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* s390/vdso: filter out -mstack-guard and -mstack-sizeSven Schnelle2021-11-161-2/+3
| | | | | | | | | | | | | | | | | 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>
* s390/vdso: remove -nostdlib compiler flagMasahiro Yamada2021-11-161-1/+1
| | | | | | | | | | | | | 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>
* Merge tag 's390-5.15-1' of ↵Linus Torvalds2021-08-301-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * s390: enable KCSANIlya Leoshkevich2021-07-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | 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>
* | s390/vdso: add .got.plt in vdso linker scriptSumanth Korikkar2021-07-301-0/+1
|/ | | | | | | | | | | | | | | | | | 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>
* s390/vdso: add minimal compat vdsoSven Schnelle2021-07-082-0/+23
| | | | | | | | | | | | | | | | | | 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>
* s390/vdso: rename VDSO64_LBASE to VDSO_LBASESven Schnelle2021-07-081-1/+1
| | | | | | | | 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>
* s390/vdso64: add sigreturn,rt_sigreturn and restart_syscallSven Schnelle2021-07-082-0/+20
| | | | | | | | | | | | | | 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>
* s390/vdso: use union tod_clockHeiko Carstens2021-02-131-3/+3
| | | | | Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/vdso: implement generic vdso time namespace supportHeiko Carstens2021-02-091-1/+4
| | | | | | | | | 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>
* s390/vdso: move data page before code pagesHeiko Carstens2021-02-091-3/+1
| | | | | | | | | | 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>
* s390/vdso: add missing prototypes for vdso functionsHeiko Carstens2020-11-303-0/+16
| | | | | | | | | | | | | 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>
* s390/vdso: reimplement getcpu vdso syscallHeiko Carstens2020-11-234-2/+24
| | | | | | | | 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>
* s390/mm: remove set_fs / rework address space handlingHeiko Carstens2020-11-233-33/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge tag 'kbuild-v5.10' of ↵Linus Torvalds2020-10-221-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * kbuild: explicitly specify the build id styleBill Wendling2020-10-091-1/+1
| | | | | | | | | | | | | | | | | | | | 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>
| * arch: vdso: add vdso linker script to 'targets' instead of extra-yMasahiro Yamada2020-09-071-1/+1
| | | | | | | | | | | | | | | | | | The vdso linker script is preprocessed on demand. Adding it to 'targets' is enough to include the .cmd file. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Greentime Hu <green.hu@gmail.com>
* | s390: disable branch profiling for vdsoSven Schnelle2020-09-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | 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>
* | s390: convert to GENERIC_VDSOSven Schnelle2020-08-266-288/+71
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert s390 to generic vDSO. There are a few special things on s390: - vDSO can be called without a stack frame - glibc did this in the past. So we need to allocate a stackframe on our own. - The former assembly code used stcke to get the TOD clock and applied time steering to it. We need to do the same in the new code. This is done in the architecture specific __arch_get_hw_counter function. The steering information is stored in an architecure specific area in the vDSO data. - CPUCLOCK_VIRT is now handled with a syscall fallback, which might be slower/less accurate than the old implementation. The getcpu() function stays as an assembly function because there is no generic implementation and the code is just a few lines. Performance number from my system do 100 mio gettimeofday() calls: Plain syscall: 8.6s Generic VDSO: 1.3s old ASM VDSO: 1s So it's a bit slower but still much faster than syscalls. 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>
* s390/vdso: fix vDSO clock_getres()Vincenzo Frascino2020-06-161-5/+5
| | | | | | | | | | | | | | | | | | | | | clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the s390 vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Link: https://lkml.kernel.org/r/20200324121027.21665-1-vincenzo.frascino@arm.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [heiko.carstens@de.ibm.com: use llgf for proper zero extension] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/vdso: Use $(LD) instead of $(CC) to link vDSONathan Chancellor2020-06-161-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the VDSO is being linked through $(CC). This does not match how the rest of the kernel links objects, which is through the $(LD) variable. When clang is built in a default configuration, it first attempts to use the target triple's default linker, which is just ld. However, the user can override this through the CLANG_DEFAULT_LINKER cmake define so that clang uses another linker by default, such as LLVM's own linker, ld.lld. This can be useful to get more optimized links across various different projects. However, this is problematic for the s390 vDSO because ld.lld does not have any s390 emulatiom support: https://github.com/llvm/llvm-project/blob/llvmorg-10.0.1-rc1/lld/ELF/Driver.cpp#L132-L150 Thus, if a user is using a toolchain with ld.lld as the default, they will see an error, even if they have specified ld.bfd through the LD make variable: $ make -j"$(nproc)" -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- LLVM=1 \ LD=s390x-linux-gnu-ld \ defconfig arch/s390/kernel/vdso64/ ld.lld: error: unknown emulation: elf64_s390 clang-11: error: linker command failed with exit code 1 (use -v to see invocation) Normally, '-fuse-ld=bfd' could be used to get around this; however, this can be fragile, depending on paths and variable naming. The cleaner solution for the kernel is to take advantage of the fact that $(LD) can be invoked directly, which bypasses the heuristics of $(CC) and respects the user's choice. Similar changes have been done for ARM, ARM64, and MIPS. Link: https://lkml.kernel.org/r/20200602192523.32758-1-natechancellor@gmail.com Link: https://github.com/ClangBuiltLinux/linux/issues/1041 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> [heiko.carstens@de.ibm.com: add --build-id flag] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* .gitignore: add SPDX License IdentifierMasahiro Yamada2020-03-251-0/+1
| | | | | | | Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/vdso: fix getcpuHeiko Carstens2019-11-301-3/+1
| | | | | | | | | | | | | | | | | getcpu reads the required values for cpu and node with two instructions. This might lead to an inconsistent result if user space gets preempted and migrated to a different CPU between the two instructions. Fix this by using just a single instruction to read both values at once. This is currently rather a theoretical bug, since there is no real NUMA support available (except for NUMA emulation). Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/vdso: drop unnecessary cc-ldoptionNick Desaulniers2019-05-031-1/+1
| | | | | | | | | | | | | | Towards the goal of removing cc-ldoption, it seems that --hash-style= was added to binutils 2.17.50.0.2 in 2006. The minimal required version of binutils for the kernel according to Documentation/process/changes.rst is 2.20. Link: https://gcc.gnu.org/ml/gcc/2007-01/msg01141.html Cc: clang-built-linux@googlegroups.com Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: add missing FORCE to build targetsVasily Gorbik2018-10-261-3/+3
| | | | | | | | | | | According to Documentation/kbuild/makefiles.txt all build targets using if_changed should use FORCE as well. Add missing FORCE to make sure vdso targets are rebuild properly when not just immediate prerequisites have changed but also when build command differs. Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/kasan: avoid vdso instrumentationVasily Gorbik2018-10-091-1/+2
| | | | | | | | | vdso is mapped into user space processes, which won't have kasan shodow mapped. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: correct CFI annotations of vDSO functionsVasily Gorbik2018-09-202-13/+15
| | | | | | | | | | | | Correct stack frame overhead for 31-bit vdso, which should be 96 rather then 160. This is done by reusing STACK_FRAME_OVERHEAD definition which contains correct value based on build flags. This fixes stack unwinding within vdso code for 31-bit processes. While at it replace all hard coded stack frame overhead values with the same definition in vdso64 as well. Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: revise CFI annotations of vDSO functionsHendrik Brueckner2017-12-134-8/+28
| | | | | | | | | | | | | | | | | | | | | | | Revise and add CFI CFA and register rule annotations to the vDSO functions for proper stack unwinding and debugging. Because glibc might call the vDSO in special ways, the vDSO code does not rely on a stack frame created by the caller. The TOD clock value can be therefore not stored in the pre-allocated stack area and additional stack space is required. To correctly annotate these situations with CFI, the .cfi_val_offset directive is required to create relative offsets on the value of the stack register %r15. Because the .cfi_val_offset directive is available with recent GNU assembler versions only, additional checks are necessary. Note that if the vDSO is assembled with an older assembler version, stack unwinding and debugging from within the vDSO code might not be possible. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/kernel: emit CFI data in .debug_frame and discard .eh_frame sectionsHendrik Brueckner2017-12-135-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | Using perf probe and libdw on kernel modules failed to find CFI data for symbols. The CFI data is stored in the .eh_frame section. The elfutils libdw is not able to extract the CFI data correctly, because the .eh_frame section requires "non-simple" relocations for kernel modules. The suggestion is to avoid these "non-simple" relocations by emitting the CFI data in the .debug_frame section. Let gcc emit respective directives by specifying the -fno-asynchronous-unwind-tables option. Using the .debug_frame section for CFI data, the .eh_frame section becomes unused and, thus, discard it for kernel and modules builds The vDSO requires the .eh_frame section and, hence, emit the CFI data in both, the .eh_frame and .debug_frame sections. See also discussion on elfutils/libdw bugzilla: https://sourceware.org/bugzilla/show_bug.cgi?id=22452 Suggested-by: Mark Wielaard <mark@klomp.org> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: add a few more SPDX identifiersMartin Schwidefsky2017-12-051-0/+1
| | | | | | | | | Add the correct SPDX license to a few more files under arch/s390 and drivers/s390 which have been missed to far. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: kernel: Remove redundant license textGreg Kroah-Hartman2017-11-243-12/+0
| | | | | | | | | | | | | | | | | | | | | | | | | Now that the SPDX tag is in all arch/s390/kernel/ files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: kernel: add SPDX identifiers to the remaining filesGreg Kroah-Hartman2017-11-243-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the arch/s390/kernel/ files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: remove all code using the access register modeMartin Schwidefsky2017-11-142-28/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vdso code for the getcpu() and the clock_gettime() call use the access register mode to access the per-CPU vdso data page with the current code. An alternative to the complicated AR mode is to use the secondary space mode. This makes the vdso faster and quite a bit simpler. The downside is that the uaccess code has to be changed quite a bit. Which instructions are used depends on the machine and what kind of uaccess operation is requested. The instruction dictates which ASCE value needs to be loaded into %cr1 and %cr7. The different cases: * User copy with MVCOS for z10 and newer machines The MVCOS instruction can copy between the primary space (aka user) and the home space (aka kernel) directly. For set_fs(KERNEL_DS) the kernel ASCE is loaded into %cr1. For set_fs(USER_DS) the user space is already loaded in %cr1. * User copy with MVCP/MVCS for older machines To be able to execute the MVCP/MVCS instructions the kernel needs to switch to primary mode. The control register %cr1 has to be set to the kernel ASCE and %cr7 to either the kernel ASCE or the user ASCE dependent on set_fs(KERNEL_DS) vs set_fs(USER_DS). * Data access in the user address space for strnlen / futex To use "normal" instruction with data from the user address space the secondary space mode is used. The kernel needs to switch to primary mode, %cr1 has to contain the kernel ASCE and %cr7 either the user ASCE or the kernel ASCE, dependent on set_fs. To load a new value into %cr1 or %cr7 is an expensive operation, the kernel tries to be lazy about it. E.g. for multiple user copies in a row with MVCP/MVCS the replacement of the vdso ASCE in %cr7 with the user ASCE is done only once. On return to user space a CPU bit is checked that loads the vdso ASCE again. To enable and disable the data access via the secondary space two new functions are added, enable_sacf_uaccess and disable_sacf_uaccess. The fact that a context is in secondary space uaccess mode is stored in the mm_segment_t value for the task. The code of an interrupt may use set_fs as long as it returns to the previous state it got with get_fs with another call to set_fs. The code in finish_arch_post_lock_switch simply has to do a set_fs with the current mm_segment_t value for the task. For CPUs with MVCOS: CPU running in | %cr1 ASCE | %cr7 ASCE | --------------------------------------|-----------|-----------| user space | user | vdso | kernel, USER_DS, normal-mode | user | vdso | kernel, USER_DS, normal-mode, lazy | user | user | kernel, USER_DS, sacf-mode | kernel | user | kernel, KERNEL_DS, normal-mode | kernel | vdso | kernel, KERNEL_DS, normal-mode, lazy | kernel | kernel | kernel, KERNEL_DS, sacf-mode | kernel | kernel | For CPUs without MVCOS: CPU running in | %cr1 ASCE | %cr7 ASCE | --------------------------------------|-----------|-----------| user space | user | vdso | kernel, USER_DS, normal-mode | user | vdso | kernel, USER_DS, normal-mode lazy | kernel | user | kernel, USER_DS, sacf-mode | kernel | user | kernel, KERNEL_DS, normal-mode | kernel | vdso | kernel, KERNEL_DS, normal-mode, lazy | kernel | kernel | kernel, KERNEL_DS, sacf-mode | kernel | kernel | The lines with "lazy" refer to the state after a copy via the secondary space with a delayed reload of %cr1 and %cr7. There are three hardware address spaces that can cause a DAT exception, primary, secondary and home space. The exception can be related to four different fault types: user space fault, vdso fault, kernel fault, and the gmap faults. Dependent on the set_fs state and normal vs. sacf mode there are a number of fault combinations: 1) user address space fault via the primary ASCE 2) gmap address space fault via the primary ASCE 3) kernel address space fault via the primary ASCE for machines with MVCOS and set_fs(KERNEL_DS) 4) vdso address space faults via the secondary ASCE with an invalid address while running in secondary space in problem state 5) user address space fault via the secondary ASCE for user-copy based on the secondary space mode, e.g. futex_ops or strnlen_user 6) kernel address space fault via the secondary ASCE for user-copy with secondary space mode with set_fs(KERNEL_DS) 7) kernel address space fault via the primary ASCE for user-copy with secondary space mode with set_fs(USER_DS) on machines without MVCOS. 8) kernel address space fault via the home space ASCE Replace user_space_fault() with a new function get_fault_type() that can distinguish all four different fault types. With these changes the futex atomic ops from the kernel and the strnlen_user will get a little bit slower, as well as the old style uaccess with MVCP/MVCS. All user accesses based on MVCOS will be as fast as before. On the positive side, the user space vdso code is a lot faster and Linux ceases to use the complicated AR mode. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-024-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/mm: use new mm defines instead of magic valuesHeiko Carstens2017-07-261-1/+3
| | | | | | Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/time: steer clocksource on STP sync eventsMartin Schwidefsky2016-10-282-2/+20
| | | | | | | | | | | | | On STP sync events the TOD clock will jump in time, either forward or backward. The TOD clocksource claims to be continuous but in case of an STP sync with a negative offset it is not. Subtract the offset injected by the STP sync check from the result of the TOD clocksource to make it continuous again. Add code to drift the offset towards zero with a fixed rate, steering 1 second in ~9 hours. Suggested-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: enable UBSANChristian Borntraeger2016-09-201-1/+2
| | | | | | | | | | This enables UBSAN for s390. We have to disable the null sanitizer as s390 code does access memory via a null pointer (the prefix page). Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: enable kcov supportHeiko Carstens2016-06-281-0/+2
| | | | | | | | | | | | | | Now that hopefully all inline assemblies have been converted to single basic blocks we can enable kcov on s390. Note that this patch does not disable as many files on s390 like the x86 variant does. Right now I didn't see a reason to do that, however additional files or directories can be excluded at any time. The runtime overhead seems to be quite high. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: optimize getcpu system callMartin Schwidefsky2016-01-113-1/+44
| | | | | | | | | | Add the CPU number to the per-cpu vdso data page and add the __kernel_getcpu function to the vdso object to retrieve the CPU number in user space. Suggested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: emit a GNU hashMartin Schwidefsky2015-08-071-1/+1
| | | | | | | | As proposed by Andy Lutomirski create the SysV and the GNU hash for the vdso objects. This may make some dynamic loaders a bit faster. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: fix clock_gettime for CLOCK_THREAD_CPUTIME_ID, -2 and -3Martin Schwidefsky2015-02-121-4/+2
| | | | | | | | | | | | | | | | | | Git commit 8d8f2e18a6dbd3d09dd918788422e6ac8c878e96 "s390/vdso: ectg gettime support for CLOCK_THREAD_CPUTIME_ID" broke clock_gettime for CLOCK_THREAD_CPUTIME_ID. Git commit c742b31c03f37c5c499178f09f57381aa6c70131 "fast vdso implementation for CLOCK_THREAD_CPUTIME_ID" introduced the ECTG for clock id -2. Correct would have been clock id -3. Fix the whole mess, CLOCK_THREAD_CPUTIME_ID is based on CPUCLOCK_SCHED and can not be speed up by the vdso. A speedup is only available for clock id -3 which is CPUCLOCK_VIRT for the task currently running on the CPU. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: fix stack corruptionHeiko Carstens2014-10-272-6/+13
| | | | | | | | | | | | | | The kernel provided vdso functions do not get a stack frame from the calling function and therefore may not change the stack contents, unless they allocate space on their own. This problem was exposed with 070b7be633dc "s390/vdso: replace stck with stcke" which writes 16 bytes instead of 8 bytes into the stack frame. These additional 8 bytes however were indeed used by the caller (glibc) to save data and therefore this data was corrupted by the vdso code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: add vdso support for coarse clocksMartin Schwidefsky2014-09-092-1/+31
| | | | | | | Add CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE optimization to the 64-bit and 31-bit vdso. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: replace stck with stckeMartin Schwidefsky2014-09-092-6/+6
| | | | | | | | | If gettimeofday / clock_gettime are called multiple times in a row the STCK instruction will stall until a difference in the result is visible. This unnecessarily slows down the vdso calls, use stcke instead of stck to get rid of the stall. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: remove NULL pointer check from clock_gettimeMartin Schwidefsky2014-09-011-7/+3
| | | | | | | The explicit NULL pointer check on the timespec argument is only required for clock_getres but not for clock_gettime. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/time,vdso: fix clock_gettime for CLOCK_MONOTONICMartin Schwidefsky2013-12-021-4/+2
| | | | | | | | | | | With git commit 79c74ecbebf76732f91b82a62ce7fc8a88326962 "s390/time,vdso: convert to the new update_vsyscall interface" the new update_vsyscall function already does the sum of xtime and wall_to_monotonic. The old update_vsyscall function only copied the wall_to_monotonic offset. The vdso code needs to be modified to take this into consideration. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vdso: ectg gettime support for CLOCK_THREAD_CPUTIME_IDMartin Schwidefsky2013-12-022-2/+6
| | | | | | | | | | The code to use the ECTG instruction to calculate the cputime for the current thread is currently used only for the per-thread CPU-clock with the clockid -2 (PID=0, VIRT=1). Use the same code for the clockid CLOCK_THREAD_CPUTIME_ID to speed up the more common clockid as well. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/time,vdso: convert to the new update_vsyscall interfaceMartin Schwidefsky2013-11-252-14/+17
| | | | | | | Switch to the improved update_vsyscall interface that provides sub-nanosecond precision for gettimeofday and clock_gettime. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390: add various .gitignore files.Heiko Carstens2012-05-161-0/+1
| | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] vdso: disable gcov profilingPeter Oberparleiter2011-05-231-0/+3
| | | | | | | | | | | | The concepts of VDSO and gcov-based profiling don't mix: the former includes kernel-provided code running in userspace, the latter adds instructions that modify counters in kernel data segments. On s390 this has not been a problem so far due to VDSO code being written in all-assembler which is exempt from gcov-based profiling. This could change in the future, so disable profiling excplicitly for VDSO code. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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