57b08b0944
to reflect the new license. These used slightly different spellings that defeated my regular expressions. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351648
87 lines
2.6 KiB
C
87 lines
2.6 KiB
C
// REQUIRES: native-run
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// UNSUPPORTED: arm, aarch64
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// RUN: %clang_builtins %s %librt -o %t && %run %t
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//===-- clear_cache_test.c - Test clear_cache -----------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include <stdio.h>
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#include <string.h>
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#include <stdint.h>
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#if defined(_WIN32)
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#include <windows.h>
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static uintptr_t get_page_size() {
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SYSTEM_INFO si;
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GetSystemInfo(&si);
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return si.dwPageSize;
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}
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#else
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#include <unistd.h>
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#include <sys/mman.h>
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static uintptr_t get_page_size() {
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return sysconf(_SC_PAGE_SIZE);
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}
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#endif
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extern void __clear_cache(void* start, void* end);
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typedef int (*pfunc)(void);
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// Make these static to avoid ILT jumps for incremental linking on Windows.
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static int func1() { return 1; }
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static int func2() { return 2; }
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void *__attribute__((noinline))
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memcpy_f(void *dst, const void *src, size_t n) {
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// ARM and MIPS nartually align functions, but use the LSB for ISA selection
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// (THUMB, MIPS16/uMIPS respectively). Ensure that the ISA bit is ignored in
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// the memcpy
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#if defined(__arm__) || defined(__mips__)
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return (void *)((uintptr_t)memcpy(dst, (void *)((uintptr_t)src & ~1), n) |
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((uintptr_t)src & 1));
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#else
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return memcpy(dst, (void *)((uintptr_t)src), n);
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#endif
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}
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unsigned char execution_buffer[128] __attribute__((aligned(8)));
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int main()
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{
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// make executable the page containing execution_buffer
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uintptr_t page_size = get_page_size();
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char* start = (char*)((uintptr_t)execution_buffer & (-page_size));
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char* end = (char*)((uintptr_t)(&execution_buffer[128+page_size]) & (-page_size));
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#if defined(_WIN32)
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DWORD dummy_oldProt;
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MEMORY_BASIC_INFORMATION b;
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if (!VirtualQuery(start, &b, sizeof(b)))
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return 1;
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if (!VirtualProtect(b.BaseAddress, b.RegionSize, PAGE_EXECUTE_READWRITE, &b.Protect))
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#else
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if (mprotect(start, end-start, PROT_READ|PROT_WRITE|PROT_EXEC) != 0)
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#endif
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return 1;
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// verify you can copy and execute a function
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pfunc f1 = (pfunc)memcpy_f(execution_buffer, func1, 128);
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__clear_cache(execution_buffer, &execution_buffer[128]);
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if ((*f1)() != 1)
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return 1;
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// verify you can overwrite a function with another
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pfunc f2 = (pfunc)memcpy_f(execution_buffer, func2, 128);
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__clear_cache(execution_buffer, &execution_buffer[128]);
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if ((*f2)() != 2)
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return 1;
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return 0;
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}
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