kernel/git/stable/linux.git/arch/s390, branch linux-5.5.y

s390/diag: fix display of diagnose call statistics

2020-04-17T14:12:16+00:00

commit 6c7c851f1b666a8a455678a0b480b9162de86052 upstream. Show the full diag statistic table and not just parts of it. The issue surfaced in a KVM guest with a number of vcpus defined smaller than NR_DIAG_STAT. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Cc: stable@vger.kernel.org Signed-off-by: Michael Mueller Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

KVM: s390: vsie: Fix delivery of addressing exceptions

2020-04-17T14:12:06+00:00

commit 4d4cee96fb7a3cc53702a9be8299bf525be4ee98 upstream. Whenever we get an -EFAULT, we failed to read in guest 2 physical address space. Such addressing exceptions are reported via a program intercept to the nested hypervisor. We faked the intercept, we have to return to guest 2. Instead, right now we would be returning -EFAULT from the intercept handler, eventually crashing the VM. the correct thing to do is to return 1 as rc == 1 is the internal representation of "we have to go back into g2". Addressing exceptions can only happen if the g2->g3 page tables reference invalid g2 addresses (say, either a table or the final page is not accessible - so something that basically never happens in sane environments. Identified by manual code inspection. Fixes: a3508fbe9dc6 ("KVM: s390: vsie: initial support for nested virtualization") Cc: # v4.8+ Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20200403153050.20569-3-david@redhat.com Reviewed-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger [borntraeger@de.ibm.com: fix patch description] Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman

KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks

2020-04-17T14:12:06+00:00

commit a1d032a49522cb5368e5dfb945a85899b4c74f65 upstream. In case we have a region 1 the following calculation (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11) results in 64. As shifts beyond the size are undefined the compiler is free to use instructions like sllg. sllg will only use 6 bits of the shift value (here 64) resulting in no shift at all. That means that ALL addresses will be rejected. The can result in endless loops, e.g. when prefix cannot get mapped. Fixes: 4be130a08420 ("s390/mm: add shadow gmap support") Tested-by: Janosch Frank Reported-by: Janosch Frank Cc: # v4.8+ Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20200403153050.20569-2-david@redhat.com Reviewed-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger [borntraeger@de.ibm.com: fix patch description, remove WARN_ON_ONCE] Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman

s390: prevent leaking kernel address in BEAR

2020-04-13T11:16:33+00:00

commit 0b38b5e1d0e2f361e418e05c179db05bb688bbd6 upstream. When userspace executes a syscall or gets interrupted, BEAR contains a kernel address when returning to userspace. This make it pretty easy to figure out where the kernel is mapped even with KASLR enabled. To fix this, add lpswe to lowcore and always execute it there, so userspace sees only the lowcore address of lpswe. For this we have to extend both critical_cleanup and the SWITCH_ASYNC macro to also check for lpswe addresses in lowcore. Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)") Cc: # v5.2+ Reviewed-by: Gerald Schaefer Signed-off-by: Sven Schnelle Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/mm: fix panic in gup_fast on large pud

2020-03-12T06:18:35+00:00

commit 582b4e55403e053d8a48ff687a05174da9cc3fb0 upstream. On s390 there currently is no implementation of pud_write(). That was ok as long as we had our own implementation of get_user_pages_fast() which checked for pud protection by testing the bit directly w/o using pud_write(). The other callers of pud_write() are not reachable on s390. After commit 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast code") we use the generic get_user_pages_fast(), which does call pud_write() in pud_access_permitted() for FOLL_WRITE access on a large pud. Without an s390 specific pud_write(), the generic version is called, which contains a BUG() statement to remind us that we don't have a proper implementation. This results in a kernel panic. Fix this by providing an implementation of pud_write(). Cc: # 5.2+ Fixes: 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast code") Signed-off-by: Gerald Schaefer Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/pci: Fix unexpected write combine on resource

2020-03-12T06:18:35+00:00

commit df057c914a9c219ac8b8ed22caf7da2f80c1fe26 upstream. In the initial MIO support introduced in commit 71ba41c9b1d9 ("s390/pci: provide support for MIO instructions") zpci_map_resource() and zpci_setup_resources() default to using the mio_wb address as the resource's start address. This means users of the mapping, which includes most drivers, will get write combining on PCI Stores. This may lead to problems when drivers expect write through behavior when not using an explicit ioremap_wc(). Cc: stable@vger.kernel.org Fixes: 71ba41c9b1d9 ("s390/pci: provide support for MIO instructions") Signed-off-by: Niklas Schnelle Reviewed-by: Pierre Morel Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/qdio: fill SL with absolute addresses

2020-03-12T06:18:27+00:00

[ Upstream commit e9091ffd6a0aaced111b5d6ead5eaab5cd7101bc ] As the comment says, sl->sbal holds an absolute address. qeth currently solves this through wild casting, while zfcp doesn't care. Handle this properly in the code that actually builds the SL. Signed-off-by: Julian Wiedmann Reviewed-by: Alexandra Winter Reviewed-by: Steffen Maier [for qdio] Reviewed-by: Benjamin Block Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390: make 'install' not depend on vmlinux

2020-03-12T06:18:26+00:00

[ Upstream commit 94e90f727f7424d827256023cace829cad6896f4 ] For the same reason as commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux"), the install targets should never trigger the rebuild of the kernel. The variable, CONFIGURE, is not set by anyone. Remove it as well. Link: https://lkml.kernel.org/r/20200216144829.27023-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/mm: Explicitly compare PAGE_DEFAULT_KEY against zero in storage_key_init_range

2020-02-28T16:23:45+00:00

commit 380324734956c64cd060e1db4304f3117ac15809 upstream. Clang warns: In file included from ../arch/s390/purgatory/purgatory.c:10: In file included from ../include/linux/kexec.h:18: In file included from ../include/linux/crash_core.h:6: In file included from ../include/linux/elfcore.h:5: In file included from ../include/linux/user.h:1: In file included from ../arch/s390/include/asm/user.h:11: ../arch/s390/include/asm/page.h:45:6: warning: converting the result of '<<' to a boolean always evaluates to false [-Wtautological-constant-compare] if (PAGE_DEFAULT_KEY) ^ ../arch/s390/include/asm/page.h:23:44: note: expanded from macro 'PAGE_DEFAULT_KEY' #define PAGE_DEFAULT_KEY (PAGE_DEFAULT_ACC << 4) ^ 1 warning generated. Explicitly compare this against zero to silence the warning as it is intended to be used in a boolean context. Fixes: de3fa841e429 ("s390/mm: fix compile for PAGE_DEFAULT_KEY != 0") Link: https://github.com/ClangBuiltLinux/linux/issues/860 Link: https://lkml.kernel.org/r/20200214064207.10381-1-natechancellor@gmail.com Acked-by: Christian Borntraeger Signed-off-by: Nathan Chancellor Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/kaslr: Fix casts in get_random

2020-02-28T16:23:45+00:00

commit 788d671517b5c81efbed9310ccbadb8cca86a08e upstream. Clang warns: ../arch/s390/boot/kaslr.c:78:25: warning: passing 'char *' to parameter of type 'const u8 *' (aka 'const unsigned char *') converts between pointers to integer types with different sign [-Wpointer-sign] (char *) entropy, (char *) entropy, ^~~~~~~~~~~~~~~~ ../arch/s390/include/asm/cpacf.h:280:28: note: passing argument to parameter 'src' here u8 *dest, const u8 *src, long src_len) ^ 2 warnings generated. Fix the cast to match what else is done in this function. Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)") Link: https://github.com/ClangBuiltLinux/linux/issues/862 Link: https://lkml.kernel.org/r/20200208141052.48476-1-natechancellor@gmail.com Signed-off-by: Nathan Chancellor Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman