user/sven/linux.git/arch/powerpc/kernel, branch v4.18.8

powerpc/64s: Make rfi_flush_fallback a little more robust

2018-09-15T07:46:54Z

[ Upstream commit 78ee9946371f5848ddfc88ab1a43867df8f17d83 ] Because rfi_flush_fallback runs immediately before the return to userspace it currently runs with the user r1 (stack pointer). This means if we oops in there we will report a bad kernel stack pointer in the exception entry path, eg: Bad kernel stack pointer 7ffff7150e40 at c0000000000023b4 Oops: Bad kernel stack pointer, sig: 6 [#1] LE SMP NR_CPUS=32 NUMA PowerNV Modules linked in: CPU: 0 PID: 1246 Comm: klogd Not tainted 4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3 #7 NIP: c0000000000023b4 LR: 0000000010053e00 CTR: 0000000000000040 REGS: c0000000fffe7d40 TRAP: 4100 Not tainted (4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3) MSR: 9000000002803031 CR: 44000442 XER: 20000000 CFAR: c00000000000bac8 IRQMASK: c0000000f1e66a80 GPR00: 0000000002000000 00007ffff7150e40 00007fff93a99900 0000000000000020 ... NIP [c0000000000023b4] rfi_flush_fallback+0x34/0x80 LR [0000000010053e00] 0x10053e00 Although the NIP tells us where we were, and the TRAP number tells us what happened, it would still be nicer if we could report the actual exception rather than barfing about the stack pointer. We an do that fairly simply by loading the kernel stack pointer on entry and restoring the user value before returning. That way we see a regular oops such as: Unrecoverable exception 4100 at c00000000000239c Oops: Unrecoverable exception, sig: 6 [#1] LE SMP NR_CPUS=32 NUMA PowerNV Modules linked in: CPU: 0 PID: 1251 Comm: klogd Not tainted 4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty #40 NIP: c00000000000239c LR: 0000000010053e00 CTR: 0000000000000040 REGS: c0000000f1e17bb0 TRAP: 4100 Not tainted (4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty) MSR: 9000000002803031 CR: 44000442 XER: 20000000 CFAR: c00000000000bac8 IRQMASK: 0 ... NIP [c00000000000239c] rfi_flush_fallback+0x3c/0x80 LR [0000000010053e00] 0x10053e00 Call Trace: [c0000000f1e17e30] [c00000000000b9e4] system_call+0x5c/0x70 (unreliable) Note this shouldn't make the kernel stack pointer vulnerable to a meltdown attack, because it should be flushed from the cache before we return to userspace. The user r1 value will be in the cache, because we load it in the return path, but that is harmless. Signed-off-by: Michael Ellerman Reviewed-by: Nicholas Piggin Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/topology: Get topology for shared processors at boot

2018-09-15T07:46:47Z

[ Upstream commit 2ea62630681027c455117aa471ea3ab8bb099ead ] On a shared LPAR, Phyp will not update the CPU associativity at boot time. Just after the boot system does recognize itself as a shared LPAR and trigger a request for correct CPU associativity. But by then the scheduler would have already created/destroyed its sched domains. This causes - Broken load balance across Nodes causing islands of cores. - Performance degradation esp if the system is lightly loaded - dmesg to wrongly report all CPUs to be in Node 0. - Messages in dmesg saying borken topology. - With commit 051f3ca02e46 ("sched/topology: Introduce NUMA identity node sched domain"), can cause rcu stalls at boot up. The sched_domains_numa_masks table which is used to generate cpumasks is only created at boot time just before creating sched domains and never updated. Hence, its better to get the topology correct before the sched domains are created. For example on 64 core Power 8 shared LPAR, dmesg reports Brought up 512 CPUs Node 0 CPUs: 0-511 Node 1 CPUs: Node 2 CPUs: Node 3 CPUs: Node 4 CPUs: Node 5 CPUs: Node 6 CPUs: Node 7 CPUs: Node 8 CPUs: Node 9 CPUs: Node 10 CPUs: Node 11 CPUs: ... BUG: arch topology borken the DIE domain not a subset of the NUMA domain BUG: arch topology borken the DIE domain not a subset of the NUMA domain numactl/lscpu output will still be correct with cores spreading across all nodes: Socket(s): 64 NUMA node(s): 12 Model: 2.0 (pvr 004d 0200) Model name: POWER8 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 64K L1i cache: 32K NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,176-183,272-279,368-375,464-471 NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,184-191,280-287,376-383,472-479 NUMA node2 CPU(s): 16-23,48-55,80-87,112-119,192-199,288-295,384-391,480-487 NUMA node3 CPU(s): 24-31,56-63,88-95,120-127,200-207,296-303,392-399,488-495 NUMA node4 CPU(s): 208-215,304-311,400-407,496-503 NUMA node5 CPU(s): 168-175,264-271,360-367,456-463 NUMA node6 CPU(s): 128-135,224-231,320-327,416-423 NUMA node7 CPU(s): 136-143,232-239,328-335,424-431 NUMA node8 CPU(s): 216-223,312-319,408-415,504-511 NUMA node9 CPU(s): 144-151,240-247,336-343,432-439 NUMA node10 CPU(s): 152-159,248-255,344-351,440-447 NUMA node11 CPU(s): 160-167,256-263,352-359,448-455 Currently on this LPAR, the scheduler detects 2 levels of Numa and created numa sched domains for all CPUs, but it finds a single DIE domain consisting of all CPUs. Hence it deletes all numa sched domains. To address this, detect the shared processor and update topology soon after CPUs are setup so that correct topology is updated just before scheduler creates sched domain. With the fix, dmesg reports: numa: Node 0 CPUs: 0-7 32-39 64-71 96-103 176-183 272-279 368-375 464-471 numa: Node 1 CPUs: 8-15 40-47 72-79 104-111 184-191 280-287 376-383 472-479 numa: Node 2 CPUs: 16-23 48-55 80-87 112-119 192-199 288-295 384-391 480-487 numa: Node 3 CPUs: 24-31 56-63 88-95 120-127 200-207 296-303 392-399 488-495 numa: Node 4 CPUs: 208-215 304-311 400-407 496-503 numa: Node 5 CPUs: 168-175 264-271 360-367 456-463 numa: Node 6 CPUs: 128-135 224-231 320-327 416-423 numa: Node 7 CPUs: 136-143 232-239 328-335 424-431 numa: Node 8 CPUs: 216-223 312-319 408-415 504-511 numa: Node 9 CPUs: 144-151 240-247 336-343 432-439 numa: Node 10 CPUs: 152-159 248-255 344-351 440-447 numa: Node 11 CPUs: 160-167 256-263 352-359 448-455 and lscpu also reports: Socket(s): 64 NUMA node(s): 12 Model: 2.0 (pvr 004d 0200) Model name: POWER8 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 64K L1i cache: 32K NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,176-183,272-279,368-375,464-471 NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,184-191,280-287,376-383,472-479 NUMA node2 CPU(s): 16-23,48-55,80-87,112-119,192-199,288-295,384-391,480-487 NUMA node3 CPU(s): 24-31,56-63,88-95,120-127,200-207,296-303,392-399,488-495 NUMA node4 CPU(s): 208-215,304-311,400-407,496-503 NUMA node5 CPU(s): 168-175,264-271,360-367,456-463 NUMA node6 CPU(s): 128-135,224-231,320-327,416-423 NUMA node7 CPU(s): 136-143,232-239,328-335,424-431 NUMA node8 CPU(s): 216-223,312-319,408-415,504-511 NUMA node9 CPU(s): 144-151,240-247,336-343,432-439 NUMA node10 CPU(s): 152-159,248-255,344-351,440-447 NUMA node11 CPU(s): 160-167,256-263,352-359,448-455 Reported-by: Manjunatha H R Signed-off-by: Srikar Dronamraju [mpe: Trim / format change log] Tested-by: Michael Ellerman Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/pkeys: Save the pkey registers before fork

2018-09-09T08:32:31Z

commit c76662e825f507b98938dc3bb141c4505bd4968c upstream. When a thread forks the contents of AMR, IAMR, UAMOR registers in the newly forked thread are not inherited. Save the registers before forking, for content of those registers to be automatically copied into the new thread. Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/fadump: handle crash memory ranges array index overflow

2018-09-09T08:32:30Z

commit 1bd6a1c4b80a28d975287630644e6b47d0f977a5 upstream. Crash memory ranges is an array of memory ranges of the crashing kernel to be exported as a dump via /proc/vmcore file. The size of the array is set based on INIT_MEMBLOCK_REGIONS, which works alright in most cases where memblock memory regions count is less than INIT_MEMBLOCK_REGIONS value. But this count can grow beyond INIT_MEMBLOCK_REGIONS value since commit 142b45a72e22 ("memblock: Add array resizing support"). On large memory systems with a few DLPAR operations, the memblock memory regions count could be larger than INIT_MEMBLOCK_REGIONS value. On such systems, registering fadump results in crash or other system failures like below: task: c00007f39a290010 ti: c00000000b738000 task.ti: c00000000b738000 NIP: c000000000047df4 LR: c0000000000f9e58 CTR: c00000000010f180 REGS: c00000000b73b570 TRAP: 0300 Tainted: G L X (4.4.140+) MSR: 8000000000009033 CR: 22004484 XER: 20000000 CFAR: c000000000008500 DAR: 000007a450000000 DSISR: 40000000 SOFTE: 0 ... NIP [c000000000047df4] smp_send_reschedule+0x24/0x80 LR [c0000000000f9e58] resched_curr+0x138/0x160 Call Trace: resched_curr+0x138/0x160 (unreliable) check_preempt_curr+0xc8/0xf0 ttwu_do_wakeup+0x38/0x150 try_to_wake_up+0x224/0x4d0 __wake_up_common+0x94/0x100 ep_poll_callback+0xac/0x1c0 __wake_up_common+0x94/0x100 __wake_up_sync_key+0x70/0xa0 sock_def_readable+0x58/0xa0 unix_stream_sendmsg+0x2dc/0x4c0 sock_sendmsg+0x68/0xa0 ___sys_sendmsg+0x2cc/0x2e0 __sys_sendmsg+0x5c/0xc0 SyS_socketcall+0x36c/0x3f0 system_call+0x3c/0x100 as array index overflow is not checked for while setting up crash memory ranges causing memory corruption. To resolve this issue, dynamically allocate memory for crash memory ranges and resize it incrementally, in units of pagesize, on hitting array size limit. Fixes: 2df173d9e85d ("fadump: Initialize elfcore header and add PT_LOAD program headers.") Cc: stable@vger.kernel.org # v3.4+ Signed-off-by: Hari Bathini Reviewed-by: Mahesh Salgaonkar [mpe: Just use PAGE_SIZE directly, fixup variable placement] Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc64s: Show ori31 availability in spectre_v1 sysfs file not v2

2018-08-24T11:04:49Z

commit 6d44acae1937b81cf8115ada8958e04f601f3f2e upstream. When I added the spectre_v2 information in sysfs, I included the availability of the ori31 speculation barrier. Although the ori31 barrier can be used to mitigate v2, it's primarily intended as a spectre v1 mitigation. Spectre v2 is mitigated by hardware changes. So rework the sysfs files to show the ori31 information in the spectre_v1 file, rather than v2. Currently we display eg: $ grep . spectre_v* spectre_v1:Mitigation: __user pointer sanitization spectre_v2:Mitigation: Indirect branch cache disabled, ori31 speculation barrier enabled After: $ grep . spectre_v* spectre_v1:Mitigation: __user pointer sanitization, ori31 speculation barrier enabled spectre_v2:Mitigation: Indirect branch cache disabled Fixes: d6fbe1c55c55 ("powerpc/64s: Wire up cpu_show_spectre_v2()") Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

Merge tag 'pci-v4.18-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2018-08-02T17:59:19Z

Pull PCI fixes from Bjorn Helgaas: - Fix integer overflow in new mobiveil driver (Dan Carpenter) - Fix race during NVMe removal/rescan (Hari Vyas) * tag 'pci-v4.18-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: PCI: Fix is_added/is_busmaster race condition PCI: mobiveil: Avoid integer overflow in IB_WIN_SIZE

PCI: Fix is_added/is_busmaster race condition

2018-07-31T16:27:54Z

When a PCI device is detected, pdev->is_added is set to 1 and proc and sysfs entries are created. When the device is removed, pdev->is_added is checked for one and then device is detached with clearing of proc and sys entries and at end, pdev->is_added is set to 0. is_added and is_busmaster are bit fields in pci_dev structure sharing same memory location. A strange issue was observed with multiple removal and rescan of a PCIe NVMe device using sysfs commands where is_added flag was observed as zero instead of one while removing device and proc,sys entries are not cleared. This causes issue in later device addition with warning message "proc_dir_entry" already registered. Debugging revealed a race condition between the PCI core setting the is_added bit in pci_bus_add_device() and the NVMe driver reset work-queue setting the is_busmaster bit in pci_set_master(). As these fields are not handled atomically, that clears the is_added bit. Move the is_added bit to a separate private flag variable and use atomic functions to set and retrieve the device addition state. This avoids the race because is_added no longer shares a memory location with is_busmaster. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200283 Signed-off-by: Hari Vyas Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Acked-by: Michael Ellerman

powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle)

2018-07-18T10:40:17Z

On 64-bit servers, SPRN_SPRG3 and its userspace read-only mirror SPRN_USPRG3 are used as userspace VDSO write and read registers respectively. SPRN_SPRG3 is lost when we enter stop4 and above, and is currently not restored. As a result, any read from SPRN_USPRG3 returns zero on an exit from stop4 (Power9 only) and above. Thus in this situation, on POWER9, any call from sched_getcpu() always returns zero, as on powerpc, we call __kernel_getcpu() which relies upon SPRN_USPRG3 to report the CPU and NUMA node information. Fix this by restoring SPRN_SPRG3 on wake up from a deep stop state with the sprg_vdso value that is cached in PACA. Fixes: e1c1cfed5432 ("powerpc/powernv: Save/Restore additional SPRs for stop4 cpuidle") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Florian Weimer Signed-off-by: Gautham R. Shenoy Reviewed-by: Michael Ellerman Signed-off-by: Michael Ellerman

Merge tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2018-06-30T20:05:30Z

Pull Kbuild fixes from Masahiro Yamada: - introduce __diag_* macros and suppress -Wattribute-alias warnings from GCC 8 - fix stack protector test script for x86_64 - fix line number handling in Kconfig - document that '#' starts a comment in Kconfig - handle P_SYMBOL property in dump debugging of Kconfig - correct help message of LD_DEAD_CODE_DATA_ELIMINATION - fix occasional segmentation faults in Kconfig * tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: loop boundary condition fix kbuild: reword help of LD_DEAD_CODE_DATA_ELIMINATION kconfig: handle P_SYMBOL in print_symbol() kconfig: document Kconfig source file comments kconfig: fix line numbers for if-entries in menu tree stack-protector: Fix test with 32-bit userland and CONFIG_64BIT=y powerpc: Remove -Wattribute-alias pragmas disable -Wattribute-alias warning for SYSCALL_DEFINEx() kbuild: add macro for controlling warnings to linux/compiler.h

powerpc: Remove -Wattribute-alias pragmas

2018-06-25T14:21:13Z

With SYSCALL_DEFINEx() disabling -Wattribute-alias generically, there's no need to duplicate that for PowerPC syscalls. This reverts commit 415520373975 ("powerpc: fix build failure by disabling attribute-alias warning in pci_32") and commit 2479bfc9bc60 ("powerpc: Fix build by disabling attribute-alias warning for SYSCALL_DEFINEx"). Signed-off-by: Paul Burton Acked-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Masahiro Yamada