This is a note to let you know that I've just added the patch titled

selftests/x86/ldt_gdt: Add infrastructure to test set_thread_area()

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: selftests-x86-ldt_gdt-add-infrastructure-to-test-set_thread_area.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From d744dcad39094c9187075e274d1cdef79c57c8b5 Mon Sep 17 00:00:00 2001

From: Andy Lutomirski luto@kernel.org Date: Sat, 4 Nov 2017 04:19:50 -0700 Subject: selftests/x86/ldt_gdt: Add infrastructure to test set_thread_area()

From: Andy Lutomirski luto@kernel.org

commit d744dcad39094c9187075e274d1cdef79c57c8b5 upstream.

Much of the test design could apply to set_thread_area() (i.e. GDT), not just modify_ldt(). Add set_thread_area() to the install_valid_mode() helper.

Signed-off-by: Andy Lutomirski luto@kernel.org Cc: Borislav Petkov bpetkov@suse.de Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/02c23f8fba5547007f741dc24c3926e5284ede02.1509794321... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- tools/testing/selftests/x86/ldt_gdt.c | 53 +++++++++++++++++++++++----------- 1 file changed, 37 insertions(+), 16 deletions(-)

--- a/tools/testing/selftests/x86/ldt_gdt.c +++ b/tools/testing/selftests/x86/ldt_gdt.c @@ -137,30 +137,51 @@ static void check_valid_segment(uint16_t } }

-static bool install_valid_mode(const struct user_desc *desc, uint32_t ar, - bool oldmode) +static bool install_valid_mode(const struct user_desc *d, uint32_t ar, + bool oldmode, bool ldt) { - int ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11, - desc, sizeof(*desc)); - if (ret < -1) - errno = -ret; + struct user_desc desc = *d; + int ret; + + if (!ldt) { +#ifndef __i386__ + /* No point testing set_thread_area in a 64-bit build */ + return false; +#endif + if (!gdt_entry_num) + return false; + desc.entry_number = gdt_entry_num; + + ret = syscall(SYS_set_thread_area, &desc); + } else { + ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11, + &desc, sizeof(desc)); + + if (ret < -1) + errno = -ret; + + if (ret != 0 && errno == ENOSYS) { + printf("[OK]\tmodify_ldt returned -ENOSYS\n"); + return false; + } + } + if (ret == 0) { - uint32_t limit = desc->limit; - if (desc->limit_in_pages) + uint32_t limit = desc.limit; + if (desc.limit_in_pages) limit = (limit << 12) + 4095; - check_valid_segment(desc->entry_number, 1, ar, limit, true); + check_valid_segment(desc.entry_number, ldt, ar, limit, true); return true; - } else if (errno == ENOSYS) { - printf("[OK]\tmodify_ldt returned -ENOSYS\n"); - return false; } else { - if (desc->seg_32bit) { - printf("[FAIL]\tUnexpected modify_ldt failure %d\n", + if (desc.seg_32bit) { + printf("[FAIL]\tUnexpected %s failure %d\n", + ldt ? "modify_ldt" : "set_thread_area", errno); nerrs++; return false; } else { - printf("[OK]\tmodify_ldt rejected 16 bit segment\n"); + printf("[OK]\t%s rejected 16 bit segment\n", + ldt ? "modify_ldt" : "set_thread_area"); return false; } } @@ -168,7 +189,7 @@ static bool install_valid_mode(const str

static bool install_valid(const struct user_desc *desc, uint32_t ar) { - return install_valid_mode(desc, ar, false); + return install_valid_mode(desc, ar, false, true); }

static void install_invalid(const struct user_desc *desc, bool oldmode)

Patches currently in stable-queue which might be from luto@kernel.org are

queue-4.14/x86-entry-64-simplify-reg-restore-code-in-the-standard-iret-paths.patch queue-4.14/x86-cpufeatures-fix-various-details-in-the-feature-definitions.patch queue-4.14/x86-entry-64-move-the-ist-stacks-into-struct-cpu_entry_area.patch queue-4.14/x86-dumpstack-add-get_stack_info-support-for-the-sysenter-stack.patch queue-4.14/x86-asm-don-t-use-the-confusing-.ifeq-directive.patch queue-4.14/selftests-x86-ldt_gdt-add-infrastructure-to-test-set_thread_area.patch queue-4.14/x86-entry-remap-the-tss-into-the-cpu-entry-area.patch queue-4.14/x86-entry-64-paravirt-use-paravirt-safe-macro-to-access-eflags.patch queue-4.14/x86-mm-fixmap-generalize-the-gdt-fixmap-mechanism-introduce-struct-cpu_entry_area.patch queue-4.14/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.14/x86-dumpstack-handle-stack-overflow-on-all-stacks.patch queue-4.14/x86-entry-64-use-pop-instead-of-movq-in-syscall_return_via_sysret.patch queue-4.14/x86-entry-64-return-to-userspace-from-the-trampoline-stack.patch queue-4.14/x86-paravirt-provide-a-way-to-check-for-hypervisors.patch queue-4.14/xen-x86-entry-64-add-xen-nmi-trap-entry.patch queue-4.14/x86-entry-64-remove-the-restore_c_regs_and_iret-label.patch queue-4.14/x86-entry-64-create-a-per-cpu-syscall-entry-trampoline.patch queue-4.14/x86-entry-64-remove-the-restore_..._regs-infrastructure.patch queue-4.14/x86-xen-64-x86-entry-64-clean-up-sp-code-in-cpu_initialize_context.patch queue-4.14/x86-entry-add-task_top_of_stack-to-find-the-top-of-a-task-s-stack.patch queue-4.14/x86-entry-64-remove-all-remaining-direct-thread_struct-sp0-reads.patch queue-4.14/x86-boot-relocate-definition-of-the-initial-state-of-cr0.patch queue-4.14/x86-entry-64-stop-initializing-tss.sp0-at-boot.patch queue-4.14/x86-entry-64-de-xen-ify-our-nmi-code.patch queue-4.14/objtool-don-t-report-end-of-section-error-after-an-empty-unwind-hint.patch queue-4.14/x86-entry-64-pass-sp0-directly-to-load_sp0.patch queue-4.14/x86-entry-64-use-a-per-cpu-trampoline-stack-for-idt-entries.patch queue-4.14/x86-entry-64-move-swapgs-into-the-common-iret-to-usermode-path.patch queue-4.14/x86-entry-64-shorten-test-instructions.patch queue-4.14/x86-cpufeature-add-user-mode-instruction-prevention-definitions.patch queue-4.14/x86-cpufeatures-make-cpu-bugs-sticky.patch queue-4.14/x86-espfix-64-stop-assuming-that-pt_regs-is-on-the-entry-stack.patch queue-4.14/x86-traps-use-a-new-on_thread_stack-helper-to-clean-up-an-assertion.patch queue-4.14/x86-xen-fix-xen-head-elf-annotations.patch queue-4.14/x86-entry-64-remove-thread_struct-sp0.patch queue-4.14/x86-entry-move-sysenter_stack-to-the-beginning-of-struct-tss_struct.patch queue-4.14/x86-entry-64-allocate-and-enable-the-sysenter-stack.patch queue-4.14/x86-unwinder-orc-dont-bail-on-stack-overflow.patch queue-4.14/x86-head-fix-head-elf-function-annotations.patch queue-4.14/selftests-x86-ldt_gdt-run-most-existing-ldt-test-cases-against-the-gdt-as-well.patch queue-4.14/x86-entry-32-pull-the-msr_ia32_sysenter_cs-update-code-out-of-native_load_sp0.patch queue-4.14/x86-entry-64-split-the-iret-to-user-and-iret-to-kernel-paths.patch queue-4.14/x86-entry-64-shrink-paranoid_exit_restore-and-make-labels-local.patch queue-4.14/x86-head-add-unwind-hint-annotations.patch queue-4.14/x86-head-remove-unused-bad_address-code.patch queue-4.14/x86-xen-add-unwind-hint-annotations.patch queue-4.14/x86-kasan-64-teach-kasan-about-the-cpu_entry_area.patch queue-4.14/x86-head-remove-confusing-comment.patch queue-4.14/x86-entry-64-remove-the-sysenter-stack-canary.patch queue-4.14/x86-mm-kasan-don-t-use-vmemmap_populate-to-initialize-shadow.patch queue-4.14/x86-entry-gdt-put-per-cpu-gdt-remaps-in-ascending-order.patch queue-4.14/x86-entry-fix-assumptions-that-the-hw-tss-is-at-the-beginning-of-cpu_tss.patch queue-4.14/x86-cpufeatures-re-tabulate-the-x86_feature-definitions.patch queue-4.14/x86-entry-32-fix-cpu_current_top_of_stack-initialization-at-boot.patch queue-4.14/ptrace-x86-make-user_64bit_mode-available-to-32-bit-builds.patch queue-4.14/x86-entry-64-make-cpu_entry_area.tss-read-only.patch queue-4.14/x86-mm-relocate-page-fault-error-codes-to-traps.h.patch queue-4.14/x86-unwinder-handle-stack-overflows-more-gracefully.patch queue-4.14/x86-entry-64-use-pop-instead-of-mov-to-restore-regs-on-nmi-return.patch queue-4.14/x86-irq-64-print-the-offending-ip-in-the-stack-overflow-warning.patch queue-4.14/x86-entry-clean-up-the-sysenter_stack-code.patch queue-4.14/x86-entry-64-merge-the-fast-and-slow-sysret-paths.patch queue-4.14/x86-entry-64-separate-cpu_current_top_of_stack-from-tss.sp0.patch queue-4.14/x86-boot-annotate-verify_cpu-as-a-callable-function.patch queue-4.14/x86-irq-remove-an-old-outdated-comment-about-context-tracking-races.patch