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path: root/arch/s390/boot/startup.c
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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>