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147 lines
3.0 KiB
147 lines
3.0 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Userspace test harness for load_unaligned_zeropad. Creates two |
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* pages and uses mprotect to prevent access to the second page and |
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* a SEGV handler that walks the exception tables and runs the fixup |
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* routine. |
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* |
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* The results are compared against a normal load that is that is |
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* performed while access to the second page is enabled via mprotect. |
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* |
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* Copyright (C) 2014 Anton Blanchard <[email protected]>, IBM |
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*/ |
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#include <stdlib.h> |
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#include <string.h> |
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#include <stdio.h> |
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#include <stdbool.h> |
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#include <signal.h> |
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#include <unistd.h> |
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#include <sys/mman.h> |
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#define FIXUP_SECTION ".ex_fixup" |
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static inline unsigned long __fls(unsigned long x); |
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#include "word-at-a-time.h" |
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#include "utils.h" |
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static inline unsigned long __fls(unsigned long x) |
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{ |
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int lz; |
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asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x)); |
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return sizeof(unsigned long) - 1 - lz; |
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} |
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static int page_size; |
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static char *mem_region; |
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static int protect_region(void) |
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{ |
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if (mprotect(mem_region + page_size, page_size, PROT_NONE)) { |
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perror("mprotect"); |
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return 1; |
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} |
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return 0; |
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} |
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static int unprotect_region(void) |
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{ |
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if (mprotect(mem_region + page_size, page_size, PROT_READ|PROT_WRITE)) { |
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perror("mprotect"); |
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return 1; |
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} |
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return 0; |
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} |
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extern char __start___ex_table[]; |
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extern char __stop___ex_table[]; |
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struct extbl_entry { |
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int insn; |
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int fixup; |
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}; |
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static void segv_handler(int signr, siginfo_t *info, void *ptr) |
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{ |
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ucontext_t *uc = (ucontext_t *)ptr; |
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unsigned long addr = (unsigned long)info->si_addr; |
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unsigned long *ip = &UCONTEXT_NIA(uc); |
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struct extbl_entry *entry = (struct extbl_entry *)__start___ex_table; |
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while (entry < (struct extbl_entry *)__stop___ex_table) { |
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unsigned long insn, fixup; |
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insn = (unsigned long)&entry->insn + entry->insn; |
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fixup = (unsigned long)&entry->fixup + entry->fixup; |
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if (insn == *ip) { |
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*ip = fixup; |
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return; |
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} |
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} |
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printf("No exception table match for NIA %lx ADDR %lx\n", *ip, addr); |
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abort(); |
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} |
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static void setup_segv_handler(void) |
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{ |
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struct sigaction action; |
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memset(&action, 0, sizeof(action)); |
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action.sa_sigaction = segv_handler; |
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action.sa_flags = SA_SIGINFO; |
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sigaction(SIGSEGV, &action, NULL); |
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} |
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static int do_one_test(char *p, int page_offset) |
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{ |
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unsigned long should; |
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unsigned long got; |
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FAIL_IF(unprotect_region()); |
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should = *(unsigned long *)p; |
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FAIL_IF(protect_region()); |
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got = load_unaligned_zeropad(p); |
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if (should != got) { |
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printf("offset %u load_unaligned_zeropad returned 0x%lx, should be 0x%lx\n", page_offset, got, should); |
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return 1; |
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} |
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return 0; |
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} |
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static int test_body(void) |
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{ |
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unsigned long i; |
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page_size = getpagesize(); |
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mem_region = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, |
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MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); |
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FAIL_IF(mem_region == MAP_FAILED); |
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for (i = 0; i < page_size; i++) |
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mem_region[i] = i; |
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memset(mem_region+page_size, 0, page_size); |
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setup_segv_handler(); |
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for (i = 0; i < page_size; i++) |
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FAIL_IF(do_one_test(mem_region+i, i)); |
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return 0; |
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} |
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int main(void) |
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{ |
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return test_harness(test_body, "load_unaligned_zeropad"); |
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}
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