user/sven/linux.git, branch v4.18.16

Linux 4.18.16

2018-10-20T07:47:10Z

ARC: build: Don't set CROSS_COMPILE in arch's Makefile

2018-10-20T07:47:10Z

commit 40660f1fcee8d524a60b5101538e42b1f39f106d upstream. There's not much sense in doing that because if user or his build-system didn't set CROSS_COMPILE we still may very well make incorrect guess. But as it turned out setting CROSS_COMPILE is not as harmless as one may think: with recent changes that implemented automatic discovery of __host__ gcc features unconditional setup of CROSS_COMPILE leads to failures on execution of "make xxx_defconfig" with absent cross-compiler, for more info see [1]. Set CROSS_COMPILE as well gets in the way if we want only to build .dtb's (again with absent cross-compiler which is not really needed for building .dtb's), see [2]. Note, we had to change LIBGCC assignment type from ":=" to "=" so that is is resolved on its usage, otherwise if it is resolved at declaration time with missing CROSS_COMPILE we're getting this error message from host GCC: | gcc: error: unrecognized command line option -mmedium-calls | gcc: error: unrecognized command line option -mno-sdata [1] http://lists.infradead.org/pipermail/linux-snps-arc/2018-September/004308.html [2] http://lists.infradead.org/pipermail/linux-snps-arc/2018-September/004320.html Signed-off-by: Alexey Brodkin Cc: Masahiro Yamada Cc: Rob Herring Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman

ARC: build: Get rid of toolchain check

2018-10-20T07:47:10Z

commit 615f64458ad890ef94abc879a66d8b27236e733a upstream. This check is very naive: we simply test if GCC invoked without "-mcpu=XXX" has ARC700 define set. In that case we think that GCC was built with "--with-cpu=arc700" and has libgcc built for ARC700. Otherwise if ARC700 is not defined we think that everythng was built for ARCv2. But in reality our life is much more interesting. 1. Regardless of GCC configuration (i.e. what we pass in "--with-cpu" it may generate code for any ARC core). 2. libgcc might be built with explicitly specified "--mcpu=YYY" That's exactly what happens in case of multilibbed toolchains: - GCC is configured with default settings - All the libs built for many different CPU flavors I.e. that check gets in the way of usage of multilibbed toolchains. And even non-multilibbed toolchains are affected. OpenEmbedded also builds GCC without "--with-cpu" because each and every target component later is compiled with explicitly set "-mcpu=ZZZ". Acked-by: Rob Herring Signed-off-by: Alexey Brodkin Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman

mremap: properly flush TLB before releasing the page

2018-10-20T07:47:09Z

commit eb66ae030829605d61fbef1909ce310e29f78821 upstream. Jann Horn points out that our TLB flushing was subtly wrong for the mremap() case. What makes mremap() special is that we don't follow the usual "add page to list of pages to be freed, then flush tlb, and then free pages". No, mremap() obviously just _moves_ the page from one page table location to another. That matters, because mremap() thus doesn't directly control the lifetime of the moved page with a freelist: instead, the lifetime of the page is controlled by the page table locking, that serializes access to the entry. As a result, we need to flush the TLB not just before releasing the lock for the source location (to avoid any concurrent accesses to the entry), but also before we release the destination page table lock (to avoid the TLB being flushed after somebody else has already done something to that page). This also makes the whole "need_flush" logic unnecessary, since we now always end up flushing the TLB for every valid entry. Reported-and-tested-by: Jann Horn Acked-by: Will Deacon Tested-by: Ingo Molnar Acked-by: Peter Zijlstra (Intel) Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Revert "vfs: fix freeze protection in mnt_want_write_file() for overlayfs"

2018-10-20T07:47:09Z

This reverts commit 5e1002ab5c9bde81a0c1eed12f243987e98f7bd0 which was commit a6795a585929d94ca3e931bc8518f8deb8bbe627 upstream. Turns out this causes problems and was to fix a patch only in the 4.19 and newer tree. Reported-by: Amir Goldstein Cc: Miklos Szeredi Cc: Christoph Hellwig Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

x86/boot: Fix kexec booting failure in the SEV bit detection code

2018-10-20T07:47:09Z

[ Upstream commit bdec8d7fa55e6f5314ed72e5a0b435d90ff90548 ] Commit 1958b5fc4010 ("x86/boot: Add early boot support when running with SEV active") can occasionally cause system resets when kexec-ing a second kernel even if SEV is not active. That's because get_sev_encryption_bit() uses 32-bit rIP-relative addressing to read the value of enc_bit - a variable which caches a previously detected encryption bit position - but kexec may allocate the early boot code to a higher location, beyond the 32-bit addressing limit. In this case, garbage will be read and get_sev_encryption_bit() will return the wrong value, leading to accessing memory with the wrong encryption setting. Therefore, remove enc_bit, and thus get rid of the need to do 32-bit rIP-relative addressing in the first place. [ bp: massage commit message heavily. ] Fixes: 1958b5fc4010 ("x86/boot: Add early boot support when running with SEV active") Suggested-by: Borislav Petkov Signed-off-by: Kairui Song Signed-off-by: Borislav Petkov Reviewed-by: Tom Lendacky Cc: linux-kernel@vger.kernel.org Cc: tglx@linutronix.de Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: brijesh.singh@amd.com Cc: kexec@lists.infradead.org Cc: dyoung@redhat.com Cc: bhe@redhat.com Cc: ghook@redhat.com Link: https://lkml.kernel.org/r/20180927123845.32052-1-kasong@redhat.com Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

iommu/amd: Return devid as alias for ACPI HID devices

2018-10-20T07:47:09Z

[ Upstream commit 5ebb1bc2d63d90dd204169e21fd7a0b4bb8c776e ] ACPI HID devices do not actually have an alias for them in the IVRS. But dev_data->alias is still used for indexing into the IOMMU device table for devices being handled by the IOMMU. So for ACPI HID devices, we simply return the corresponding devid as an alias, as parsed from IVRS table. Signed-off-by: Arindam Nath Fixes: 2bf9a0a12749 ('iommu/amd: Add iommu support for ACPI HID devices') Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/numa: Use associativity if VPHN hcall is successful

2018-10-20T07:47:09Z

[ Upstream commit 2483ef056f6e42f61cd266452e2841165dfe1b5c ] Currently associativity is used to lookup node-id even if the preceding VPHN hcall failed. However this can cause CPU to be made part of the wrong node, (most likely to be node 0). This is because VPHN is not enabled on KVM guests. With 2ea6263 ("powerpc/topology: Get topology for shared processors at boot"), associativity is used to set to the wrong node. Hence KVM guest topology is broken. For example : A 4 node KVM guest before would have reported. [root@localhost ~]# numactl -H available: 4 nodes (0-3) node 0 cpus: 0 1 2 3 node 0 size: 1746 MB node 0 free: 1604 MB node 1 cpus: 4 5 6 7 node 1 size: 2044 MB node 1 free: 1765 MB node 2 cpus: 8 9 10 11 node 2 size: 2044 MB node 2 free: 1837 MB node 3 cpus: 12 13 14 15 node 3 size: 2044 MB node 3 free: 1903 MB node distances: node 0 1 2 3 0: 10 40 40 40 1: 40 10 40 40 2: 40 40 10 40 3: 40 40 40 10 Would now report: [root@localhost ~]# numactl -H available: 4 nodes (0-3) node 0 cpus: 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 node 0 size: 1746 MB node 0 free: 1244 MB node 1 cpus: node 1 size: 2044 MB node 1 free: 2032 MB node 2 cpus: 1 node 2 size: 2044 MB node 2 free: 2028 MB node 3 cpus: node 3 size: 2044 MB node 3 free: 2032 MB node distances: node 0 1 2 3 0: 10 40 40 40 1: 40 10 40 40 2: 40 40 10 40 3: 40 40 40 10 Fix this by skipping associativity lookup if the VPHN hcall failed. Fixes: 2ea626306810 ("powerpc/topology: Get topology for shared processors at boot") Signed-off-by: Srikar Dronamraju Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Avoid possible userspace r1 corruption on reclaim

2018-10-20T07:47:09Z

[ Upstream commit 96dc89d526ef77604376f06220e3d2931a0bfd58 ] Current we store the userspace r1 to PACATMSCRATCH before finally saving it to the thread struct. In theory an exception could be taken here (like a machine check or SLB miss) that could write PACATMSCRATCH and hence corrupt the userspace r1. The SLB fault currently doesn't touch PACATMSCRATCH, but others do. We've never actually seen this happen but it's theoretically possible. Either way, the code is fragile as it is. This patch saves r1 to the kernel stack (which can't fault) before we turn MSR[RI] back on. PACATMSCRATCH is still used but only with MSR[RI] off. We then copy r1 from the kernel stack to the thread struct once we have MSR[RI] back on. Suggested-by: Breno Leitao Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Fix userspace r13 corruption

2018-10-20T07:47:09Z

[ Upstream commit cf13435b730a502e814c63c84d93db131e563f5f ] When we treclaim we store the userspace checkpointed r13 to a scratch SPR and then later save the scratch SPR to the user thread struct. Unfortunately, this doesn't work as accessing the user thread struct can take an SLB fault and the SLB fault handler will write the same scratch SPRG that now contains the userspace r13. To fix this, we store r13 to the kernel stack (which can't fault) before we access the user thread struct. Found by running P8 guest + powervm + disable_1tb_segments + TM. Seen as a random userspace segfault with r13 looking like a kernel address. Signed-off-by: Michael Neuling Reviewed-by: Breno Leitao Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman