*/
#define _GNU_SOURCE
+#define _LGPL_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 <ust-fd.h>
#include "lttng-tracer-core.h"
#define BUF_LEN 4096
+#ifndef NT_GNU_BUILD_ID
+# define NT_GNU_BUILD_ID 3
+#endif
+
/*
* Retrieve the nth (where n is the `index` argument) phdr (program
* header) from the given elf instance.
uint8_t e_ident[EI_NIDENT];
struct lttng_ust_elf_shdr *section_names_shdr;
struct lttng_ust_elf *elf = NULL;
+ int ret, fd;
elf = zmalloc(sizeof(struct lttng_ust_elf));
if (!elf) {
goto error;
}
+ /* Initialize fd field to -1. 0 is a valid fd number */
+ elf->fd = -1;
+
elf->path = strdup(path);
if (!elf->path) {
goto error;
}
- elf->fd = open(elf->path, O_RDONLY | O_CLOEXEC);
- if (elf->fd < 0) {
+ lttng_ust_lock_fd_tracker();
+ fd = open(elf->path, O_RDONLY | O_CLOEXEC);
+ if (fd < 0) {
+ lttng_ust_unlock_fd_tracker();
+ goto error;
+ }
+
+ ret = lttng_ust_add_fd_to_tracker(fd);
+ if (ret < 0) {
+ ret = close(fd);
+ if (ret) {
+ PERROR("close on elf->fd");
+ }
+ ret = -1;
+ lttng_ust_unlock_fd_tracker();
goto error;
}
+ elf->fd = ret;
+ lttng_ust_unlock_fd_tracker();
if (lttng_ust_read(elf->fd, e_ident, EI_NIDENT) < EI_NIDENT) {
goto error;
return elf;
error:
- if (elf) {
- free(elf->ehdr);
- if (elf->fd >= 0) {
- if (close(elf->fd)) {
- abort();
- }
- }
- free(elf->path);
- free(elf);
- }
+ lttng_ust_elf_destroy(elf);
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.
*/
void lttng_ust_elf_destroy(struct lttng_ust_elf *elf)
{
+ int ret;
+
if (!elf) {
return;
}
- free(elf->ehdr);
- if (close(elf->fd)) {
- abort();
+ if (elf->fd >= 0) {
+ lttng_ust_lock_fd_tracker();
+ ret = close(elf->fd);
+ if (!ret) {
+ lttng_ust_delete_fd_from_tracker(elf->fd);
+ } else {
+ PERROR("close");
+ abort();
+ }
+ lttng_ust_unlock_fd_tracker();
}
+
+ free(elf->ehdr);
free(elf->path);
free(elf);
}
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;