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18f6e68548
Eliminate the following coccicheck warning: ./tools/testing/selftests/x86/ldt_gdt.c:610:2-3: Unneeded semicolon Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
928 lines
22 KiB
C
928 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ldt_gdt.c - Test cases for LDT and GDT access
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* Copyright (c) 2015 Andrew Lutomirski
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*/
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#define _GNU_SOURCE
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#include <err.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <signal.h>
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#include <setjmp.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <sys/syscall.h>
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#include <asm/ldt.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <stdbool.h>
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#include <pthread.h>
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#include <sched.h>
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#include <linux/futex.h>
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#include <sys/mman.h>
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#include <asm/prctl.h>
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#include <sys/prctl.h>
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#define AR_ACCESSED (1<<8)
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#define AR_TYPE_RODATA (0 * (1<<9))
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#define AR_TYPE_RWDATA (1 * (1<<9))
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#define AR_TYPE_RODATA_EXPDOWN (2 * (1<<9))
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#define AR_TYPE_RWDATA_EXPDOWN (3 * (1<<9))
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#define AR_TYPE_XOCODE (4 * (1<<9))
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#define AR_TYPE_XRCODE (5 * (1<<9))
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#define AR_TYPE_XOCODE_CONF (6 * (1<<9))
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#define AR_TYPE_XRCODE_CONF (7 * (1<<9))
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#define AR_DPL3 (3 * (1<<13))
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#define AR_S (1 << 12)
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#define AR_P (1 << 15)
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#define AR_AVL (1 << 20)
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#define AR_L (1 << 21)
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#define AR_DB (1 << 22)
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#define AR_G (1 << 23)
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#ifdef __x86_64__
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# define INT80_CLOBBERS "r8", "r9", "r10", "r11"
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#else
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# define INT80_CLOBBERS
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#endif
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static int nerrs;
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/* Points to an array of 1024 ints, each holding its own index. */
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static const unsigned int *counter_page;
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static struct user_desc *low_user_desc;
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static struct user_desc *low_user_desc_clear; /* Use to delete GDT entry */
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static int gdt_entry_num;
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static void check_invalid_segment(uint16_t index, int ldt)
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{
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uint32_t has_limit = 0, has_ar = 0, limit, ar;
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uint32_t selector = (index << 3) | (ldt << 2) | 3;
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asm ("lsl %[selector], %[limit]\n\t"
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"jnz 1f\n\t"
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"movl $1, %[has_limit]\n\t"
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"1:"
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: [limit] "=r" (limit), [has_limit] "+rm" (has_limit)
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: [selector] "r" (selector));
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asm ("larl %[selector], %[ar]\n\t"
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"jnz 1f\n\t"
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"movl $1, %[has_ar]\n\t"
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"1:"
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: [ar] "=r" (ar), [has_ar] "+rm" (has_ar)
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: [selector] "r" (selector));
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if (has_limit || has_ar) {
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printf("[FAIL]\t%s entry %hu is valid but should be invalid\n",
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(ldt ? "LDT" : "GDT"), index);
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nerrs++;
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} else {
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printf("[OK]\t%s entry %hu is invalid\n",
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(ldt ? "LDT" : "GDT"), index);
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}
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}
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static void check_valid_segment(uint16_t index, int ldt,
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uint32_t expected_ar, uint32_t expected_limit,
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bool verbose)
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{
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uint32_t has_limit = 0, has_ar = 0, limit, ar;
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uint32_t selector = (index << 3) | (ldt << 2) | 3;
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asm ("lsl %[selector], %[limit]\n\t"
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"jnz 1f\n\t"
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"movl $1, %[has_limit]\n\t"
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"1:"
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: [limit] "=r" (limit), [has_limit] "+rm" (has_limit)
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: [selector] "r" (selector));
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asm ("larl %[selector], %[ar]\n\t"
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"jnz 1f\n\t"
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"movl $1, %[has_ar]\n\t"
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"1:"
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: [ar] "=r" (ar), [has_ar] "+rm" (has_ar)
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: [selector] "r" (selector));
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if (!has_limit || !has_ar) {
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printf("[FAIL]\t%s entry %hu is invalid but should be valid\n",
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(ldt ? "LDT" : "GDT"), index);
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nerrs++;
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return;
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}
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/* The SDM says "bits 19:16 are undefined". Thanks. */
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ar &= ~0xF0000;
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/*
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* NB: Different Linux versions do different things with the
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* accessed bit in set_thread_area().
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*/
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if (ar != expected_ar && ar != (expected_ar | AR_ACCESSED)) {
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printf("[FAIL]\t%s entry %hu has AR 0x%08X but expected 0x%08X\n",
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(ldt ? "LDT" : "GDT"), index, ar, expected_ar);
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nerrs++;
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} else if (limit != expected_limit) {
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printf("[FAIL]\t%s entry %hu has limit 0x%08X but expected 0x%08X\n",
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(ldt ? "LDT" : "GDT"), index, limit, expected_limit);
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nerrs++;
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} else if (verbose) {
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printf("[OK]\t%s entry %hu has AR 0x%08X and limit 0x%08X\n",
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(ldt ? "LDT" : "GDT"), index, ar, limit);
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}
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}
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static bool install_valid_mode(const struct user_desc *d, uint32_t ar,
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bool oldmode, bool ldt)
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{
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struct user_desc desc = *d;
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int ret;
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if (!ldt) {
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#ifndef __i386__
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/* No point testing set_thread_area in a 64-bit build */
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return false;
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#endif
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if (!gdt_entry_num)
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return false;
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desc.entry_number = gdt_entry_num;
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ret = syscall(SYS_set_thread_area, &desc);
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} else {
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ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11,
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&desc, sizeof(desc));
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if (ret < -1)
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errno = -ret;
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if (ret != 0 && errno == ENOSYS) {
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printf("[OK]\tmodify_ldt returned -ENOSYS\n");
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return false;
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}
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}
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if (ret == 0) {
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uint32_t limit = desc.limit;
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if (desc.limit_in_pages)
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limit = (limit << 12) + 4095;
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check_valid_segment(desc.entry_number, ldt, ar, limit, true);
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return true;
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} else {
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if (desc.seg_32bit) {
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printf("[FAIL]\tUnexpected %s failure %d\n",
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ldt ? "modify_ldt" : "set_thread_area",
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errno);
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nerrs++;
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return false;
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} else {
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printf("[OK]\t%s rejected 16 bit segment\n",
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ldt ? "modify_ldt" : "set_thread_area");
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return false;
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}
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}
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}
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static bool install_valid(const struct user_desc *desc, uint32_t ar)
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{
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bool ret = install_valid_mode(desc, ar, false, true);
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if (desc->contents <= 1 && desc->seg_32bit &&
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!desc->seg_not_present) {
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/* Should work in the GDT, too. */
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install_valid_mode(desc, ar, false, false);
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}
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return ret;
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}
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static void install_invalid(const struct user_desc *desc, bool oldmode)
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{
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int ret = syscall(SYS_modify_ldt, oldmode ? 1 : 0x11,
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desc, sizeof(*desc));
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if (ret < -1)
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errno = -ret;
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if (ret == 0) {
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check_invalid_segment(desc->entry_number, 1);
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} else if (errno == ENOSYS) {
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printf("[OK]\tmodify_ldt returned -ENOSYS\n");
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} else {
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if (desc->seg_32bit) {
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printf("[FAIL]\tUnexpected modify_ldt failure %d\n",
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errno);
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nerrs++;
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} else {
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printf("[OK]\tmodify_ldt rejected 16 bit segment\n");
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}
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}
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}
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static int safe_modify_ldt(int func, struct user_desc *ptr,
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unsigned long bytecount)
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{
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int ret = syscall(SYS_modify_ldt, 0x11, ptr, bytecount);
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if (ret < -1)
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errno = -ret;
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return ret;
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}
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static void fail_install(struct user_desc *desc)
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{
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if (safe_modify_ldt(0x11, desc, sizeof(*desc)) == 0) {
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printf("[FAIL]\tmodify_ldt accepted a bad descriptor\n");
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nerrs++;
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} else if (errno == ENOSYS) {
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printf("[OK]\tmodify_ldt returned -ENOSYS\n");
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} else {
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printf("[OK]\tmodify_ldt failure %d\n", errno);
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}
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}
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static void do_simple_tests(void)
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{
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struct user_desc desc = {
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.entry_number = 0,
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.base_addr = 0,
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.limit = 10,
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.seg_32bit = 1,
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.contents = 2, /* Code, not conforming */
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.read_exec_only = 0,
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.limit_in_pages = 0,
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.seg_not_present = 0,
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.useable = 0
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};
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | AR_S | AR_P | AR_DB);
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desc.limit_in_pages = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
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AR_S | AR_P | AR_DB | AR_G);
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check_invalid_segment(1, 1);
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desc.entry_number = 2;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
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AR_S | AR_P | AR_DB | AR_G);
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check_invalid_segment(1, 1);
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desc.base_addr = 0xf0000000;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
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AR_S | AR_P | AR_DB | AR_G);
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desc.useable = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
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AR_S | AR_P | AR_DB | AR_G | AR_AVL);
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desc.seg_not_present = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
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AR_S | AR_DB | AR_G | AR_AVL);
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desc.seg_32bit = 0;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
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AR_S | AR_G | AR_AVL);
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desc.seg_32bit = 1;
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desc.contents = 0;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA |
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AR_S | AR_DB | AR_G | AR_AVL);
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desc.read_exec_only = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA |
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AR_S | AR_DB | AR_G | AR_AVL);
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desc.contents = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA_EXPDOWN |
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AR_S | AR_DB | AR_G | AR_AVL);
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desc.read_exec_only = 0;
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desc.limit_in_pages = 0;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA_EXPDOWN |
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AR_S | AR_DB | AR_AVL);
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desc.contents = 3;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE_CONF |
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AR_S | AR_DB | AR_AVL);
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desc.read_exec_only = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE_CONF |
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AR_S | AR_DB | AR_AVL);
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desc.read_exec_only = 0;
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desc.contents = 2;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE |
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AR_S | AR_DB | AR_AVL);
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desc.read_exec_only = 1;
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#ifdef __x86_64__
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desc.lm = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE |
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AR_S | AR_DB | AR_AVL);
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desc.lm = 0;
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#endif
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bool entry1_okay = install_valid(&desc, AR_DPL3 | AR_TYPE_XOCODE |
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AR_S | AR_DB | AR_AVL);
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if (entry1_okay) {
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printf("[RUN]\tTest fork\n");
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pid_t child = fork();
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if (child == 0) {
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nerrs = 0;
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check_valid_segment(desc.entry_number, 1,
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AR_DPL3 | AR_TYPE_XOCODE |
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AR_S | AR_DB | AR_AVL, desc.limit,
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true);
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check_invalid_segment(1, 1);
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exit(nerrs ? 1 : 0);
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} else {
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int status;
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if (waitpid(child, &status, 0) != child ||
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!WIFEXITED(status)) {
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printf("[FAIL]\tChild died\n");
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nerrs++;
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} else if (WEXITSTATUS(status) != 0) {
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printf("[FAIL]\tChild failed\n");
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nerrs++;
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} else {
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printf("[OK]\tChild succeeded\n");
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}
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}
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printf("[RUN]\tTest size\n");
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int i;
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for (i = 0; i < 8192; i++) {
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desc.entry_number = i;
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desc.limit = i;
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if (safe_modify_ldt(0x11, &desc, sizeof(desc)) != 0) {
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printf("[FAIL]\tFailed to install entry %d\n", i);
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nerrs++;
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break;
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}
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}
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for (int j = 0; j < i; j++) {
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check_valid_segment(j, 1, AR_DPL3 | AR_TYPE_XOCODE |
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AR_S | AR_DB | AR_AVL, j, false);
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}
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printf("[DONE]\tSize test\n");
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} else {
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printf("[SKIP]\tSkipping fork and size tests because we have no LDT\n");
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}
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/* Test entry_number too high. */
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desc.entry_number = 8192;
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fail_install(&desc);
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/* Test deletion and actions mistakeable for deletion. */
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memset(&desc, 0, sizeof(desc));
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install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P);
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desc.seg_not_present = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S);
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desc.seg_not_present = 0;
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desc.read_exec_only = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S | AR_P);
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desc.read_exec_only = 0;
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desc.seg_not_present = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S);
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desc.read_exec_only = 1;
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desc.limit = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S);
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desc.limit = 0;
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desc.base_addr = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S);
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desc.base_addr = 0;
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install_invalid(&desc, false);
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desc.seg_not_present = 0;
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desc.seg_32bit = 1;
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desc.read_exec_only = 0;
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desc.limit = 0xfffff;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB);
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desc.limit_in_pages = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA | AR_S | AR_P | AR_DB | AR_G);
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desc.read_exec_only = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA | AR_S | AR_P | AR_DB | AR_G);
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desc.contents = 1;
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desc.read_exec_only = 0;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RWDATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
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desc.read_exec_only = 1;
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install_valid(&desc, AR_DPL3 | AR_TYPE_RODATA_EXPDOWN | AR_S | AR_P | AR_DB | AR_G);
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desc.limit = 0;
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install_invalid(&desc, true);
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}
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/*
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* 0: thread is idle
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* 1: thread armed
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* 2: thread should clear LDT entry 0
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* 3: thread should exit
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*/
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static volatile unsigned int ftx;
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static void *threadproc(void *ctx)
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{
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cpu_set_t cpuset;
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CPU_ZERO(&cpuset);
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CPU_SET(1, &cpuset);
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if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0)
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err(1, "sched_setaffinity to CPU 1"); /* should never fail */
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while (1) {
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syscall(SYS_futex, &ftx, FUTEX_WAIT, 0, NULL, NULL, 0);
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while (ftx != 2) {
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if (ftx >= 3)
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return NULL;
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}
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/* clear LDT entry 0 */
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const struct user_desc desc = {};
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if (syscall(SYS_modify_ldt, 1, &desc, sizeof(desc)) != 0)
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err(1, "modify_ldt");
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/* If ftx == 2, set it to zero. If ftx == 100, quit. */
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unsigned int x = -2;
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asm volatile ("lock xaddl %[x], %[ftx]" :
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[x] "+r" (x), [ftx] "+m" (ftx));
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if (x != 2)
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return NULL;
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}
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}
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#ifdef __i386__
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#ifndef SA_RESTORE
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#define SA_RESTORER 0x04000000
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#endif
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/*
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* The UAPI header calls this 'struct sigaction', which conflicts with
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* glibc. Sigh.
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*/
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|
struct fake_ksigaction {
|
|
void *handler; /* the real type is nasty */
|
|
unsigned long sa_flags;
|
|
void (*sa_restorer)(void);
|
|
unsigned char sigset[8];
|
|
};
|
|
|
|
static void fix_sa_restorer(int sig)
|
|
{
|
|
struct fake_ksigaction ksa;
|
|
|
|
if (syscall(SYS_rt_sigaction, sig, NULL, &ksa, 8) == 0) {
|
|
/*
|
|
* glibc has a nasty bug: it sometimes writes garbage to
|
|
* sa_restorer. This interacts quite badly with anything
|
|
* that fiddles with SS because it can trigger legacy
|
|
* stack switching. Patch it up. See:
|
|
*
|
|
* https://sourceware.org/bugzilla/show_bug.cgi?id=21269
|
|
*/
|
|
if (!(ksa.sa_flags & SA_RESTORER) && ksa.sa_restorer) {
|
|
ksa.sa_restorer = NULL;
|
|
if (syscall(SYS_rt_sigaction, sig, &ksa, NULL,
|
|
sizeof(ksa.sigset)) != 0)
|
|
err(1, "rt_sigaction");
|
|
}
|
|
}
|
|
}
|
|
#else
|
|
static void fix_sa_restorer(int sig)
|
|
{
|
|
/* 64-bit glibc works fine. */
|
|
}
|
|
#endif
|
|
|
|
static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
|
|
int flags)
|
|
{
|
|
struct sigaction sa;
|
|
memset(&sa, 0, sizeof(sa));
|
|
sa.sa_sigaction = handler;
|
|
sa.sa_flags = SA_SIGINFO | flags;
|
|
sigemptyset(&sa.sa_mask);
|
|
if (sigaction(sig, &sa, 0))
|
|
err(1, "sigaction");
|
|
|
|
fix_sa_restorer(sig);
|
|
}
|
|
|
|
static jmp_buf jmpbuf;
|
|
|
|
static void sigsegv(int sig, siginfo_t *info, void *ctx_void)
|
|
{
|
|
siglongjmp(jmpbuf, 1);
|
|
}
|
|
|
|
static void do_multicpu_tests(void)
|
|
{
|
|
cpu_set_t cpuset;
|
|
pthread_t thread;
|
|
int failures = 0, iters = 5, i;
|
|
unsigned short orig_ss;
|
|
|
|
CPU_ZERO(&cpuset);
|
|
CPU_SET(1, &cpuset);
|
|
if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
|
|
printf("[SKIP]\tCannot set affinity to CPU 1\n");
|
|
return;
|
|
}
|
|
|
|
CPU_ZERO(&cpuset);
|
|
CPU_SET(0, &cpuset);
|
|
if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) {
|
|
printf("[SKIP]\tCannot set affinity to CPU 0\n");
|
|
return;
|
|
}
|
|
|
|
sethandler(SIGSEGV, sigsegv, 0);
|
|
#ifdef __i386__
|
|
/* True 32-bit kernels send SIGILL instead of SIGSEGV on IRET faults. */
|
|
sethandler(SIGILL, sigsegv, 0);
|
|
#endif
|
|
|
|
printf("[RUN]\tCross-CPU LDT invalidation\n");
|
|
|
|
if (pthread_create(&thread, 0, threadproc, 0) != 0)
|
|
err(1, "pthread_create");
|
|
|
|
asm volatile ("mov %%ss, %0" : "=rm" (orig_ss));
|
|
|
|
for (i = 0; i < 5; i++) {
|
|
if (sigsetjmp(jmpbuf, 1) != 0)
|
|
continue;
|
|
|
|
/* Make sure the thread is ready after the last test. */
|
|
while (ftx != 0)
|
|
;
|
|
|
|
struct user_desc desc = {
|
|
.entry_number = 0,
|
|
.base_addr = 0,
|
|
.limit = 0xfffff,
|
|
.seg_32bit = 1,
|
|
.contents = 0, /* Data */
|
|
.read_exec_only = 0,
|
|
.limit_in_pages = 1,
|
|
.seg_not_present = 0,
|
|
.useable = 0
|
|
};
|
|
|
|
if (safe_modify_ldt(0x11, &desc, sizeof(desc)) != 0) {
|
|
if (errno != ENOSYS)
|
|
err(1, "modify_ldt");
|
|
printf("[SKIP]\tmodify_ldt unavailable\n");
|
|
break;
|
|
}
|
|
|
|
/* Arm the thread. */
|
|
ftx = 1;
|
|
syscall(SYS_futex, &ftx, FUTEX_WAKE, 0, NULL, NULL, 0);
|
|
|
|
asm volatile ("mov %0, %%ss" : : "r" (0x7));
|
|
|
|
/* Go! */
|
|
ftx = 2;
|
|
|
|
while (ftx != 0)
|
|
;
|
|
|
|
/*
|
|
* On success, modify_ldt will segfault us synchronously,
|
|
* and we'll escape via siglongjmp.
|
|
*/
|
|
|
|
failures++;
|
|
asm volatile ("mov %0, %%ss" : : "rm" (orig_ss));
|
|
}
|
|
|
|
ftx = 100; /* Kill the thread. */
|
|
syscall(SYS_futex, &ftx, FUTEX_WAKE, 0, NULL, NULL, 0);
|
|
|
|
if (pthread_join(thread, NULL) != 0)
|
|
err(1, "pthread_join");
|
|
|
|
if (failures) {
|
|
printf("[FAIL]\t%d of %d iterations failed\n", failures, iters);
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tAll %d iterations succeeded\n", iters);
|
|
}
|
|
}
|
|
|
|
static int finish_exec_test(void)
|
|
{
|
|
/*
|
|
* Older kernel versions did inherit the LDT on exec() which is
|
|
* wrong because exec() starts from a clean state.
|
|
*/
|
|
check_invalid_segment(0, 1);
|
|
|
|
return nerrs ? 1 : 0;
|
|
}
|
|
|
|
static void do_exec_test(void)
|
|
{
|
|
printf("[RUN]\tTest exec\n");
|
|
|
|
struct user_desc desc = {
|
|
.entry_number = 0,
|
|
.base_addr = 0,
|
|
.limit = 42,
|
|
.seg_32bit = 1,
|
|
.contents = 2, /* Code, not conforming */
|
|
.read_exec_only = 0,
|
|
.limit_in_pages = 0,
|
|
.seg_not_present = 0,
|
|
.useable = 0
|
|
};
|
|
install_valid(&desc, AR_DPL3 | AR_TYPE_XRCODE | AR_S | AR_P | AR_DB);
|
|
|
|
pid_t child = fork();
|
|
if (child == 0) {
|
|
execl("/proc/self/exe", "ldt_gdt_test_exec", NULL);
|
|
printf("[FAIL]\tCould not exec self\n");
|
|
exit(1); /* exec failed */
|
|
} else {
|
|
int status;
|
|
if (waitpid(child, &status, 0) != child ||
|
|
!WIFEXITED(status)) {
|
|
printf("[FAIL]\tChild died\n");
|
|
nerrs++;
|
|
} else if (WEXITSTATUS(status) != 0) {
|
|
printf("[FAIL]\tChild failed\n");
|
|
nerrs++;
|
|
} else {
|
|
printf("[OK]\tChild succeeded\n");
|
|
}
|
|
}
|
|
}
|
|
|
|
static void setup_counter_page(void)
|
|
{
|
|
unsigned int *page = mmap(NULL, 4096, PROT_READ | PROT_WRITE,
|
|
MAP_ANONYMOUS | MAP_PRIVATE | MAP_32BIT, -1, 0);
|
|
if (page == MAP_FAILED)
|
|
err(1, "mmap");
|
|
|
|
for (int i = 0; i < 1024; i++)
|
|
page[i] = i;
|
|
counter_page = page;
|
|
}
|
|
|
|
static int invoke_set_thread_area(void)
|
|
{
|
|
int ret;
|
|
asm volatile ("int $0x80"
|
|
: "=a" (ret), "+m" (low_user_desc) :
|
|
"a" (243), "b" (low_user_desc)
|
|
: INT80_CLOBBERS);
|
|
return ret;
|
|
}
|
|
|
|
static void setup_low_user_desc(void)
|
|
{
|
|
low_user_desc = mmap(NULL, 2 * sizeof(struct user_desc),
|
|
PROT_READ | PROT_WRITE,
|
|
MAP_ANONYMOUS | MAP_PRIVATE | MAP_32BIT, -1, 0);
|
|
if (low_user_desc == MAP_FAILED)
|
|
err(1, "mmap");
|
|
|
|
low_user_desc->entry_number = -1;
|
|
low_user_desc->base_addr = (unsigned long)&counter_page[1];
|
|
low_user_desc->limit = 0xfffff;
|
|
low_user_desc->seg_32bit = 1;
|
|
low_user_desc->contents = 0; /* Data, grow-up*/
|
|
low_user_desc->read_exec_only = 0;
|
|
low_user_desc->limit_in_pages = 1;
|
|
low_user_desc->seg_not_present = 0;
|
|
low_user_desc->useable = 0;
|
|
|
|
if (invoke_set_thread_area() == 0) {
|
|
gdt_entry_num = low_user_desc->entry_number;
|
|
printf("[NOTE]\tset_thread_area is available; will use GDT index %d\n", gdt_entry_num);
|
|
} else {
|
|
printf("[NOTE]\tset_thread_area is unavailable\n");
|
|
}
|
|
|
|
low_user_desc_clear = low_user_desc + 1;
|
|
low_user_desc_clear->entry_number = gdt_entry_num;
|
|
low_user_desc_clear->read_exec_only = 1;
|
|
low_user_desc_clear->seg_not_present = 1;
|
|
}
|
|
|
|
static void test_gdt_invalidation(void)
|
|
{
|
|
if (!gdt_entry_num)
|
|
return; /* 64-bit only system -- we can't use set_thread_area */
|
|
|
|
unsigned short prev_sel;
|
|
unsigned short sel;
|
|
unsigned int eax;
|
|
const char *result;
|
|
#ifdef __x86_64__
|
|
unsigned long saved_base;
|
|
unsigned long new_base;
|
|
#endif
|
|
|
|
/* Test DS */
|
|
invoke_set_thread_area();
|
|
eax = 243;
|
|
sel = (gdt_entry_num << 3) | 3;
|
|
asm volatile ("movw %%ds, %[prev_sel]\n\t"
|
|
"movw %[sel], %%ds\n\t"
|
|
#ifdef __i386__
|
|
"pushl %%ebx\n\t"
|
|
#endif
|
|
"movl %[arg1], %%ebx\n\t"
|
|
"int $0x80\n\t" /* Should invalidate ds */
|
|
#ifdef __i386__
|
|
"popl %%ebx\n\t"
|
|
#endif
|
|
"movw %%ds, %[sel]\n\t"
|
|
"movw %[prev_sel], %%ds"
|
|
: [prev_sel] "=&r" (prev_sel), [sel] "+r" (sel),
|
|
"+a" (eax)
|
|
: "m" (low_user_desc_clear),
|
|
[arg1] "r" ((unsigned int)(unsigned long)low_user_desc_clear)
|
|
: INT80_CLOBBERS);
|
|
|
|
if (sel != 0) {
|
|
result = "FAIL";
|
|
nerrs++;
|
|
} else {
|
|
result = "OK";
|
|
}
|
|
printf("[%s]\tInvalidate DS with set_thread_area: new DS = 0x%hx\n",
|
|
result, sel);
|
|
|
|
/* Test ES */
|
|
invoke_set_thread_area();
|
|
eax = 243;
|
|
sel = (gdt_entry_num << 3) | 3;
|
|
asm volatile ("movw %%es, %[prev_sel]\n\t"
|
|
"movw %[sel], %%es\n\t"
|
|
#ifdef __i386__
|
|
"pushl %%ebx\n\t"
|
|
#endif
|
|
"movl %[arg1], %%ebx\n\t"
|
|
"int $0x80\n\t" /* Should invalidate es */
|
|
#ifdef __i386__
|
|
"popl %%ebx\n\t"
|
|
#endif
|
|
"movw %%es, %[sel]\n\t"
|
|
"movw %[prev_sel], %%es"
|
|
: [prev_sel] "=&r" (prev_sel), [sel] "+r" (sel),
|
|
"+a" (eax)
|
|
: "m" (low_user_desc_clear),
|
|
[arg1] "r" ((unsigned int)(unsigned long)low_user_desc_clear)
|
|
: INT80_CLOBBERS);
|
|
|
|
if (sel != 0) {
|
|
result = "FAIL";
|
|
nerrs++;
|
|
} else {
|
|
result = "OK";
|
|
}
|
|
printf("[%s]\tInvalidate ES with set_thread_area: new ES = 0x%hx\n",
|
|
result, sel);
|
|
|
|
/* Test FS */
|
|
invoke_set_thread_area();
|
|
eax = 243;
|
|
sel = (gdt_entry_num << 3) | 3;
|
|
#ifdef __x86_64__
|
|
syscall(SYS_arch_prctl, ARCH_GET_FS, &saved_base);
|
|
#endif
|
|
asm volatile ("movw %%fs, %[prev_sel]\n\t"
|
|
"movw %[sel], %%fs\n\t"
|
|
#ifdef __i386__
|
|
"pushl %%ebx\n\t"
|
|
#endif
|
|
"movl %[arg1], %%ebx\n\t"
|
|
"int $0x80\n\t" /* Should invalidate fs */
|
|
#ifdef __i386__
|
|
"popl %%ebx\n\t"
|
|
#endif
|
|
"movw %%fs, %[sel]\n\t"
|
|
: [prev_sel] "=&r" (prev_sel), [sel] "+r" (sel),
|
|
"+a" (eax)
|
|
: "m" (low_user_desc_clear),
|
|
[arg1] "r" ((unsigned int)(unsigned long)low_user_desc_clear)
|
|
: INT80_CLOBBERS);
|
|
|
|
#ifdef __x86_64__
|
|
syscall(SYS_arch_prctl, ARCH_GET_FS, &new_base);
|
|
#endif
|
|
|
|
/* Restore FS/BASE for glibc */
|
|
asm volatile ("movw %[prev_sel], %%fs" : : [prev_sel] "rm" (prev_sel));
|
|
#ifdef __x86_64__
|
|
if (saved_base)
|
|
syscall(SYS_arch_prctl, ARCH_SET_FS, saved_base);
|
|
#endif
|
|
|
|
if (sel != 0) {
|
|
result = "FAIL";
|
|
nerrs++;
|
|
} else {
|
|
result = "OK";
|
|
}
|
|
printf("[%s]\tInvalidate FS with set_thread_area: new FS = 0x%hx\n",
|
|
result, sel);
|
|
|
|
#ifdef __x86_64__
|
|
if (sel == 0 && new_base != 0) {
|
|
nerrs++;
|
|
printf("[FAIL]\tNew FSBASE was 0x%lx\n", new_base);
|
|
} else {
|
|
printf("[OK]\tNew FSBASE was zero\n");
|
|
}
|
|
#endif
|
|
|
|
/* Test GS */
|
|
invoke_set_thread_area();
|
|
eax = 243;
|
|
sel = (gdt_entry_num << 3) | 3;
|
|
#ifdef __x86_64__
|
|
syscall(SYS_arch_prctl, ARCH_GET_GS, &saved_base);
|
|
#endif
|
|
asm volatile ("movw %%gs, %[prev_sel]\n\t"
|
|
"movw %[sel], %%gs\n\t"
|
|
#ifdef __i386__
|
|
"pushl %%ebx\n\t"
|
|
#endif
|
|
"movl %[arg1], %%ebx\n\t"
|
|
"int $0x80\n\t" /* Should invalidate gs */
|
|
#ifdef __i386__
|
|
"popl %%ebx\n\t"
|
|
#endif
|
|
"movw %%gs, %[sel]\n\t"
|
|
: [prev_sel] "=&r" (prev_sel), [sel] "+r" (sel),
|
|
"+a" (eax)
|
|
: "m" (low_user_desc_clear),
|
|
[arg1] "r" ((unsigned int)(unsigned long)low_user_desc_clear)
|
|
: INT80_CLOBBERS);
|
|
|
|
#ifdef __x86_64__
|
|
syscall(SYS_arch_prctl, ARCH_GET_GS, &new_base);
|
|
#endif
|
|
|
|
/* Restore GS/BASE for glibc */
|
|
asm volatile ("movw %[prev_sel], %%gs" : : [prev_sel] "rm" (prev_sel));
|
|
#ifdef __x86_64__
|
|
if (saved_base)
|
|
syscall(SYS_arch_prctl, ARCH_SET_GS, saved_base);
|
|
#endif
|
|
|
|
if (sel != 0) {
|
|
result = "FAIL";
|
|
nerrs++;
|
|
} else {
|
|
result = "OK";
|
|
}
|
|
printf("[%s]\tInvalidate GS with set_thread_area: new GS = 0x%hx\n",
|
|
result, sel);
|
|
|
|
#ifdef __x86_64__
|
|
if (sel == 0 && new_base != 0) {
|
|
nerrs++;
|
|
printf("[FAIL]\tNew GSBASE was 0x%lx\n", new_base);
|
|
} else {
|
|
printf("[OK]\tNew GSBASE was zero\n");
|
|
}
|
|
#endif
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
if (argc == 1 && !strcmp(argv[0], "ldt_gdt_test_exec"))
|
|
return finish_exec_test();
|
|
|
|
setup_counter_page();
|
|
setup_low_user_desc();
|
|
|
|
do_simple_tests();
|
|
|
|
do_multicpu_tests();
|
|
|
|
do_exec_test();
|
|
|
|
test_gdt_invalidation();
|
|
|
|
return nerrs ? 1 : 0;
|
|
}
|