kernel.git/arch/s390/kernel/vdso.c, branch linux-4.14.y

s390/mm: tag normal pages vs pages used in page tables

2017-07-25T04:55:28Z

The ESSA instruction has a new option that allows to tag pages that are not used as a page table. Without the tag the hypervisor has to assume that any guest page could be used in a page table inside the guest. This forces the hypervisor to flush all guest TLB entries whenever a host page table entry is invalidated. With the tag the host can skip the TLB flush if the page is tagged as normal page. Signed-off-by: Martin Schwidefsky

s390/vdso: use _install_special_mapping to establish vdso

2017-06-12T14:25:57Z

Switch to the improved _install_special_mapping function to install the vdso mapping. This has two advantages, the arch_vma_name function is not needed anymore and the vdso vma still has its name after its memory location has been changed with mremap. Tested-by: Michael Holzheu Signed-off-by: Martin Schwidefsky

s390: kernel: Audit and remove any unnecessary uses of module.h

2017-02-17T06:40:31Z

Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each change instance for the presence of either and replace as needed. Build testing revealed some implicit header usage that was fixed up accordingly. Signed-off-by: Paul Gortmaker Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

vdso: make arch_setup_additional_pages wait for mmap_sem for write killable

2016-05-24T00:04:14Z

most architectures are relying on mmap_sem for write in their arch_setup_additional_pages. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by: Michal Hocko Acked-by: Andy Lutomirski [x86 vdso] Acked-by: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

s390/vdso: optimize getcpu system call

2016-01-11T12:01:24Z

Add the CPU number to the per-cpu vdso data page and add the __kernel_getcpu function to the vdso object to retrieve the CPU number in user space. Suggested-by: Heiko Carstens Reviewed-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: drop smp_mb in vdso_init

2016-01-11T11:27:22Z

The initial s390 vdso code is heavily influenced by the powerpc version which does have a smp_wmb in vdso_init right before the vdso_ready=1 assignment. s390 has no need for that. Signed-off-by: Michael S. Tsirkin Message-Id: <1452010645-25380-1-git-send-email-mst@redhat.com> Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky

s390: rename struct _lowcore to struct lowcore

2016-01-11T11:27:15Z

Finally get rid of the leading underscore. I tried this already two or three years ago, however Michael Holzheu objected since this would break the crash utility (again). However Michael integrated support for the new name into the crash utility back then, so it doesn't break if the name will be changed now. So finally get rid of the ever confusing leading underscore. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/vdso: use correct memory barrier

2015-10-14T12:32:01Z

By definition smp_wmb only orders writes against writes. (Finish all previous writes, and do not start any future write). To protect the vdso init code against early reads on other CPUs, let's use a full smp_mb at the end of vdso init. As right now smp_wmb is implemented as full serialization, this needs no stable backport, but this change will be necessary if we reimplement smp_wmb. Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky

s390: remove 31 bit support

2015-03-25T10:49:33Z

Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area

2014-08-08T22:57:27Z

The core mm code will provide a default gate area based on FIXADDR_USER_START and FIXADDR_USER_END if !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR). This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit UML, and x86_32 have their own code just to disable it. arm, 32-bit UML, and x86_64 have gate areas, but they have their own implementations. This gets rid of the default and moves the code into ia64. This should save some code on architectures without a gate area: it's now possible to inline the gate_area functions in the default case. Signed-off-by: Andy Lutomirski Acked-by: Nathan Lynch Acked-by: H. Peter Anvin Acked-by: Benjamin Herrenschmidt [in principle] Acked-by: Richard Weinberger [for um] Acked-by: Will Deacon [for arm64] Cc: Catalin Marinas Cc: Will Deacon Cc: Tony Luck Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chris Metcalf Cc: Jeff Dike Cc: Richard Weinberger Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Nathan Lynch Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds