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| // SPDX-License-Identifier: GPL-2.0-only
| /*
| * check_initial_reg_state.c - check that execve sets the correct state
| * Copyright (c) 2014-2016 Andrew Lutomirski
| */
|
| #define _GNU_SOURCE
|
| #include <stdio.h>
|
| unsigned long ax, bx, cx, dx, si, di, bp, sp, flags;
| unsigned long r8, r9, r10, r11, r12, r13, r14, r15;
|
| asm (
| ".pushsection .text\n\t"
| ".type real_start, @function\n\t"
| ".global real_start\n\t"
| "real_start:\n\t"
| #ifdef __x86_64__
| "mov %rax, ax\n\t"
| "mov %rbx, bx\n\t"
| "mov %rcx, cx\n\t"
| "mov %rdx, dx\n\t"
| "mov %rsi, si\n\t"
| "mov %rdi, di\n\t"
| "mov %rbp, bp\n\t"
| "mov %rsp, sp\n\t"
| "mov %r8, r8\n\t"
| "mov %r9, r9\n\t"
| "mov %r10, r10\n\t"
| "mov %r11, r11\n\t"
| "mov %r12, r12\n\t"
| "mov %r13, r13\n\t"
| "mov %r14, r14\n\t"
| "mov %r15, r15\n\t"
| "pushfq\n\t"
| "popq flags\n\t"
| #else
| "mov %eax, ax\n\t"
| "mov %ebx, bx\n\t"
| "mov %ecx, cx\n\t"
| "mov %edx, dx\n\t"
| "mov %esi, si\n\t"
| "mov %edi, di\n\t"
| "mov %ebp, bp\n\t"
| "mov %esp, sp\n\t"
| "pushfl\n\t"
| "popl flags\n\t"
| #endif
| "jmp _start\n\t"
| ".size real_start, . - real_start\n\t"
| ".popsection");
|
| int main()
| {
| int nerrs = 0;
|
| if (sp == 0) {
| printf("[FAIL]\tTest was built incorrectly\n");
| return 1;
| }
|
| if (ax || bx || cx || dx || si || di || bp
| #ifdef __x86_64__
| || r8 || r9 || r10 || r11 || r12 || r13 || r14 || r15
| #endif
| ) {
| printf("[FAIL]\tAll GPRs except SP should be 0\n");
| #define SHOW(x) printf("\t" #x " = 0x%lx\n", x);
| SHOW(ax);
| SHOW(bx);
| SHOW(cx);
| SHOW(dx);
| SHOW(si);
| SHOW(di);
| SHOW(bp);
| SHOW(sp);
| #ifdef __x86_64__
| SHOW(r8);
| SHOW(r9);
| SHOW(r10);
| SHOW(r11);
| SHOW(r12);
| SHOW(r13);
| SHOW(r14);
| SHOW(r15);
| #endif
| nerrs++;
| } else {
| printf("[OK]\tAll GPRs except SP are 0\n");
| }
|
| if (flags != 0x202) {
| printf("[FAIL]\tFLAGS is 0x%lx, but it should be 0x202\n", flags);
| nerrs++;
| } else {
| printf("[OK]\tFLAGS is 0x202\n");
| }
|
| return nerrs ? 1 : 0;
| }
|
|
