BMC/Intel-BMC/linux.git/arch/x86/kernel/machine_kexec_64.c, branch dev-4.18

x86/mm: Stop pretending pgtable_l5_enabled is a variable

2018-05-19T09:56:57+00:00

pgtable_l5_enabled is defined using cpu_feature_enabled() but we refer to it as a variable. This is misleading. Make pgtable_l5_enabled() a function. We cannot literally define it as a function due to circular dependencies between header files. Function-alike macros is close enough. Signed-off-by: Kirill A. Shutemov Reviewed-by: Thomas Gleixner Cc: Hugh Dickins Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20180518103528.59260-4-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar

x86/kexec: Avoid double free_page() upon do_kexec_load() failure

2018-05-13T17:50:06+00:00

>From ff82bedd3e12f0d3353282054ae48c3bd8c72012 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Wed, 9 May 2018 12:12:39 +0900 Subject: [PATCH v3] x86/kexec: avoid double free_page() upon do_kexec_load() failure. syzbot is reporting crashes after memory allocation failure inside do_kexec_load() [1]. This is because free_transition_pgtable() is called by both init_transition_pgtable() and machine_kexec_cleanup() when memory allocation failed inside init_transition_pgtable(). Regarding 32bit code, machine_kexec_free_page_tables() is called by both machine_kexec_alloc_page_tables() and machine_kexec_cleanup() when memory allocation failed inside machine_kexec_alloc_page_tables(). Fix this by leaving the error handling to machine_kexec_cleanup() (and optionally setting NULL after free_page()). [1] https://syzkaller.appspot.com/bug?id=91e52396168cf2bdd572fe1e1bc0bc645c1c6b40 Fixes: f5deb79679af6eb4 ("x86: kexec: Use one page table in x86_64 machine_kexec") Fixes: 92be3d6bdf2cb349 ("kexec/i386: allocate page table pages dynamically") Reported-by: syzbot Signed-off-by: Tetsuo Handa Signed-off-by: Thomas Gleixner Acked-by: Baoquan He Cc: thomas.lendacky@amd.com Cc: prudo@linux.vnet.ibm.com Cc: Huang Ying Cc: syzkaller-bugs@googlegroups.com Cc: takahiro.akashi@linaro.org Cc: H. Peter Anvin Cc: akpm@linux-foundation.org Cc: dyoung@redhat.com Cc: kirill.shutemov@linux.intel.com Link: https://lkml.kernel.org/r/201805091942.DGG12448.tMFVFSJFQOOLHO@I-love.SAKURA.ne.jp

kernel/kexec_file.c: remove mis-use of sh_offset field during purgatory load

2018-04-14T00:10:28+00:00

The current code uses the sh_offset field in purgatory_info->sechdrs to store a pointer to the current load address of the section. Depending whether the section will be loaded or not this is either a pointer into purgatory_info->purgatory_buf or kexec_purgatory. This is not only a violation of the ELF standard but also makes the code very hard to understand as you cannot tell if the memory you are using is read-only or not. Remove this misuse and store the offset of the section in pugaroty_info->purgatory_buf in sh_offset. Link: http://lkml.kernel.org/r/20180321112751.22196-10-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo Acked-by: Dave Young Cc: AKASHI Takahiro Cc: Eric Biederman Cc: Heiko Carstens Cc: Ingo Molnar Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Thiago Jung Bauermann Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations*

2018-04-14T00:10:28+00:00

When the relocations are applied to the purgatory only the section the relocations are applied to is writable. The other sections, i.e. the symtab and .rel/.rela, are in read-only kexec_purgatory. Highlight this by marking the corresponding variables as 'const'. While at it also change the signatures of arch_kexec_apply_relocations* to take section pointers instead of just the index of the relocation section. This removes the second lookup and sanity check of the sections in arch code. Link: http://lkml.kernel.org/r/20180321112751.22196-6-prudo@linux.vnet.ibm.com Signed-off-by: Philipp Rudo Acked-by: Dave Young Cc: AKASHI Takahiro Cc: Eric Biederman Cc: Heiko Carstens Cc: Ingo Molnar Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Thiago Jung Bauermann Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kexec_file,x86,powerpc: factor out kexec_file_ops functions

2018-04-14T00:10:27+00:00

As arch_kexec_kernel_image_{probe,load}(), arch_kimage_file_post_load_cleanup() and arch_kexec_kernel_verify_sig() are almost duplicated among architectures, they can be commonalized with an architecture-defined kexec_file_ops array. So let's factor them out. Link: http://lkml.kernel.org/r/20180306102303.9063-3-takahiro.akashi@linaro.org Signed-off-by: AKASHI Takahiro Acked-by: Dave Young Tested-by: Dave Young Cc: Vivek Goyal Cc: Baoquan He Cc: Michael Ellerman Cc: Thiago Jung Bauermann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

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

2018-04-02T22:45:30+00:00

Pull x86 mm updates from Ingo Molnar: - Extend the memmap= boot parameter syntax to allow the redeclaration and dropping of existing ranges, and to support all e820 range types (Jan H. Schönherr) - Improve the W+X boot time security checks to remove false positive warnings on Xen (Jan Beulich) - Support booting as Xen PVH guest (Juergen Gross) - Improved 5-level paging (LA57) support, in particular it's possible now to have a single kernel image for both 4-level and 5-level hardware (Kirill A. Shutemov) - AMD hardware RAM encryption support (SME/SEV) fixes (Tom Lendacky) - Preparatory commits for hardware-encrypted RAM support on Intel CPUs. (Kirill A. Shutemov) - Improved Intel-MID support (Andy Shevchenko) - Show EFI page tables in page_tables debug files (Andy Lutomirski) - ... plus misc fixes and smaller cleanups * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits) x86/cpu/tme: Fix spelling: "configuation" -> "configuration" x86/boot: Fix SEV boot failure from change to __PHYSICAL_MASK_SHIFT x86/mm: Update comment in detect_tme() regarding x86_phys_bits x86/mm/32: Remove unused node_memmap_size_bytes() & CONFIG_NEED_NODE_MEMMAP_SIZE logic x86/mm: Remove pointless checks in vmalloc_fault x86/platform/intel-mid: Add special handling for ACPI HW reduced platforms ACPI, x86/boot: Introduce the ->reduced_hw_early_init() ACPI callback ACPI, x86/boot: Split out acpi_generic_reduce_hw_init() and export x86/pconfig: Provide defines and helper to run MKTME_KEY_PROG leaf x86/pconfig: Detect PCONFIG targets x86/tme: Detect if TME and MKTME is activated by BIOS x86/boot/compressed/64: Handle 5-level paging boot if kernel is above 4G x86/boot/compressed/64: Use page table in trampoline memory x86/boot/compressed/64: Use stack from trampoline memory x86/boot/compressed/64: Make sure we have a 32-bit code segment x86/mm: Do not use paravirtualized calls in native_set_p4d() kdump, vmcoreinfo: Export pgtable_l5_enabled value x86/boot/compressed/64: Prepare new top-level page table for trampoline x86/boot/compressed/64: Set up trampoline memory x86/boot/compressed/64: Save and restore trampoline memory ...

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

2018-04-02T20:38:43+00:00

Pull x86 apic updates from Ingo Molnar: "The main x86 APIC/IOAPIC changes in this cycle were: - Robustify kexec support to more carefully restore IRQ hardware state before calling into kexec/kdump kernels. (Baoquan He) - Clean up the local APIC code a bit (Dou Liyang) - Remove unused callbacks (David Rientjes)" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Finish removing unused callbacks x86/apic: Drop logical_smp_processor_id() inline x86/apic: Modernize the pending interrupt code x86/apic: Move pending interrupt check code into it's own function x86/apic: Set up through-local-APIC mode on the boot CPU if 'noapic' specified x86/apic: Rename variables and functions related to x86_io_apic_ops x86/apic: Remove the (now) unused disable_IO_APIC() function x86/apic: Fix restoring boot IRQ mode in reboot and kexec/kdump x86/apic: Split disable_IO_APIC() into two functions to fix CONFIG_KEXEC_JUMP=y x86/apic: Split out restore_boot_irq_mode() from disable_IO_APIC() x86/apic: Make setup_local_APIC() static x86/apic: Simplify init_bsp_APIC() usage x86/x2apic: Mark set_x2apic_phys_mode() as __init

kdump, vmcoreinfo: Export pgtable_l5_enabled value

2018-03-12T08:43:56+00:00

User-space utilities examining crash-kernels need to know if the crashed kernel was in 5-level paging mode or not. So write 'pgtable_l5_enabled' to vmcoreinfo, which covers these three cases: pgtable_l5_enabled == 0 when: - Compiled with !CONFIG_X86_5LEVEL - Compiled with CONFIG_X86_5LEVEL=y while CPU has no 'la57' flag pgtable_l5_enabled != 0 when: - Compiled with CONFIG_X86_5LEVEL=y and CPU has 'la57' flag Signed-off-by: Baoquan He Acked-by: Kirill A. Shutemov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: douly.fnst@cn.fujitsu.com Cc: dyoung@redhat.com Cc: ebiederm@xmission.com Cc: kirill.shutemov@linux.intel.com Cc: vgoyal@redhat.com Link: http://lkml.kernel.org/r/20180302051801.19594-1-bhe@redhat.com Signed-off-by: Ingo Molnar

x86: Treat R_X86_64_PLT32 as R_X86_64_PC32

2018-02-22T17:01:10+00:00

On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared objects must use PIC PLT. To use PIC PLT, you need to load _GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on x86-64 since x86-64 uses PC-relative PLT. On x86-64, for 32-bit PC-relative branches, we can generate PLT32 relocation, instead of PC32 relocation, which can also be used as a marker for 32-bit PC-relative branches. Linker can always reduce PLT32 relocation to PC32 if function is defined locally. Local functions should use PC32 relocation. As far as Linux kernel is concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32 since Linux kernel doesn't use PLT. R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in binutils master branch which will become binutils 2.31. [ hjl is working on having better documentation on this all, but a few more notes from him: "PLT32 relocation is used as marker for PC-relative branches. Because of EBX, it looks odd to generate PLT32 relocation on i386 when EBX doesn't have GOT. As for symbol resolution, PLT32 and PC32 relocations are almost interchangeable. But when linker sees PLT32 relocation against a protected symbol, it can resolved locally at link-time since it is used on a branch instruction. Linker can't do that for PC32 relocation" but for the kernel use, the two are basically the same, and this commit gets things building and working with the current binutils master - Linus ] Signed-off-by: H.J. Lu Signed-off-by: Linus Torvalds

x86/apic: Remove the (now) unused disable_IO_APIC() function

2018-02-17T10:47:45+00:00

No one uses it anymore. Signed-off-by: Baoquan He Reviewed-by: Eric W. Biederman Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: douly.fnst@cn.fujitsu.com Cc: joro@8bytes.org Cc: prarit@redhat.com Cc: uobergfe@redhat.com Link: http://lkml.kernel.org/r/20180214054656.3780-5-bhe@redhat.com [ Rewrote the changelog. ] Signed-off-by: Ingo Molnar