talos-obmc-linux/arch/x86/kernel, branch dev-5.0

x86/build: Mark per-CPU symbols as absolute explicitly for LLD

2019-04-05T20:34:52+00:00

[ Upstream commit d071ae09a4a1414c1433d5ae9908959a7325b0ad ] Accessing per-CPU variables is done by finding the offset of the variable in the per-CPU block and adding it to the address of the respective CPU's block. Section 3.10.8 of ld.bfd's documentation states: For expressions involving numbers, relative addresses and absolute addresses, ld follows these rules to evaluate terms: Other binary operations, that is, between two relative addresses not in the same section, or between a relative address and an absolute address, first convert any non-absolute term to an absolute address before applying the operator." Note that LLVM's linker does not adhere to the GNU ld's implementation and as such requires implicitly-absolute terms to be explicitly marked as absolute in the linker script. If not, it fails currently with: ld.lld: error: ./arch/x86/kernel/vmlinux.lds:153: at least one side of the expression must be absolute ld.lld: error: ./arch/x86/kernel/vmlinux.lds:154: at least one side of the expression must be absolute Makefile:1040: recipe for target 'vmlinux' failed This is not a functional change for ld.bfd which converts the term to an absolute symbol anyways as specified above. Based on a previous submission by Tri Vo . Reported-by: Dmitry Golovin Signed-off-by: Rafael Ávila de Espíndola [ Update commit message per Boris' and Michael's suggestions. ] Signed-off-by: Nick Desaulniers [ Massage commit message more, fix typos. ] Signed-off-by: Borislav Petkov Tested-by: Dmitry Golovin Cc: "H. Peter Anvin" Cc: Andy Lutomirski Cc: Brijesh Singh Cc: Cao Jin Cc: Ingo Molnar Cc: Joerg Roedel Cc: Masahiro Yamada Cc: Masami Hiramatsu Cc: Thomas Gleixner Cc: Tri Vo Cc: dima@golovin.in Cc: morbo@google.com Cc: x86-ml Link: https://lkml.kernel.org/r/20181219190145.252035-1-ndesaulniers@google.com Signed-off-by: Sasha Levin

x86/kexec: Fill in acpi_rsdp_addr from the first kernel

2019-04-05T20:34:42+00:00

[ Upstream commit ccec81e4251f5a5421e02874e394338a897056ca ] When efi=noruntime or efi=oldmap is used on the kernel command line, EFI services won't be available in the second kernel, therefore the second kernel will not be able to get the ACPI RSDP address from firmware by calling EFI services and so it won't boot. Commit e6e094e053af ("x86/acpi, x86/boot: Take RSDP address from boot params if available") added an acpi_rsdp_addr field to boot_params which stores the RSDP address for other kernel users. Recently, after 3a63f70bf4c3 ("x86/boot: Early parse RSDP and save it in boot_params") the acpi_rsdp_addr will always be filled with a valid RSDP address. So fill in that value into the second kernel's boot_params thus ensuring that the second kernel receives the RSDP value from the first kernel. [ bp: massage commit message. ] Signed-off-by: Kairui Song Signed-off-by: Borislav Petkov Cc: AKASHI Takahiro Cc: Andrew Morton Cc: Baoquan He Cc: Chao Fan Cc: Dave Young Cc: David Howells Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: kexec@lists.infradead.org Cc: Philipp Rudo Cc: Thomas Gleixner Cc: x86-ml Cc: Yannik Sembritzki Link: https://lkml.kernel.org/r/20190204173852.4863-1-kasong@redhat.com Signed-off-by: Sasha Levin

x86/unwind: Add hardcoded ORC entry for NULL

2019-03-27T05:18:00+00:00

commit ac5ceccce5501e43d217c596e4ee859f2a3fef79 upstream. When the ORC unwinder is invoked for an oops caused by IP==0, it currently has no idea what to do because there is no debug information for the stack frame of NULL. But if RIP is NULL, it is very likely that the last successfully executed instruction was an indirect CALL/JMP, and it is possible to unwind out in the same way as for the first instruction of a normal function. Hardcode a corresponding ORC entry. With an artificially-added NULL call in prctl_set_seccomp(), before this patch, the trace is: Call Trace: ? __x64_sys_prctl+0x402/0x680 ? __ia32_sys_prctl+0x6e0/0x6e0 ? __do_page_fault+0x457/0x620 ? do_syscall_64+0x6d/0x160 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 After this patch, the trace looks like this: Call Trace: __x64_sys_prctl+0x402/0x680 ? __ia32_sys_prctl+0x6e0/0x6e0 ? __do_page_fault+0x457/0x620 do_syscall_64+0x6d/0x160 entry_SYSCALL_64_after_hwframe+0x44/0xa9 prctl_set_seccomp() still doesn't show up in the trace because for some reason, tail call optimization is only disabled in builds that use the frame pointer unwinder. Signed-off-by: Jann Horn Signed-off-by: Thomas Gleixner Acked-by: Josh Poimboeuf Cc: Borislav Petkov Cc: Andrew Morton Cc: syzbot Cc: "H. Peter Anvin" Cc: Masahiro Yamada Cc: Michal Marek Cc: linux-kbuild@vger.kernel.org Link: https://lkml.kernel.org/r/20190301031201.7416-2-jannh@google.com Signed-off-by: Greg Kroah-Hartman

x86/unwind: Handle NULL pointer calls better in frame unwinder

2019-03-27T05:17:59+00:00

commit f4f34e1b82eb4219d8eaa1c7e2e17ca219a6a2b5 upstream. When the frame unwinder is invoked for an oops caused by a call to NULL, it currently skips the parent function because BP still points to the parent's stack frame; the (nonexistent) current function only has the first half of a stack frame, and BP doesn't point to it yet. Add a special case for IP==0 that calculates a fake BP from SP, then uses the real BP for the next frame. Note that this handles first_frame specially: Return information about the parent function as long as the saved IP is >=first_frame, even if the fake BP points below it. With an artificially-added NULL call in prctl_set_seccomp(), before this patch, the trace is: Call Trace: ? prctl_set_seccomp+0x3a/0x50 __x64_sys_prctl+0x457/0x6f0 ? __ia32_sys_prctl+0x750/0x750 do_syscall_64+0x72/0x160 entry_SYSCALL_64_after_hwframe+0x44/0xa9 After this patch, the trace is: Call Trace: prctl_set_seccomp+0x3a/0x50 __x64_sys_prctl+0x457/0x6f0 ? __ia32_sys_prctl+0x750/0x750 do_syscall_64+0x72/0x160 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Jann Horn Signed-off-by: Thomas Gleixner Acked-by: Josh Poimboeuf Cc: Borislav Petkov Cc: Andrew Morton Cc: syzbot Cc: "H. Peter Anvin" Cc: Masahiro Yamada Cc: Michal Marek Cc: linux-kbuild@vger.kernel.org Link: https://lkml.kernel.org/r/20190301031201.7416-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman

x86/ftrace: Fix warning and considate ftrace_jmp_replace() and ftrace_call_replace()

2019-03-23T19:11:38+00:00

commit 745cfeaac09ce359130a5451d90cb0bd4094c290 upstream. Arnd reported the following compiler warning: arch/x86/kernel/ftrace.c:669:23: error: 'ftrace_jmp_replace' defined but not used [-Werror=unused-function] The ftrace_jmp_replace() function now only has a single user and should be simply moved by that user. But looking at the code, it shows that ftrace_jmp_replace() is similar to ftrace_call_replace() except that instead of using the opcode of 0xe8 it uses 0xe9. It makes more sense to consolidate that function into one implementation that both ftrace_jmp_replace() and ftrace_call_replace() use by passing in the op code separate. The structure in ftrace_code_union is also modified to replace the "e8" field with the more appropriate name "op". Cc: stable@vger.kernel.org Reported-by: Arnd Bergmann Acked-by: Arnd Bergmann Link: http://lkml.kernel.org/r/20190304200748.1418790-1-arnd@arndb.de Fixes: d2a68c4effd8 ("x86/ftrace: Do not call function graph from dynamic trampolines") Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

x86/kvmclock: set offset for kvm unstable clock

2019-03-23T19:11:38+00:00

commit b5179ec4187251a751832193693d6e474d3445ac upstream. VMs may show incorrect uptime and dmesg printk offsets on hypervisors with unstable clock. The problem is produced when VM is rebooted without exiting from qemu. The fix is to calculate clock offset not only for stable clock but for unstable clock as well, and use kvm_sched_clock_read() which substracts the offset for both clocks. This is safe, because pvclock_clocksource_read() does the right thing and makes sure that clock always goes forward, so once offset is calculated with unstable clock, we won't get new reads that are smaller than offset, and thus won't get negative results. Thank you Jon DeVree for helping to reproduce this issue. Fixes: 857baa87b642 ("sched/clock: Enable sched clock early") Cc: stable@vger.kernel.org Reported-by: Dominique Martinet Signed-off-by: Pavel Tatashin Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

x86/kprobes: Prohibit probing on optprobe template code

2019-03-23T19:11:23+00:00

commit 0192e6535ebe9af68614198ced4fd6d37b778ebf upstream. Prohibit probing on optprobe template code, since it is not a code but a template instruction sequence. If we modify this template, copied template must be broken. Signed-off-by: Masami Hiramatsu Cc: Alexander Shishkin Cc: Andrea Righi Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: 9326638cbee2 ("kprobes, x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation") Link: http://lkml.kernel.org/r/154998787911.31052.15274376330136234452.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86/CPU/AMD: Set the CPB bit unconditionally on F17h

2019-03-10T06:09:00+00:00

commit 0237199186e7a4aa5310741f0a6498a20c820fd7 upstream. Some F17h models do not have CPB set in CPUID even though the CPU supports it. Set the feature bit unconditionally on all F17h. [ bp: Rewrite commit message and patch. ] Signed-off-by: Jiaxun Yang Signed-off-by: Borislav Petkov Acked-by: Tom Lendacky Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Sherry Hurwitz Cc: Suravee Suthikulpanit Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20181120030018.5185-1-jiaxun.yang@flygoat.com Signed-off-by: Greg Kroah-Hartman

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-02-10T17:57:42+00:00

Pull x86 fixes from Ingo Molnar: "A handful of fixes: - Fix an MCE corner case bug/crash found via MCE injection testing - Fix 5-level paging boot crash - Fix MCE recovery cache invalidation bug - Fix regression on Xen guests caused by a recent PMD level mremap speedup optimization" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Make set_pmd_at() paravirt aware x86/mm/cpa: Fix set_mce_nospec() x86/boot/compressed/64: Do not corrupt EDX on EFER.LME=1 setting x86/MCE: Initialize mce.bank in the case of a fatal error in mce_no_way_out()

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-02-03T17:08:12+00:00

Pull x86 fixes from Thomas Gleixner: "A few updates for x86: - Fix an unintended sign extension issue in the fault handling code - Rename the new resource control config switch so it's less confusing - Avoid setting up EFI info in kexec when the EFI runtime is disabled. - Fix the microcode version check in the AMD microcode loader so it only loads higher version numbers and never downgrades - Set EFER.LME in the 32bit trampoline before returning to long mode to handle older AMD/KVM behaviour properly. - Add Darren and Andy as x86/platform reviewers" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/resctrl: Avoid confusion over the new X86_RESCTRL config x86/kexec: Don't setup EFI info if EFI runtime is not enabled x86/microcode/amd: Don't falsely trick the late loading mechanism MAINTAINERS: Add Andy and Darren as arch/x86/platform/ reviewers x86/fault: Fix sign-extend unintended sign extension x86/boot/compressed/64: Set EFER.LME=1 in 32-bit trampoline before returning to long mode x86/cpu: Add Atom Tremont (Jacobsville)