Pull x86 linker bug workarounds from Peter Anvin. GNU ld-2.22.52.0.[12] (*) has an unfortunate bug where it incorrectly turns certain relocation entries absolute. Section-relative symbols that are part of otherwise empty sections are silently changed them to absolute. We rely on section-relative symbols staying section-relative, and actually have several sections in the linker script solely for this purpose. See for example http://sourceware.org/bugzilla/show_bug.cgi?id=14052 We could just black-list the buggy linker, but it appears that it got shipped in at least F17, and possibly other distros too, so it's sadly not some rare unusual case. This backports the workaround from the x86/trampoline branch, and as Peter says: "This is not a minimal fix, not at all, but it is a tested code base." * 'x86/ld-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, relocs: When printing an error, say relative or absolute x86, relocs: Workaround for binutils 2.22.52.0.1 section bug x86, realmode: 16-bit real-mode code support for relocs tool (*) That's a manly release numbering system. Stupid, sure. But manly.
When the relocs tool throws an error, let the error message say if it is an absolute or relative symbol. This should make it a lot more clear what action the programmer needs to take and should help us find the reason if additional symbol bugs show up. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: <stable@vger.kernel.org>
GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from section-relative to absolute if they are in a section of zero length. This turns the symbols __init_begin and __init_end into absolute symbols. Let the relocs program know that those should be treated as relative symbols. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: <stable@vger.kernel.org> Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
A new option is added to the relocs tool called '--realmode'. This option causes the generation of 16-bit segment relocations and 32-bit linear relocations for the real-mode code. When the real-mode code is moved to the low-memory during kernel initialization, these relocation entries can be used to relocate the code properly. In the assembly code 16-bit segment relocations must be relative to the 'real_mode_seg' absolute symbol. Linear relocations must be relative to a symbol prefixed with 'pa_'. 16-bit segment relocation is used to load cs:ip in 16-bit code. Linear relocations are used in the 32-bit code for relocatable data references. They are declared in the linker script of the real-mode code. The relocs tool is moved to arch/x86/tools/relocs.c, and added new target archscripts that can be used to build scripts needed building an architecture. be compiled before building the arch/x86 tree. [ hpa: accelerating this because it detects invalid absolute relocations, a serious bug in binutils 2.22.52.0.x which currently produces bad kernels. ] Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org>
Pull a machine check recovery fix from Tony Luck. I really don't like how the MCE code does some of the things it does, but this does seem to be an improvement. * tag 'linus-mce-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: x86/mce: Only restart instruction after machine check recovery if it is safe
Pull perf, x86 and scheduler updates from Ingo Molnar. * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tracing: Do not enable function event with enable perf stat: handle ENXIO error for perf_event_open perf: Turn off compiler warnings for flex and bison generated files perf stat: Fix case where guest/host monitoring is not supported by kernel perf build-id: Fix filename size calculation * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, kvm: KVM paravirt kernels don't check for CPUID being unavailable x86: Fix section annotation of acpi_map_cpu2node() x86/microcode: Ensure that module is only loaded on supported Intel CPUs * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix KVM and ia64 boot crash due to sched_groups circular linked list assumption
Section 15.3.1.2 of the software developer manual has this to say about the RIPV bit in the IA32_MCG_STATUS register: RIPV (restart IP valid) flag, bit 0 — Indicates (when set) that program execution can be restarted reliably at the instruction pointed to by the instruction pointer pushed on the stack when the machine-check exception is generated. When clear, the program cannot be reliably restarted at the pushed instruction pointer. We need to save the state of this bit in do_machine_check() and use it in mce_notify_process() to force a signal; even if memory_failure() says it made a complete recovery ... e.g. replaced a clean LRU page. Acked-by: Borislav Petkov <bp@amd64.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
We set cpuid_level to -1 if there is no CPUID instruction (only possible on i386). Signed-off-by: Alan Cox <alan@linux.intel.com> Link: http://lkml.kernel.org/r/20120514174059.30236.1064.stgit@bluebook Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=12122 Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull KVM fixes from Avi Kivity: "Two asynchronous page fault fixes (one guest, one host), a powerpc page refcount fix, and an ia64 build fix." * git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: ia64: fix build due to typo KVM: PPC: Book3S HV: Fix refcounting of hugepages KVM: Do not take reference to mm during async #PF KVM: ensure async PF event wakes up vcpu from halt
Pull xen fixes from Konrad Rzeszutek Wilk: - fix to Kconfig to make it fit within 80 line characters, - two bootup fixes (AMD 8-core and with PCI BIOS), - cleanup code in a Xen PV fb driver, - and a crash fix when trying to see non-existent PTE's * tag 'stable/for-linus-3.4-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/Kconfig: fix Kconfig layout xen/pci: don't use PCI BIOS service for configuration space accesses xen/pte: Fix crashes when trying to see non-existent PGD/PMD/PUD/PTEs xen/apic: Return the APIC ID (and version) for CPU 0. drivers/video/xen-fbfront.c: add missing cleanup code