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* s390/boot: move dma sections from decompressor to decompressed kernelAlexander Egorenkov2021-07-271-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change simplifies the task of making the decompressor relocatable. The decompressor's image contains special DMA sections between _sdma and _edma. This DMA segment is loaded at boot as part of the decompressor and then simply handed over to the decompressed kernel. The decompressor itself never uses it in any way. The primary reason for this is the need to keep the aforementioned DMA segment below 2GB which is required by architecture, and because the decompressor is always loaded at a fixed low physical address, it is guaranteed that the DMA region will not cross the 2GB memory limit. If the DMA region had been placed in the decompressed kernel, then KASLR would make this guarantee impossible to fulfill or it would be restricted to the first 2GB of memory address space. This commit moves all DMA sections between _sdma and _edma from the decompressor's image to the decompressed kernel's image. The complete DMA region is placed in the init section of the decompressed kernel and immediately relocated below 2GB at start-up before it is needed by other parts of the decompressed kernel. The relocation of the DMA region happens even if the decompressed kernel is already located below 2GB in order to keep the first implementation simple. The relocation should not have any noticeable impact on boot time because the DMA segment is only a couple of pages. After relocating the DMA sections, the kernel has to fix all references which point into it. In order to automate this, place all variables pointing into the DMA sections in a special .dma.refs section. All such variables must be defined using the new __dma_ref macro. Only variables containing addresses within the DMA sections must be placed in the new .dma.refs section. Furthermore, move the initialization of control registers from the decompressor to the decompressed kernel because some control registers reference tables that must be placed in the DMA data section to guarantee that their addresses are below 2G. Because the decompressed kernel relocates the DMA sections at startup, the content of control registers CR2, CR5 and CR15 must be updated with new addresses after the relocation. The decompressed kernel initializes all control registers early at boot and then updates the content of CR2, CR5 and CR15 as soon as the DMA relocation has occurred. This practically reverts the commit a80313ff91ab ("s390/kernel: introduce .dma sections"). Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/boot: move sclp early buffer from fixed address in asm to CAlexander Egorenkov2021-07-271-0/+1
| | | | | | | | | | | | | | | | To make the decompressor relocatable, the early SCLP buffer with a fixed address must be replaced with a relocatable C buffer of the according size and alignment as required by SCLP. Introduce a new function sclp_early_set_buffer() into the SCLP driver which enables the decompressor to change the SCLP early buffer at any time. This will be useful when the decompressor becomes fully relocatable and might need to change the SCLP early buffer to one with an address < 2G as required by SCLP because it was loaded at an address >= 2G. Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/boot: make stacks part of the decompressor's imageAlexander Egorenkov2021-07-271-7/+2
| | | | | | | | | | | | | | | | | Instead of using constant addresses for the normal and dump-info stacks, allocate both stacks in the decompressor's image and load the stack register in a position-independent manner. This will allow loading and entering the decompressor at an arbitrary memory address without corrupting the content at the fixed addresses used until now for both stacks. This is one of the prerequisites for being able to kexec the decompressor from its load address without relocating it first. Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/boot: move all linker symbol declarations from c to h filesAlexander Egorenkov2021-07-271-1/+9
| | | | | | | | | | To prevent multiple incompatible declarations of symbols and to catch such mistakes at compile time. Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390: setup kernel memory layout earlyVasily Gorbik2021-06-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | Currently there are two separate places where kernel memory layout has to be known and adjusted: 1. early kasan setup. 2. paging setup later. Those 2 places had to be kept in sync and adjusted to reflect peculiar technical details of one another. With additional factors which influence kernel memory layout like ultravisor secure storage limit, complexity of keeping two things in sync grew up even more. Besides that if we look forward towards creating identity mapping and enabling DAT before jumping into uncompressed kernel - that would also require full knowledge of and control over kernel memory layout. So, de-duplicate and move kernel memory layout setup logic into the decompressor. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/decompressor: add stacktrace supportVasily Gorbik2020-11-201-0/+5
| | | | | | | | | | | | | | | | | | | | | | Decompressor works on a single statically allocated stack. Stacktrace implementation with -mbackchain just takes few lines of code. Linux version 5.10.0-rc3-22793-g0f84a355b776-dirty (gor@tuxmaker) #27 SMP PREEMPT Mon Nov 9 17:30:18 CET 2020 Kernel fault: interruption code 0005 ilc:2 PSW : 0000000180000000 0000000000012f92 (parse_boot_command_line+0x27a/0x46c) R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3 GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 000000000001a62c 000000000000bf60 0000000000000000 00000000000003c0 0000000000000000 0000000000000080 000000000002322d 000000007f29ef20 0000000000efd018 000000000311c000 0000000000010070 0000000000012f82 000000000000bea8 Call Trace: (sp:000000000000bea8 [<000000000002016e>] 000000000002016e) sp:000000000000bf18 [<0000000000012408>] startup_kernel+0x88/0x2fc sp:000000000000bf60 [<00000000000100c4>] startup_normal+0xb0/0xb0 Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/decompressor: add decompressor_printkVasily Gorbik2020-11-201-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | The decompressor does not have any special debug means. Running the kernel under qemu with gdb is helpful but tedious exercise if done repeatedly. It is also not applicable to debugging under LPAR and z/VM. One special thing which stands out is a working sclp_early_printk, which could be used once the kernel switches to 64-bit addressing mode. But sclp_early_printk does not provide any string formating capabilities. Formatting and printing string without printk-alike function is a not fun. The lack of printk-alike function means people would save up on testing and introduce more bugs. So, finally, provide decompressor_printk function, which fits on one screen and trades features for simplicity. It only supports "%s", "%x" and "%lx" specifiers and zero padding for hex values. Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390: unify identity mapping limits handlingVasily Gorbik2020-11-201-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | Currently we have to consider too many different values which in the end only affect identity mapping size. These are: 1. max_physmem_end - end of physical memory online or standby. Always <= end of the last online memory block (get_mem_detect_end()). 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the kernel is able to support. 3. "mem=" kernel command line option which limits physical memory usage. 4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as crash kernel. 5. "hsa" size which is a memory limit when the kernel is executed during zfcp/nvme dump. Through out kernel startup and run we juggle all those values at once but that does not bring any amusement, only confusion and complexity. Unify all those values to a single one we should really care, that is our identity mapping size. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/mm: let vmalloc area size depend on physical memory sizeHeiko Carstens2020-11-091-0/+1
| | | | | | | | | | | | To make sure that the vmalloc area size is for almost all cases large enough let it depend on the (potential) physical memory size. There is still the possibility to override this with the vmalloc kernel command line parameter. Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* Merge tag 's390-5.4-1' of ↵Linus Torvalds2019-09-171-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add support for IBM z15 machines. - Add SHA3 and CCA AES cipher key support in zcrypt and pkey refactoring. - Move to arch_stack_walk infrastructure for the stack unwinder. - Various kasan fixes and improvements. - Various command line parsing fixes. - Improve decompressor phase debuggability. - Lift no bss usage restriction for the early code. - Use refcount_t for reference counters for couple of places in mm code. - Logging improvements and return code fix in vfio-ccw code. - Couple of zpci fixes and minor refactoring. - Remove some outdated documentation. - Fix secure boot detection. - Other various minor code clean ups. * tag 's390-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits) s390: remove pointless drivers-y in drivers/s390/Makefile s390/cpum_sf: Fix line length and format string s390/pci: fix MSI message data s390: add support for IBM z15 machines s390/crypto: Support for SHA3 via CPACF (MSA6) s390/startup: add pgm check info printing s390/crypto: xts-aes-s390 fix extra run-time crypto self tests finding vfio-ccw: fix error return code in vfio_ccw_sch_init() s390: vfio-ap: fix warning reset not completed s390/base: remove unused s390_base_mcck_handler s390/sclp: Fix bit checked for has_sipl s390/zcrypt: fix wrong handling of cca cipher keygenflags s390/kasan: add kdump support s390/setup: avoid using strncmp with hardcoded length s390/sclp: avoid using strncmp with hardcoded length s390/module: avoid using strncmp with hardcoded length s390/pci: avoid using strncmp with hardcoded length s390/kaslr: reserve memory for kasan usage s390/mem_detect: provide single get_mem_detect_end s390/cmma: reuse kstrtobool for option value parsing ...
| * s390/startup: add pgm check info printingVasily Gorbik2019-09-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Try to print out startup pgm check info including exact linux kernel version, pgm interruption code and ilc, psw and general registers. Like the following: Linux version 5.3.0-rc7-07282-ge7b4d41d61bd-dirty (gor@tuxmaker) #3 SMP PREEMPT Thu Sep 5 16:07:34 CEST 2019 Kernel fault: interruption code 0005 ilc:2 PSW : 0000000180000000 0000000000012e52 R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3 GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 0000000000019a58 000000000000bf68 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 000000000001a041 0000000000000000 0000000004c9c000 0000000000010070 0000000000012e42 000000000000beb0 This info makes it apparent that kernel startup failed and might help to understand what went wrong without actual standalone dump. Printing code runs on its own stack of 1 page (at unused 0x5000), which should be sufficient for sclp_early_printk usage (typical stack usage observed has been around 512 bytes). The code has pgm check recursion prevention, despite pgm check info printing failure (follow on pgm check) or success it restores original faulty psw and gprs and does disabled wait. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* | s390/boot: add missing declarations and includesVasily Gorbik2019-07-291-0/+1
|/ | | | | | | | | | | | | | | Add __swsusp_reset_dma declaration to avoid the following sparse warnings: arch/s390/kernel/setup.c:107:15: warning: symbol '__swsusp_reset_dma' was not declared. Should it be static? arch/s390/boot/startup.c:52:15: warning: symbol '__swsusp_reset_dma' was not declared. Should it be static? Add verify_facilities declaration to avoid the following sparse warning: arch/s390/boot/als.c:105:6: warning: symbol 'verify_facilities' was not declared. Should it be static? Include "boot.h" into arch/s390/boot/kaslr.c to expose get_random_base function declaration and avoid the following sparse warning: arch/s390/boot/kaslr.c:90:15: warning: symbol 'get_random_base' was not declared. Should it be static? Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390: enable detection of kernel version from bzImageVasily Gorbik2019-07-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | Extend "parmarea" to include an offset of the version string, which is stored as 8-byte big endian value. To retrieve version string from bzImage reliably, one should check the presence of "S390EP" ascii string at 0x10008 (available since v3.2), then read the version string offset from 0x10428 (which has been 0 since v3.2 up to now). The string is null terminated. Could be retrieved with the following "file" command magic (requires file v5.34): 8 string \x02\x00\x00\x18\x60\x00\x00\x50\x02\x00\x00\x68\x60\x00\x00\x50\x40\x40\x40\x40\x40\x40\x40\x40 Linux S390 >0x10008 string S390EP >>0x10428 bequad >0 >>>(0x10428.Q) string >\0 \b, version %s Reported-by: Petr Tesarik <ptesarik@suse.com> Suggested-by: Petr Tesarik <ptesarik@suse.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* s390/kernel: add support for kernel address space layout randomization (KASLR)Gerald Schaefer2019-04-291-0/+3
| | | | | | | | | | | | 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>
* s390/ipl: read IPL report at early bootMartin Schwidefsky2019-04-261-0/+2
| | | | | | | | | | | | | 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>
* s390: warn about clearing als implied facilitiesVasily Gorbik2019-03-011-0/+1
| | | | | | | | | Add a warning about removing required architecture level set facilities via "facilities=" command line option. 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>
* s390: allow overriding facilities via command lineVasily Gorbik2019-03-011-0/+1
| | | | | | | | | | | | | | | | | 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>
* s390: move ipl block and cmd line handling to early boot phaseVasily Gorbik2018-10-091-0/+3
| | | | | | | | | | | | | | | | 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>
* s390/mem_detect: move tprot loop to early boot phaseVasily Gorbik2018-10-091-0/+1
| | | | | | | | | | | | | | | 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>
* s390: remove decompressor's head.SVasily Gorbik2018-10-091-0/+7
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>