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-rw-r--r--include/libelfu/modelops.h6
-rw-r--r--src/model/layout.c217
-rw-r--r--src/model/phdr.c19
-rw-r--r--src/model/reladd.c229
4 files changed, 248 insertions, 223 deletions
diff --git a/include/libelfu/modelops.h b/include/libelfu/modelops.h
index 9495aca..8374b02 100644
--- a/include/libelfu/modelops.h
+++ b/include/libelfu/modelops.h
@@ -8,6 +8,7 @@
size_t elfu_mPhdrCount(ElfuElf *me);
+void elfu_mPhdrUpdateChildOffsets(ElfuPhdr *mp);
typedef int (SectionHandlerFunc)(ElfuElf *me, ElfuScn *ms, void *aux1, void *aux2);
@@ -18,6 +19,11 @@ char* elfu_mScnName(ElfuElf *me, ElfuScn *ms);
ElfuScn** elfu_mScnSortedByOffset(ElfuElf *me, size_t *count);
+GElf_Addr elfu_mLayoutGetSpaceInPhdr(ElfuElf *me, GElf_Word size,
+ GElf_Word align, int w, int x,
+ ElfuPhdr **injPhdr);
+
+
int elfu_mCheck(ElfuElf *me);
ElfuScn* elfu_mCloneScn(ElfuScn *ms);
diff --git a/src/model/layout.c b/src/model/layout.c
new file mode 100644
index 0000000..2febed1
--- /dev/null
+++ b/src/model/layout.c
@@ -0,0 +1,217 @@
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <libelfu/libelfu.h>
+
+
+
+static GElf_Word shiftStuffAtAfterOffset(ElfuElf *me,
+ GElf_Off offset,
+ GElf_Word size)
+{
+ ElfuPhdr *mp;
+ ElfuScn *ms;
+ /* Force a minimum alignment, just to be sure. */
+ GElf_Word align = 64;
+
+ /* Find maximum alignment size by which we have to shift.
+ * Assumes alignment sizes are always 2^x. */
+ CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
+ if (mp->phdr.p_offset >= offset) {
+ if (mp->phdr.p_align > align) {
+ align = mp->phdr.p_align;
+ }
+ }
+ }
+
+ CIRCLEQ_FOREACH(ms, &me->orphanScnList, elemChildScn) {
+ if (ms->shdr.sh_offset >= offset) {
+ if (ms->shdr.sh_addralign > align) {
+ align = ms->shdr.sh_addralign;
+ }
+ }
+ }
+
+ size = ROUNDUP(size, align);
+
+ /* Shift stuff */
+ CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
+ if (mp->phdr.p_type != PT_LOAD) {
+ continue;
+ }
+
+ if (mp->phdr.p_offset >= offset) {
+ mp->phdr.p_offset += size;
+
+ elfu_mPhdrUpdateChildOffsets(mp);
+ }
+ }
+
+ CIRCLEQ_FOREACH(ms, &me->orphanScnList, elemChildScn) {
+ if (ms->shdr.sh_offset >= offset) {
+ ms->shdr.sh_offset += size;
+ }
+ }
+
+ if (me->ehdr.e_phoff >= offset) {
+ me->ehdr.e_phoff += size;
+ }
+
+ if (me->ehdr.e_shoff >= offset) {
+ me->ehdr.e_shoff += size;
+ }
+
+ return size;
+}
+
+
+
+
+
+/* Finds a suitable PHDR to insert a hole into and expands it
+ * if necessary.
+ * Returns memory address the hole will be mapped to, or 0 if
+ * the operation failed. */
+GElf_Addr elfu_mLayoutGetSpaceInPhdr(ElfuElf *me, GElf_Word size,
+ GElf_Word align, int w, int x,
+ ElfuPhdr **injPhdr)
+{
+ ElfuPhdr *first = NULL;
+ ElfuPhdr *last = NULL;
+ ElfuPhdr *mp;
+
+ assert(!(w && x));
+
+ /* Find first and last LOAD PHDRs.
+ * Don't compare p_memsz - segments don't overlap in memory. */
+ CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
+ if (mp->phdr.p_type != PT_LOAD) {
+ continue;
+ }
+ if (!first || mp->phdr.p_vaddr < first->phdr.p_vaddr) {
+ first = mp;
+ }
+ if (!last || mp->phdr.p_vaddr > last->phdr.p_vaddr) {
+ last = mp;
+ }
+ }
+
+ if ((w && (last->phdr.p_flags & PF_W))
+ || (x && (last->phdr.p_flags & PF_X))) {
+ /* Need to append. */
+ GElf_Off injOffset = OFFS_END(last->phdr.p_offset, last->phdr.p_filesz);
+ GElf_Word injSpace = 0;
+ GElf_Word nobitsize = last->phdr.p_memsz - last->phdr.p_filesz;
+
+ /* Expand NOBITS if any */
+ if (nobitsize > 0) {
+ GElf_Off endOff = OFFS_END(last->phdr.p_offset, last->phdr.p_filesz);
+ GElf_Off endAddr = OFFS_END(last->phdr.p_vaddr, last->phdr.p_filesz);
+ ElfuScn *ms;
+
+ ELFU_INFO("Expanding NOBITS at address 0x%jx...\n", endAddr);
+
+ CIRCLEQ_FOREACH(ms, &last->childScnList, elemChildScn) {
+ if (ms->shdr.sh_offset == endOff) {
+ assert(ms->shdr.sh_type == SHT_NOBITS);
+ assert(ms->shdr.sh_size == nobitsize);
+ ms->data.d_buf = malloc(ms->shdr.sh_size);
+ memset(ms->data.d_buf, '\0', ms->shdr.sh_size);
+ if (!ms->data.d_buf) {
+ ELFU_WARN("mExpandNobits: Could not allocate %jd bytes for NOBITS expansion. Data may be inconsistent.\n", ms->shdr.sh_size);
+ assert(0);
+ goto ERROR;
+ }
+
+ ms->data.d_align = 1;
+ ms->data.d_off = 0;
+ ms->data.d_type = ELF_T_BYTE;
+ ms->data.d_size = ms->shdr.sh_size;
+ ms->data.d_version = elf_version(EV_NONE);
+
+ ms->shdr.sh_type = SHT_PROGBITS;
+ ms->shdr.sh_addr = endAddr;
+ }
+ }
+
+ injSpace += shiftStuffAtAfterOffset(me, endOff, nobitsize);
+ injSpace -= nobitsize;
+ injOffset += nobitsize;
+ last->phdr.p_filesz += nobitsize;
+ assert(last->phdr.p_filesz == last->phdr.p_memsz);
+ }
+
+ /* Calculate how much space we need, taking alignment into account */
+ size += ROUNDUP(injOffset, align) - injOffset;
+
+ /* If there is not enough space left, create even more. */
+ if (injSpace < size) {
+ injSpace += shiftStuffAtAfterOffset(me, injOffset, size - injSpace);
+ }
+ assert(injSpace >= size);
+
+ /* Remap ourselves */
+ last->phdr.p_filesz += size;
+ last->phdr.p_memsz += size;
+
+ injOffset = ROUNDUP(injOffset, align);
+
+ if (injPhdr) {
+ *injPhdr = last;
+ }
+ return last->phdr.p_vaddr + (injOffset - last->phdr.p_offset);
+ } else if ((w && (first->phdr.p_flags & PF_W))
+ || (x && (first->phdr.p_flags & PF_X))) {
+ /* Need to prepend or split up the PHDR. */
+ GElf_Off injOffset = OFFS_END(first->phdr.p_offset, first->phdr.p_filesz);
+ ElfuScn *ms;
+
+ /* Round up size to take PHDR alignment into account.
+ * We assume that this is a multiple of the alignment asked for. */
+ assert(first->phdr.p_align >= align);
+ size = ROUNDUP(size, first->phdr.p_align);
+
+ /* Find first section. We assume there is at least one. */
+ assert(!CIRCLEQ_EMPTY(&first->childScnList));
+ injOffset = CIRCLEQ_FIRST(&first->childScnList)->shdr.sh_offset;
+
+ /* Move our sections */
+ CIRCLEQ_FOREACH(ms, &first->childScnList, elemChildScn) {
+ if (ms->shdr.sh_offset >= injOffset) {
+ ms->shdr.sh_offset += size;
+ }
+ }
+
+ /* Move our PHDRs */
+ CIRCLEQ_FOREACH(mp, &first->childPhdrList, elemChildPhdr) {
+ if (mp->phdr.p_offset >= injOffset) {
+ mp->phdr.p_offset += size;
+ } else {
+ mp->phdr.p_vaddr -= size;
+ mp->phdr.p_paddr -= size;
+ }
+ }
+
+ /* Move other PHDRs and sections */
+ assert(size <= shiftStuffAtAfterOffset(me, injOffset, size));
+
+ /* Remap ourselves */
+ first->phdr.p_vaddr -= size;
+ first->phdr.p_paddr -= size;
+ first->phdr.p_filesz += size;
+ first->phdr.p_memsz += size;
+
+ injOffset = ROUNDUP(injOffset, align);
+
+ if (injPhdr) {
+ *injPhdr = first;
+ }
+ return first->phdr.p_vaddr + (injOffset - first->phdr.p_offset);
+ }
+
+ ERROR:
+ if (injPhdr) {
+ *injPhdr = NULL;
+ }
+ return 0;
+}
diff --git a/src/model/phdr.c b/src/model/phdr.c
index 26a26e3..d26eb77 100644
--- a/src/model/phdr.c
+++ b/src/model/phdr.c
@@ -15,3 +15,22 @@ size_t elfu_mPhdrCount(ElfuElf *me)
return i;
}
+
+
+
+void elfu_mPhdrUpdateChildOffsets(ElfuPhdr *mp)
+{
+ ElfuScn *ms;
+ ElfuPhdr *mpc;
+
+ assert(mp);
+ assert(mp->phdr.p_type == PT_LOAD);
+
+ CIRCLEQ_FOREACH(mpc, &mp->childPhdrList, elemChildPhdr) {
+ mpc->phdr.p_offset = mp->phdr.p_offset + (mpc->phdr.p_vaddr - mp->phdr.p_vaddr);
+ }
+
+ CIRCLEQ_FOREACH(ms, &mp->childScnList, elemChildScn) {
+ ms->shdr.sh_offset = mp->phdr.p_offset + (ms->shdr.sh_addr - mp->phdr.p_vaddr);
+ }
+}
diff --git a/src/model/reladd.c b/src/model/reladd.c
index bc13b97..ffd02f4 100644
--- a/src/model/reladd.c
+++ b/src/model/reladd.c
@@ -6,224 +6,6 @@
#include <libelfu/libelfu.h>
-
-static GElf_Word makeSpaceAtOffset(ElfuElf *me, GElf_Off offset, GElf_Word size)
-{
- ElfuPhdr *mp;
- ElfuScn *ms;
- /* Force a minimum alignment, just to be sure. */
- GElf_Word align = 64;
-
- /* Find maximum alignment size by which we have to shift.
- * Assumes alignment sizes are always 2^x. */
- CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
- if (mp->phdr.p_offset >= offset) {
- if (mp->phdr.p_align > align) {
- align = mp->phdr.p_align;
- }
- }
- }
-
- CIRCLEQ_FOREACH(ms, &me->orphanScnList, elemChildScn) {
- if (ms->shdr.sh_offset >= offset) {
- if (ms->shdr.sh_addralign > align) {
- align = ms->shdr.sh_addralign;
- }
- }
- }
-
- size = ROUNDUP(size, align);
-
- /* Shift stuff */
- CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
- if (mp->phdr.p_type != PT_LOAD) {
- continue;
- }
-
- if (mp->phdr.p_offset >= offset) {
- ElfuScn *ms;
- ElfuPhdr *mpc;
-
- mp->phdr.p_offset += size;
- CIRCLEQ_FOREACH(mpc, &mp->childPhdrList, elemChildPhdr) {
- mpc->phdr.p_offset += size;
- }
- CIRCLEQ_FOREACH(ms, &mp->childScnList, elemChildScn) {
- ms->shdr.sh_offset += size;
- }
- }
- }
-
- CIRCLEQ_FOREACH(ms, &me->orphanScnList, elemChildScn) {
- if (ms->shdr.sh_offset >= offset) {
- ms->shdr.sh_offset += size;
- }
- }
-
- if (me->ehdr.e_phoff >= offset) {
- me->ehdr.e_phoff += size;
- }
-
- if (me->ehdr.e_shoff >= offset) {
- me->ehdr.e_shoff += size;
- }
-
- return size;
-}
-
-
-
-/* Finds a suitable PHDR to insert a hole into and expands it
- * if necessary.
- * Returns memory address the hole will be mapped to, or 0 if
- * the operation failed. */
-static GElf_Addr getSpaceInPhdr(ElfuElf *me, GElf_Word size,
- GElf_Word align, int w, int x,
- ElfuPhdr **injPhdr)
-{
- ElfuPhdr *first = NULL;
- ElfuPhdr *last = NULL;
- ElfuPhdr *mp;
-
- assert(!(w && x));
-
- /* Find first and last LOAD PHDRs.
- * Don't compare p_memsz - segments don't overlap in memory. */
- CIRCLEQ_FOREACH(mp, &me->phdrList, elem) {
- if (mp->phdr.p_type != PT_LOAD) {
- continue;
- }
- if (!first || mp->phdr.p_vaddr < first->phdr.p_vaddr) {
- first = mp;
- }
- if (!last || mp->phdr.p_vaddr > last->phdr.p_vaddr) {
- last = mp;
- }
- }
-
- if ((w && (last->phdr.p_flags & PF_W))
- || (x && (last->phdr.p_flags & PF_X))) {
- /* Need to append. */
- GElf_Off injOffset = OFFS_END(last->phdr.p_offset, last->phdr.p_filesz);
- GElf_Word injSpace = 0;
- GElf_Word nobitsize = last->phdr.p_memsz - last->phdr.p_filesz;
-
- /* Expand NOBITS if any */
- if (nobitsize > 0) {
- GElf_Off endOff = OFFS_END(last->phdr.p_offset, last->phdr.p_filesz);
- GElf_Off endAddr = OFFS_END(last->phdr.p_vaddr, last->phdr.p_filesz);
- ElfuScn *ms;
-
- ELFU_INFO("Expanding NOBITS at address 0x%jx...\n", endAddr);
-
- CIRCLEQ_FOREACH(ms, &last->childScnList, elemChildScn) {
- if (ms->shdr.sh_offset == endOff) {
- assert(ms->shdr.sh_type == SHT_NOBITS);
- assert(ms->shdr.sh_size == nobitsize);
- ms->data.d_buf = malloc(ms->shdr.sh_size);
- memset(ms->data.d_buf, '\0', ms->shdr.sh_size);
- if (!ms->data.d_buf) {
- ELFU_WARN("mExpandNobits: Could not allocate %jd bytes for NOBITS expansion. Data may be inconsistent.\n", ms->shdr.sh_size);
- assert(0);
- goto ERROR;
- }
-
- ms->data.d_align = 1;
- ms->data.d_off = 0;
- ms->data.d_type = ELF_T_BYTE;
- ms->data.d_size = ms->shdr.sh_size;
- ms->data.d_version = elf_version(EV_NONE);
-
- ms->shdr.sh_type = SHT_PROGBITS;
- ms->shdr.sh_addr = endAddr;
- }
- }
-
- injSpace += makeSpaceAtOffset(me, endOff, nobitsize);
- injSpace -= nobitsize;
- injOffset += nobitsize;
- last->phdr.p_filesz += nobitsize;
- assert(last->phdr.p_filesz == last->phdr.p_memsz);
- }
-
- /* Calculate how much space we need, taking alignment into account */
- size += ROUNDUP(injOffset, align) - injOffset;
-
- /* If there is not enough space left, create even more. */
- if (injSpace < size) {
- injSpace += makeSpaceAtOffset(me, injOffset, size - injSpace);
- }
- assert(injSpace >= size);
-
- /* Remap ourselves */
- last->phdr.p_filesz += size;
- last->phdr.p_memsz += size;
-
- injOffset = ROUNDUP(injOffset, align);
-
- if (injPhdr) {
- *injPhdr = last;
- }
- return last->phdr.p_vaddr + (injOffset - last->phdr.p_offset);
- } else if ((w && (first->phdr.p_flags & PF_W))
- || (x && (first->phdr.p_flags & PF_X))) {
- /* Need to prepend or split up the PHDR. */
- GElf_Off injOffset = OFFS_END(first->phdr.p_offset, first->phdr.p_filesz);
- ElfuScn *ms;
-
- /* Round up size to take PHDR alignment into account.
- * We assume that this is a multiple of the alignment asked for. */
- assert(first->phdr.p_align >= align);
- size = ROUNDUP(size, first->phdr.p_align);
-
- /* Find first section. We assume there is at least one. */
- assert(!CIRCLEQ_EMPTY(&first->childScnList));
- injOffset = CIRCLEQ_FIRST(&first->childScnList)->shdr.sh_offset;
-
- /* Move our sections */
- CIRCLEQ_FOREACH(ms, &first->childScnList, elemChildScn) {
- if (ms->shdr.sh_offset >= injOffset) {
- ms->shdr.sh_offset += size;
- }
- }
-
- /* Move our PHDRs */
- CIRCLEQ_FOREACH(mp, &first->childPhdrList, elemChildPhdr) {
- if (mp->phdr.p_offset >= injOffset) {
- mp->phdr.p_offset += size;
- } else {
- mp->phdr.p_vaddr -= size;
- mp->phdr.p_paddr -= size;
- }
- }
-
- /* Move other PHDRs and sections */
- assert(size <= makeSpaceAtOffset(me, injOffset, size));
-
- /* Remap ourselves */
- first->phdr.p_vaddr -= size;
- first->phdr.p_paddr -= size;
- first->phdr.p_filesz += size;
- first->phdr.p_memsz += size;
-
- injOffset = ROUNDUP(injOffset, align);
-
- if (injPhdr) {
- *injPhdr = first;
- }
- return first->phdr.p_vaddr + (injOffset - first->phdr.p_offset);
- }
-
- ERROR:
- if (injPhdr) {
- *injPhdr = NULL;
- }
- return 0;
-}
-
-
-
-
static ElfuScn* insertSection(ElfuElf *me, ElfuElf *mrel, ElfuScn *oldscn)
{
ElfuScn *newscn = NULL;
@@ -238,11 +20,12 @@ static ElfuScn* insertSection(ElfuElf *me, ElfuElf *mrel, ElfuScn *oldscn)
}
- injAddr = getSpaceInPhdr(me, newscn->shdr.sh_size,
- newscn->shdr.sh_addralign,
- newscn->shdr.sh_flags & SHF_WRITE,
- newscn->shdr.sh_flags & SHF_EXECINSTR,
- &injPhdr);
+ injAddr = elfu_mLayoutGetSpaceInPhdr(me,
+ newscn->shdr.sh_size,
+ newscn->shdr.sh_addralign,
+ newscn->shdr.sh_flags & SHF_WRITE,
+ newscn->shdr.sh_flags & SHF_EXECINSTR,
+ &injPhdr);
if (!injPhdr) {
ELFU_WARN("insertSection: Could not find a place to insert section.\n");
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-16 14:13:08 +0000