 'scp_data' for dump ipl s390/ipl: Introduce macros for (re)ipl sysfs attribute 'scp_data' s390/ipl: Fix incorrect initialization of nvme dump block s390/ipl: Fix incorrect initialization of len fields in nvme reipl block s390/ipl: Do not accept z/VM CP diag X'008' cmds longer than max length s390/ipl: Fix size of vmcmd buffers for sending z/VM CP diag X'008' cmds s390/alternatives: Convert runtime sanity check into compile time check s390/iucv: Unexport iucv_root tty: hvc-iucv: Make use of iucv_alloc_device() s390/smsgiucv_app: Make use of iucv_alloc_device() s390/netiucv: Make use of iucv_alloc_device() s390/vmlogrdr: Make use of iucv_alloc_device() s390/iucv: Provide iucv_alloc_device() / iucv_release_device() ...
2024-05-18Merge tag 'kbuild-v6.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Avoid 'constexpr', which is a keyword in C23 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of 'dt_binding_check' - Fix weak references to avoid GOT entries in position-independent code generation - Convert the last use of 'optional' property in arch/sh/Kconfig - Remove support for the 'optional' property in Kconfig - Remove support for Clang's ThinLTO caching, which does not work with the .incbin directive - Change the semantics of $(src) so it always points to the source directory, which fixes Makefile inconsistencies between upstream and downstream - Fix 'make tar-pkg' for RISC-V to produce a consistent package - Provide reasonable default coverage for objtool, sanitizers, and profilers - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc. - Remove the last use of tristate choice in drivers/rapidio/Kconfig - Various cleanups and fixes in Kconfig * tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits) kconfig: use sym_get_choice_menu() in sym_check_prop() rapidio: remove choice for enumeration kconfig: lxdialog: remove initialization with A_NORMAL kconfig: m/nconf: merge two item_add_str() calls kconfig: m/nconf: remove dead code to display value of bool choice kconfig: m/nconf: remove dead code to display children of choice members kconfig: gconf: show checkbox for choice correctly kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal Makefile: remove redundant tool coverage variables kbuild: provide reasonable defaults for tool coverage modules: Drop the .export_symbol section from the final modules kconfig: use menu_list_for_each_sym() in sym_check_choice_deps() kconfig: use sym_get_choice_menu() in conf_write_defconfig() kconfig: add sym_get_choice_menu() helper kconfig: turn defaults and additional prompt for choice members into error kconfig: turn missing prompt for choice members into error kconfig: turn conf_choice() into void function kconfig: use linked list in sym_set_changed() kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED kconfig: gconf: remove debug code ...
2024-05-14Makefile: remove redundant tool coverage variablesMasahiro Yamada
Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
2024-05-14s390/stackstrace: Detect vdso stack framesHeiko Carstens
Clear the backchain of the extra stack frame added by the vdso user wrapper code. This allows the user stack walker to detect and skip the non-standard stack frame. Without this an incorrect instruction pointer would be added to stack traces, and stack frame walking would be continued with a more or less random back chain. Fixes: aa44433ac4ee ("s390: add USER_STACKTRACE support") Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-05-14s390/vdso: Introduce and use struct stack_frame_vdso_wrapperHeiko Carstens
Introduce and use struct stack_frame_vdso_wrapper within vdso user wrapper code. With this structure it is possible to automatically generate an asm-offset define which can be used to save and restore the return address of the calling function. Also use STACK_FRAME_USER_OVERHEAD instead of STACK_FRAME_OVERHEAD to document that the code works with user space stack frames with the standard stack frame layout. Fixes: aa44433ac4ee ("s390: add USER_STACKTRACE support") Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-05-14s390/vdso: Use standard stack frame layoutHeiko Carstens
By default user space is compiled with standard stack frame layout and not with the packed stack layout. The vdso code however inherited the -mpacked-stack compiler option from the kernel. Remove this option to make sure the vdso is compiled with standard stack frame layout. This makes sure that the stack frame backchain location for vdso generated stack frames is the same like for calling code (if compiled with default options). This allows to manually walk stack frames without DWARF information, like the kernel is doing it e.g. with arch_stack_walk_user(). Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO") Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-05-14s390/vdso: Generate unwind information for C modulesJens Remus
GDB fails to unwind vDSO functions with error message "PC not saved", for instance when stepping through gettimeofday(). Add -fasynchronous-unwind-tables to CFLAGS to generate .eh_frame DWARF unwind information for the vDSO C modules. Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO") Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-05-10kbuild: use $(src) instead of $(srctree)/$(src) for source directoryMasahiro Yamada
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-02arch: use $(obj)/ instead of $(src)/ for preprocessed linker scriptsMasahiro Yamada
These are generated files. Prefix them with $(obj)/ instead of $(src)/. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Helge Deller <deller@gmx.de> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-04-26s390/vdso: Add CFI for RA register to asm macro vdso_funcJens Remus
The return-address (RA) register r14 is specified as volatile in the s390x ELF ABI [1]. Nevertheless proper CFI directives must be provided for an unwinder to restore the return address, if the RA register value is changed from its value at function entry, as it is the case. [1]: s390x ELF ABI, https://github.com/IBM/s390x-abi/releases Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO") Signed-off-by: Jens Remus <jremus@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-02-20s390/vdso64: filter out munaligned-symbols flag for vdsoSumanth Korikkar
Gcc recently implemented an optimization [1] for loading symbols without explicit alignment, aligning with the IBM Z ELF ABI. This ABI mandates symbols to reside on a 2-byte boundary, enabling the use of the larl instruction. However, kernel linker scripts may still generate unaligned symbols. To address this, a new -munaligned-symbols option has been introduced [2] in recent gcc versions. [1] https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622872.html [2] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625986.html However, when -munaligned-symbols is used in vdso code, it leads to the following compilation error: `.data.rel.ro.local' referenced in section `.text' of arch/s390/kernel/vdso64/vdso64_generic.o: defined in discarded section `.data.rel.ro.local' of arch/s390/kernel/vdso64/vdso64_generic.o vdso linker script discards .data section to make it lightweight. However, -munaligned-symbols in vdso object files references literal pool and accesses _vdso_data. Hence, compile vdso code without -munaligned-symbols. This means in the future, vdso code should deal with alignment of newly introduced unaligned linker symbols. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Link: https://lore.kernel.org/r/20240219132734.22881-2-sumanthk@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-14s390/vdso: remove unused ENTRY in linker scriptsHeiko Carstens
When linking vdso64.so.dbg with ld.lld, there is a warning about not finding _start for the starting address: ld.lld: warning: cannot find entry symbol _start; not setting start address Fix this by removing the unused ENTRY in both vdso linker scripts. See commit e247172854a5 ("powerpc/vdso: Remove unused ENTRY in linker scripts"), which solved the same problem for powerpc, for further details. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-09s390/vdso: drop '-fPIC' from LDFLAGSNathan Chancellor
'-fPIC' as an option to the linker does not do what it seems like it should. With ld.bfd, it is treated as '-f PIC', which does not make sense based on the meaning of '-f': -f SHLIB, --auxiliary SHLIB Auxiliary filter for shared object symbol table When building with ld.lld (currently under review in a GitHub pull request), it just errors out because '-f' means nothing and neither does '-fPIC': ld.lld: error: unknown argument '-fPIC' '-fPIC' was blindly copied from CFLAGS when the vDSO stopped being linked with '$(CC)', it should not be needed. Remove it to clear up the build failure with ld.lld. Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO") Link: https://github.com/llvm/llvm-project/pull/75643 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Fangrui Song <maskray@google.com> Link: https://lore.kernel.org/r/20240130-s390-vdso-drop-fpic-from-ldflags-v1-1-094ad104fc55@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-10-28kbuild: unify vdso_install rulesMasahiro Yamada
Currently, there is no standard implementation for vdso_install, leading to various issues: 1. Code duplication Many architectures duplicate similar code just for copying files to the install destination. Some architectures (arm, sparc, x86) create build-id symlinks, introducing more code duplication. 2. Unintended updates of in-tree build artifacts The vdso_install rule depends on the vdso files to install. It may update in-tree build artifacts. This can be problematic, as explained in commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux"). 3. Broken code in some architectures Makefile code is often copied from one architecture to another without proper adaptation. 'make vdso_install' for parisc does not work. 'make vdso_install' for s390 installs vdso64, but not vdso32. To address these problems, this commit introduces a generic vdso_install rule. Architectures that support vdso_install need to define vdso-install-y in arch/*/Makefile. vdso-install-y lists the files to install. For example, arch/x86/Makefile looks like this: vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix, if exists, stripped away. vdso-install-y can optionally take the second field after the colon separator. This is needed because some architectures install a vdso file as a different base name. The following is a snippet from arch/arm64/Makefile. vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so This will rename vdso.so.dbg to vdso32.so during installation. If such architectures change their implementation so that the base names match, this workaround will go away. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390 Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Guo Ren <guoren@kernel.org> Acked-by: Helge Deller <deller@gmx.de> # parisc Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-06-28s390/vdso: filter out mno-pic-data-is-text-relative cflagSumanth Korikkar
cmd_vdso_check checks if there are any dynamic relocations in vdso64.so.dbg. When kernel is compiled with -mno-pic-data-is-text-relative, R_390_RELATIVE relocs are generated and this results in kernel build error. kpatch uses -mno-pic-data-is-text-relative option when building the kernel to prevent relative addressing between code and data. The flag avoids relocation error when klp text and data are too far apart kpatch does not patch vdso code and hence the mno-pic-data-is-text-relative flag is not essential. Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-06-28s390/vdso: check for undefined symbols after buildSven Schnelle
When adding an undefined symbol the build still succeeds, but userspace is crashing trying to execute vdso because the undefined symbol is not resolved. Add the check for undefined symbols to prevent this. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-04-30Merge tag 's390-6.4-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add support for stackleak feature. Also allow specifying architecture-specific stackleak poison function to enable faster implementation. On s390, the mvc-based implementation helps decrease typical overhead from a factor of 3 to just 25% - Convert all assembler files to use SYM* style macros, deprecating the ENTRY() macro and other annotations. Select ARCH_USE_SYM_ANNOTATIONS - Improve KASLR to also randomize module and special amode31 code base load addresses - Rework decompressor memory tracking to support memory holes and improve error handling - Add support for protected virtualization AP binding - Add support for set_direct_map() calls - Implement set_memory_rox() and noexec module_alloc() - Remove obsolete overriding of mem*() functions for KASAN - Rework kexec/kdump to avoid using nodat_stack to call purgatory - Convert the rest of the s390 code to use flexible-array member instead of a zero-length array - Clean up uaccess inline asm - Enable ARCH_HAS_MEMBARRIER_SYNC_CORE - Convert to using CONFIG_FUNCTION_ALIGNMENT and enable DEBUG_FORCE_FUNCTION_ALIGN_64B - Resolve last_break in userspace fault reports - Simplify one-level sysctl registration - Clean up branch prediction handling - Rework CPU counter facility to retrieve available counter sets just once - Other various small fixes and improvements all over the code * tag 's390-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (118 commits) s390/stackleak: provide fast __stackleak_poison() implementation stackleak: allow to specify arch specific stackleak poison function s390: select ARCH_USE_SYM_ANNOTATIONS s390/mm: use VM_FLUSH_RESET_PERMS in module_alloc() s390: wire up memfd_secret system call s390/mm: enable ARCH_HAS_SET_DIRECT_MAP s390/mm: use BIT macro to generate SET_MEMORY bit masks s390/relocate_kernel: adjust indentation s390/relocate_kernel: use SYM* macros instead of ENTRY(), etc. s390/entry: use SYM* macros instead of ENTRY(), etc. s390/purgatory: use SYM* macros instead of ENTRY(), etc. s390/kprobes: use SYM* macros instead of ENTRY(), etc. s390/reipl: use SYM* macros instead of ENTRY(), etc. s390/head64: use SYM* macros instead of ENTRY(), etc. s390/earlypgm: use SYM* macros instead of ENTRY(), etc. s390/mcount: use SYM* macros instead of ENTRY(), etc. s390/crc32le: use SYM* macros instead of ENTRY(), etc. s390/crc32be: use SYM* macros instead of ENTRY(), etc. s390/crypto,chacha: use SYM* macros instead of ENTRY(), etc. s390/amode31: use SYM* macros instead of ENTRY(), etc. ...
2023-03-21vdso: Improve cmd_vdso_check to check all dynamic relocationsFangrui Song
The actual intention is that no dynamic relocation exists in the VDSO. For this the VDSO build validates that the resulting .so file does not have any relocations which are specified via $(ARCH_REL_TYPE_ABS) per architecture, which is fragile as e.g. ARM64 lacks an entry for R_AARCH64_RELATIVE. Aside of that ARCH_REL_TYPE_ABS is a misnomer as it checks for relative relocations too. However, some GNU ld ports produce unneeded R_*_NONE relocation entries. If a port fails to determine the exact .rel[a].dyn size, the trailing zeros become R_*_NONE relocations. E.g. ld's powerpc port recently fixed https://sourceware.org/bugzilla/show_bug.cgi?id=29540). R_*_NONE are generally a no-op in the dynamic loaders. So just ignore them. Remove the ARCH_REL_TYPE_ABS defines and just validate that the resulting .so file does not contain any R_* relocation entries except R_*_NONE. Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for aarch64 Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # for vDSO, aarch64 Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Link: https://lore.kernel.org/r/20230310190750.3323802-1-maskray@google.com
2023-03-20s390/vdso: use __ALIGN instead of open coded .alignHeiko Carstens
Use __ALIGN instead of open coded .align statement to make sure that vdso code follows global kernel function alignment rules. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-01-26s390/vdso: Drop '-shared' from KBUILD_CFLAGS_64Nathan Chancellor
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it points out that there is a linking phase flag added to CFLAGS, which will only be used for compiling clang-16: error: argument unused during compilation: '-shared' [-Werror,-Wunused-command-line-argument] '-shared' is already present in ldflags-y so it can just be dropped. Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-01-26s390/vdso: Drop unused '-s' flag from KBUILD_AFLAGS_64Nathan Chancellor
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it warns: clang-16: error: argument unused during compilation: '-s' [-Werror,-Wunused-command-line-argument] The compiler's '-s' flag is a linking option (it is passed along to the linker directly), which means it does nothing when the linker is not invoked by the compiler. The kernel builds all .o files with '-c', which stops the compilation pipeline before linking, so '-s' can be safely dropped from KBUILD_AFLAGS_64. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-11-16s390/vdso: filter out -mstack-guard and -mstack-sizeSven Schnelle
When CONFIG_VMAP_STACK is disabled, the user can enable CONFIG_STACK_CHECK, which adds a stack overflow check to each C function in the kernel. This is also done for functions in the vdso page. These functions are run in user context and user stack sizes are usually different to what the kernel uses. This might trigger the stack check although the stack size is valid. Therefore filter the -mstack-guard and -mstack-size flags when compiling vdso C files. Cc: stable@kernel.org # 5.10+ Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO") Reported-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-11-16s390/vdso: remove -nostdlib compiler flagMasahiro Yamada
The -nostdlib option requests the compiler to not use the standard system startup files or libraries when linking. It is effective only when $(CC) is used as a linker driver. Since commit 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO"), $(LD) is directly used, hence -nostdlib is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20211107162111.323701-1-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-08-30Merge tag 's390-5.15-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Improve ftrace code patching so that stop_machine is not required anymore. This requires a small common code patch acked by Steven Rostedt: https://lore.kernel.org/linux-s390/20210730220741.4da6fdf6@oasis.local.home/ - Enable KCSAN for s390. This comes with a small common code change to fix a compile warning. Acked by Marco Elver: https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.com - Add KFENCE support for s390. This also comes with a minimal x86 patch from Marco Elver who said also this can be carried via the s390 tree: https://lore.kernel.org/linux-s390/YQJdarx6XSUQ1tFZ@elver.google.com/ - More changes to prepare the decompressor for relocation. - Enable DAT also for CPU restart path. - Final set of register asm removal patches; leaving only three locations where needed and sane. - Add NNPA, Vector-Packed-Decimal-Enhancement Facility 2, PCI MIO support to hwcaps flags. - Cleanup hwcaps implementation. - Add new instructions to in-kernel disassembler. - Various QDIO cleanups. - Add SCLP debug feature. - Various other cleanups and improvements all over the place. * tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (105 commits) s390: remove SCHED_CORE from defconfigs s390/smp: do not use nodat_stack for secondary CPU start s390/smp: enable DAT before CPU restart callback is called s390: update defconfigs s390/ap: fix state machine hang after failure to enable irq KVM: s390: generate kvm hypercall functions s390/sclp: add tracing of SCLP interactions s390/debug: add early tracing support s390/debug: fix debug area life cycle s390/debug: keep debug data on resize s390/diag: make restart_part2 a local label s390/mm,pageattr: fix walk_pte_level() early exit s390: fix typo in linker script s390: remove do_signal() prototype and do_notify_resume() function s390/crypto: fix all kernel-doc warnings in vfio_ap_ops.c s390/pci: improve DMA translation init and exit s390/pci: simplify CLP List PCI handling s390/pci: handle FH state mismatch only on disable s390/pci: fix misleading rc in clp_set_pci_fn() s390/boot: factor out offset_vmlinux_info() function ...
2021-07-30s390: enable KCSANIlya Leoshkevich
s390x GCC and SystemZ Clang have ThreadSanitizer support now [1] [2], so enable KCSAN for s390. [1] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ea22954e7c58 [2] https://reviews.llvm.org/D105629 Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-30s390/vdso: add .got.plt in vdso linker scriptSumanth Korikkar
KCFLAGS="-mno-pic-data-is-text-relative" make leads to bfd assertion error in s390_got_pointer(): LD arch/s390/kernel/vdso64/vdso64.so.dbg ld: BFD version 2.35-18.fc33 assertion fail elf-s390-common.c:74 readelf -Wr vdso64_generic.o | grep GOT 0000000000000032 000000110000001a R_390_GOTENT 0000000000000000 _vdso_data + 2 (...) Add .got.plt in linker script to avoid this. Suggested-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-08s390/vdso: add minimal compat vdsoSven Schnelle
Add a small vdso for 31 bit compat application that provides trampolines for calls to sigreturn,rt_sigreturn,syscall_restart. This is requird for moving these syscalls away from the signal frame to the vdso. Note that this patch effectively disables CONFIG_COMPAT when using clang to compile the kernel. clang doesn't support 31 bit mode. We want to redirect sigreturn and restart_syscall to the vdso. However, the kernel cannot parse the ELF vdso file, so we need to generate header files which contain the offsets of the syscall instructions in the vdso page. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-07-08s390/vdso: rename VDSO64_LBASE to VDSO_LBASESven Schnelle
Will be used by both vdso32 and vdso64, so change the name. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-07-08s390/vdso64: add sigreturn,rt_sigreturn and restart_syscallSven Schnelle
Add minimalistic trampolines to vdso64 so we can return from signal without using the stack which requires pgm check handler hacks when NX is enabled. restart_syscall will be called from vdso to work around the architectural limitation that the syscall number might be encoded in the svc instruction, and therefore can not be changed. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13s390/vdso: use union tod_clockHeiko Carstens
Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09s390/vdso: implement generic vdso time namespace supportHeiko Carstens
Implement generic vdso time namespace support which also enables time namespaces for s390. This is quite similar to what arm64 has. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09s390/vdso: move data page before code pagesHeiko Carstens
For consistency with x86 and arm64 move the data page before code pages. Similar to commit 601255ae3c98 ("arm64: vdso: move data page before code pages"). Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-11-30s390/vdso: add missing prototypes for vdso functionsHeiko Carstens
clang W=1 warns about missing prototypes: >> arch/s390/kernel/vdso64/getcpu.c:8:5: warning: no previous prototype for function '__s390_vdso_getcpu' [-Wmissing-prototypes] int __s390_vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) ^ Add a local header file in order to get rid of this warnings. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23s390/vdso: reimplement getcpu vdso syscallHeiko Carstens
Implement the previously removed getcpu vdso syscall by using the TOD programmable field to pass the cpu number to user space. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-23s390/mm: remove set_fs / rework address space handlingHeiko Carstens
Remove set_fs support from s390. With doing this rework address space handling and simplify it. As a result address spaces are now setup like this: CPU running in | %cr1 ASCE | %cr7 ASCE | %cr13 ASCE ----------------------------|-----------|-----------|----------- user space | user | user | kernel kernel, normal execution | kernel | user | kernel kernel, kvm guest execution | gmap | user | kernel To achieve this the getcpu vdso syscall is removed in order to avoid secondary address mode and a separate vdso address space in for user space. The getcpu vdso syscall will be implemented differently with a subsequent patch. The kernel accesses user space always via secondary address space. This happens in different ways: - with mvcos in home space mode and directly read/write to secondary address space - with mvcs/mvcp in primary space mode and copy from primary space to secondary space or vice versa - with e.g. cs in secondary space mode and access secondary space Switching translation modes happens with sacf before and after instructions which access user space, like before. Lazy handling of control register reloading is removed in the hope to make everything simpler, but at the cost of making kernel entry and exit a bit slower. That is: on kernel entry the primary asce is always changed to contain the kernel asce, and on kernel exit the primary asce is changed again so it contains the user asce. In kernel mode there is only one exception to the primary asce: when kvm guests are executed the primary asce contains the gmap asce (which describes the guest address space). The primary asce is reset to kernel asce whenever kvm guest execution is interrupted, so that this doesn't has to be taken into account for any user space accesses. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-22Merge tag 'kbuild-v5.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Support 'make compile_commands.json' to generate the compilation database more easily, avoiding stale entries - Support 'make clang-analyzer' and 'make clang-tidy' for static checks using clang-tidy - Preprocess scripts/modules.lds.S to allow CONFIG options in the module linker script - Drop cc-option tests from compiler flags supported by our minimal GCC/Clang versions - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y - Use sha1 build id for both BFD linker and LLD - Improve deb-pkg for reproducible builds and rootless builds - Remove stale, useless scripts/namespace.pl - Turn -Wreturn-type warning into error - Fix build error of deb-pkg when CONFIG_MODULES=n - Replace 'hostname' command with more portable 'uname -n' - Various Makefile cleanups * tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: Use uname for LINUX_COMPILE_HOST detection kbuild: Only add -fno-var-tracking-assignments for old GCC versions kbuild: remove leftover comment for filechk utility treewide: remove DISABLE_LTO kbuild: deb-pkg: clean up package name variables kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n kbuild: enforce -Werror=return-type scripts: remove namespace.pl builddeb: Add support for all required debian/rules targets builddeb: Enable rootless builds builddeb: Pass -n to gzip for reproducible packages kbuild: split the build log of kallsyms kbuild: explicitly specify the build id style scripts/setlocalversion: make git describe output more reliable kbuild: remove cc-option test of -Werror=date-time kbuild: remove cc-option test of -fno-stack-check kbuild: remove cc-option test of -fno-strict-overflow kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan kbuild: do not create built-in objects for external module builds ...
2020-10-09kbuild: explicitly specify the build id styleBill Wendling
ld's --build-id defaults to "sha1" style, while lld defaults to "fast". The build IDs are very different between the two, which may confuse programs that reference them. Signed-off-by: Bill Wendling <morbo@google.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-09-14s390: disable branch profiling for vdsoSven Schnelle
When branch profiling is enabled, if () gets annotated with code to instrument the hit/miss ratio. This doesn't work for VDSO as we can't access kernel code. Add -DDISABLE_BRANCH_PROFILING to fix this. Reported-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>