* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#define _GNU_SOURCE
#include <helper.h>
#include <string.h>
#include <lttng/align.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
+#include <stdbool.h>
#include "lttng-tracer-core.h"
#define BUF_LEN 4096
return NULL;
}
+/*
+ * Test whether the ELF file is position independent code (PIC)
+ */
+uint8_t lttng_ust_elf_is_pic(struct lttng_ust_elf *elf)
+{
+ /*
+ * PIC has and e_type value of ET_DYN, see ELF specification
+ * version 1.1 p. 1-3.
+ */
+ return elf->ehdr->e_type == ET_DYN;
+}
+
/*
* Destroy the given lttng_ust_elf instance.
*/
int lttng_ust_elf_get_memsz(struct lttng_ust_elf *elf, uint64_t *memsz)
{
uint16_t i;
- uint64_t _memsz = 0;
+ uint64_t low_addr = UINT64_MAX, high_addr = 0;
if (!elf || !memsz) {
goto error;
for (i = 0; i < elf->ehdr->e_phnum; ++i) {
struct lttng_ust_elf_phdr *phdr;
- uint64_t align;
phdr = lttng_ust_elf_get_phdr(elf, i);
if (!phdr) {
goto next_loop;
}
- /*
- * A p_align of 0 means no alignment, i.e. aligned to
- * 1 byte.
- */
- align = phdr->p_align == 0 ? 1 : phdr->p_align;
- /* Align the start of the segment. */
- _memsz += offset_align(_memsz, align);
- _memsz += phdr->p_memsz;
- /*
- * Add padding at the end of the segment, so it ends
- * on a multiple of the align value (which usually
- * means a page boundary). This makes the computation
- * valid even in cases where p_align would change from
- * one segment to the next.
- */
- _memsz += offset_align(_memsz, align);
+ low_addr = min_t(uint64_t, low_addr, phdr->p_vaddr);
+ high_addr = max_t(uint64_t, high_addr,
+ phdr->p_vaddr + phdr->p_memsz);
next_loop:
free(phdr);
}
- *memsz = _memsz;
+ if (high_addr < low_addr) {
+ /* No PT_LOAD segments or corrupted data. */
+ goto error;
+ }
+
+ *memsz = high_addr - low_addr;
return 0;
error:
return -1;