kernel.git/arch/x86/kernel/head64.c, branch linux-5.18.y

x86: Clear .brk area at early boot

2022-07-22T08:21:54Z

[ Upstream commit 38fa5479b41376dc9d7f57e71c83514285a25ca0 ] The .brk section has the same properties as .bss: it is an alloc-only section and should be cleared before being used. Not doing so is especially a problem for Xen PV guests, as the hypervisor will validate page tables (check for writable page tables and hypervisor private bits) before accepting them to be used. Make sure .brk is initially zero by letting clear_bss() clear the brk area, too. Signed-off-by: Juergen Gross Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20220630071441.28576-3-jgross@suse.com Signed-off-by: Sasha Levin

x86/xen: Use clear_bss() for Xen PV guests

2022-07-22T08:21:16Z

commit 96e8fc5818686d4a1591bb6907e7fdb64ef29884 upstream. Instead of clearing the bss area in assembly code, use the clear_bss() function. This requires to pass the start_info address as parameter to xen_start_kernel() in order to avoid the xen_start_info being zeroed again. Signed-off-by: Juergen Gross Signed-off-by: Borislav Petkov Reviewed-by: Jan Beulich Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20220630071441.28576-2-jgross@suse.com Signed-off-by: Greg Kroah-Hartman

x86/head64: Add missing __head annotation to sme_postprocess_startup()

2022-02-12T10:37:09Z

This function was previously part of __startup_64() which is marked __head, and is currently only called from there. Mark it __head too. Signed-off-by: Marco Bonelli Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20220211162350.11780-1-marco@mebeim.net

Merge tag 'x86_mm_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-01-10T17:51:38Z

Pull x86 mm updates from Borislav Petkov: - Flush *all* mappings from the TLB after switching to the trampoline pagetable to prevent any stale entries' presence - Flush global mappings from the TLB, in addition to the CR3-write, after switching off of the trampoline_pgd during boot to clear the identity mappings - Prevent instrumentation issues resulting from the above changes * tag 'x86_mm_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Prevent early boot triple-faults with instrumentation x86/mm: Include spinlock_t definition in pgtable. x86/mm: Flush global TLB when switching to trampoline page-table x86/mm/64: Flush global TLB on boot and AP bringup x86/realmode: Add comment for Global bit usage in trampoline_pgd x86/mm: Add missing dependency to

x86/mm: Prevent early boot triple-faults with instrumentation

2021-12-22T10:51:20Z

Commit in Fixes added a global TLB flush on the early boot path, after the kernel switches off of the trampoline page table. Compiler profiling options enabled with GCOV_PROFILE add additional measurement code on clang which needs to be initialized prior to use. The global flush in x86_64_start_kernel() happens before those initializations can happen, leading to accessing invalid memory. GCOV_PROFILE builds with gcc are still ok so this is clang-specific. The second issue this fixes is with KASAN: for a similar reason, kasan_early_init() needs to have happened before KASAN-instrumented functions are called. Therefore, reorder the flush to happen after the KASAN early init and prevent the compilers from adding profiling instrumentation to native_write_cr4(). Fixes: f154f290855b ("x86/mm/64: Flush global TLB on boot and AP bringup") Reported-by: "J. Bruce Fields" Reported-by: kernel test robot Signed-off-by: Borislav Petkov Tested-by: Carel Si Tested-by: "J. Bruce Fields" Link: https://lore.kernel.org/r/20211209144141.GC25654@xsang-OptiPlex-9020

x86/mm/64: Flush global TLB on boot and AP bringup

2021-12-06T08:38:48Z

The AP bringup code uses the trampoline_pgd page-table which establishes global mappings in the user range of the address space. Flush the global TLB entries after the indentity mappings are removed so no stale entries remain in the TLB. Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/r/20211202153226.22946-3-joro@8bytes.org

x86/head64: Carve out the guest encryption postprocessing into a helper

2021-11-15T20:05:14Z

Carve it out so that it is abstracted out of the main boot path. All other encrypted guest-relevant processing should be placed in there. No functional changes. Signed-off-by: Borislav Petkov Signed-off-by: Brijesh Singh Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20211110220731.2396491-7-brijesh.singh@amd.com

treewide: Replace the use of mem_encrypt_active() with cc_platform_has()

2021-10-04T09:47:24Z

Replace uses of mem_encrypt_active() with calls to cc_platform_has() with the CC_ATTR_MEM_ENCRYPT attribute. Remove the implementation of mem_encrypt_active() across all arches. For s390, since the default implementation of the cc_platform_has() matches the s390 implementation of mem_encrypt_active(), cc_platform_has() does not need to be implemented in s390 (the config option ARCH_HAS_CC_PLATFORM is not set). Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210928191009.32551-9-bp@alien8.de

x86/sev-es: Rename sev-es.{ch} to sev.{ch}

2021-05-10T05:40:27Z

SEV-SNP builds upon the SEV-ES functionality while adding new hardware protection. Version 2 of the GHCB specification adds new NAE events that are SEV-SNP specific. Rename the sev-es.{ch} to sev.{ch} so that all SEV* functionality can be consolidated in one place. Signed-off-by: Brijesh Singh Signed-off-by: Borislav Petkov Acked-by: Joerg Roedel Link: https://lkml.kernel.org/r/20210427111636.1207-2-brijesh.singh@amd.com

x86: Fix various typos in comments

2021-03-18T14:31:53Z

Fix ~144 single-word typos in arch/x86/ code comments. Doing this in a single commit should reduce the churn. Signed-off-by: Ingo Molnar Cc: Borislav Petkov Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Paolo Bonzini Cc: Bjorn Helgaas Cc: linux-kernel@vger.kernel.org