From 35ecfa7b62c1737e7d1edfc5c9ead2ddf692bd08 Mon Sep 17 00:00:00 2001 From: Adrien Devresse Date: Mon, 20 Jul 2015 16:00:51 +0200 Subject: Configure automatically the page size with a runtime call, solve the issue #53 related to prtability on powerpc64 architecture --- configure.ac | 2 ++ src/patchelf.cc | 48 +++++++++++++++++++++++++++--------------------- 2 files changed, 29 insertions(+), 21 deletions(-) diff --git a/configure.ac b/configure.ac index 69e12de..6592493 100644 --- a/configure.ac +++ b/configure.ac @@ -14,5 +14,7 @@ AC_CHECK_HEADERS([sys/acl.h acl/libacl.h]) AC_SEARCH_LIBS(perm_copy_file, acl) AC_CHECK_FUNCS([perm_copy_file]) +AC_CHECK_FUNCS([sysconf]) + AC_CONFIG_FILES([Makefile src/Makefile tests/Makefile patchelf.spec]) AC_OUTPUT diff --git a/src/patchelf.cc b/src/patchelf.cc index df75593..74a61b4 100644 --- a/src/patchelf.cc +++ b/src/patchelf.cc @@ -32,12 +32,6 @@ using namespace std; -#ifdef MIPSEL -/* The lemote fuloong 2f kernel defconfig sets a page size of 16KB */ -const unsigned int pageSize = 4096*4; -#else -const unsigned int pageSize = 4096; -#endif static bool debugMode = false; @@ -55,6 +49,16 @@ unsigned char * contents = 0; #define ElfFileParamNames Elf_Ehdr, Elf_Phdr, Elf_Shdr, Elf_Addr, Elf_Off, Elf_Dyn, Elf_Sym +static unsigned int getPageSize(){ +#if (defined HAVE_SYSCONF) + // if present, use sysconf to get kernel page size + return sysconf(_SC_PAGESIZE); +#else + return 4096; +#endif +} + + template class ElfFile { @@ -415,9 +419,9 @@ void ElfFile::shiftFile(unsigned int extraPages, Elf_Addr sta /* Move the entire contents of the file `extraPages' pages further. */ unsigned int oldSize = fileSize; - unsigned int shift = extraPages * pageSize; - growFile(fileSize + extraPages * pageSize); - memmove(contents + extraPages * pageSize, contents, oldSize); + unsigned int shift = extraPages * getPageSize(); + growFile(fileSize + extraPages * getPageSize()); + memmove(contents + extraPages * getPageSize(), contents, oldSize); memset(contents + sizeof(Elf_Ehdr), 0, shift - sizeof(Elf_Ehdr)); /* Adjust the ELF header. */ @@ -434,8 +438,8 @@ void ElfFile::shiftFile(unsigned int extraPages, Elf_Addr sta if (rdi(phdrs[i].p_align) != 0 && (rdi(phdrs[i].p_vaddr) - rdi(phdrs[i].p_offset)) % rdi(phdrs[i].p_align) != 0) { debug("changing alignment of program header %d from %d to %d\n", i, - rdi(phdrs[i].p_align), pageSize); - wri(phdrs[i].p_align, pageSize); + rdi(phdrs[i].p_align), getPageSize()); + wri(phdrs[i].p_align, getPageSize()); } } @@ -449,7 +453,7 @@ void ElfFile::shiftFile(unsigned int extraPages, Elf_Addr sta wri(phdr.p_vaddr, wri(phdr.p_paddr, startPage)); wri(phdr.p_filesz, wri(phdr.p_memsz, shift)); wri(phdr.p_flags, PF_R | PF_W); - wri(phdr.p_align, pageSize); + wri(phdr.p_align, getPageSize()); } @@ -578,7 +582,7 @@ void ElfFile::rewriteSectionsLibrary() page of other segments. */ Elf_Addr startPage = 0; for (unsigned int i = 0; i < phdrs.size(); ++i) { - Elf_Addr thisPage = roundUp(rdi(phdrs[i].p_vaddr) + rdi(phdrs[i].p_memsz), pageSize); + Elf_Addr thisPage = roundUp(rdi(phdrs[i].p_vaddr) + rdi(phdrs[i].p_memsz), getPageSize()); if (thisPage > startPage) startPage = thisPage; } @@ -594,7 +598,7 @@ void ElfFile::rewriteSectionsLibrary() debug("needed space is %d\n", neededSpace); - size_t startOffset = roundUp(fileSize, pageSize); + size_t startOffset = roundUp(fileSize, getPageSize()); growFile(startOffset + neededSpace); @@ -618,7 +622,7 @@ void ElfFile::rewriteSectionsLibrary() size_t hole = startPage - startOffset; /* Print a warning, because the hole could be very big. */ fprintf(stderr, "warning: working around a Linux kernel bug by creating a hole of %zu bytes in ‘%s’\n", hole, fileName.c_str()); - assert(hole % pageSize == 0); + assert(hole % getPageSize() == 0); /* !!! We could create an actual hole in the file here, but it's probably not worth the effort. */ growFile(fileSize + hole); @@ -638,7 +642,7 @@ void ElfFile::rewriteSectionsLibrary() wri(phdr.p_vaddr, wri(phdr.p_paddr, startPage)); wri(phdr.p_filesz, wri(phdr.p_memsz, neededSpace)); wri(phdr.p_flags, PF_R | PF_W); - wri(phdr.p_align, pageSize); + wri(phdr.p_align, getPageSize()); /* Write out the replaced sections. */ @@ -709,7 +713,7 @@ void ElfFile::rewriteSectionsExecutable() debug("first reserved offset/addr is 0x%x/0x%llx\n", startOffset, (unsigned long long) startAddr); - assert(startAddr % pageSize == startOffset % pageSize); + assert(startAddr % getPageSize() == startOffset % getPageSize()); Elf_Addr firstPage = startAddr - startOffset; debug("first page is 0x%llx\n", (unsigned long long) firstPage); @@ -738,13 +742,13 @@ void ElfFile::rewriteSectionsExecutable() neededSpace += sizeof(Elf_Phdr); debug("needed space is %d\n", neededSpace); - unsigned int neededPages = roundUp(neededSpace - startOffset, pageSize) / pageSize; + unsigned int neededPages = roundUp(neededSpace - startOffset, getPageSize()) / getPageSize(); debug("needed pages is %d\n", neededPages); - if (neededPages * pageSize > firstPage) + if (neededPages * getPageSize() > firstPage) error("virtual address space underrun!"); - firstPage -= neededPages * pageSize; - startOffset += neededPages * pageSize; + firstPage -= neededPages * getPageSize(); + startOffset += neededPages * getPageSize(); shiftFile(neededPages, firstPage); } @@ -1386,6 +1390,8 @@ static void patchElf() if (!printInterpreter && !printRPath && !printSoname) debug("patching ELF file `%s'\n", fileName.c_str()); + debug("Kernel page size is %u bytes\n", getPageSize()); + mode_t fileMode; readFile(fileName, &fileMode); -- cgit v0.12