diff options
author | norly <ny-git@enpas.org> | 2013-02-23 15:41:35 +0000 |
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committer | norly <ny-git@enpas.org> | 2013-02-23 15:42:42 +0000 |
commit | 5b7078265bb864ddec23162b2dfc5c02dacb0e1d (patch) | |
tree | f8973076c5f93c0e8e31d432b32a808c72bdb8db /src/elfops | |
parent | 6f12fafdc4102a9b8c3ffee060cab48f50f4c37d (diff) |
Move ELF-related files together
Diffstat (limited to 'src/elfops')
-rw-r--r-- | src/elfops/first-section-in-segment.c | 36 | ||||
-rw-r--r-- | src/elfops/last-section-in-segment.c | 54 | ||||
-rw-r--r-- | src/elfops/phdr.c | 41 | ||||
-rw-r--r-- | src/elfops/scnSize.c | 13 | ||||
-rw-r--r-- | src/elfops/section-by-name.c | 39 | ||||
-rw-r--r-- | src/elfops/section-name.c | 24 | ||||
-rw-r--r-- | src/elfops/segment-contains-section.c | 19 |
7 files changed, 226 insertions, 0 deletions
diff --git a/src/elfops/first-section-in-segment.c b/src/elfops/first-section-in-segment.c new file mode 100644 index 0000000..58065a5 --- /dev/null +++ b/src/elfops/first-section-in-segment.c @@ -0,0 +1,36 @@ +#include <stdlib.h> + +#include <libelf.h> +#include <gelf.h> + +#include <libelfu/libelfu.h> + + +/* + * Returns the section that starts at the same point in the file as + * the segment AND is wholly contained in the memory image. + * + * If no section fits, NULL is returned. + */ +Elf_Scn* elfu_firstSectionInSegment(Elf *e, GElf_Phdr *phdr) +{ + Elf_Scn *scn; + + scn = elf_getscn(e, 1); + while (scn) { + GElf_Shdr shdr; + + if (gelf_getshdr(scn, &shdr) != &shdr) { + return NULL; + } + + if (shdr.sh_offset == phdr->p_offset + && elfu_segmentContainsSection(phdr, &shdr)) { + return scn; + } + + scn = elf_nextscn(e, scn); + } + + return NULL; +} diff --git a/src/elfops/last-section-in-segment.c b/src/elfops/last-section-in-segment.c new file mode 100644 index 0000000..53323f6 --- /dev/null +++ b/src/elfops/last-section-in-segment.c @@ -0,0 +1,54 @@ +#include <stdio.h> +#include <stdlib.h> + +#include <libelf.h> +#include <gelf.h> + +#include <libelfu/libelfu.h> + + +/* + * Returns the first section that is contained in the segment and + * ends as close to its memory image of as possible (the "last" + * section in the segment). + * + * If no section fits, NULL is returned. + */ +Elf_Scn* elfu_lastSectionInSegment(Elf *e, GElf_Phdr *phdr) +{ + Elf_Scn *last = NULL; + Elf_Scn *scn; + + + scn = elf_getscn(e, 1); + while (scn) { + GElf_Shdr shdr; + + if (gelf_getshdr(scn, &shdr) != &shdr) { + fprintf(stderr, "gelf_getshdr() failed: %s\n", elf_errmsg(-1)); + continue; + } + + if (elfu_segmentContainsSection(phdr, &shdr)) { + if (!last) { + last = scn; + } else { + GElf_Shdr shdrOld; + + if (gelf_getshdr(last, &shdrOld) != &shdrOld) { + continue; + } + + if (shdr.sh_offset + shdr.sh_size + > shdrOld.sh_offset + shdrOld.sh_size) { + // TODO: Check (leftover space in memory image) < (p_align) + last = scn; + } + } + } + + scn = elf_nextscn(e, scn); + } + + return last; +} diff --git a/src/elfops/phdr.c b/src/elfops/phdr.c new file mode 100644 index 0000000..ccdc021 --- /dev/null +++ b/src/elfops/phdr.c @@ -0,0 +1,41 @@ +#include <stdio.h> + +#include <libelf.h> +#include <gelf.h> + +void elfu_fixupPhdrSelfRef(Elf *e) +{ + GElf_Ehdr ehdr; + size_t i, n; + + if (!gelf_getehdr(e, &ehdr)) { + fprintf(stderr, "gelf_getehdr() failed: %s.", elf_errmsg(-1)); + return; + } + + if (elf_getphdrnum(e, &n)) { + fprintf(stderr, "elf_getphdrnum() failed: %s\n", elf_errmsg(-1)); + } + + for (i = 0; i < n; i++) { + GElf_Phdr phdr; + + if (gelf_getphdr(e, i, &phdr) != &phdr) { + fprintf(stderr, "gelf_getphdr() failed for #%d: %s\n", i, elf_errmsg(-1)); + continue; + } + + if (phdr.p_type == PT_PHDR) { + phdr.p_offset = ehdr.e_phoff; + phdr.p_filesz = elf32_fsize(ELF_T_PHDR, n, EV_CURRENT); + phdr.p_memsz = phdr.p_filesz; + + if (!gelf_update_phdr (e, i, &phdr)) { + fprintf(stderr, "gelf_update_ehdr() failed: %s\n", elf_errmsg(-1)); + } + } + } + + /* Tell libelf that phdrs have changed */ + elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY); +} diff --git a/src/elfops/scnSize.c b/src/elfops/scnSize.c new file mode 100644 index 0000000..2c65ca1 --- /dev/null +++ b/src/elfops/scnSize.c @@ -0,0 +1,13 @@ +#include <assert.h> +#include <sys/types.h> +#include <gelf.h> +#include <libelfu/libelfu.h> + + + +size_t elfu_scnSizeFile(const GElf_Shdr *shdr) +{ + assert(shdr); + + return shdr->sh_type == SHT_NOBITS ? 0 : shdr->sh_size; +} diff --git a/src/elfops/section-by-name.c b/src/elfops/section-by-name.c new file mode 100644 index 0000000..1697140 --- /dev/null +++ b/src/elfops/section-by-name.c @@ -0,0 +1,39 @@ +#include <string.h> + +#include <libelf.h> +#include <gelf.h> + +#include <libelfu/libelfu.h> + + +Elf_Scn* elfu_sectionByName(Elf *e, char *name) +{ + size_t shstrndx; + Elf_Scn *scn; + + if (elf_getshdrstrndx(e, &shstrndx) != 0) { + return NULL; + } + + scn = elf_getscn(e, 1); + while (scn) { + GElf_Shdr shdr; + char *curname; + + if (gelf_getshdr(scn, &shdr) != &shdr) { + return NULL; + } + + /* elf_strptr returns NULL if there was an error */ + curname = elf_strptr(e, shstrndx, shdr.sh_name); + + /* strcmp... but we really have no bounds on the lengths here */ + if (!strcmp(curname, name)) { + return scn; + } + + scn = elf_nextscn(e, scn); + } + + return NULL; +} diff --git a/src/elfops/section-name.c b/src/elfops/section-name.c new file mode 100644 index 0000000..1365eb6 --- /dev/null +++ b/src/elfops/section-name.c @@ -0,0 +1,24 @@ +#include <stdlib.h> + +#include <libelf.h> +#include <gelf.h> + +#include <libelfu/libelfu.h> + + +char* elfu_sectionName(Elf *e, Elf_Scn *scn) +{ + size_t shstrndx; + GElf_Shdr shdr; + + if (elf_getshdrstrndx(e, &shstrndx) != 0) { + return NULL; + } + + if (gelf_getshdr(scn, &shdr) != &shdr) { + return NULL; + } + + /* elf_strptr returns NULL if there was an error */ + return elf_strptr(e, shstrndx, shdr.sh_name); +} diff --git a/src/elfops/segment-contains-section.c b/src/elfops/segment-contains-section.c new file mode 100644 index 0000000..298cf72 --- /dev/null +++ b/src/elfops/segment-contains-section.c @@ -0,0 +1,19 @@ +#include <libelf.h> +#include <gelf.h> + +#include <libelfu/libelfu.h> + + +int elfu_segmentContainsSection(GElf_Phdr *phdr, GElf_Shdr *shdr) +{ + size_t secStart = shdr->sh_offset; + size_t secEnd = shdr->sh_offset + shdr->sh_size; + size_t segStart = phdr->p_offset; + size_t segEnd = phdr->p_offset + phdr->p_memsz; + + if (secStart < segStart || secEnd > segEnd) { + return 0; + } + + return 1; +} |