kernel.git/arch/s390, branch linux-5.0.y

s390/mm: silence compiler warning when compiling without CONFIG_PGSTE

2019-05-31T13:45:07Z

[ Upstream commit 81a8f2beb32a5951ecf04385301f50879abc092b ] If CONFIG_PGSTE is not set (e.g. when compiling without KVM), GCC complains: CC arch/s390/mm/pgtable.o arch/s390/mm/pgtable.c:413:15: warning: ‘pmd_alloc_map’ defined but not used [-Wunused-function] static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr) ^~~~~~~~~~~~~ Wrap the function with "#ifdef CONFIG_PGSTE" to silence the warning. Signed-off-by: Thomas Huth Reviewed-by: David Hildenbrand Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin

s390/kexec_file: Fix detection of text segment in ELF loader

2019-05-31T13:44:57Z

[ Upstream commit 729829d775c9a5217abc784b2f16087d79c4eec8 ] To register data for the next kernel (command line, oldmem_base, etc.) the current kernel needs to find the ELF segment that contains head.S. This is currently done by checking ifor 'phdr->p_paddr == 0'. This works fine for the current kernel build but in theory the first few pages could be skipped. Make the detection more robust by checking if the entry point lies within the segment. Signed-off-by: Philipp Rudo Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin

s390/mm: convert to the generic get_user_pages_fast code

2019-05-22T05:38:58Z

commit 1a42010cdc26bb7e5912984f3c91b8c6d55f089a upstream. Define the gup_fast_permitted to check against the asce_limit of the mm attached to the current task, then replace the s390 specific gup code with the generic implementation in mm/gup.c. Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/mm: make the pxd_offset functions more robust

2019-05-22T05:38:58Z

commit d1874a0c2805fcfa9162c972d6b7541e57adb542 upstream. Change the way how pgd_offset, p4d_offset, pud_offset and pmd_offset walk the page tables. pgd_offset now always calculates the index for the top-level page table and adds it to the pgd, this is either a segment table offset for a 2-level setup, a region-3 offset for 3-levels, region-2 offset for 4-levels, or a region-1 offset for a 5-level setup. The other three functions p4d_offset, pud_offset and pmd_offset will only add the respective offset if they dereference the passed pointer. With the new way of walking the page tables a sequence like this from mm/gup.c now works: pgdp = pgd_offset(current->mm, addr); pgd = READ_ONCE(*pgdp); p4dp = p4d_offset(&pgd, addr); p4d = READ_ONCE(*p4dp); pudp = pud_offset(&p4d, addr); pud = READ_ONCE(*pudp); pmdp = pmd_offset(&pud, addr); pmd = READ_ONCE(*pmdp); Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

s390/speculation: Support 'mitigations=' cmdline option

2019-05-14T17:17:13Z

commit 0336e04a6520bdaefdb0769d2a70084fa52e81ed upstream Configure s390 runtime CPU speculation bug mitigations in accordance with the 'mitigations=' cmdline option. This affects Spectre v1 and Spectre v2. The default behavior is unchanged. Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Tested-by: Jiri Kosina (on x86) Reviewed-by: Jiri Kosina Cc: Borislav Petkov Cc: "H . Peter Anvin" Cc: Andy Lutomirski Cc: Peter Zijlstra Cc: Jiri Kosina Cc: Waiman Long Cc: Andrea Arcangeli Cc: Jon Masters Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: linux-s390@vger.kernel.org Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Cc: Greg Kroah-Hartman Cc: Tyler Hicks Cc: Linus Torvalds Cc: Randy Dunlap Cc: Steven Price Cc: Phil Auld Link: https://lkml.kernel.org/r/e4a161805458a5ec88812aac0307ae3908a030fc.1555085500.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman

s390: limit brk randomization to 32MB

2019-05-04T07:21:12Z

[ Upstream commit cd479eccd2e057116d504852814402a1e68ead80 ] For a 64-bit process the randomization of the program break is quite large with 1GB. That is as big as the randomization of the anonymous mapping base, for a test case started with '/lib/ld64.so.1 ' it can happen that the heap is placed after the stack. To avoid this limit the program break randomization to 32MB for 64-bit and keep 8MB for 31-bit. Reported-by: Stefan Liebler Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin (Microsoft)

s390/mem_detect: Use IS_ENABLED(CONFIG_BLK_DEV_INITRD)

2019-04-27T07:37:42Z

commit 2d4ea4b95cae3133de6b18ec5d5a42ee824fa0ef upstream. IS_ENABLED should generally use CONFIG_ prefaced symbols and it doesn't appear as if there is a BLK_DEV_INITRD define. Cc: # 4.20 Signed-off-by: Joe Perches Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

perf/aux: Make perf_event accessible to setup_aux()

2019-04-05T20:34:42Z

[ Upstream commit 840018668ce2d96783356204ff282d6c9b0e5f66 ] When pmu::setup_aux() is called the coresight PMU needs to know which sink to use for the session by looking up the information in the event's attr::config2 field. As such simply replace the cpu information by the complete perf_event structure and change all affected customers. Signed-off-by: Mathieu Poirier Reviewed-by: Suzuki Poulouse Acked-by: Peter Zijlstra Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Greg Kroah-Hartman Cc: H. Peter Anvin Cc: Heiko Carstens Cc: Jiri Olsa Cc: Mark Rutland Cc: Martin Schwidefsky Cc: Namhyung Kim Cc: Thomas Gleixner Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-s390@vger.kernel.org Link: http://lkml.kernel.org/r/20190131184714.20388-2-mathieu.poirier@linaro.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

s390/setup: fix boot crash for machine without EDAT-1

2019-03-23T19:11:41Z

commit 86a86804e4f18fc3880541b3d5a07f4df0fe29cb upstream. The fix to make WARN work in the early boot code created a problem on older machines without EDAT-1. The setup_lowcore_dat_on function uses the pointer from lowcore_ptr[0] to set the DAT bit in the new PSWs. That does not work if the kernel page table is set up with 4K pages as the prefix address maps to absolute zero. To make this work the PSWs need to be changed with via address 0 in form of the S390_lowcore definition. Reported-by: Guenter Roeck Tested-by: Cornelia Huck Fixes: 94f85ed3e2f8 ("s390/setup: fix early warning messages") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman

KVM: Call kvm_arch_memslots_updated() before updating memslots

2019-03-23T19:11:40Z

commit 152482580a1b0accb60676063a1ac57b2d12daf6 upstream. kvm_arch_memslots_updated() is at this point in time an x86-specific hook for handling MMIO generation wraparound. x86 stashes 19 bits of the memslots generation number in its MMIO sptes in order to avoid full page fault walks for repeat faults on emulated MMIO addresses. Because only 19 bits are used, wrapping the MMIO generation number is possible, if unlikely. kvm_arch_memslots_updated() alerts x86 that the generation has changed so that it can invalidate all MMIO sptes in case the effective MMIO generation has wrapped so as to avoid using a stale spte, e.g. a (very) old spte that was created with generation==0. Given that the purpose of kvm_arch_memslots_updated() is to prevent consuming stale entries, it needs to be called before the new generation is propagated to memslots. Invalidating the MMIO sptes after updating memslots means that there is a window where a vCPU could dereference the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO spte that was created with (pre-wrap) generation==0. Fixes: e59dbe09f8e6 ("KVM: Introduce kvm_arch_memslots_updated()") Cc: Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman