llvm-project/openmp/libomptarget/plugins/common/elf_common.c

112 lines
2.7 KiB
C

//===-- elf_common.c - Common ELF functionality -------------------*- C -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Common ELF functionality for target plugins.
// Must be included in the plugin source file AFTER omptarget.h has been
// included and macro DP(...) has been defined.
// .
//
//===----------------------------------------------------------------------===//
#if !(defined(_OMPTARGET_DEBUG_H))
#error Include elf_common.c in the plugin source AFTER Debug.h has\
been included.
#endif
#include <elf.h>
#include <libelf.h>
// Check whether an image is valid for execution on target_id
static inline int32_t elf_check_machine(__tgt_device_image *image,
uint16_t target_id) {
// Is the library version incompatible with the header file?
if (elf_version(EV_CURRENT) == EV_NONE) {
DP("Incompatible ELF library!\n");
return 0;
}
char *img_begin = (char *)image->ImageStart;
char *img_end = (char *)image->ImageEnd;
size_t img_size = img_end - img_begin;
// Obtain elf handler
Elf *e = elf_memory(img_begin, img_size);
if (!e) {
DP("Unable to get ELF handle: %s!\n", elf_errmsg(-1));
return 0;
}
// Check if ELF is the right kind.
if (elf_kind(e) != ELF_K_ELF) {
DP("Unexpected ELF type!\n");
elf_end(e);
return 0;
}
Elf64_Ehdr *eh64 = elf64_getehdr(e);
Elf32_Ehdr *eh32 = elf32_getehdr(e);
if (!eh64 && !eh32) {
DP("Unable to get machine ID from ELF file!\n");
elf_end(e);
return 0;
}
uint16_t MachineID;
if (eh64 && !eh32)
MachineID = eh64->e_machine;
else if (eh32 && !eh64)
MachineID = eh32->e_machine;
else {
DP("Ambiguous ELF header!\n");
elf_end(e);
return 0;
}
elf_end(e);
return MachineID == target_id;
}
static inline int32_t elf_is_dynamic(__tgt_device_image *image) {
char *img_begin = (char *)image->ImageStart;
char *img_end = (char *)image->ImageEnd;
size_t img_size = img_end - img_begin;
// Obtain elf handler
Elf *e = elf_memory(img_begin, img_size);
if (!e) {
DP("Unable to get ELF handle: %s!\n", elf_errmsg(-1));
return 0;
}
Elf64_Ehdr *eh64 = elf64_getehdr(e);
Elf32_Ehdr *eh32 = elf32_getehdr(e);
if (!eh64 && !eh32) {
DP("Unable to get machine ID from ELF file!\n");
elf_end(e);
return 0;
}
uint16_t Type;
if (eh64 && !eh32)
Type = eh64->e_type;
else if (eh32 && !eh64)
Type = eh32->e_type;
else {
DP("Ambiguous ELF header!\n");
elf_end(e);
return 0;
}
elf_end(e);
DP("ELF Type: %d\n", Type);
return Type == ET_DYN;
}