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2019-11-30s390/kaslr: store KASLR offset for early dumpsGerald Schaefer
The KASLR offset is added to vmcoreinfo in arch_crash_save_vmcoreinfo(), so that it can be found by crash when processing kernel dumps. However, arch_crash_save_vmcoreinfo() is called during a subsys_initcall, so if the kernel crashes before that, we have no vmcoreinfo and no KASLR offset. Fix this by storing the KASLR offset in the lowcore, where the vmcore_info pointer will be stored, and where it can be found by crash. In order to make it distinguishable from a real vmcore_info pointer, mark it as uneven (KASLR offset itself is aligned to THREAD_SIZE). When arch_crash_save_vmcoreinfo() stores the real vmcore_info pointer in the lowcore, it overwrites the KASLR offset. At that point, the KASLR offset is not yet added to vmcoreinfo, so we also need to move the mem_assign_absolute() behind the vmcoreinfo_append_str(). Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)") Cc: <stable@vger.kernel.org> # v5.2+ Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-11-25Merge tag 's390-5.5-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Adjust PMU device drivers registration to avoid WARN_ON and few other perf improvements. - Enhance tracing in vfio-ccw. - Few stack unwinder fixes and improvements, convert get_wchan custom stack unwinding to generic api usage. - Fixes for mm helpers issues uncovered with tests validating architecture page table helpers. - Fix noexec bit handling when hardware doesn't support it. - Fix memleak and unsigned value compared with zero bugs in crypto code. Minor code simplification. - Fix crash during kdump with kasan enabled kernel. - Switch bug and alternatives from asm to asm_inline to improve inlining decisions. - Use 'depends on cc-option' for MARCH and TUNE options in Kconfig, add z13s and z14 ZR1 to TUNE descriptions. - Minor head64.S simplification. - Fix physical to logical CPU map for SMT. - Several cleanups in qdio code. - Other minor cleanups and fixes all over the code. * tag 's390-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (41 commits) s390/cpumf: Adjust registration of s390 PMU device drivers s390/smp: fix physical to logical CPU map for SMT s390/early: move access registers setup in C code s390/head64: remove unnecessary vdso_per_cpu_data setup s390/early: move control registers setup in C code s390/kasan: support memcpy_real with TRACE_IRQFLAGS s390/crypto: Fix unsigned variable compared with zero s390/pkey: use memdup_user() to simplify code s390/pkey: fix memory leak within _copy_apqns_from_user() s390/disassembler: don't hide instruction addresses s390/cpum_sf: Assign error value to err variable s390/cpum_sf: Replace function name in debug statements s390/cpum_sf: Use consistant debug print format for sampling s390/unwind: drop unnecessary code around calling ftrace_graph_ret_addr() s390: add error handling to perf_callchain_kernel s390: always inline current_stack_pointer() s390/mm: add mm_pxd_folded() checks to pxd_free() s390/mm: properly clear _PAGE_NOEXEC bit when it is not supported s390/mm: simplify page table helpers for large entries s390/mm: make pmd/pud_bad() report large entries as bad ...
2019-10-31s390/boot: fix section name escapingNick Desaulniers
GCC unescapes escaped string section names while Clang does not. Because __section uses the `#` stringification operator for the section name, it doesn't need to be escaped. This antipattern was found with: $ grep -e __section\(\" -e __section__\(\" -r Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Message-Id: <20190812215052.71840-1-ndesaulniers@google.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-10-22s390/kaslr: add support for R_390_GLOB_DAT relocation typeGerald Schaefer
Commit "bpf: Process in-kernel BTF" in linux-next introduced an undefined __weak symbol, which results in an R_390_GLOB_DAT relocation type. That is not yet handled by the KASLR relocation code, and the kernel stops with the message "Unknown relocation type". Add code to detect and handle R_390_GLOB_DAT relocation types and undefined symbols. Fixes: 805bc0bc238f ("s390/kernel: build a relocatable kernel") Cc: <stable@vger.kernel.org> # v5.2+ Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-21s390: clean .bss before running uncompressed kernelVasily Gorbik
Clean uncompressed kernel .bss section in the startup code before the uncompressed kernel is executed. At this point of time initrd and certificates have been already rescued. Uncompressed kernel .bss size is known from vmlinux_info. It is also taken into consideration during uncompressed kernel positioning by kaslr (so it is safe to clean it). With that uncompressed kernel is starting with .bss section zeroed and no .bss section usage restrictions apply. Which makes chkbss checks for uncompressed kernel objects obsolete and they can be removed. early_nobss.c is also not needed anymore. Parts of it which are still relevant are moved to early.c. Kasan initialization code is now called directly from head64 (early.c is instrumented and should not be executed before kasan shadow memory is set up). Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-05-02s390: simplify disabled_waitMartin Schwidefsky
The disabled_wait() function uses its argument as the PSW address when it stops the CPU with a wait PSW that is disabled for interrupts. The different callers sometimes use a specific number like 0xdeadbeef to indicate a specific failure, the early boot code uses 0 and some other calls sites use __builtin_return_address(0). At the time a dump is created the current PSW and the registers of a CPU are written to lowcore to make them avaiable to the dump analysis tool. For a CPU stopped with disabled_wait the PSW and the registers do not really make sense together, the PSW address does not point to the function the registers belong to. Simplify disabled_wait() by using _THIS_IP_ for the PSW address and drop the argument to the function. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kernel: add support for kernel address space layout randomization (KASLR)Gerald Schaefer
This patch adds support for relocating the kernel to a random address. The random kernel offset is obtained from cpacf, using either TRNG, PRNO, or KMC_PRNG, depending on supported MSA level. KERNELOFFSET is added to vmcoreinfo, for crash --kaslr support. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kernel: introduce .dma sectionsGerald Schaefer
With a relocatable kernel that could reside at any place in memory, code and data that has to stay below 2 GB needs special handling. This patch introduces .dma sections for such text, data and ex_table. The sections will be part of the decompressor kernel, so they will not be relocated and stay below 2 GB. Their location is passed over to the decompressed / relocated kernel via the .boot.preserved.data section. The duald and aste for control register setup also need to stay below 2 GB, so move the setup code from arch/s390/kernel/head64.S to arch/s390/boot/head.S. The duct and linkage_stack could reside above 2 GB, but their content has to be preserved for the decompresed kernel, so they are also moved into the .dma section. The start and end address of the .dma sections is added to vmcoreinfo, for crash support, to help debugging in case the kernel crashed there. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kernel: build a relocatable kernelGerald Schaefer
This patch adds support for building a relocatable kernel with -fPIE. The kernel will be relocated to 0 early in the boot process. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26s390/ipl: read IPL report at early bootMartin Schwidefsky
Read the IPL Report block provided by secure-boot, add the entries of the certificate list to the system key ring and print the list of components. PR: Adjust to Vasilys bootdata_preserved patch set. Preserve ipl_cert_list for later use in kexec_file. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10s390/uv: introduce guest side ultravisor codeVasily Gorbik
The Ultravisor Call Facility (stfle bit 158) defines an API to the Ultravisor (UV calls), a mini hypervisor located at machine level. With help of the Ultravisor, KVM will be able to run "protected" VMs, special VMs whose memory and management data are unavailable to KVM. The protected VMs can also request services from the Ultravisor. The guest api consists of UV calls to share and unshare memory with the kvm hypervisor. To enable this feature support PROTECTED_VIRTUALIZATION_GUEST kconfig option has been introduced. Co-developed-by: Janosch Frank <frankja@de.ibm.com> Signed-off-by: Janosch Frank <frankja@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10s390: introduce .boot.preserved.data sectionGerald Schaefer
Introduce .boot.preserve.data section which is similar to .boot.data and "shared" between the decompressor code and the decompressed kernel. The decompressor will store values in it, and copy over to the decompressed image before starting it. This method allows to avoid using pre-defined addresses and other hacks to pass values between those boot phases. Unlike .boot.data section .boot.preserved.data is NOT a part of init data, and hence will be preserved for the kernel life time. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-03-01s390: allow overriding facilities via command lineVasily Gorbik
Add "facilities=" command line option which allows to override facility bits returned by stfle. The main purpose of that is debugging aids which allows to test specific kernel behaviour depending on specific facilities presence. It also affects CPU alternatives. "facilities=" command line option format is comma separated list of integer values to be additionally set or cleared (if value is starting with "!"). Values ranges are also supported. e.g.: facilities=!130-160,159,167-169 Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09s390: move ipl block and cmd line handling to early boot phaseVasily Gorbik
To distinguish zfcpdump case and to be able to parse some of the kernel command line arguments early (e.g. mem=) ipl block retrieval and command line construction code is moved to the early boot phase. "memory_end" is set up correctly respecting "mem=" and hsa_size in case of the zfcpdump. arch/s390/boot/string.c is introduced to provide string handling and command line parsing functions to early boot phase code for the compressed kernel image case. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09s390/mem_detect: move tprot loop to early boot phaseVasily Gorbik
Move memory detection to early boot phase. To store online memory regions "struct mem_detect_info" has been introduced together with for_each_mem_detect_block iterator. mem_detect_info is later converted to memblock. Also introduces sclp_early_get_meminfo function to get maximum physical memory and maximum increment number. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> 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>
2018-10-09s390/sclp: move sclp_early_read_info to sclp_early_core.cVasily Gorbik
To enable early online memory detection sclp_early_read_info has been moved to sclp_early_core.c. sclp_info_sccb has been made a part of .boot.data, which allows to reuse it later during early kernel startup and make sclp_early_read_info call just once. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> 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>
2018-10-09s390: introduce .boot.data sectionVasily Gorbik
Introduce .boot.data section which is "shared" between the decompressor code and the decompressed kernel. The decompressor will store values in it, and copy over to the decompressed image before starting it. This method allows to avoid using pre-defined addresses and other hacks to pass values between those boot phases. .boot.data section is a part of init data, and will be freed after kernel initialization is complete. For uncompressed kernel image, .boot.data section is basically the same as .init.data 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>
2018-10-09s390/decompressor: clean up and rename compressed/misc.cVasily Gorbik
Since compressed/misc.c is conditionally compiled move error reporting code to boot/main.c. With that being done compressed/misc.c has no "miscellaneous" functions left and is all about plain decompression now. Rename it accordingly. 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>
2018-10-09s390: rescue initrd as early as possibleVasily Gorbik
To avoid multi-stage initrd rescue operation and to simplify assumptions during early memory allocations move initrd at some final safe destination as early as possible. This would also allow us to drop .bss usage restrictions for some files. 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>
2018-10-09s390/decompressor: rework uncompressed image info collectionVasily Gorbik
The kernel decompressor has to know several bits of information about uncompressed image. Currently this info is collected by running "nm" on uncompressed vmlinux + "sed" and producing sizes.h file. This method worked well, but it has several disadvantages. Obscure symbols name pattern matching is fragile. Adding new values makes pattern even longer. Logic is spread across code and make file. Limited ability to adjust symbols values (currently magic lma value of 0x100000 is always subtracted). Apart from that same pieces of information (and more) would be needed for early memory detection and features like KASLR outside of boot/compressed/ folder where sizes.h is generated. To overcome limitations new "struct vmlinux_info" has been introduced to include values needed for the decompressor and the rest of the boot code. The only static instance of vmlinux_info is produced during vmlinux link step by filling in struct fields by the linker (like it is done with input_data in boot/compressed/vmlinux.scr.lds.S). This way individual values could be adjusted with all the knowledge linker has and arithmetic it supports. Later .vmlinux.info section (which contains struct vmlinux_info) is transplanted into the decompressor image and dropped from uncompressed image altogether. While doing that replace "compressed/vmlinux.scr.lds.S" linker script (whose purpose is to rename .data section in piggy.o to .rodata.compressed) with plain objcopy command. And simplify decompressor's linker script. 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>
2018-10-09s390: remove decompressor's head.SVasily Gorbik
Decompressor's head.S provided "data mover" sole purpose of which has been to safely move uncompressed kernel at 0x100000 and jump to it. With current bzImage layout entire decompressor's code guaranteed to be in a safe location under 0x100000, and hence could not be overwritten during kernel move. For that reason head.S could be replaced with simple memmove function. To do so introduce early boot code phase which is executed from arch/s390/boot/head.S after "verify_facilities" and takes care of optional kernel image decompression and transition to it. 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>