When loading an elf file from a mtd device, this allows to parse the
header and load only the needed data according to the elf size. Without
that support, loading a elf file from a /dev/mtd would try to read the
entire partition.
Signed-off-by: Clement Leger <cleger@xxxxxxxxx>
---
common/elf.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/elf.h | 7 +++++
2 files changed, 90 insertions(+)
diff --git a/common/elf.c b/common/elf.c
index 5534632b2..291f883cb 100644
--- a/common/elf.c
+++ b/common/elf.c
@@ -5,7 +5,12 @@
#include <common.h>
#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libfile.h>
#include <memory.h>
+#include <unistd.h>
+#include <linux/fs.h>
struct elf_section {
struct list_head list;
@@ -158,3 +163,81 @@ void elf_release_image(struct elf_image *elf)
free(elf);
}
+
+static u64 elf_get_size(struct elf_image *elf)
+{
+ u64 sh_size = elf_hdr_e_shentsize(elf, elf->buf) *
+ elf_hdr_e_shnum(elf, elf->buf);
+
+ /*
+ * The section header table is located at the end of the elf file thus
+ * we can take the offset and add the size of this table to obtain the
+ * file size.
+ */
+ return elf_hdr_e_shoff(elf, elf->buf) + sh_size;
+}
+
+struct elf_image *elf_open(const char *filename)
+{
+ int fd, ret;
+ u64 size;
+ struct elf64_hdr hdr;
+ struct elf_image *elf;
+ ssize_t read_ret;
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0) {
+ printf("could not open: %s\n", errno_str());
+ return ERR_PTR(-errno);
+ }
+
+ if (read(fd, &hdr, sizeof(hdr)) < 0) {
+ printf("could not read elf header: %s\n", errno_str());
+ ret = -errno;
+ goto err_close_fd;
+ }
+
+ elf = xzalloc(sizeof(*elf));
+
+ ret = elf_check_init(elf, &hdr);
+ if (ret) {
+ ret = -errno;
+ goto err_free_elf;
+ }
+
+ size = elf_get_size(elf);
+
+ elf->buf = xmalloc(size);
+
+ lseek(fd, 0, SEEK_SET);
+
+ read_ret = read_full(fd, elf->buf, size);
+ if (read_ret < 0) {
+ printf("could not read elf file: %s\n", errno_str());
+ ret = -errno;
+ goto err_free_buf;
+ }
+
+ ret = load_elf_image_phdr(elf);
+ if (ret)
+ goto err_release_elf;
+
+ return elf;
+
+err_release_elf:
+ elf_release_regions(elf);
+err_free_buf:
+ free(elf->buf);
+err_free_elf:
+ free(elf);
+err_close_fd:
+ close(fd);
+
+ return ERR_PTR(ret);
+}
+
+void elf_close(struct elf_image *elf)
+{
+ free(elf->buf);
+ elf_release_image(elf);
+}
diff --git a/include/elf.h b/include/elf.h
index 403412f3f..e9fe977a2 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -416,6 +416,9 @@ static inline size_t elf_get_mem_size(struct elf_image *elf)
struct elf_image *elf_load_image(void *buf);
void elf_release_image(struct elf_image *elf);
+struct elf_image *elf_open(const char *filename);
+void elf_close(struct elf_image *elf);
+
#define ELF_GET_FIELD(__s, __field, __type) \
static inline __type elf_##__s##_##__field(struct elf_image *elf, void *arg) { \
if (elf->class == ELFCLASS32) \
@@ -427,6 +430,10 @@ static inline __type elf_##__s##_##__field(struct elf_image *elf, void *arg) { \
ELF_GET_FIELD(hdr, e_entry, u64)
ELF_GET_FIELD(hdr, e_phnum, u16)
ELF_GET_FIELD(hdr, e_phoff, u64)
+ELF_GET_FIELD(hdr, e_shoff, u64)
+ELF_GET_FIELD(hdr, e_shentsize, u16)
+ELF_GET_FIELD(hdr, e_machine, u16)
+ELF_GET_FIELD(hdr, e_shnum, u16)
ELF_GET_FIELD(hdr, e_type, u16)
ELF_GET_FIELD(phdr, p_paddr, u64)
ELF_GET_FIELD(phdr, p_filesz, u64)
--
2.17.1
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