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* s390: workaround invalid gcc-11 out of bounds read warningHeiko Carstens2023-01-171-2/+3
| | | | | | | | | | | | | | | | | | | | | | GCC 11.1.0 and 11.2.0 generate a wrong warning when compiling the kernel e.g. with allmodconfig: arch/s390/kernel/setup.c: In function ‘setup_lowcore_dat_on’: ./include/linux/fortify-string.h:57:33: error: ‘__builtin_memcpy’ reading 128 bytes from a region of size 0 [-Werror=stringop-overread] ... arch/s390/kernel/setup.c:526:9: note: in expansion of macro ‘memcpy’ 526 | memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area, | ^~~~~~ This could be addressed by using absolute_pointer() with the S390_lowcore macro, but this is not a good idea since this generates worse code for performance critical paths. Therefore simply use a for loop to copy the array in question and get rid of the warning. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* random: do not include <asm/archrandom.h> from random.hJason A. Donenfeld2022-12-201-0/+1
| | | | | | | | | | | The <asm/archrandom.h> header is a random.c private detail, not something to be called by other code. As such, don't make it automatically available by way of random.h. Cc: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
* s390/nmi: move storage error checking back to C, enter with DAT onHeiko Carstens2022-12-061-1/+2
| | | | | | | | | | | | | | Checking for storage errors in machine check entry code was done in order to handle also storage errors on kernel page tables. However this is extremely unlikely and some basic assumptions what works on machine check entry are necessary anyway. In order to simplify machine check handling delay checking for storage errors to C code. With this also change the machine check new PSW to have DAT on, which simplifies the entry code even further. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
* s390/mm: rework memcpy_real() to avoid DAT-off modeAlexander Gordeev2022-09-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Function memcpy_real() is an univeral data mover that does not require DAT mode to be able reading from a physical address. Its advantage is an ability to read from any address, even those for which no kernel virtual mapping exists. Although memcpy_real() is interrupt-safe, there are no handlers that make use of this function. The compiler instrumentation have to be disabled and separate no-DAT stack used to allow execution of the function once DAT mode is disabled. Rework memcpy_real() to overcome these shortcomings. As result, data copying (which is primarily reading out a crashed system memory by a user process) is executed on a regular stack with enabled interrupts. Also, use of memcpy_real_buf swap buffer becomes unnecessary and the swapping is eliminated. The above is achieved by using a fixed virtual address range that spans a single page and remaps that page repeatedly when memcpy_real() is called for a particular physical address. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/dump: save IPL CPU registers once DAT is availableAlexander Gordeev2022-09-141-2/+5
| | | | | | | | | | | | | | | | | | Function smp_save_dump_cpus() collects CPU state of a crashed system for secondary CPUs and for the IPL CPU very differently. The Signal Processor stop-and-store-status orders are used for the former while Hardware System Area requests and memcpy_real() routine are called for the latter. In addition a system reset is triggered, which pins smp_save_dump_cpus() function call before CPU and device initialization. Move the collection of IPL CPU state to a later stage when DAT becomes available. That is needed to allow a follow-up rework of memcpy_real() routine. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/smp: rework absolute lowcore accessAlexander Gordeev2022-09-141-14/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Temporary unsetting of the prefix page in memcpy_absolute() routine poses a risk of executing code path with unexpectedly disabled prefix page. This rework avoids the prefix page uninstalling and disabling of normal and machine check interrupts when accessing the absolute zero memory. Although memcpy_absolute() routine can access the whole memory, it is only used to update the absolute zero lowcore. This rework therefore introduces a new mechanism for the absolute zero lowcore access and scraps memcpy_absolute() routine for good. Instead, an area is reserved in the virtual memory that is used for the absolute lowcore access only. That area holds an array of 8KB virtual mappings - one per CPU. Whenever a CPU is brought online, the corresponding item is mapped to the real address of the previously installed prefix page. The absolute zero lowcore access works like this: a CPU calls the new primitive get_abs_lowcore() to obtain its 8KB mapping as a pointer to the struct lowcore. Virtual address references to that pointer get translated to the real addresses of the prefix page, which in turn gets swapped with the absolute zero memory addresses due to prefixing. Once the pointer is not needed it must be released with put_abs_lowcore() primitive: struct lowcore *abs_lc; unsigned long flags; abs_lc = get_abs_lowcore(&flags); abs_lc->... = ...; put_abs_lowcore(abs_lc, flags); To ensure the described mechanism works large segment- and region- table entries must be avoided for the 8KB mappings. Failure to do so results in usage of Region-Frame Absolute Address (RFAA) or Segment-Frame Absolute Address (SFAA) large page fields. In that case absolute addresses would be used to address the prefix page instead of the real ones and the prefixing would get bypassed. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/smp: call smp_reinit_ipl_cpu() before scheduler is availableAlexander Gordeev2022-09-141-0/+1
| | | | | | | | | | | | | | | | | Currently smp_reinit_ipl_cpu() is a pre-SMP early initcall. That ensures no CPU is running in parallel, but still not enough to assume the code is exclusive, since the scheduling is already available. Move the function call to arch_call_rest_init() callback to ensure no thread could be preempted and allow lockless allocation of the kernel page tables. That is needed to allow a follow-up rework of the absolute lowcore access mechanism. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/smp: enforce lowcore protection on CPU restartAlexander Gordeev2022-09-071-1/+1
| | | | | | | | | | | | | | As result of commit 915fea04f932 ("s390/smp: enable DAT before CPU restart callback is called") the low-address protection bit gets mistakenly unset in control register 0 save area of the absolute zero memory. That area is used when manual PSW restart happened to hit an offline CPU. In this case the low-address protection for that CPU will be dropped. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Fixes: 915fea04f932 ("s390/smp: enable DAT before CPU restart callback is called") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/boot: fix absolute zero lowcore corruption on bootAlexander Gordeev2022-09-071-0/+1
| | | | | | | | | | | | | | Crash dump always starts on CPU0. In case CPU0 is offline the prefix page is not installed and the absolute zero lowcore is used. However, struct lowcore::mcesad is never assigned and stays zero. That leads to __machine_kdump() -> save_vx_regs() call silently stores vector registers to the absolute lowcore at 0x11b0 offset. Fixes: a62bc0739253 ("s390/kdump: add support for vector extension") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* Merge tag 's390-5.20-1' of ↵Linus Torvalds2022-08-061-7/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Alexander Gordeev: - Rework copy_oldmem_page() callback to take an iov_iter. This includes a few prerequisite updates and fixes to the oldmem reading code. - Rework cpufeature implementation to allow for various CPU feature indications, which is not only limited to hardware capabilities, but also allows CPU facilities. - Use the cpufeature rework to autoload Ultravisor module when CPU facility 158 is available. - Add ELF note type for encrypted CPU state of a protected virtual CPU. The zgetdump tool from s390-tools package will decrypt the CPU state using a Customer Communication Key and overwrite respective notes to make the data accessible for crash and other debugging tools. - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto test. - Fix incorrect recovery of kretprobe modified return address in stacktrace. - Switch the NMI handler to use generic irqentry_nmi_enter() and irqentry_nmi_exit() helper functions. - Rework the cryptographic Adjunct Processors (AP) pass-through design to support dynamic changes to the AP matrix of a running guest as well as to implement more of the AP architecture. - Minor boot code cleanups. - Grammar and typo fixes to hmcdrv and tape drivers. * tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits) Revert "s390/smp: enforce lowcore protection on CPU restart" Revert "s390/smp: rework absolute lowcore access" Revert "s390/smp,ptdump: add absolute lowcore markers" s390/unwind: fix fgraph return address recovery s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit() s390: add ELF note type for encrypted CPU state of a PV VCPU s390/smp,ptdump: add absolute lowcore markers s390/smp: rework absolute lowcore access s390/setup: rearrange absolute lowcore initialization s390/boot: cleanup adjust_to_uv_max() function s390/smp: enforce lowcore protection on CPU restart s390/tape: fix comment typo s390/hmcdrv: fix Kconfig "its" grammar s390/docs: fix warnings for vfio_ap driver doc s390/docs: fix warnings for vfio_ap driver lock usage doc s390/crash: support multi-segment iterators s390/crash: use static swap buffer for copy_to_user_real() s390/crash: move copy_to_user_real() to crash_dump.c s390/zcore: fix race when reading from hardware system area s390/crash: fix incorrect number of bytes to copy to user space ...
| * Revert "s390/smp: enforce lowcore protection on CPU restart"Alexander Gordeev2022-08-061-1/+1
| | | | | | | | | | | | | | | | This reverts commit 6f5c672d17f583b081e283927f5040f726c54598. This breaks normal crash dump when CPU0 is offline. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
| * Revert "s390/smp: rework absolute lowcore access"Alexander Gordeev2022-08-061-21/+13
| | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 7d06fed77b7d8fc9f6cc41b4e3f2823d32532ad8. This introduced vmem_mutex locking from vmem_map_4k_page() function called from smp_reinit_ipl_cpu() with interrupts disabled. While it is a pre-SMP early initcall no other CPUs running in parallel nor other code taking vmem_mutex on this boot stage - it still needs to be fixed. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
| * s390/smp: rework absolute lowcore accessAlexander Gordeev2022-07-281-13/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Temporary unsetting of the prefix page in memcpy_absolute() routine poses a risk of executing code path with unexpectedly disabled prefix page. This rework avoids the prefix page uninstalling and disabling of normal and machine check interrupts when accessing the absolute zero memory. Although memcpy_absolute() routine can access the whole memory, it is only used to update the absolute zero lowcore. This rework therefore introduces a new mechanism for the absolute zero lowcore access and scraps memcpy_absolute() routine for good. Instead, an area is reserved in the virtual memory that is used for the absolute lowcore access only. That area holds an array of 8KB virtual mappings - one per CPU. Whenever a CPU is brought online, the corresponding item is mapped to the real address of the previously installed prefix page. The absolute zero lowcore access works like this: a CPU calls the new primitive get_abs_lowcore() to obtain its 8KB mapping as a pointer to the struct lowcore. Virtual address references to that pointer get translated to the real addresses of the prefix page, which in turn gets swapped with the absolute zero memory addresses due to prefixing. Once the pointer is not needed it must be released with put_abs_lowcore() primitive: struct lowcore *abs_lc; unsigned long flags; abs_lc = get_abs_lowcore(&flags); abs_lc->... = ...; put_abs_lowcore(abs_lc, flags); To ensure the described mechanism works large segment- and region- table entries must be avoided for the 8KB mappings. Failure to do so results in usage of Region-Frame Absolute Address (RFAA) or Segment-Frame Absolute Address (SFAA) large page fields. In that case absolute addresses would be used to address the prefix page instead of the real ones and the prefixing would get bypassed. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
| * s390/setup: rearrange absolute lowcore initializationAlexander Gordeev2022-07-281-7/+6
| | | | | | | | | | | | | | | | | | | | Make the absolute lowcore assignments immediately follow the boot CPU lowcore same member assignments. This way readability improves when reading from up to down, with no out of order mcck stack allocation in-between. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
| * s390/smp: enforce lowcore protection on CPU restartAlexander Gordeev2022-07-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | As result of commit 915fea04f932 ("s390/smp: enable DAT before CPU restart callback is called") the low-address protection bit gets mistakenly unset in control register 0 save area of the absolute zero memory. That area is used when manual PSW restart happened to hit an offline CPU. In this case the low-address protection for that CPU will be dropped. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Fixes: 915fea04f932 ("s390/smp: enable DAT before CPU restart callback is called") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
* | random: remove CONFIG_ARCH_RANDOMJason A. Donenfeld2022-07-181-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When RDRAND was introduced, there was much discussion on whether it should be trusted and how the kernel should handle that. Initially, two mechanisms cropped up, CONFIG_ARCH_RANDOM, a compile time switch, and "nordrand", a boot-time switch. Later the thinking evolved. With a properly designed RNG, using RDRAND values alone won't harm anything, even if the outputs are malicious. Rather, the issue is whether those values are being *trusted* to be good or not. And so a new set of options were introduced as the real ones that people use -- CONFIG_RANDOM_TRUST_CPU and "random.trust_cpu". With these options, RDRAND is used, but it's not always credited. So in the worst case, it does nothing, and in the best case, maybe it helps. Along the way, CONFIG_ARCH_RANDOM's meaning got sort of pulled into the center and became something certain platforms force-select. The old options don't really help with much, and it's a bit odd to have special handling for these instructions when the kernel can deal fine with the existence or untrusted existence or broken existence or non-existence of that CPU capability. Simplify the situation by removing CONFIG_ARCH_RANDOM and using the ordinary asm-generic fallback pattern instead, keeping the two options that are actually used. For now it leaves "nordrand" for now, as the removal of that will take a different route. Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
* | s390/archrandom: simplify back to earlier design and initialize earlierJason A. Donenfeld2022-06-301-0/+5
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | s390x appears to present two RNG interfaces: - a "TRNG" that gathers entropy using some hardware function; and - a "DRBG" that takes in a seed and expands it. Previously, the TRNG was wired up to arch_get_random_{long,int}(), but it was observed that this was being called really frequently, resulting in high overhead. So it was changed to be wired up to arch_get_random_ seed_{long,int}(), which was a reasonable decision. Later on, the DRBG was then wired up to arch_get_random_{long,int}(), with a complicated buffer filling thread, to control overhead and rate. Fortunately, none of the performance issues matter much now. The RNG always attempts to use arch_get_random_seed_{long,int}() first, which means a complicated implementation of arch_get_random_{long,int}() isn't really valuable or useful to have around. And it's only used when reseeding, which means it won't hit the high throughput complications that were faced before. So this commit returns to an earlier design of just calling the TRNG in arch_get_random_seed_{long,int}(), and returning false in arch_get_ random_{long,int}(). Part of what makes the simplification possible is that the RNG now seeds itself using the TRNG at bootup. But this only works if the TRNG is detected early in boot, before random_init() is called. So this commit also causes that check to happen in setup_arch(). Cc: stable@vger.kernel.org Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Ingo Franzki <ifranzki@linux.ibm.com> Cc: Juergen Christ <jchrist@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20220610222023.378448-1-Jason@zx2c4.com Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
* s390/smp: sort out physical vs virtual CPU0 lowcore pointerAlexander Gordeev2022-04-251-1/+1
| | | | | | | | | | | | | SPX instruction called from set_prefix() expects physical address of the lowcore to be installed, but instead the virtual address is passed. Note: this does not fix a bug currently, since virtual and physical addresses are identical. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/maccess: rework absolute lowcore accessorsAlexander Gordeev2022-03-271-9/+10
| | | | | | | | | | | | Macro mem_assign_absolute() is able to access the whole memory, but is only used and makes sense when updating the absolute lowcore. Instead, introduce get_abs_lowcore() and put_abs_lowcore() macros that limit access to absolute lowcore addresses only. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390: raise minimum supported machine generation to z10Vasily Gorbik2022-03-101-1/+0
| | | | | | | | | | | | | | | | | | | | | | Machine generations up to z9 (released in May 2006) have been officially out of service for several years now (z9 end of service - January 31, 2019). No distributions build kernels supporting those old machine generations anymore, except Debian, which seems to pick the oldest supported generation. The team supporting Debian on s390 has been notified about the change. Raising minimum supported machine generation to z10 helps to reduce maintenance cost and effectively remove code, which is not getting enough testing coverage due to lack of older hardware and distributions support. Besides that this unblocks some optimization opportunities and allows to use wider instruction set in asm files for future features implementation. Due to this change spectre mitigation and usercopy implementations could be drastically simplified and many newer instructions could be converted from ".insn" encoding to instruction names. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZEAlexander Egorenkov2022-03-011-0/+2
| | | | | | | | | | | | | We need to preserve the values at OLDMEM_BASE and OLDMEM_SIZE which are used by zgetdump in case when kdump crashes. In that case zgetdump will attempt to read OLDMEM_BASE and OLDMEM_SIZE in order to find out where the memory range [0 - OLDMEM_SIZE] belonging to the production kernel is. Fixes: f1a546947431 ("s390/setup: don't reserve memory that occupied decompressor's head") Cc: stable@vger.kernel.org # 5.15+ Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* s390/nmi: disable interrupts on extended save area updateAlexander Gordeev2021-12-161-1/+1
| | | | | | | | | | | Updating of the pointer to machine check extended save area on the IPL CPU needs the lowcore protection to be disabled. Disable interrupts while the protection is off to avoid unnoticed writes to the lowcore. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/setup: re-arrange memblock setupVasily Gorbik2021-11-161-5/+4
| | | | | | | | | | | | | | | | | - Avoid using ULONG_MAX in memblock_remove, it has no functional change but makes memblock_dbg output a range which makes sense. - Actually finish memblock memory setup before doing amode31/cr/uv setup. - Move memblock_dump_all() debug output after memblock memory setup is complete. This gives us final "memory" regions if they were trimmed due to addressing limits and still "physmem" regions as original info which came from mem_detect. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/setup: avoid using memblock_enforce_memory_limitVasily Gorbik2021-11-161-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a difference in how architectures treat "mem=" option. For some that is an amount of online memory, for s390 and x86 this is the limiting max address. Some memblock api like memblock_enforce_memory_limit() take limit argument and explicitly treat it as the size of online memory, and use __find_max_addr to convert it to an actual max address. Current s390 usage: memblock_enforce_memory_limit(memblock_end_of_DRAM()); yields different results depending on presence of memory holes (offline memory blocks in between online memory). If there are no memory holes limit == max_addr in memblock_enforce_memory_limit() and it does trim online memory and reserved memory regions. With memory holes present it actually does nothing. Since we already use memblock_remove() explicitly to trim online memory regions to potential limit (think mem=, kdump, addressing limits, etc.) drop the usage of memblock_enforce_memory_limit() altogether. Trimming reserved regions should not be required, since we now use memblock_set_current_limit() to limit allocations and any explicit memory reservations above the limit is an actual problem we should not hide. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* s390/setup: avoid reserving memory above identity mappingVasily Gorbik2021-11-161-9/+1
| | | | | | | | | | | | | | | | | | Such reserved memory region, if not cleaned up later causes problems when memblock_free_all() is called to release free pages to the buddy allocator and those reserved regions are carried over to reserve_bootmem_region() which marks the pages as PageReserved. Instead use memblock_set_current_limit() to make sure memblock allocations do not go over identity mapping (which could happen when "mem=" option is used or during kdump). Cc: stable@vger.kernel.org Fixes: 73045a08cf55 ("s390: unify identity mapping limits handling") Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* Merge tag 's390-5.16-1' of ↵Linus Torvalds2021-11-061-23/+19
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add support for ftrace with direct call and ftrace direct call samples. - Add support for kernel command lines longer than current 896 bytes and make its length configurable. - Add support for BEAR enhancement facility to improve last breaking event instruction tracking. - Add kprobes sanity checks and testcases to prevent kprobe in the mid of an instruction. - Allow concurrent access to /dev/hwc for the CPUMF users. - Various ftrace / jump label improvements. - Convert unwinder tests to KUnit. - Add s390_iommu_aperture kernel parameter to tweak the limits on concurrently usable DMA mappings. - Add ap.useirq AP module option which can be used to disable interrupt use. - Add add_disk() error handling support to block device drivers. - Drop arch specific and use generic implementation of strlcpy and strrchr. - Several __pa/__va usages fixes. - Various cio, crypto, pci, kernel doc and other small fixes and improvements all over the code. [ Merge fixup as per https://lore.kernel.org/all/YXAqZ%2FEszRisunQw@osiris/ ] * tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (63 commits) s390: make command line configurable s390: support command lines longer than 896 bytes s390/kexec_file: move kernel image size check s390/pci: add s390_iommu_aperture kernel parameter s390/spinlock: remove incorrect kernel doc indicator s390/string: use generic strlcpy s390/string: use generic strrchr s390/ap: function rework based on compiler warning s390/cio: make ccw_device_dma_* more robust s390/vfio-ap: s390/crypto: fix all kernel-doc warnings s390/hmcdrv: fix kernel doc comments s390/ap: new module option ap.useirq s390/cpumf: Allow multiple processes to access /dev/hwc s390/bitops: return true/false (not 1/0) from bool functions s390: add support for BEAR enhancement facility s390: introduce nospec_uses_trampoline() s390: rename last_break to pgm_last_break s390/ptrace: add last_break member to pt_regs s390/sclp: sort out physical vs virtual pointers usage s390/setup: convert start and end initrd pointers to virtual ...
| * s390: add support for BEAR enhancement facilitySven Schnelle2021-10-261-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Breaking-Event-Address-Register (BEAR) stores the address of the last breaking event instruction. Breaking events are usually instructions that change the program flow - for example branches, and instructions that modify the address in the PSW like lpswe. This is useful for debugging wild branches, because one could easily figure out where the wild branch was originating from. What is problematic is that lpswe is considered a breaking event, and therefore overwrites BEAR on kernel exit. The BEAR enhancement facility adds new instructions that allow to save/restore BEAR and also an lpswey instruction that doesn't cause a breaking event. So we can save BEAR on kernel entry and restore it on exit to user space. 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/setup: convert start and end initrd pointers to virtualAlexander Gordeev2021-10-261-1/+1
| | | | | | | | | | | | | | | | | | Variables initrd_start and initrd_end are expected to hold virtual memory pointers, not physical. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * s390/setup: use physical pointers for memblock_reserve()Alexander Gordeev2021-10-261-5/+2
| | | | | | | | | | | | | | | | | | memblock_reserve() function accepts physcal address of a memory block to be reserved, but provided with virtual memory pointers. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * s390/setup: use virtual address for STSI instructionAlexander Gordeev2021-10-261-4/+2
| | | | | | | | | | | | | | | | Provide virtual memory pointer for system-information block. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * s390/boot: allocate amode31 section in decompressorAlexander Gordeev2021-10-041-13/+9
| | | | | | | | | | | | | | | | | | | | | | The memory for amode31 section is allocated from the decompressed kernel. Instead, allocate that memory from the decompressor. This is a prerequisite to allow initialization of the virtual memory before the decompressed kernel takes over. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* | memblock: allow to specify flags with memblock_add_node()David Hildenbrand2021-11-061-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to specify flags when hotplugging memory. Let's prepare to pass flags to memblock_add_node() by adjusting all existing users. Note that when hotplugging memory the system is already up and running and we might have concurrent memblock users: for example, while we're hotplugging memory, kexec_file code might search for suitable memory regions to place kexec images. It's important to add the memory directly to memblock via a single call with the right flags, instead of adding the memory first and apply flags later: otherwise, concurrent memblock users might temporarily stumble over memblocks with wrong flags, which will be important in a follow-up patch that introduces a new flag to properly handle add_memory_driver_managed(). Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Shahab Vahedi <shahab@synopsys.com> [arch/arc] Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Jianyong Wu <Jianyong.Wu@arm.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memblock: rename memblock_free to memblock_phys_freeMike Rapoport2021-11-061-4/+4
|/ | | | | | | | | | | | | | | | | | | | | | | Since memblock_free() operates on a physical range, make its name reflect it and rename it to memblock_phys_free(), so it will be a logical counterpart to memblock_phys_alloc(). The callers are updated with the below semantic patch: @@ expression addr; expression size; @@ - memblock_free(addr, size); + memblock_phys_free(addr, size); Link: https://lkml.kernel.org/r/20210930185031.18648-6-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Juergen Gross <jgross@suse.com> Cc: Shahab Vahedi <Shahab.Vahedi@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 's390-5.15-2' of ↵Linus Torvalds2021-09-091-3/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Heiko Carstens: "Except for the xpram device driver removal it is all about fixes and cleanups. - Fix topology update on cpu hotplug, so notifiers see expected masks. This bug was uncovered with SCHED_CORE support. - Fix stack unwinding so that the correct number of entries are omitted like expected by common code. This fixes KCSAN selftests. - Add kmemleak annotation to stack_alloc to avoid false positive kmemleak warnings. - Avoid layering violation in common I/O code and don't unregister subchannel from child-drivers. - Remove xpram device driver for which no real use case exists since the kernel is 64 bit only. Also all hypervisors got required support removed in the meantime, which means the xpram device driver is dead code. - Fix -ENODEV handling of clp_get_state in our PCI code. - Enable KFENCE in debug defconfig. - Cleanup hugetlbfs s390 specific Kconfig dependency. - Quite a lot of trivial fixes to get rid of "W=1" warnings, and and other simple cleanups" * tag 's390-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: hugetlbfs: s390 is always 64bit s390/ftrace: remove incorrect __va usage s390/zcrypt: remove incorrect kernel doc indicators scsi: zfcp: fix kernel doc comments s390/sclp: add __nonstring annotation s390/hmcdrv_ftp: fix kernel doc comment s390: remove xpram device driver s390/pci: read clp_list_pci_req only once s390/pci: fix clp_get_state() handling of -ENODEV s390/cio: fix kernel doc comment s390/ctrlchar: fix kernel doc comment s390/con3270: use proper type for tasklet function s390/cpum_cf: move array from header to C file s390/mm: fix kernel doc comments s390/topology: fix topology information when calling cpu hotplug notifiers s390/unwind: use current_frame_address() to unwind current task s390/configs: enable CONFIG_KFENCE in debug_defconfig s390/entry: make oklabel within CHKSTG macro local s390: add kmemleak annotation in stack_alloc() s390/cio: dont unregister subchannel from child-drivers
| * s390: add kmemleak annotation in stack_alloc()Sven Schnelle2021-08-311-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | kmemleak with enabled auto scanning reports that our stack allocation is lost. This is because we're saving the pointer + STACK_INIT_OFFSET to lowcore. When kmemleak now scans the objects, it thinks that this one is lost because it can't find a corresponding pointer. Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2021-09-031-3/+6
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...
| * memblock: make memblock_find_in_range method privateMike Rapoport2021-09-031-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a lot of uses of memblock_find_in_range() along with memblock_reserve() from the times memblock allocation APIs did not exist. memblock_find_in_range() is the very core of memblock allocations, so any future changes to its internal behaviour would mandate updates of all the users outside memblock. Replace the calls to memblock_find_in_range() with an equivalent calls to memblock_phys_alloc() and memblock_phys_alloc_range() and make memblock_find_in_range() private method of memblock. This simplifies the callers, ensures that (unlikely) errors in memblock_reserve() are handled and improves maintainability of memblock_find_in_range(). Link: https://lkml.kernel.org/r/20210816122622.30279-1-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Kirill A. Shutemov <kirill.shtuemov@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [ACPI] Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Nick Kossifidis <mick@ics.forth.gr> [riscv] Tested-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | s390/smp: enable DAT before CPU restart callback is calledAlexander Gordeev2021-08-261-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The restart interrupt is triggered whenever a secondary CPU is brought online, a remote function call dispatched from another CPU or a manual PSW restart is initiated and causes the system to kdump. The handling routine is always called with DAT turned off. It then initializes the stack frame and invokes a callback. The existing callbacks handle DAT as follows: * __do_restart() and __machine_kexec() turn in on upon entry; * __ipl_run(), __reipl_run() and __dump_run() do not turn it right away, but all of them call diag308() - which turns DAT on, but only if kasan is enabled; In addition to the described complexity all callbacks (and the functions they call) should avoid kasan instrumentation while DAT is off. This update enables DAT in the assembler restart handler and relieves any callbacks (which are mostly C functions) from dealing with DAT altogether. There are four types of CPU restart that initialize control registers in different ways: 1. Start of secondary CPU on boot - control registers are inherited from the IPL CPU; 2. Restart of online CPU - control registers of the CPU being restarted are kept; 3. Hotplug of offline CPU - control registers are inherited from the starting CPU; 4. Start of offline CPU triggered by manual PSW restart - the control registers are read from the absolute lowcore and contain the boot time IPL CPU values updated with all follow-up calls of smp_ctl_set_bit() and smp_ctl_clear_bit() routines; In first three cases contents of the control registers is the most recent. In the latter case control registers are good enough to facilitate successful completion of kdump operation. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | s390/sclp: reserve memory occupied by sclp early bufferAlexander Egorenkov2021-08-181-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The memory block occupied by the SCLP early buffer that is allocated by the decompressor and then handed over to the decompressed kernel, must be reserved to prevent it from being reused for other purposes. This is necessary because the SCLP early buffer is still in use during kernel initialization. Fixes: f1d3c5323772 ("s390/boot: move sclp early buffer from fixed address in asm to C") Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Reported-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* | s390: rename dma section to amode31Heiko Carstens2021-08-051-43/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The dma section name is confusing, since the code which resides within that section has nothing to do with direct memory access. Instead the limitation is that the code has to run in 31 bit addressing mode, and therefore has to reside below 2GB. So the name was chosen since ZONE_DMA is the same region. To reduce confusion rename the section to amode31, which hopefully describes better what this is about. Note: this will also change vmcoreinfo strings - SDMA=... gets renamed to SAMODE31=... - EDMA=... gets renamed to EAMODE31=... Acked-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | s390/hwcaps: move setup_hwcaps()Heiko Carstens2021-07-271-158/+0
| | | | | | | | | | | | | | | | Move setup_hwcaps() to processor.c for two reasons: - make setup.c a bit smaller - have allmost all of the hwcap code in one file Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | s390/hwcaps: shorten HWCAP definesHeiko Carstens2021-07-271-26/+26
| | | | | | | | | | | | | | | | Remove s390 part of all HWCAP defines, just to make them shorter and easier to handle. The namespace is anyway per architecture. This is similar to what arm64 has. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | s390: add HWCAP_S390_PCI_MIO to ELF hwcapsNiklas Schnelle2021-07-271-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to support the use of enhanced PCI instructions in both kernel- and userspace we need both hardware support and proper setup in the kernel. The latter can be toggled off with the pci=nomio command line option. Thus availability of this feature in userspace depends on all of kernel configuration (CONFIG_PCI), hardware support and the current kernel command line and can thus not rely solely on a facility bit. Instead let's introduce a new ELF hardware capability bit HWCAP_S390_PCI_MIO to tell userspace whether these PCI instructions can be used. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | s390: report more CPU capabilitiesHeiko Carstens2021-07-271-0/+4
| | | | | | | | | | | | | | Add hardware capability bits and feature tags to /proc/cpuinfo for NNPA and Vector-Packed-Decimal-Enhancement Facility 2. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
* | s390/setup: don't reserve memory that occupied decompressor's headAlexander Egorenkov2021-07-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | There is no useful information within [STARTUP_NORMAL_OFFSET, HEAD_END] now. But the memory region [0, STARTUP_NORMAL_OFFSET] is used by: * lowcore * kdump for swapping memory * stand-alone zipl dumpers for code, data, stack and heap 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 dma sections from decompressor to decompressed kernelAlexander Egorenkov2021-07-271-7/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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/dump: introduce boot data 'oldmem_data'Alexander Egorenkov2021-07-271-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | The new boot data struct shall replace global variables OLDMEM_BASE and OLDMEM_SIZE. It is initialized in the decompressor and passed to the decompressed kernel. In comparison to the old solution, this one doesn't access data at fixed physical addresses which will become important when the decompressor becomes relocatable. 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: introduce boot data 'initrd_data'Alexander Egorenkov2021-07-271-7/+8
|/ | | | | | | | | | | | The new boot data struct shall replace global variables INITRD_START and INITRD_SIZE. It is initialized in the decompressor and passed to the decompressed kernel. In comparison to the old solution, this one doesn't access data at fixed physical addresses which will become important when the decompressor becomes relocatable. 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>
* Merge tag 's390-5.14-2' of ↵Linus Torvalds2021-07-101-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Vasily Gorbik: - Fix preempt_count initialization. - Rework call_on_stack() macro to add proper type handling and avoid possible register corruption. - More error prone "register asm" removal and fixes. - Fix syscall restarting when multiple signals are coming in. This adds minimalistic trampolines to vdso so we can return from signal without using the stack which requires pgm check handler hacks when NX is enabled. - Remove HAVE_IRQ_EXIT_ON_IRQ_STACK since this is no longer true after switch to generic entry. - Fix protected virtualization secure storage access exception handling. - Make machine check C handler always enter with DAT enabled and move register validation to C code. - Fix tinyconfig boot problem by avoiding MONITOR CALL without CONFIG_BUG. - Increase asm symbols alignment to 16 to make it consistent with compilers. - Enable concurrent access to the CPU Measurement Counter Facility. - Add support for dynamic AP bus size limit and rework ap_dqap to deal with messages greater than recv buffer. * tag 's390-5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (41 commits) s390: preempt: Fix preempt_count initialization s390/linkage: increase asm symbols alignment to 16 s390: rename CALL_ON_STACK_NORETURN() to call_on_stack_noreturn() s390: add type checking to CALL_ON_STACK_NORETURN() macro s390: remove old CALL_ON_STACK() macro s390/softirq: use call_on_stack() macro s390/lib: use call_on_stack() macro s390/smp: use call_on_stack() macro s390/kexec: use call_on_stack() macro s390/irq: use call_on_stack() macro s390/mm: use call_on_stack() macro s390: introduce proper type handling call_on_stack() macro s390/irq: simplify on_async_stack() s390/irq: inline do_softirq_own_stack() s390/irq: simplify do_softirq_own_stack() s390/ap: get rid of register asm in ap_dqap() s390: rename PIF_SYSCALL_RESTART to PIF_EXECVE_PGSTE_RESTART s390: move restart of execve() syscall s390/signal: remove sigreturn on stack s390/signal: switch to using vdso for sigreturn and syscall restart ...
| * s390: preempt: Fix preempt_count initializationValentin Schneider2021-07-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | S390's init_idle_preempt_count(p, cpu) doesn't actually let us initialize the preempt_count of the requested CPU's idle task: it unconditionally writes to the current CPU's. This clearly conflicts with idle_threads_init(), which intends to initialize *all* the idle tasks, including their preempt_count (or their CPU's, if the arch uses a per-CPU preempt_count). Unfortunately, it seems the way s390 does things doesn't let us initialize every possible CPU's preempt_count early on, as the pages where this resides are only allocated when a CPU is brought up and are freed when it is brought down. Let the arch-specific code set a CPU's preempt_count when its lowcore is allocated, and turn init_idle_preempt_count() into an empty stub. Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20210707163338.1623014-1-valentin.schneider@arm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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